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1. Pulsed production of antihydrogen

Author

Claude Amsler, Massimiliano Antonello, Alexander Belov, Germano Bonomi, Roberto Sennen Brusa, Massimo Caccia, Antoine Camper, Ruggero Caravita, Fabrizio Castelli, Patrick Cheinet, Daniel Comparat, Giovanni Consolati, Andrea Demetrio, Lea Di Noto, Michael Doser, Mattia Fanì, Rafael Ferragut, Julian Fesel, Sebastian Gerber, Marco Giammarchi, Angela Gligorova, Lisa Theresa Glöggler, Francesco Guatieri, Stefan Haider, Alexander Hinterberger, Alban Kellerbauer, Olga Khalidova, Daniel Krasnický, Vittorio Lagomarsino, Chloé Malbrunot, Sebastiano Mariazzi, Viktor Matveev, Simon Müller, Giancarlo Nebbia, Patrick Nedelec, Lilian Nowak, Markus Oberthaler, Emmanuel Oswald, Davide Pagano, Luca Penasa, Vojtech Petracek, Luca Povolo, Francesco Prelz, Marco Prevedelli, Benjamin Rienäcker, Ole Røhne, Alberto Rotondi, Heidi Sandaker, Romualdo Santoro, Gemma Testera, Ingmari Tietje, Valerio Toso, Tim Wolz, Pauline Yzombard, Christian Zimmer, and Nicola Zurlo

Subjects
Astrophysics, QB460-466, Physics, QC1-999
Abstract

Antihydrogen atoms are a unique type of antimatter that can be used to probe small violations of fundamental laws of physics. The authors present experimental results obtained with the AEgIS project at CERN for the production of antihydrogen atoms (Hbar) via charge exchange with laser excited positronium that allow for precise timing of Hbar production.

Published
2021
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2. Photodetachment and Doppler laser cooling of anionic molecules

Author

Sebastian Gerber, Julian Fesel, Michael Doser, and Daniel Comparat

Subjects
non neutral plasma, anionic molecules, sympathetic Doppler cooling, Penning trap, Science, Physics, QC1-999
Abstract

We propose to extend laser-cooling techniques, so far only achieved for neutral molecules, to molecular anions. A detailed computational study is performed for ${{\rm{C}}}_{2}^{-}$ molecules stored in Penning traps using GPU based Monte Carlo simulations. Two cooling schemes—Doppler laser cooling and photodetachment cooling—are investigated. The sympathetic cooling of antiprotons is studied for the Doppler cooling scheme, where it is shown that cooling of antiprotons to subKelvin temperatures could becomes feasible, with impacts on the field of antimatter physics. The presented cooling schemes also have applications for the generation of cold, negatively charged particle sources and for the sympathetic cooling of other molecular anions.

Published
2018
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3. Universal deceleration of highly polar molecules

Author

Mehdi Hamamda, Pierre Pillet, Hans Lignier, and Daniel Comparat

Subjects
cold molecular beam, deceleration, Rydberg, 37.10.Mn, 34.60.+z, Science, Physics, QC1-999
Abstract

We propose a method to produce, in a pulsed or continuous way, cold samples of highly polar molecules. Using a pulsed or continuous standard (supersonic) beam of these molecules, our idea consists of transforming the molecules into their anionic counterparts, which are decelerated to a standstill by a well-controlled external electric field and ultimately neutralized. The neutral-to-anion transformation occurs through collisions with Rydberg atoms coming from an additional atomic beam. This Rydberg electron transfer process is possible provided that the molecular species has a sufficiently strong electric dipole ( $\gt 2.5$ D, i.e., $\gt 8.3\times {{10}^{-30}}$ cm). Whatever the mass of the species, the deceleration stage is realized by a temporally and spatially controlled electric field within a range of less than one centimeter, which is much shorter than in current deceleration experiments of neutral molecules. Once stopped, the molecular anions are neutralized by laser photodetachment or a pulsed electric field process. The resulting molecules might be held and accumulated, for instance, in a magnetic trap.

Published
2015
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5. Experiments with mid-heavy antiprotonic atoms in AEgIS

Author

Georgy Kornakov, Marcis Auzins, Benedikt Bergmann, Petr Burian, Germano Bonomi, Roberto Sennen Brusa, Antoine Camper, Ruggero Caravita, Fabrizio Castelli, Patrick Cheinet, Roman Ciurylo, Daniel Comparat, Giovanni Consolati, Michael Doser, Havard Gjersdal, Lisa Teresa Gloggler, Lukasz Graczykowski, Francesco Guatieri, Stefan Haider, Saiva Huck, Malgorzata Janik, Grzegorz Kasprowicz, Gunn Khatri, Lukasz Klosowski, Lidia Lappo, Chloe Malbrunot, Sebastiano Mariazzi, Giancarlo Nebbia, Lilian Nowak, Dorota Nowicka, Emanuel Oswald, Davide PAGANO, Luca Penasa, Vojtech Petracek, Mariusz Piwinski, Stanislav Pospišil, Luca Povolo, Francesco Prelz, Sadiqali Rangwala, Benjamin Rienacker, Alberto Rotondi, Ole Rohne, Heidi Sandaker, Ivan Štekl, Dariusz Tefelski, Ingmari Christa Tietje, Marco Volponi, Tim Wolz, Michal Zawada, Christian Zimmer, and Nicola Zurlo

Published
2022

6. Positronium laser cooling in a magnetic field

Author

Daniel Comparat, C. Zimmer, Pauline Yzombard, Antoine Camper, Laboratoire Aimé Cotton (LAC), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire Kastler Brossel (LKB [Collège de France]), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Collège de France (CdF (institution)), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan)

Subjects
Physics, Annihilation, Zeeman effect, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Field (physics), 7. Clean energy, 01 natural sciences, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], 010305 fluids & plasmas, Positronium, symbols.namesake, Cover (topology), Stark effect, Physics in General, Laser cooling, 0103 physical sciences, symbols, Physics::Atomic Physics, Atomic physics, 010306 general physics, Energy (signal processing)
Abstract

We study realistic 3D laser cooling of positronium (Ps) in the presence of a magnetic field. Triplet and singlet states mixing due to the magnetic field, and dynamical Stark effect, generally produce higher annihilation rates than in the zero-field case. 3D cooling is efficient only at very low field $B\ensuremath{\lesssim}50\phantom{\rule{0.16em}{0ex}}\mathrm{mT}$ and at high field values $B⪆0.7\phantom{\rule{0.16em}{0ex}}\phantom{\rule{0.16em}{0ex}}\mathrm{T}$. Near $100\phantom{\rule{0.16em}{0ex}}\mathrm{ns}$ long laser pulses, spectrally broad enough to cover most of the Ps Doppler profile and with energy in the $\mathrm{mJ}$ range, are required to cool Ps. Simulations based on full diagonalization of the Stark and Zeeman Hamiltonian and a kinetic Monte Carlo algorithm exactly solving the rate equations indicate that an efficient cooling (typically from $300\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ down to below $50\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) is possible even in a magnetic field. We also propose 3D moving molasses cooling that can produce a well-defined monochromatic Ps beam useful for applications.

Published
2021

7. Pulsed production of antihydrogen

Author

G. Nebbia, Marco Prevedelli, M. Antonello, I. C. Tietje, B. Rienäcker, Daniel Comparat, Alberto Rotondi, M. Fanì, Sebastiano Mariazzi, O. Khalidova, Roberto S. Brusa, Nicola Zurlo, Davide Pagano, A. Camper, S.R. Müller, Markus K. Oberthaler, V. Petracek, Ole Røhne, C. Zimmer, Patrick Nedelec, Giovanni Consolati, Valerio Toso, Chloé Malbrunot, A. Hinterberger, Germano Bonomi, Lea Di Noto, P. Cheinet, Rafael Ferragut, Luca Povolo, P. Yzombard, Marco Giammarchi, Lilian Nowak, F. Prelz, J. Fesel, Sebastian Gerber, Ruggero Caravita, Emmanuel Oswald, Heidi Sandaker, Romualdo Santoro, Alban Kellerbauer, A. S. Belov, Luca Penasa, F. Guatieri, Angela Gligorova, Lisa Theresa Glöggler, Viktor Matveev, T. Wolz, Claude Amsler, D. Krasnický, A. Demetrio, G. Testera, Fabrizio Castelli, Michael Doser, S. Haider, Massimo Caccia, V. Lagomarsino, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire Kastler Brossel (LKB [Collège de France]), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Collège de France (CdF (institution)), Amsler, Claude, Antonello, Massimiliano, Belov, Alexander, Bonomi, Germano, Brusa, Roberto Sennen, Caccia, Massimo, Camper, Antoine, Caravita, Ruggero, Castelli, Fabrizio, Cheinet, Patrick, Comparat, Daniel, Consolati, Giovanni, Demetrio, Andrea, Di Noto, Lea, Doser, Michael, Fanì, Mattia, Ferragut, Rafael, Fesel, Julian, Gerber, Sebastian, Giammarchi, Marco, Gligorova, Angela, Glöggler, Lisa Theresa, Guatieri, Francesco, Haider, Stefan, Hinterberger, Alexander, Kellerbauer, Alban, Khalidova, Olga, Krasnický, Daniel, Lagomarsino, Vittorio, Malbrunot, Chloé, Mariazzi, Sebastiano, Matveev, Viktor, Müller, Simon, Nebbia, Giancarlo, Nedelec, Patrick, Nowak, Lilian, Oberthaler, Marku, Oswald, Emmanuel, Pagano, Davide, Penasa, Luca, Petracek, Vojtech, Povolo, Luca, Prelz, Francesco, Prevedelli, Marco, Rienäcker, Benjamin, Røhne, Ole, Rotondi, Alberto, Sandaker, Heidi, Santoro, Romualdo, Testera, Gemma, Tietje, Ingmari, Toso, Valerio, Wolz, Tim, Yzombard, Pauline, Zimmer, Christian, and Zurlo, Nicola

Subjects
Physics::General Physics, experimental methods, QC1-999, positronium, antihydrogen: annihilation, General Physics and Astronomy, Astrophysics, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, law.invention, Positronium, antihydrogen: energy levels, symbols.namesake, law, 0103 physical sciences, Atom, Physics::Atomic and Molecular Clusters, antimatter, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], antihydrogen: temperature, Physics::Atomic Physics, 010306 general physics, Antihydrogen, Physics, laser: pulsed, Antimatter gravity, atom, antihydrogen: production, Laser, charge exchange, anti-p, electric field, positron: beam, QB460-466, electromagnetic, injection, equivalence principle, Antiproton, Antimatter, Excited state, Rydberg formula, symbols, Atomic physics, Particle Physics - Experiment, experimental results
Abstract

Antihydrogen atoms with K or sub-K temperature are a powerful tool to precisely probe the validity of fundamental physics laws and the design of highly sensitive experiments needs antihydrogen with controllable and well defined conditions. We present here experimental results on the production of antihydrogen in a pulsed mode in which the time when 90% of the atoms are produced is known with an uncertainty of ~250 ns. The pulsed source is generated by the charge-exchange reaction between Rydberg positronium atoms—produced via the injection of a pulsed positron beam into a nanochanneled Si target, and excited by laser pulses—and antiprotons, trapped, cooled and manipulated in electromagnetic traps. The pulsed production enables the control of the antihydrogen temperature, the tunability of the Rydberg states, their de-excitation by pulsed lasers and the manipulation through electric field gradients. The production of pulsed antihydrogen is a major landmark in the AE $$\bar{g}$$ IS experiment to perform direct measurements of the validity of the Weak Equivalence Principle for antimatter. Antihydrogen atoms are a unique type of antimatter that can be used to probe small violations of fundamental laws of physics. The authors present experimental results obtained with the AEgIS project at CERN for the production of antihydrogen atoms (Hbar) via charge exchange with laser excited positronium that allow for precise timing of Hbar production.

Published
2021

8. Cesium Rydberg-state ionization study by three-dimensional ion-electron correlation: Toward a monochromatic electron source

Author

C. Lopez, Daniel Comparat, R. Hahn, Y. J. Picard, A. Trimeche, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Laboratoire Lumière, Matière et Interfaces (LuMIn), CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), and Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Binding energy, Electron, Photoionization, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, Ion, symbols.namesake, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Excited state, Ionization, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Rydberg formula, symbols, Physics::Atomic Physics, Rydberg state, Atomic physics, 010306 general physics, ComputingMilieux_MISCELLANEOUS
Abstract

We study the excitation and ionization of cesium Rydberg states in an electric field ($\ensuremath{\approx}\phantom{\rule{0.16em}{0ex}}2200\phantom{\rule{4pt}{0ex}}\mathrm{V}/\mathrm{cm}$) near the classical field-ionization threshold ($\ensuremath{\approx}\ensuremath{-}280\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ binding energy) by three-dimensional (3D) ion-electron coincidence spectroscopy. Cesium atoms are produced by an effusive oven and excited with lasers to Stark-shifted Rydberg states or directly ionized. Using a double time-of-flight setup we record 3D ($X, Y$, time of flight) coincidence imaging of electrons and ions. Above-threshold photoionization creates broad images with poor electron-ion spatial correlation. Fast ionizing states produce very good correlations and the images reveal the electric-field map of the ionization region. Slow ionizing states show that the relatively high atomic velocity is detrimental to the correlations. Experimental data are accurately reproduced by detailed Monte Carlo excitation and ionization simulations based on Stark maps obtained with local-frame transformation (LFT) theory. Agreement between our spectroscopic experiment and LFT theory is very good, with better that hundreds of megahertz accuracy. But, on rare particular states, several gigahertz discrepancy is found. This study can be used to select appropriate states for the creation of ion and electron beams with high brightness, good correlation, and low energy dispersion.

Published
2021

9. Induced THz transitions in Rydberg caesium atoms for application in antihydrogen experiments

Author

Emiliya Dimova, Daniel Comparat, Mélissa Vieille-Grosjean, C. Malbrunot, Z. Mazzotta, T. Wolz, Laboratoire Aimé Cotton (LAC), and École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
CERN Lab, Atomic Physics (physics.atom-ph), Other Fields of Physics, FOS: Physical sciences, chemistry.chemical_element, 02 engineering and technology, Photoionization, physics.atom-ph, 01 natural sciences, Physics - Atomic Physics, symbols.namesake, photon: particle source, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Spontaneous emission, Physics::Atomic Physics, 010306 general physics, Antihydrogen, Physics, photon: production, antihydrogen: production, Optical physics, bibliography, binding energy, photon: energy, 021001 nanoscience & nanotechnology, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Atomic and Molecular Physics, and Optics, chemistry, atom: ground state, Excited state, Caesium, Rydberg formula, symbols, cesium: atom, atom: excited state, Atomic physics, 0210 nano-technology, Ground state
Abstract

Antihydrogen atoms are produced at CERN in highly excited Rydberg states. However, precision measurements require anti-atoms in ground state. Whereas experiments currently rely on spontaneous emission only, simulations have shown that THz light can be used to stimulate the decay towards ground state and thus increase the number of anti-atoms available for measurements. We review different possibilities at hand to generate light in the THz range required for the purpose of stimulated deexcitation. We demonstrate the effect of a blackbody type light source, which however presents drawbacks for this application including strong photoionization. Further, we report on the first THz transitions in a beam of Rydberg caesium atoms induced by photomixers and conclude with the implications of the results for the antihydrogen case.[graphic not available: see fulltext][graphic not available: see fulltext] Antihydrogen atoms are produced at CERN in highly excited Rydberg states. However, precision measurements require anti-atoms in ground state. Whereas experiments currently rely on spontaneous emission only, simulations have shown that THz light can be used to stimulate the decay towards ground state and thus increase the number of anti-atoms available for measurements. We review different possibilities at hand to generate light in the THz range required for the purpose of stimulated deexcitation. We demonstrate the effect of a blackbody type light source, which however presents drawbacks for this application including strong photoionization. Further, we report on the first THz transitions in a beam of Rydberg caesium atoms induced by photomixers and conclude with the implications of the results for the antihydrogen case.

Published
2021

10. Reflection of Rydberg antihydrogen by surfaces

Author

Daniel Comparat, Laboratoire Aimé Cotton (LAC), and Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], 01 natural sciences, 010305 fluids & plasmas, Positronium, symbols.namesake, Reflection (mathematics), Positron, Antiproton, Antimatter, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Rydberg formula, symbols, Work function, Physics::Atomic Physics, Atomic physics, 010306 general physics, Antihydrogen, ComputingMilieux_MISCELLANEOUS
Abstract

We study Rydberg antihydrogen interaction with a metallic or dielectric surface by calculating the adiabatic potential curves. For a metallic or pure dielectric surface with permittivity $\ensuremath{\epsilon}=\ensuremath{\infty}$, the image charges create an attractive potential that pulls the positron away from the antiproton when the atom approaches the surface. This is no longer the case with low-dielectric-constant materials ($\ensuremath{\epsilon}\ensuremath{\approx}1$). Furthermore, using a negative positron work function, meaning that positrons are repelled by these surfaces, only repulsive potential curves exists. This suggests that Rydberg antihydrogen can probably be repelled by such ultralow-$k$ materials, opening the way for simple manipulation and guiding of antimatter (antihydrogen or positronium) systems.

Published
2020

11. Comparative analysis of recirculating and collimating cesium ovens

Author

Raphaël Hahn, Thomas Battard, Oscar Boucher, Yan J. Picard, Hans Lignier, Daniel Comparat, Nolwenn-Amandine Keriel, Colin Lopez, Emanuel Oswald, Morgan Reveillard, and Matthieu Viteau

Subjects
Instrumentation
Abstract

We have performed a study of several cesium oven designs. A comparison between recirculating (or sticking-wall) and collimating (or re-emitting-wall) ovens is made in order to extract the most efficient design in terms of beam brightness. Unfortunately, non-reproducible behaviors have been observed, and the most often observed output flux is similar to the sticking-wall case, which is the lowest theoretical value of the two cases, with a beam brightness close to 1018 at. sr−1 s−1 cm−2. The reason of this universally observed behavior is unclear despite having tested several materials for the collimating tube. Conclusion on possible improved design based on sticking of cesium on several (un)cleaned surfaces is given.

Published
2022

12. Cesium Rydberg states ionization study by 3-D ion-electron correlation

Author

Hahn, R., Trimeche, A., Lopez, C., Daniel Comparat, Picard, Y. J., Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and comparat, daniel

Subjects
[PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Physics::Atomic Physics, [PHYS.PHYS.PHYS-ATOM-PH] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph]
Abstract

We study the excitation and ionization of cesium Rydberg states in an electric field (∼ 2200 V/cm) near the classical field ionization threshold (∼ −280 cm −1 binding energy at this field) by 3-D ionelectron coincidence spectroscopy. Cesium atoms are produced by an effusive oven and excited with lasers to Stark-shifted Rydberg states or directly ionised. Using a double Time of Flight setup we record 3-D (X, Y, Time of Flight) coincidence imaging of cesium produced electrons and ions. Above-threshold photo-ionisation creates broad images with poor electron/ion-coordinates correlation. Depending on the coupling of particular Rydberg states to the continuum, various images and correlations are observed. Fast ionising states show very good correlations and reveal the electric field lines, creating an efficient electric field mapping of the ionisation region. Slow ionising states show that the relatively high atomic velocity is detrimental to the correlations. Experimental data are accurately reproduced by detailed Monte Carlo excitation and ionization simulations based on Stark maps obtained with local-frame transformation (LFT) theory. Spectroscopic LFT agreement is usually very good with better that hundreds of MHz accuracy but on particular states several GHz discrepancy is found. The study can be used to select appropriate states for the creation of ion and electron beams with high brightness, good correlation and low energy dispersion, as well as to provide a detailed analysis of LFT-theory shortcomings.

Published
2020

13. Refroidir les molécules

Author

Nadia Bouloufa-Maafa, Daniel Comparat, Olivier Dulieu, Hans Lignier, Goulven Quéméner, Laboratoire Aimé Cotton (LAC), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), EDP Sciences, and Quéméner, Goulven

Subjects
[PHYS.COND.GAS]Physics [physics]/Condensed Matter [cond-mat]/Quantum Gases [cond-mat.quant-gas], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], [PHYS.COND.GAS] Physics [physics]/Condensed Matter [cond-mat]/Quantum Gases [cond-mat.quant-gas], [PHYS.PHYS.PHYS-ATOM-PH] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], [PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2020

14. Determining a vibrational distribution with a broadband optical source

Author

H. Lignier, T. Courageux, Daniel Comparat, Anne Cournol, and B. Viaris de Lesegno

Subjects
Work (thermodynamics), Atomic Physics (physics.atom-ph), Monofluoride, Population, FOS: Physical sciences, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, Signal, Physics - Atomic Physics, chemistry.chemical_compound, Physics - Chemical Physics, 0103 physical sciences, Broadband, Physics::Atomic and Molecular Clusters, Physical and Theoretical Chemistry, Physics::Chemical Physics, 010306 general physics, education, Chemical Physics (physics.chem-ph), Physics, education.field_of_study, Argon, 021001 nanoscience & nanotechnology, chemistry, Atomic physics, 0210 nano-technology, Excitation, Beam (structure)
Abstract

This work presents an experimental protocol conceived to determine the vibrational distribution of barium monofluoride molecules seeded in a supersonic beam of argon. Here, as in many cases, the detection signal is related to the number of molecules by an efficiency involving several parameters that may be difficult to determine properly. In particular, this efficiency depends on the vibrational level of the detected molecules. Our approach avoids these complications by comparing different detection signals generated by different vibrational excitations. Such an excitation is made possible by the use of a broadband optical source that depletes a specific vibrational level whose population is redistributed in the other levels., 6 pages, 4 figures

Published
2020

16. Stimulated decay and formation of antihydrogen atoms

Author

Chloé Malbrunot, Daniel Comparat, Mélissa Vieille-Grosjean, T. Wolz, Laboratoire Aimé Cotton (LAC), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan)

Subjects
experimental methods, CERN Lab, Atomic Physics (physics.atom-ph), Population, Other Fields of Physics, FOS: Physical sciences, physics.atom-ph, 01 natural sciences, microwaves, 010305 fluids & plasmas, law.invention, Physics - Atomic Physics, antihydrogen: energy levels, antihydrogen: formation, symbols.namesake, law, 0103 physical sciences, Spontaneous emission, Physics::Atomic Physics, 010306 general physics, education, Antihydrogen, Physics, education.field_of_study, antihydrogen: production, bibliography, including interactions with strong fields and short pulses, Laser, recombination, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], laser, anti-p, Antiproton Decelerator, Automatic Keywords, atom: antimatter, efficiency, atom: ground state, Antimatter, Atomic and molecular processes in external fields, Rydberg formula, symbols, Atomic physics, Ground state
Abstract

Antihydrogen atoms are routinely formed at the Antiproton Decelerator at CERN in a wide range of Rydberg states. To perform precision measurements, experiments rely on ground-state antimatter atoms which are currently obtained only after spontaneous decay. In order to enhance the number of atoms in ground state, we propose and assess the efficiency of different methods to stimulate their decay. First, we investigate the use of THz radiation to simultaneously couple all n-manifolds down to a low-lying one with sufficiently fast spontaneous emission toward ground state. We further study a deexcitation scheme relying on state mixing via microwave and/or THz light and a coupled (visible) deexcitation laser. We obtain close to unity ground-state fractions within a few tens of μs for a population initiated in the n=30 manifold. Finally, we study how the production of antihydrogen atoms via stimulated radiative recombination can favorably change the initial distribution of states and improve the overall number of ground-state atoms when combined with stimulated deexcitation. Antihydrogen atoms are routinely formed at the Antiproton Decelerator at CERN in a wide range of Rydberg states. To perform precision measurements, experiments rely on ground state antimatter atoms which are currently obtained only after spontaneous decay. In order to enhance the number of atoms in ground state, we propose and assess the efficiency of different methods to stimulate their decay. First, we investigate the use of THz radiation to simultaneously couple all n-manifolds down to a low lying one with sufficiently fast spontaneous emission toward ground state. We further study a deexcitation scheme relying on state-mixing via microwave and/or THz light and a coupled (visible) deexcitation laser. We obtain close to unity ground state fractions with

Published
2020

17. Narrow-band pulsed electron source based on near-threshold photoionization of Cs in a magneto-optical trap

Author

Gerd Schönhense, O. Fedchenko, R. Hahn, Daniel Comparat, S. Chernov, Johannes Gutenberg - Universität Mainz (JGU), Institute for Nuclear Research of Russian Academy of Sciences (INR), Russian Academy of Sciences [Moscow] (RAS), Laboratoire Aimé Cotton (LAC), and Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Atomic Physics (physics.atom-ph), FOS: Physical sciences, Physics::Optics, Electron, Photoionization, Photon energy, 01 natural sciences, Physics - Atomic Physics, 010305 fluids & plasmas, law.invention, symbols.namesake, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], law, Ionization, Magneto-optical trap, 0103 physical sciences, Physics::Atomic Physics, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, Physics, Condensed Matter - Materials Science, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Materials Science (cond-mat.mtrl-sci), Laser, 3. Good health, Femtosecond, Rydberg formula, symbols, Atomic physics
Abstract

The newly developed method of time-of-flight (ToF) momentum microscopy was used to analyse the cold electron emission from a Cs 3D magneto-optical trap (MOT). Three-step resonant photoionization was implemented via two intermediate states (6P3/2 pumped with 852 nm laser and 7S1/2 with 1470 nm) and a tuneable femtosecond Ti:sapphire laser for the final ionization step. The magnetic field of the MOT is switched off during the photoionization step. The natural bandwidth of the fs-laser is reduced to 4 meV using optical spectral filters. Precise tuning of the photon energy makes it possible to observe the transition regime between direct photoemission into the open continuum and field induced ionization of highly-excited Rydberg states. The paths can be identified by their characteristic dependency on the extraction field and on the Ti:sapphire polarization. ToF analysis allowed us to disentangle the ionization paths and the dependence of the spatio-temporal distribution of the cold electrons on the polarization of the ionizing laser., 7 pages, 5 figures

Published
2020

18. Hybrid imaging and timing ps laser excitation diagnostics for pulsed antihydrogen production

Author

G. Testera, G. Nebbia, D. Krasnický, Fabrizio Castelli, A. Demetrio, Michael Doser, V. Lagomarsino, Rafael Ferragut, Alberto Rotondi, Giovanni Consolati, Germano Bonomi, Sebastiano Mariazzi, L. T. Glöggler, T. Wolz, A. Camper, Heidi Sandaker, M. Oberthaler, Angela Gligorova, Ruggero Caravita, Daniel Comparat, L. Di Noto, Sebastian Gerber, O. Khalidova, Patrick Nedelec, V. A. Matveev, F. Guatieri, A. Hinterberger, Marco Giammarchi, Massimo Caccia, Davide Pagano, V. Toso, C. Zimmer, F. Prelz, M. Fanì, M. Antonello, I. C. Tietje, E. Oswald, Luca Penasa, S.R. Müller, B. Rienäcker, Roberto S. Brusa, Romualdo Santoro, V. Petracek, A. S. Belov, S. Haider, Chloé Malbrunot, Ole Røhne, Nicola Zurlo, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
010302 applied physics, Physics, Bar (music), business.industry, Physics::Instrumentation and Detectors, Detector, General Physics and Astronomy, 02 engineering and technology, Scintillator, 021001 nanoscience & nanotechnology, Laser, 01 natural sciences, Signal, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], law.invention, Optics, law, 0103 physical sciences, Microchannel plate detector, 0210 nano-technology, business, Antihydrogen, Excitation
Abstract

International audience; In this work we present a hybrid detection method providing simultaneous imaging and timing information suitable for fully monitoring positronium (Ps) formation, its laser excitation, and its spatial propagation for the first trials of pulsed antihydrogen ($\bar{H}$) production through a charge-exchange reaction with trapped antiprotons ($\bar{p}$). This combined method, based on the synchronous acquisition of an EJ-200 scintillation detector and a microchannel plate (MCP) detector with a dual readout (phosphor screen image and electrical pick-up signal), allows all relevant events in the experiment to be accurately determined in time while allowing high resolution images of e$^{+}$ from Ps laser photodissociations to be acquired. The timing calibration process of the two detectors discussed in details as well as the future perspectives opened by this method.

Published
2020

19. Ion and Electron Ghost Imaging

Author

C. Lopez, Daniel Comparat, A. Trimeche, Y. J. Picard, Picard, Yan, Laboratoire Aimé Cotton (LAC), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Laboratoire Lumière, Matière et Interfaces (LuMIn), CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), Laboratoire de l'intégration, du matériau au système (IMS), and Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université Sciences et Technologies - Bordeaux 1

Subjects
Physics - Instrumentation and Detectors, Atomic Physics (physics.atom-ph), FOS: Physical sciences, Electron, Ghost imaging, 01 natural sciences, Ion, Physics - Atomic Physics, 010309 optics, Optics, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Physics::Plasma Physics, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], [PHYS.PHYS.PHYS-ATOM-PH] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], 010306 general physics, Image resolution, ComputingMilieux_MISCELLANEOUS, Physics, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], business.industry, Detector, Instrumentation and Detectors (physics.ins-det), [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], [PHYS.PHYS.PHYS-INS-DET] Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], business
Abstract

In this Letter, we report a demonstration of ion and electron ghost imaging. Two beams of correlated ions and electrons are produced by a photoionization process and accelerated into opposite directions. Using a single time and position sensitive detector for one beam, we can image an object seen by the other beam even when the detector that sees this object has no spatial resolution. The extra information given by this second detector can, therefore, be used to reconstruct the image thanks to the correlation between the ions and the electrons. In our example, a metallic mask placed in front of a time-sensitive detector is used as the object to image. We demonstrated ion and electron ghost imaging using this mask in a transmission mode. These primary results are very promising and open applications especially in ion and electron imaging in surface science and nanophysics., Comment: 4 pages, 2 figures

Published
2020
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20. Rydberg-positronium velocity and self-ionization studies in a 1T magnetic field and cryogenic environment

Author

G. Nebbia, Patrick Nedelec, Sebastiano Mariazzi, Giovanni Consolati, Germano Bonomi, G. Testera, L. T. Glöggler, Luca Penasa, Fabrizio Castelli, F. Prelz, Michael Doser, V. Lagomarsino, Ruggero Caravita, M. Oberthaler, Angela Gligorova, Daniel Comparat, Nicola Zurlo, B. Rienäcker, Roberto S. Brusa, V. Petracek, M. Antonello, Massimo Caccia, I. C. Tietje, Davide Pagano, S. Haider, T. Wolz, C. Zimmer, A. Hinterberger, L. Di Noto, M. Fanì, Sebastian Gerber, L. Nowak, F. Guatieri, E. Oswald, A. Camper, Heidi Sandaker, Rafael Ferragut, D. Krasnický, J. Fesel, Romualdo Santoro, Alberto Rotondi, V. Matveev, A. S. Belov, Ole Røhne, O. Khalidova, S. Müller, Chloé Malbrunot, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and AEgIS

Subjects
Stark effect, Atomic Physics (physics.atom-ph), positronium, FOS: Physical sciences, Light-induced processes in atomic-scale systems, Penning traps, 7. Clean energy, 01 natural sciences, Physics - Atomic Physics, 010305 fluids & plasmas, Positronium, Charge-transfer collisions, symbols.namesake, molecular processes in external fields, Physics in General, 0103 physical sciences, Principal quantum number, Physics::Atomic and Molecular Clusters, Multiphoton or tunneling ionization &amp, Atomic & molecular processes in external fields, Charge-transfer collisions, Multiphoton or tunneling ionization & excitation, Penning traps, Stark effect, Physics::Atomic Physics, 010306 general physics, Antihydrogen, Physics, Atomic &amp, excitation, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Magnetic field, Excited state, Antimatter, symbols, Rydberg formula, Atomic physics
Abstract

We characterized the pulsed Rydberg-positronium production inside the Antimatter Experiment: Gravity, Interferometry, Spectroscopy (AE$\overline{\textrm{g}}$IS) apparatus in view of antihydrogen formation by means of a charge exchange reaction between cold antiprotons and slow Rydberg-positronium atoms. Velocity measurements on the positronium along two axes in a cryogenic environment (≈10K) and in 1T magnetic field were performed. The velocimetry was done by microchannel-plate (MCP) imaging of a photoionized positronium previously excited to the $n$=3 state. One direction of velocity was measured via Doppler scan of this $n$=3 line, another direction perpendicular to the former by delaying the exciting laser pulses in a time-of-flight measurement. Self-ionization in the magnetic field due to the motional Stark effect was also quantified by using the same MCP-imaging technique for Rydberg positronium with an effective principal quantum number $n_\textrm{eff}$ ranging between 14 and 22. We conclude with a discussion about the optimization of our experimental parameters for creating Rydberg positronium in preparation for an efficient pulsed production of antihydrogen. We characterized the pulsed Rydberg-positronium production inside the AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) apparatus in view of antihydrogen formation by means of a charge exchange reaction between cold antiprotons and slow Rydberg-positronium atoms. Velocity measurements on positronium along two axes in a cryogenic environment (10K) and in 1T magnetic field were performed. The velocimetry was done by MCP-imaging of photoionized positronium previously excited to the $n=3$ state. One direction of velocity was measured via Doppler-scan of this $n=3$-line, another direction perpendicular to the former by delaying the exciting laser pulses in a time-of-flight measurement. Self-ionization in the magnetic field due to motional Stark effect was also quantified by using the same MCP-imaging technique for Rydberg positronium with an effective principal quantum number $n_{eff}$ ranging between 14 and 22. We conclude with a discussion about the optimization of our experimental parameters for creating Rydberg-positronium in preparation for an efficient pulsed production of antihydrogen.

Published
2020
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21. Gravity and antimatter: The AEgIS experiment at CERN

Author

A. Hinterberger, L. Smestad, G. Nebbia, G. Testera, Marco Prevedelli, Marco Giammarchi, J. Robert, Nicola Pacifico, I. C. Tietje, Luca Penasa, Johann Marton, Fabrizio Castelli, Fiodor Sorrentino, Z. Mazzotta, P. Lebrun, Michael Doser, Alban Kellerbauer, Rafael Ferragut, Victor Matveev, Heidi Sandaker, Nicola Zurlo, L. Ravelli, O. Khalidova, S. Haider, Davide Pagano, Giovanni Consolati, Germano Bonomi, C. Zimmer, H. Holmestad, Sebastiano Mariazzi, Ole Røhne, M. Oberthaler, Angela Gligorova, Stefano Aghion, Chloé Malbrunot, Sebastian Gerber, S.R. Müller, Ruggero Caravita, Patrick Nedelec, Johann Zmeskal, F. Guatieri, Romualdo Santoro, P. Yzombard, Alberto Rotondi, J. Fesel, Eberhard Widmann, P. Lansonneur, V. Lagomarsino, B. Rienaecker, L. Di Noto, Claude Amsler, Massimo Caccia, Daniel Comparat, Giovanni Cerchiari, D. Krasnický, A. Demetrio, F. Prelz, Roberto S. Brusa, V. Petracek, M. Fanì, A. Evans, Adriano Fontana, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Pagano D., Aghion S., Amsler C., Bonomi G., Brusa R.S., Caccia M., Caravita R., Castelli F., Cerchiari G., Comparat D., Consolati G., Demetrio A., Noto L.D., Doser M., Evans A., Fani M., Ferragut R., Fesel J., Fontana A., Gerber S., Giammarchi M., Gligorova A., Guatieri F., Haider S., Hinterberger A., Holmestad H., Kellerbauer A., Khalidova O., Krasnicky D., Lagomarsino V., Lansonneur P., Lebrun P., Malbrunot C., Mariazzi S., Marton J., Matveev V., Mazzotta Z., Muller S.R., Nebbia G., Nedelec P., Oberthaler M., Pacifico N., Penasa L., Petracek V., Prelz F., Prevedelli M., Ravelli L., Rienaecker B., Robert J., Rohne O.M., Rotondi A., Sandaker H., Santoro R., Smestad L., Sorrentino F., Testera G., Tietje I.C., Widmann E., Yzombard P., Zimmer C., Zmeskal J., and Zurlo N.

Subjects
History, Particle physics, Physics::General Physics, experimental methods, CERN Lab, General relativity, Measure (physics), 01 natural sciences, Education, Gravitational field, 0103 physical sciences, Physics::Atomic and Molecular Clusters, general relativity, antimatter, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Equivalence principle, 010306 general physics, Antihydrogen, Physics, antihydrogen, Large Hadron Collider, General Relativity and Cosmology, 010308 nuclear & particles physics, atom, gravitation: interaction, Computer Science Applications, experimental equipment, equivalence principle, Antimatter, force: gravitation, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], gravity, antimatter, Particle Physics - Experiment, Beam (structure), experimental results
Abstract

From the experimental point of view, very little is known about the gravitational interaction between matter and antimatter. In particular, the Weak Equivalence Principle, which is of paramount importance for the General Relativity, has not yet been directly probed with antimatter. The main goal of the AEgIS experiment at CERN is to perform a direct measurement of the gravitational force on antimatter. The idea is to measure the vertical displacement of a beam of cold antihydrogen atoms, traveling in the gravitational field of the Earth, by the means of a moiré deflectometer. An overview of the physics goals of the experiment, of its apparatus and of the first results is presented.

Published
2020

22. Developments for pulsed antihydrogen production towards direct gravitational measurement on antimatter

Author

Alberto Rotondi, S. Müller, G. Nebbia, Davide Pagano, O. Khalidova, Massimo Caccia, L. Povolo, Giovanni Consolati, V. Toso, Germano Bonomi, Heidi Sandaker, V. Petráček, A. Hinterberger, L. T. Glöggler, Sebastiano Mariazzi, B. Rienäcker, C. Zimmer, L. Di Noto, Marco Giammarchi, Marco Prevedelli, M. Antonello, Chloé Malbrunot, G. Testera, Angela Gligorova, Ole Røhne, Nicola Zurlo, Sebastian Gerber, Fabrizio Castelli, Alban Kellerbauer, A. S. Belov, I. C. Tietje, D. Krasnicky, V. Lagomarsino, M. Fanì, L. Nowak, Romualdo Santoro, Michael Doser, Patrick Nedelec, E. Oswald, J. Fesel, V. Matveev, S. Haider, P. Cheinet, A. Demetrio, F. Guatieri, Luca Penasa, A. Camper, F. Prelz, Daniel Comparat, Ruggero Caravita, T. Wolz, Markus K. Oberthaler, R. S. Brusa, Rafael Ferragut, Fani M., Antonello M., Belov A., Bonomi G., Brusa R.S., Caccia M., Camper A., Caravita R., Castelli F., Comparat D., Cheinet P., Consolati G., Demetrio A., Di Noto L., Doser M., Ferragut R., Fesel J., Gerber S., Giammarchi M., Gligorova A., Gloggler L.T., Guatieri F., Haider S., Hinterberger A., Kellerbauer A., Khalidova O., Krasnicky D., Lagomarsino V., Malbrunot C., Nowak L., Mariazzi S., Matveev V., Muller S.R., Nebbia G., Nedelec P., Oberthaler M., Oswald E., Pagano D., Penasa L., Petracek V., Povolo L., Prelz F., Prevedelli M., Rienacker B., Rohne O.M., Rotondi A., Sandaker H., Santoro R., Testera G., Tietje I.C., Toso V., Wolz T., Zimmer C., Zurlo N., Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Gravity (chemistry), Physics::General Physics, Antimatter, experimental methods, Gravity, Antiproton, magnetic field, Positronium, 01 natural sciences, 010305 fluids & plasmas, Nuclear physics, Gravitation, temperature: low, 0103 physical sciences, general relativity, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, 010306 general physics, Antihydrogen, Mathematical Physics, Physics, gravitation: interaction, antihydrogen: production, talk: Kolymbari 2019/08/21, sensitivity, charge exchange, Condensed Matter Physics, pulsed, Atomic and Molecular Physics, and Optics, anti-p, equivalence principle, gravitation: acceleration, gravitation: local, experimental results
Abstract

International audience; A main scientific goal of the experiment is the direct measurement of the Earth’s local gravitational acceleration g on antihydrogen. The Weak Equivalence Principle is a foundation of General Relativity. It has been extensively tested with ordinary matter but very little is known about the gravitational interaction between matter and antimatter. Antihydrogen is produced in via resonant charge-exchange reaction between cold Rydberg-excited positronium and cooled down antiprotons. The achievements for the development of a pulsed cold antihydrogen source are presented. Large number of antiprotons, necessary for a significant production rate of antihydrogen, are captured, accumulated, compressed and cooled over an extended period of time. Positronium (Ps) is formed through e$^{+}$-Ps conversion in a silica porous target at 10 K temperature in a reflection geometry inside the main apparatus. The so-formed Ps cloud is then laser-excited to Rydberg levels, for the first time in a 1 T magnetic field. Consequently, a detailed characterization of the Ps source for antihydrogen production in magnetic field needed to be performed. Several detection techniques are extensively used to monitor antiproton and positron manipulations in the formation process of antihydrogen inside the main apparatus. Positronium detection techniques underwent extensive improvements in sensitivity during the last antiproton run. At the same time, major efforts to improve integrate and commission the detectors sensitive to antihydrogen production took place.

Published
2020

23. Limitations for field-enhanced atom interferometry

Author

Daniel Comparat, Laboratoire Aimé Cotton (LAC), and École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Atom interferometer, Quantum Physics, Field (physics), [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Atomic Physics (physics.atom-ph), Order (ring theory), FOS: Physical sciences, 01 natural sciences, 010305 fluids & plasmas, Magnetic field, Physics - Atomic Physics, Interferometry, Orders of magnitude (time), [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 0103 physical sciences, Sensitivity (control systems), Atomic physics, 010306 general physics, Quantum Physics (quant-ph), Electric field gradient
Abstract

We discuss the possibility to enhance the sensitivity of optical interferometric devices by increasing their open area using an external field gradient that acts differently on the two arms of the interferometers. The use of a combined electric and magnetic field cancels nonlinear terms that dephase the interferometer. This is possible using well-defined (typically with $n\ensuremath{\sim}20$ Rydberg) states, a magnetic field of a few Tesla, and an electric field gradient of $\ensuremath{\sim}10\phantom{\rule{0.28em}{0ex}}\mathrm{V}/{\mathrm{cm}}^{2}$. However, this allows for interaction times only on the order of tens of microseconds, leading to a reachable accuracy of only 1 or 2 orders of magnitude higher than standard light-pulse atom interferometers. Furthermore, the control of fields and states and three-dimensional (3D) trajectories puts severe limits to the reachable accuracy. This idea is therefore not suitable for precision measurement but might eventually be used for gravity or neutrality in antimatter studies.

Published
2020
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24. Laser-stimulated deexcitation of Rydberg antihydrogen atoms

Author

Chloé Malbrunot, Daniel Comparat, Laboratoire Aimé Cotton (LAC), and École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Angular momentum, CERN Lab, Atomic Physics (physics.atom-ph), Other Fields of Physics, FOS: Physical sciences, decay: induced, physics.atom-ph, 7. Clean energy, 01 natural sciences, Physics - Atomic Physics, 010305 fluids & plasmas, law.invention, symbols.namesake, excited state: mixing, law, excited state, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, 010306 general physics, Antihydrogen, antihydrogen: ground state, Spontaneous decay, Physics, Range (particle radiation), Large Hadron Collider, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], angular momentum: high, including interactions with strong fields and short pulses, antihydrogen: excited state, Laser, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], laser, Atomic and molecular processes in external fields, Rydberg formula, symbols, excited state: lifetime, Atomic physics, Beam (structure)
Abstract

Antihydrogen atoms are routinely formed at CERN in a broad range of Rydberg states. Ground-state anti-atoms, those useful for precision measurements, are eventually produced through spontaneous decay. However given the long lifetime of Rydberg states the number of ground-state antihydrogen atoms usable is small, in particular for experiments relying on the production of a beam of antihydrogen atoms. Therefore, it is of high interest to efficiently stimulate the decay in order to retain a higher fraction of ground-state atoms for measurements. We propose a method that optimally mixes the high angular momentum states with low ones enabling to stimulate, using a broadband frequency laser, the deexcitation toward low-lying states, which then spontaneously decay to ground-state. We evaluated the method in realistic antihydrogen experimental conditions. For instance, starting with an initial distribution of atoms within the $n=20-30$ manifolds, as formed through charge exchange mechanism, we show that more than 80\% of antihydrogen atoms will be deexcited to the ground-state within 100 ns using a laser producing 2 J at 828 nm., 10 pages

Published
2020

25. A cryogenic tracking detector for antihydrogen detection in the AEgIS experiment

Author

J. Wuethrich, Alberto Rotondi, Daniel Comparat, O. Khalidova, Alban Kellerbauer, Ole Røhne, P.A. Ekman, G. Testera, G. Nebbia, Davide Pagano, P. Hackstock, Marco Prevedelli, M. Antonello, Fabrizio Castelli, A. Camper, Sebastian Gerber, Massimo Caccia, D. Haider, C. Zimmer, Michael Doser, F. Prelz, I. C. Tietje, L. Nowak, Heidi Sandaker, Sebastiano Mariazzi, A. Hinterberger, S. Haider, F. Guatieri, Romualdo Santoro, Marco Giammarchi, A. S. Belov, Rafael Ferragut, D. Krasnický, J. Robert, A. Demetrio, Chloé Malbrunot, V. Toso, P. Yzombard, Giovanni Consolati, Germano Bonomi, L. Di Noto, V. Lagomarsino, James William Storey, Claude Amsler, T. Wolz, S.R. Müller, Ruggero Caravita, V. A. Matveev, B. Rienaecker, Luca Penasa, M. Oberthaler, Roberto S. Brusa, V. Petracek, Angela Gligorova, Patrick Nedelec, Nicola Zurlo, M. Fanì, E. Oswald, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Amsler, C., Antonello, M., Belov, A., Bonomi, G., Brusa, R.S., Caccia, M., Camper, A., Caravita, R., Castelli, F., Comparat, D., Consolati, G., Demetrio, A., Di Noto, L., Doser, M., Ekman, P.A., Fanì, M., Ferragut, R., Gerber, S., Giammarchi, M., Gligorova, A., Guatieri, F., Hackstock, P., Haider, D., Haider, S., Hinterberger, A., Kellerbauer, A., Khalidova, O., Krasnický, D., Lagomarsino, V., Malbrunot, C., Mariazzi, S., Matveev, V., Müller, S.R., Nebbia, G., Nedelec, P., Nowak, L., Oberthaler, M., Oswald, E., Pagano, D., Penasa, L., Petracek, V., Prelz, F., Prevedelli, M., Rienaecker, B., Robert, J., Røhne, O.M., Rotondi, A., Sandaker, H., Santoro, R., Storey, J., Testera, G., Tietje, I.C., Toso, V., Wolz, T., Wuethrich, J., Yzombard, P., Zimmer, C., Zurlo, N., École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics - Instrumentation and Detectors, Atomic Physics (physics.atom-ph), Physics::Instrumentation and Detectors, Antiproton, Cryogenics, Antihydrogen, Antimatter, Cryogenic tracker, Gravity, Positron, Scintillator detector, Tracking (particle physics), 01 natural sciences, High Energy Physics - Experiment, Physics - Atomic Physics, High Energy Physics - Experiment (hep-ex), tracking detector, Physics::Atomic Physics, Detectors and Experimental Techniques, Instrumentation, time resolution, Physics, Detector, Instrumentation and Detectors (physics.ins-det), cryogenics, performance, Nuclear and High Energy Physics, antihydrogen: annihilation, FOS: Physical sciences, Superconducting magnet, Silicon photomultiplier, Optics, 0103 physical sciences, Physics::Atomic and Molecular Clusters, scintillation counter: fibre, photomultiplier: silicon, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, detector: design, activity report, antimatter, gravity, 010308 nuclear & particles physics, business.industry, Physics::Accelerator Physics, business, pi: particle identification
Abstract

We present the commissioning of the Fast Annihilation Cryogenic Tracker detector (FACT), installed around the antihydrogen production trap inside the 1 T superconducting magnet of the AEgIS experiment. FACT is designed to detect pions originating from the annihilation of antiprotons. Its 794 scintillating fibers operate at 4K and are read out by silicon photomultipliers (MPPCs) at near room temperature. FACT provides the antiproton/antihydrogen annihilation position information with a few ns timing resolution. We present the hardware and software developments which led to the successful operation of the detector for antihydrogen detection and the results of an antiproton-loss based efficiency assessment. The main background to the antihydrogen signal is that of the positrons impinging onto the positronium conversion target and creating a large amount of gamma rays which produce a sizeable signal in the MPPCs shortly before the antihydrogen signal is expected. We detail the characterization of this background signal and its impact on the antihydrogen detection efficiency. We present the commissioning of the Fast Annihilation Cryogenic Tracker detector (FACT), installed around the antihydrogen production trap inside the 1 T superconducting magnet of the AEḡIS experiment. FACT is designed to detect pions originating from the annihilation of antiprotons. Its 794 scintillating fibers operate at 4 K and are read out by silicon photomultipliers (MPPCs) at near room temperature. FACT provides the antiproton/antihydrogen annihilation position information with a few ns timing resolution. We present the hardware and software developments which led to the successful operation of the detector for antihydrogen detection and the results of an antiproton-loss based efficiency assessment. The main background to the antihydrogen signal is that of the positrons impinging onto the positronium conversion target and creating a large amount of gamma rays which produce a sizeable signal in the MPPCs shortly before the antihydrogen signal is expected. We detail the characterization of this background signal and its impact on the antihydrogen detection efficiency.

Published
2020

26. Efficient 2S3 positronium production by stimulated decay from the 3P3 level

Author

R. S. Brusa, P. Hackstock, E. Widmann, B. Rienaecker, Heidi Sandaker, S. Haider, M. Fanì, A. Hinterberger, V. Matveev, Ph. Lebrun, Sebastian Gerber, Daniel Comparat, A. S. Belov, Ole Røhne, Ruggero Caravita, Patrick Nedelec, E. Oswald, M. Antonello, C. Zimmer, I. C. Tietje, G. Testera, S. Müller, Alban Kellerbauer, Luca Penasa, Fabrizio Castelli, Giovanni Consolati, Germano Bonomi, A. Camper, Michael Doser, Alberto Rotondi, F. Prelz, Nicola Zurlo, P. Yzombard, Chloé Malbrunot, M. Oberthaler, Angela Gligorova, G. Nebbia, Romualdo Santoro, Davide Pagano, Sebastiano Mariazzi, V. Lagomarsino, Giovanni Cerchiari, F. Guatieri, L. Di Noto, T. Wolz, D. Krasnický, A. Demetrio, J. Robert, Massimo Caccia, V. Petráček, and O. Khalidova

Subjects
Spontaneous decay, Physics, Pulse (signal processing), Branching fraction, Ir laser, Production efficiency, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, Positronium, 0103 physical sciences, Atomic physics, Experimental methods, 010306 general physics, Intensity (heat transfer)
Abstract

We investigate experimentally the possibility of enhancing the production of 2S3 positronium atoms by driving the 1S3–3P3 and 3P3–2S3 transitions, overcoming the natural branching ratio limitation of spontaneous decay from 3P3 to 2S3. The decay of 3P3 positronium atoms toward the 2S3 level has been efficiently stimulated by a 1312.2 nm broadband IR laser pulse. The dependence of the stimulating transition efficiency on the intensity of the IR pulse has been measured to find the optimal enhancement conditions. A maximum relative increase of ×(3.1±1.0) in the 2S3 production efficiency, with respect to the case in which only spontaneous decay is present, was obtained.

Published
2019

27. Correction to: Compression of a mixed antiproton and electron non-neutral plasma to high densities

Author

S.R. Müller, Romualdo Santoro, G. Nebbia, Daniel Comparat, Davide Pagano, H. Holmestad, Marco Prevedelli, M. Antonello, C. Zimmer, A. Hinterberger, I. C. Tietje, D. Krasnický, A. Demetrio, Sebastiano Mariazzi, C. Evans, Rafael Ferragut, Claude Amsler, O. Khalidova, G. Testera, Markus K. Oberthaler, Nicola Zurlo, Angela Gligorova, L. Smestad, B. Rienaecker, Vojtech Petracek, Luca Penasa, Patrick Nedelec, Sebastian Gerber, Johann Marton, Stefano Aghion, Fabrizio Castelli, Massimo Caccia, Johann Zmeskal, Michael Doser, Giovanni Cerchiari, F. Prelz, Victor Matveev, F. Guatieri, Nicola Pacifico, P. Lansonneur, Adriano Fontana, S. Haider, Roberto S. Brusa, Giovanni Consolati, Germano Bonomi, Lea Di Noto, P. Yzombard, J. Robert, M. Fanì, Ruggero Caravita, Ole Røhne, Fiodor Sorrentino, Eberhard Widmann, V. Lagomarsino, J. Fesel, Chloé Malbrunot, Heidi Sandaker, Patrice Lebrun, Marco Giammarchi, Z. Mazzotta, Alban Kellerbauer, and Alberto Rotondi

Subjects
Political science, European research, Technical university, media_common.cataloged_instance, Library science, Christian ministry, Russian federation, European Social Fund, European union, Atomic and Molecular Physics, and Optics, Excellence initiative, Quality enhancement, media_common
Abstract

This correction provides updated acknowledgements: This work was supported by Istituto Nazionale di Fisica Nucleare; the Swiss National Science Foundation Ambizione Grant (No. 154833); a Deutsche Forschungsgemeinschaft research grant; an excellence initiative of Heidelberg University; Marie Sklodowska-Curie Innovative Training Network Fellowship of the European Commission’s Horizon 2020 Programme (No. 721559 AVA); European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement ANGRAM No 748826; European Research Council under the European Union’s Seventh Framework Program FP7/2007-2013 (Grants Nos. 291242 and 277762); Austrian Ministry for Science, Research, and Economy; Research Council of Norway; Bergen Research Foundation; John Templeton Foundation; Ministry of Education and Science of the Russian Federation and Russian Academy of Sciences; and the European Social Fund within the framework of realizing the project, in support of intersectoral mobility and quality enhancement of research teams at Czech Technical University in Prague (Grant No. CZ.1.07/2.3.00/30.0034).

Published
2019

28. Techniques for Production and Detection of $2^3S$ Positronium

Author

Eberhard Widmann, V. Lagomarsino, S.R. Müller, Marco Prevedelli, M. Antonello, I. C. Tietje, Sebastiano Mariazzi, Ole Røhne, Ruggero Caravita, F. Prelz, M. Fanì, V. A. Matveev, Luca Penasa, Alban Kellerbauer, A. S. Belov, Massimo Caccia, Daniel Comparat, P. Lebrun, Giovanni Consolati, Germano Bonomi, Giovanni Cerchiari, Nicola Zurlo, E. Oswald, J. Fesel, P. Hackstock, B. Rienäcker, Roberto S. Brusa, Romualdo Santoro, T. Wolz, Chloé Malbrunot, V. Petracek, M. Oberthaler, O. Khalidova, Angela Gligorova, J. Robert, Patrick Nedelec, D. Krasnicky, Davide Pagano, C. Zimmer, A. Camper, Sebastian Gerber, A. Demetrio, A. Hinterberger, F. Guatieri, A. Vespertini, P. Yzombard, Di Noto, Alberto Rotondi, Heidi Sandaker, S. Haider, G. Testera, Fabrizio Castelli, Michael Doser, G. Nebbia, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
010302 applied physics, Nuclear physics, Materials science, Physics in General, 0103 physical sciences, General Physics and Astronomy, Production (economics), 02 engineering and technology, 021001 nanoscience & nanotechnology, 0210 nano-technology, 01 natural sciences, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Positronium
Abstract

International audience; In this work, we show recent measurements of $2^{3}S$ long-lived positronium production via spontaneous decay from the 3 3P level. The possibility to tune the velocity of the $2^{3}S$ positronium, excited following this scheme, is presented. In the light of these results, we discuss the use of the $3^{3}P$→ $2^{3}S$ transition to realize a monochromatic pulsed $2^{3}S$ positronium beam with low angular divergence. Preliminary tests of $2^{3}S$ beam production are presented. The possibility to overcome the natural $3^{3}P$ → $2^{3}S$ branching ratio via stimulated emission, and thus increasing the intensity of the $2^{3}S$ source, is also shown. A position-sensitive detector for a pulsed beam of positronium, with spatial resolution of ≈ 90 $\mu m$, is finally described in view of its possible application for the spatial characterization of the $2^{3}S$ beam

Published
2019

29. Calibration and Equalisation of Plastic Scintillator Detectors for Antiproton Annihilation Identification Over Positron/Positronium Background

Author

Ole Røhne, F. Prelz, G. Nebbia, S. Haider, D. Krasnicky, B. Rienaecker, Daniel Comparat, C. Zimmer, G. Testera, P. Yzombard, Claude Amsler, Giovanni Consolati, Germano Bonomi, Sebastiano Mariazzi, Massimo Caccia, V. Toso, Ruggero Caravita, Luca Penasa, A. Hinterberger, Fabrizio Castelli, Michael Doser, T. Wolz, V. Matveev, Roberto S. Brusa, Marco Giammarchi, Giovanni Cerchiari, V. Petracek, L. Di Noto, L. T. Glöggler, Rafael Ferragut, Alban Kellerbauer, Chloé Malbrunot, V. Lagomarsino, A. Demetrio, Alberto Rotondi, Davide Pagano, Heidi Sandaker, Sebastian Gerber, F. Guatieri, A. Camper, M. Oberthaler, Angela Gligorova, Patrick Nedelec, M. Fanì, E. Oswald, Romualdo Santoro, Marco Prevedelli, M. Antonello, I. C. Tietje, A. S. Belov, O. Khalidova, S. Müller, Nicola Zurlo, Laboratoire Aimé Cotton (LAC), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Zurlo N., Amsler C., Antonello M., Belov A., Bonomi G., Brusa R.S., Caccia M., Camper A., Caravita R., Castelli F., Cerchiari G., Comparat D., Consolati G., Demetrio A., Di Noto L., Doser M., Fani M., Ferragut R., Gerber S., Giammarchi M., Gligorova A., Gloggler L., Guatieri F., Haider S., Hinterberger A., Kellerbauer A., Khalidova O., Krasnicky D., Lagomarsino V., Malbrunot C., Mariazzi S., Matveev V., Muller S.R., Nebbia G., Nedelec P., Oberthaler M., Oswald E., Pagano D., Penasa L., Petracek V., Prelz F., Prevedelli M., Rienaecker B., Rohne O.M., Rotondi A., Sandaker H., Santoro R., Testera G., Tietje I.C., Toso V., Wolz T., Yzombard P., and Zimmer C.

Subjects
Physics::Instrumentation and Detectors, positronium: annihilation, General Physics and Astronomy, positron: annihilation, scintillation counter: plastics, Scintillator, 01 natural sciences, Positronium, Nuclear physics, Positron, Positronium, Particle detectors, 0103 physical sciences, Calibration, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Detectors and Experimental Techniques, 010306 general physics, Physics, Annihilation, photomultiplier, 010308 nuclear & particles physics, background, Detector, calibration, Identification (information), Antiproton, cosmic radiation, Scintillators, numerical calculations: Monte Carlo
Abstract

International audience; In this contribution, the system of the external plastic scintillator slabs of the AEgIS experiment is presented. These slabs, surrounding the superconducting magnet and operating at room temperature, are read out by photomultiplier tubes (PMTs) that are calibrated and equalised to be exploited as a whole detector with useful segmentation and redundancy to effectively detect single antiparticle annihilations. In particular, thanks to periodically recurring calibrations with cosmic rays and to a detailed study of the system in different operational conditions, including extensive Monte Carlo (MC) simulations, these scintillators can be used to identify antiproton annihilations over the constant background represented by cosmic rays and over the strongly time-dependent background due to positrons/positronium annihilations. By means of the sampling and digitization of the analog signal produced by each phototube and the consequent analysis of the amplitude of the recorded events, the energy released by the particle in the scintillator slab can be estimated consistently and with good accuracy. As a consequence, we are able to identify an amplitude range where positrons/positronium annihilations can be univocally excluded. This prerequisite allows us to exploit the array of external plastic scintillators for antihydrogen annihilations tagging.

Published
2019

30. Real-Time Trajectory Control of Deterministically Produced Ions

Author

Y.J. Picard, A. Trimeche, C. Lopez, Daniel Comparat, Laboratoire Lumière, Matière et Interfaces (LuMIn), CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), Systèmes de Référence Temps Espace (SYRTE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), and École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], General Physics and Astronomy, 02 engineering and technology, Photoionization, Electron, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, Charged particle, Ion, Computational physics, Quantum technology, Momentum, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Position (vector), Physics::Plasma Physics, 0103 physical sciences, Trajectory, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, 0210 nano-technology, Hardware_REGISTER-TRANSFER-LEVELIMPLEMENTATION, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; The major challenge to improve deterministic single-ion sources is to control the position and momentum of each ion. On the basis of the extra information given by the electron created in a photoionization process, the trajectory of the correlated ion can be corrected with use of a fast real-time feedback system. In this paper, we report on a proof-of-principle experiment that demonstrates the performance of this feedback control with individual cesium ions. The electron produced is detected with a time- and position-sensitive detector, the information from which is used to quickly infer the position of the corresponding ion. Then the feedback system drives the ion trajectory through steering plates, and the individual ion can thus be sent to any dedicated location. This enables us to perform deterministic patterning and achieve a factor-of-1000 reduction in spot area. The single-ion feedback control is versatile and can be applied to different kinds of ion sources. It provides a powerful tool to optimize the ion beam and offers a complete portfolio for quantum systems and applications in materials science.

Published
2019

31. Design for a high resolution electron energy loss microscope

Author

A. Lafosse, Marian Mankos, Gerd Schönhense, L. Amiaud, Daniel Comparat, Nicholas Barrett, Khashayar Shadman, Raphaël Hahn, Yan J. Picard, O. Fedchenko, Electron Optica Inc., Laboratoire Aimé Cotton (LAC), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Institut des Sciences Moléculaires d'Orsay (ISMO), Laboratoire d'Etude des NanoStructures et Imagerie de Surface (LENSIS), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU)

Subjects
Microscope, Materials science, EELS, Phonon, 02 engineering and technology, Electron, 01 natural sciences, law.invention, Optics, law, surface imaging, 0103 physical sciences, Microscopy, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation, Image resolution, LEEM, 010302 applied physics, Spectrometer, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], business.industry, 021001 nanoscience & nanotechnology, Laser, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Excited state, 0210 nano-technology, business
Abstract

International audience; An electron optical column has been designed for High Resolution Electron Energy Loss Microscopy (HREELM). The column is composed of electron lenses and a beam separator that are placed between an electron source based on a laser excited cesium atom beam and a time-of-flight (ToF) spectrometer or a hemispherical analyzer (HSA). The instrument will be able to perform full field low energy electron imaging of surfaces with sub-micron spatial resolution and meV energy resolution necessary for the analysis of local vibrational spectra. Thus, noncontact, real space mapping of microscopic variations in vibrational levels will be made possible. A second imaging mode will allow for the mapping of the phonon dispersion relations from microscopic regions defined by an appropriate field aperture.

Published
2019

32. Velocity-selected production of 2S3 metastable positronium

Author

R. S. Brusa, Giovanni Consolati, Germano Bonomi, P. Hackstock, Ph. Lebrun, H. Holmestad, D. Krasnický, A. Demetrio, Giovanni Cerchiari, Ruggero Caravita, Claude Amsler, G. Nebbia, G. Testera, S. Haider, V. Matveev, Ole Røhne, Sebastian Gerber, Alban Kellerbauer, M. Fanì, Heidi Sandaker, J. Robert, Fabrizio Castelli, L. Di Noto, M. Oberthaler, F. Prelz, B. Rienaecker, Chloé Malbrunot, E. Widmann, Felice Sorrentino, Sebastiano Mariazzi, Michael Doser, Luca Penasa, Angela Gligorova, Marco Prevedelli, M. Antonello, Alberto Rotondi, I. C. Tietje, S. Müller, Daniel Comparat, Patrick Nedelec, F. Guatieri, Romualdo Santoro, Massimo Caccia, O. Khalidova, P. Lansonneur, A. S. Belov, C. Zimmer, V. Petráček, Lillian Smestad, Davide Pagano, V. Lagomarsino, Nicola Zurlo, A. Camper, A. Hinterberger, and P. Yzombard

Subjects
Physics, Branching fraction, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, Positronium, Pulse (physics), Positron, Polarizability, Electric field, Metastability, 0103 physical sciences, Production (computer science), Physics::Atomic Physics, Atomic physics, 010306 general physics
Abstract

Positronium in the $2^3S$ metastable state exhibits a low electrical polarizability and a long lifetime (1140 ns) making it a promising candidate for interferometry experiments with a neutral matter-antimatter system. In the present work, $2^3S$ positronium is produced - in absence of electric field - via spontaneous radiative decay from the $3^3P$ level populated with a 205nm UV laser pulse. Thanks to the short temporal length of the pulse, 1.5 ns full-width at half maximum, different velocity populations of a positronium cloud emitted from a nanochannelled positron/positronium converter were selected by delaying the excitation pulse with respect to the production instant. $ 2^3S $ positronium atoms with velocity tuned between $ 7 \cdot 10^4 $ m/s and $ 10 \cdot 10^4 $ m/s were thus produced. Depending on the selected velocity, a $2^3S$ production effciency ranging from $\sim 0.8 \%$ to $\sim 1.7%$, with respect to the total amount of emitted positronium, was obtained. The observed results give a branching ratio for the $3^3P$-$2^3S$ spontaneous decay of $(9.7 \pm 2.7) \% $. The present velocity selection technique could allow to produce an almost monochromatic beam of $\sim 1 \cdot 10^3 $ $2^3S$ atoms with a velocity spread $ < 10^4 $ m/s and an angular divergence of $\sim$ 50 mrad.

Published
2019

33. A ∼100 μm-resolution position-sensitive detector for slow positronium

Author

Chloé Malbrunot, Alban Kellerbauer, Giovanni Consolati, Germano Bonomi, Ruggero Caravita, P. Hackstock, T. Wolz, R. S. Brusa, G. Nebbia, Patrick Nedelec, A. Camper, Claude Amsler, V. A. Matveev, Sebastian Gerber, O. Khalidova, F. Guatieri, J. Fesel, A. Hinterberger, A. S. Belov, M. Oberthaler, Luca Penasa, Angela Gligorova, Marco Prevedelli, M. Antonello, M. Fanì, I. C. Tietje, Marco Giammarchi, S. Haider, Sebastiano Mariazzi, Daniel Comparat, B. Rienaecker, Massimo Caccia, E. Oswald, Rafael Ferragut, Davide Pagano, P. Yzombard, Ole Røhne, F. Prelz, G. Testera, Nicola Zurlo, C. Zimmer, P. Lebrun, Fabrizio Castelli, V. Petráček, Michael Doser, J. Robert, Eberhard Widmann, V. Lagomarsino, L. Di Noto, Heidi Sandaker, Alberto Rotondi, S.R. Müller, Romualdo Santoro, Giovanni Cerchiari, D. Krasnický, A. Demetrio, Amsler, C., Antonello, M., Belov, A., Bonomi, G., Brusa, R.S., Caccia, M., Camper, A., Caravita, R., Castelli, F., Cerchiari, G., Comparat, D., Consolati, G., Demetrio, A., Di Noto, L., Doser, M., Fanì, M., Ferragut, R., Fesel, J., Gerber, S., Giammarchi, M., Gligorova, A., Guatieri, F., Hackstock, P., Haider, S., Hinterberger, A., Kellerbauer, A., Khalidova, O., Krasnický, D., Lagomarsino, V., Lebrun, P., Malbrunot, C., Mariazzi, S., Matveev, V., Müller, S.R., Nebbia, G., Nedelec, P., Oberthaler, M., Oswald, E., Pagano, D., Penasa, L., Petracek, V., Prelz, F., Prevedelli, M., Rienaecker, B., Robert, J., Røhne, O.M., Rotondi, A., Sandaker, H., Santoro, R., Testera, G., Tietje, I.C., Widmann, E., Wolz, T., Yzombard, P., Zimmer, C., Zurlo, N., Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Detector, Photoionization, Positronium, 01 natural sciences, Magnetic field, Imaging, Positron, Ionization, Excited state, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Microchannel plate detector, Positronium, Imaging, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Physics::Atomic Physics, Atomic physics, Physics::Chemical Physics, 010306 general physics, Instrumentation
Abstract

In this work we describe a high-resolution position-sensitive detector for positronium. The detection scheme is based on the photoionization of positronium in a magnetic field and the imaging of the freed positrons with a Microchannel Plate assembly. A spatial resolution of ( 88 ± 5 ) μm on the position of the ionized positronium –in the plane perpendicular to a 1.0 T magnetic field– is obtained. The possibility to apply the detection scheme for monitoring the emission into vacuum of positronium from positron/positronium converters, imaging positronium excited to a selected state and characterizing its spatial distribution is discussed. Ways to further improve the spatial resolution of the method are presented.

Published
2019

34. Positronium Rydberg excitation diagnostic in a 1T cryogenic environment

Author

Ole Røhne, Johann Marton, Chloé Malbrunot, B. Rienaecker, Davide Pagano, P. Hackstock, M. Fanì, Giovanni Consolati, Germano Bonomi, S. Müller, R. S. Brusa, M. Vujanovic, A. Camper, G. Nebbia, S. Haider, V. Matveev, Patrick Nedelec, Sebastiano Mariazzi, Johann Zmeskal, C. Zimmer, A. Hinterberger, Ruggero Caravita, E. Widmann, A. S. Belov, O. Khalidova, Marco Giammarchi, Marco Prevedelli, M. Antonello, Lillian Smestad, I. C. Tietje, Fabrizio Castelli, Stefano Aghion, Alban Kellerbauer, Romualdo Santoro, Michael Doser, Claude Amsler, Ph. Lebrun, H. Holmestad, Rafael Ferragut, M. Oberthaler, G. Testera, Angela Gligorova, F. Prelz, J. Robert, P. Yzombard, Felice Sorrentino, Nicola Zurlo, Daniel Comparat, D. Krasnický, A. Demetrio, C. Evans, Andrea Fontana, Giovanni Cerchiari, Massimo Caccia, Luca Penasa, Heidi Sandaker, V. Petráček, Alberto Rotondi, L. Di Noto, Sebastian Gerber, F. Guatieri, P. Lansonneur, V. Lagomarsino, J. Fesel, Caravita R., Mariazzi S., Aghion S., Amsler C., Antonello M., Belov A., Bonomi G., Brusa R.S., Caccia M., Camper A., Castelli F., Cerchiari G., Comparat D., Consolati G., Demetrio A., Di Noto L., Doser M., Evans C., Fani M., Ferragut R., Fesel J., Fontana A., Gerber S., Giammarchi M., Gligorova A., Guatieri F., Hackstock P., Haider S., Hinterberger A., Holmestad H., Kellerbauer A., Khalidova O., Krasnicky D., Lagomarsino V., Lansonneur P., Lebrun P., Malbrunot C., Marton J., Matveev V., Muller S.R., Nebbia G., Nedelec P., Oberthaler M., Pagano D., Penasa L., Petracek V., Prelz F., Prevedelli M., Rienaecker B., Robert J., Rohne O.M., Rotondi A., Sandaker H., Santoro R., Smestad L., Sorrentino F., Testera G., Tietje I.C., Vujanovic M., Widmann E., Yzombard P., Zimmer C., Zmeskal J., and Zurlo N.

Subjects
positronium, spectroscopy, Materials science, Laser, Positronium, law.invention, symbols.namesake, law, Antimatter, Field desorption, Rydberg formula, symbols, Physics::Atomic Physics, Atomic physics, Spectroscopy, Antihydrogen, Excitation
Abstract

Forming a pulsed beam of cold antihydrogen using charge-exchange with Rydberg positronium (Ps) is the goal of the AEgIS collaboration, which aims to a first gravity measurement on neutral antimatter. Recently achieved results in Ps formation and laser spectroscopy in the main AEgIS apparatus are summarized. First, Ps has been produced using nanochanneled silicon targets in a cryogenic environment (~ 15 K) with 1 T magnetic field and observed by means of Single-Shot Positron Annihilation Lifetime Spectroscopy. The first demonstration of Ps n=3 excitation has been obtained as well using the same technique, validating the proof-of-concept of AEgIS. Subsequently, a new fast and high sensitivity detection method for laser-excited Ps in high magnetic field has been developed, using the combination of laser/field ionization and an high sensitivity MCP detector coupled to a low-noise CMOS camera. This technique will form the basis of future experiments involving Rydberg Ps spectroscopy in AEgIS.

Published
2019

35. Imaging a positronium cloud in a 1 Tesla

Author

Stefano Aghion, P. Hackstock, G. Nebbia, Alban Kellerbauer, A. Hinterberger, Sebastian Gerber, Rafael Ferragut, Ruggero Caravita, Daniel Comparat, Marco Prevedelli, M. Antonello, D. Krasnický, A. Demetrio, Sebastiano Mariazzi, F. Guatieri, A. M. Belov, I. C. Tietje, C. Evans, Markus K. Oberthaler, Roberto S. Brusa, B. Rienaecker, L. Smestad, F. Sorrentino, Giovanni Consolati, Chloé Malbrunot, M. Vujanovic, Germano Bonomi, Johann Marton, S. Haider, J. Robert, M. Fanì, Marco Giammarchi, F. Prelz, Heidi Sandaker, Giovanni Cerchiari, Angela Gligorova, Luca Penasa, P. Lebrun, Patrick Nedelec, Lea Di Noto, Johann Zmeskal, Davide Pagano, P. Yzombard, P. Lansonneur, A. Camper, C. Zimmer, Alberto Rotondi, G. Testera, Adriano Fontana, Fabrizio Castelli, Michael Doser, H. Holmestad, O. Khalidova, Claude Amsler, Vojtech Petracek, S.R. Müller, Romualdo Santoro, Nicola Zurlo, Viktor Matveev, J. Fesel, Ole Røhne, Massimo Caccia, Eberhard Widmann, V. Lagomarsino, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Camper, Antoine, Aghion, Stefano, Amsler, Claude, Antonello, Massimiliano, Belov, Alexander, Bonomi, Germano, Brusa, Roberto, Caccia, Massimo, Caravita, Ruggero, Castelli, Fabrizio, Cerchiari, Giovanni, Comparat, Daniel, Consolati, Giovanni, Demetrio, Andrea, Di Noto, Lea, Doser, Michael, Evans, Craig, Fanì, Mattia, Ferragut, Rafael, Fesel, Julian, Fontana, Andrea, Gerber, Sebastian, Giammarchi, Marco, Gligorova, Angela, Guatieri, Francesco, Hackstock, Philip, Haider, Stefan, Hinterberger, Alexander, Holmestad, Helga, Kellerbauer, Alban, Khalidova, Olga, Krasnický, Daniel, Lagomarsino, Vittorio, Lansonneur, Pierre, Lebrun, Patrice, Malbrunot, Chloé, Mariazzi, Sebastiano, Marton, Johann, Matveev, Viktor, Müller, Simon, Nebbia, Giancarlo, Nedelec, Patrick, Oberthaler, Marku, Pagano, Davide, Penasa, Luca, Petracek, Vojtech, Prelz, Francesco, Prevedelli, Marco, Rienaecker, Benjamin, Robert, Jacque, Røhne, Ole, Rotondi, Alberto, Sandaker, Heidi, Santoro, Romualdo, Smestad, Lillian, Sorrentino, Fiodor, Testera, Gemma, Tietje, Ingmari, Vujanovic, Milena, Widmann, Eberhard, Yzombard, Pauline, Zimmer, Christian, Zmeskal, Johann, Zurlo, Nicola, École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
QC1-999, measurement methods, positronium, Cloud computing, Photoionization, talk: Paris 2018/09/05, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, Positronium, law.invention, Nuclear physics, Positron, law, 0103 physical sciences, antimatter, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Physics::Atomic and Molecular Clusters, cloud, Physics::Atomic Physics, 010306 general physics, Spectroscopy, Antihydrogen, Physics, business.industry, background, antihydrogen: production, imaging, Laser, charge exchange, laser, Antimatter, positronium, gravity, positron, business, Particle Physics - Experiment, experimental results
Abstract

International audience; We report on recent developments in positronium work in the frame of antihydrogen production through charge exchange in the AEgIS collaboration [1]. In particular, we present a new technique based on spatially imaging a cloud of positronium by collecting the positrons emitted by photoionization. This background free diagnostic proves to be highly efficient and opens up new opportunities for spectroscopy on antimatter, control and laser manipulation of positronium clouds as well as Doppler velocimetry.

Published
2019

36. Production of long-lived positronium states via laser excitation to 33P level

Author

A. Camper, Sebastian Gerber, J. Fesel, R. S. Brusa, F. Guatieri, P. Lansonneur, Romualdo Santoro, M. Oberthaler, G. Testera, Angela Gligorova, E. Widmann, O. M. Roehne, S. R. Mueller, Luca Penasa, B. Rienaecker, Stefano Aghion, Ph. Lebrun, H. Holmestad, F. Prelz, L. Di Noto, Claude Amsler, Felice Sorrentino, D. Krasnicky, Marco Prevedelli, M. Antonello, Daniel Comparat, Chloé Malbrunot, Rafael Ferragut, J. Robert, Andrea Fontana, I. C. Tietje, Massimo Caccia, Fabrizio Castelli, Michael Doser, V. Petráček, P. Hackstock, Marco Giammarchi, G. Nebbia, Giovanni Cerchiari, S. Haider, Davide Pagano, C. Zimmer, V. Matveev, O. Khalidova, Alban Kellerbauer, Alberto Rotondi, A. Hinterberger, V. Lagomarsino, A. S. Belov, Lillian Smestad, A. Demetrio, Patrick Nedelec, Sebastiano Mariazzi, M. Fanì, C. Evans, Ruggero Caravita, Giovanni Consolati, Germano Bonomi, P. Yzombard, Heidi Sandaker, Nicola Zurlo, Mariazzi S., Caravita R., Aghion S., Amsler C., Antonello M., Belov A., Bonomi G., Brusa R.S., Caccia M., Camper A., Castelli F., Cerchiari G., Comparat D., Consolati G., Demetrio A., Di Noto L., Doser M., Evans C., Fani M., Ferragut R., Fesel J., Fontana A., Gerber S., Giammarchi M., Gligorova A., Guatieri F., Hackstock P., Haider S., Hinterberger A., Holmestad H., Kellerbauer A., Khalidova O., Krasnicky D., Lagomarsino V., Lansonneur P., Lebrun P., Malbrunot C., Matveev V., Mueller S.R., Nebbia G., Nedelec P., Oberthaler M., Pagano D., Penasa L., Petracek V., Prelz F., Prevedelli M., Rienaecker B., Robert J., Roehne O.M., Rotondi A., Sandaker H., Santoro R., Smestad L., Sorrentino F., Testera G., Tietje I.C., Widmann E., Yzombard P., Zimmer C., and Zurlo N.

Subjects
positronium, spectroscopy, Physics, Laser, 01 natural sciences, 010305 fluids & plasmas, Positronium, law.invention, Interferometry, symbols.namesake, law, Metastability, 0103 physical sciences, Rydberg formula, symbols, Intermediate state, Atomic physics, 010306 general physics, Ground state, Excitation
Abstract

The 33P state of positronium is an intermediate level suitable for producing long-lived positronium states. On one hand, it can be used in a two-step laser excitation scheme from the ground state to Rydberg levels. On the other hand, excitation of positronium to 33P level is a simple pathway for producing metastable 23S positronium atoms by spontaneous radiactive decay. In this work, experiments showing the production of such long-lived levels, using the 33P state as intermediate state, are presented. The characteristics of the two long-lived levels, in view of experiments of deflectometry/interferometry with positronium, are discussed.The 33P state of positronium is an intermediate level suitable for producing long-lived positronium states. On one hand, it can be used in a two-step laser excitation scheme from the ground state to Rydberg levels. On the other hand, excitation of positronium to 33P level is a simple pathway for producing metastable 23S positronium atoms by spontaneous radiactive decay. In this work, experiments showing the production of such long-lived levels, using the 33P state as intermediate state, are presented. The characteristics of the two long-lived levels, in view of experiments of deflectometry/interferometry with positronium, are discussed.

Published
2019

37. Real-time trajectory control on a deterministic ion source

Author

Y. J. Picard, C. Lopez, A. Trimeche, and Daniel Comparat

Subjects
History, Physics - Instrumentation and Detectors, Ion beam, 010308 nuclear & particles physics, Detector, Process (computing), FOS: Physical sciences, Photoionization, Instrumentation and Detectors (physics.ins-det), 01 natural sciences, 7. Clean energy, Ion source, Computer Science Applications, Education, Ion, Position (vector), Control theory, Physics::Plasma Physics, 0103 physical sciences, Trajectory, 010306 general physics, Hardware_REGISTER-TRANSFER-LEVELIMPLEMENTATION
Abstract

The major challenge to improve deterministic single ion sources is to control the position and momentum of each ion. Based on the extra information given by the electron created in a photoionization process, the trajectory of the correlated ion can be controlled using a fast real time feedback system. In this paper, we report on a proof-of-principle experiment that demonstrates the performances of this feedback control with individual cesium ions. The produced electron is detected with a time and position sensitive detector, whose information are used to quickly infer the position of the corresponding ion. Then the feedback system drives the ion trajectory through steering plates. Individual ion can thus be send to any dedicated location. This enables us to perform deterministic patterning and reach a factor 1000 improvement in spot area. The single ion feedback control is versatile and can be applied to different kind of ion sources. It provides a powerful tool to optimize the ion beam and offers new area for quantum systems and applications of materials science., 5 pages, 4 figures

Published
2018

38. Phase-space-density limitation in laser cooling without spontaneous emission

Author

Daniel Comparat, H. Lignier, Thierry Chanelière, Nanophysique et Semiconducteurs (NPSC), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire Aimé Cotton (LAC), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan)

Subjects
Physics, Quantum Physics, Uncertainty principle, Field (physics), [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Degrees of freedom (physics and chemistry), FOS: Physical sciences, Space (mathematics), 01 natural sciences, 010305 fluids & plasmas, Computational physics, Momentum, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Phase space, Laser cooling, 0103 physical sciences, Spontaneous emission, 010306 general physics, Quantum Physics (quant-ph), ComputingMilieux_MISCELLANEOUS
Abstract

We study the possibility to enhance the phase space density of non-interacting particles submitted to a classical laser field without spontaneous emission. We clearly state that, when no spontaneous emission is present, a quantum description of the atomic motion is more reliable than semi-classical description which can lead to large errors especially if no care is taken to smooth structures smaller than the Heisenberg uncertainty principle. Whatever the definition of position - momentum phase space density, its gain is severely bounded especially when started from a thermal sample. More precisely, the maximum phase space density, can only be improved by a factor M for M-level atoms. This bound comes from a transfer between the external and internal degrees of freedom. To circumvent this limit, one can use non-coherent light fields, informational feedback cooling schemes, involve collectives states between fields and atoms, or allow a single spontaneous emission even, Comment: 3 figures, 4 pages

Published
2018

39. Watt-level narrow-linewidth fibered laser source at 852 nm for FIB application

Author

Baptiste Battelier, Germain Guiraud, Daniel Comparat, Matthieu Viteau, Guillaume Stern, Emmanuel Pinsard, Sergio Rota-Rodrigo, Laura Antoni-Micollier, Benoit Cadier, Bruno Desruelle, Giorgio Santarelli, Morgan Reveillard, and Nicholas Traynor

Subjects
Materials science, business.industry, Energy conversion efficiency, Lithium niobate, Physics::Optics, Laser, 01 natural sciences, 7. Clean energy, Focused ion beam, Waveguide (optics), Atomic and Molecular Physics, and Optics, law.invention, 010309 optics, chemistry.chemical_compound, Laser linewidth, Optics, chemistry, law, Laser cooling, Fiber laser, 0103 physical sciences, Physics::Atomic Physics, 010306 general physics, business
Abstract

We realize a 1 W all-fibered polarized compact and robust laser source at 852 nm for laser cooling of cesium atoms. The architecture is based on the sum-frequency generation of 1540 and 1908 nm lasers, realized through a periodically poled lithium niobate waveguide with a conversion efficiency of 40%. A linewidth of 20 kHz is achieved with the development of a distributed feedback fiber laser at 1908 nm. The operation of this laser source is demonstrated on a focused ion beam (FIB) experiment based on cold cesium atoms.

Published
2018

40. Producing long-lived 23S positronium via 33P laser excitation in magnetic and electric fields

Author

Fabrizio Castelli, Giovanni Consolati, F. Sorrentino, Ole Røhne, F. Prelz, E. Widmann, P. Hackstock, D. Krasnický, J. Marton, Rafael Ferragut, G. Nebbia, Daniel Comparat, V. Petracek, M. Fanì, A. Kellerbauer, I. C. Tietje, A. Hinterberger, A. Gligorova, P. Nedelec, J. Robert, M. Vujanovic, S. Haider, Johann Zmeskal, Sebastian Gerber, D. Pagano, C. Zimmer, Luca Penasa, L. Smestad, V. N. Matveev, P. Lansonneur, F. Guatieri, Markus K. Oberthaler, B. Rienaecker, Marco Prevedelli, M. Antonello, Claude Amsler, Ruggero Caravita, A. Rotondi, J. Fesel, O. Khalidova, A. Camper, R. S. Brusa, A. Fontana, Heidi Sandaker, M. Doser, Z. Mazzotta, Marco Giammarchi, A. Demetrio, C. Evans, G. Bonomi, Giovanni Cerchiari, C. Malbrunot, A. S. Belov, L. Di Noto, Massimo Caccia, H. Holmestad, N. Zurlo, P. Yzombard, V. Lagomarsino, P. Lebrun, S.R. Müller, S. Aghion, Romualdo Santoro, S. Mariazzi, and G. Testera

Subjects
Physics, education.field_of_study, Population, 02 engineering and technology, 021001 nanoscience & nanotechnology, Laser, 01 natural sciences, Positronium, law.invention, Magnetic field, law, Electric field, Metastability, Excited state, 0103 physical sciences, Atomic physics, 010306 general physics, 0210 nano-technology, education, Excitation
Abstract

Producing positronium (Ps) in the metastable 23S state is of interest for various applications in fundamental physics. We report here on an experiment in which Ps atoms are produced in this long-lived state by spontaneous radiative decay of Ps excited to the 33P level manifold. The Ps cloud excitation is obtained with a UV laser pulse in an experimental vacuum chamber in presence of guiding magnetic field of 25mT and an average electric field of 300Vcm−1. The evidence of the 23S state production is obtained to the 3.6σ level of statistical significance using a novel analysis technique of the single-shot positronium annihilation lifetime spectra. The dynamic of the Ps population on the involved levels has been studied with a rate equation model.

Published
2018

41. Antiproton tagging and vertex fitting in a Timepix3 detector

Author

Johann Zmeskal, L. Di Noto, Sebastian Gerber, P. Lansonneur, D. Pagano, V. Petracek, V. N. Matveev, F. Guatieri, C. Malbrunot, O. Khalidova, Ruggero Caravita, A. Rotondi, H. Holmestad, A. S. Belov, R. S. Brusa, Daniel Comparat, A. Gligorova, Massimo Caccia, A. Kellerbauer, Giovanni Cerchiari, Marco Prevedelli, M. Antonello, Heidi Sandaker, I. C. Tietje, F. Sorrentino, G. Bonomi, A. Camper, G. Testera, Claude Amsler, P. Nedelec, M. Doser, Fabrizio Castelli, Ph. Hackstock, F. Prelz, A. Hinterberger, Marco Giammarchi, S. Haider, S.R. Müller, J. Robert, A. Demetrio, L. Smestad, C. Evans, S. Aghion, N. Zurlo, G. Nebbia, Luca Penasa, P. Yzombard, A. Fontana, C. Zimmer, M. Fanì, Romualdo Santoro, S. Mariazzi, J. Fesel, J. Marton, P. Lebrun, V. Lagomarsino, Ole Røhne, Giovanni Consolati, D. Krasnický, Markus K. Oberthaler, B. Rienaecker, E. Widmann, Rafael Ferragut, Nicola Pacifico, Laboratoire Aimé Cotton (LAC), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AEgIS, Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Aghion, S., Amsler, C., Antonello, M., Belov, A., Bonomi, G., Brusa, R.S., Caccia, M., Camper, A., Caravita, R., Castelli, F., Cerchiari, G., Comparat, D., Consolati, G., Demetrio, A., Noto, L. Di, Doser, M., Evans, C., Fanì, M., Ferragut, R., Fesel, J., Fontana, A., Gerber, S., Giammarchi, M., Gligorova, A., Guatieri, F., Hackstock, Ph., Haider, S., Hinterberger, A., Holmestad, H., Kellerbauer, A., Khalidova, O., Krasnický, D., Lagomarsino, V., Lansonneur, P., Lebrun, P., Malbrunot, C., Mariazzi, S., Marton, J., Matveev, V., Müller, S.R., Nebbia, G., Nedelec, P., Oberthaler, M., Pacifico, N., Pagano, D., Penasa, L., Petracek, V., Prelz, F., Prevedelli, M., Rienaecker, B., Robert, J., Røhne, O.M., Rotondi, A., Sandaker, H., Santoro, R., Smestad, L., Sorrentino, F., Testera, G., Tietje, I.C., Widmann, E., Yzombard, P., Zimmer, C., Zmeskal, J., and Zurlo, N.

Subjects
Vertex (graph theory), Physics::Instrumentation and Detectors, 01 natural sciences, Particle identification methods, Physics::Atomic Physics, Detectors and Experimental Techniques, Nuclear Experiment, Instrumentation, Image resolution, Mathematical Physics, media_common, Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc), Physics, Detector, Simulation methods and program, Hybrid detectors, Simulation methods and programs, interac- tion of photons with matter, interaction of photons with matter, Detector modelling and simulations I, interaction of hadrons with matter, force: gravitation, readout, asymmetry, Particle physics, Physics::General Physics, CERN Lab, media_common.quotation_subject, antihydrogen: annihilation, Detector modelling and simulations I (interaction of radiation with matter, Asymmetry, anti-p p: annihilation, Particle identification method, 0103 physical sciences, detector: pixel, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, Antihydrogen, spatial resolution, etc), antihydrogen, detector: position sensitive, 010308 nuclear & particles physics, Hybrid detector, interaction of radiation with matter, efficiency, Antiproton, High Energy Physics::Experiment
Abstract

International audience; Studies of antimatter are important for understanding our universe at a fundamental level. There are still unsolved problems, such as the matter-antimatter asymmetry in the universe. The AEgIS experiment at CERN aims at measuring the gravitational fall of antihydrogen in order to determine the gravitational force on antimatter. The proposed method will make use of a position-sensitive detector to measure the annihilation point of antihydrogen. Such a detector must be able to tag the antiproton, measure its time of arrival and reconstruct its annihilation point with high precision in the vertical direction. This work explores a new method for tagging antiprotons and reconstructing their annihilation point. Antiprotons from the Antiproton Decelerator at CERN were used to obtain data on direct annihilations on the surface of a silicon pixel sensor with Timepix3 readout. These data were used to develop and verify a detector response model for annihilation of antiprotons in this detector. Using this model and the antiproton data it is shown that a tagging efficiency of 50± 10% and a vertical position resolution of 22 ± 0.5 μm can be obtained.

Published
2018

42. AEgIS at ELENA: outlook for physics with a pulsed cold antihydrogen beam

Author

Giovanni Consolati, F. Sorrentino, J. Marton, H. Holmestad, M. Fanì, A. Kellerbauer, F. Prelz, Heidi Sandaker, Ole Røhne, O. Khalidova, Daniel Comparat, Massimo Caccia, G. Nebbia, R. S. Brusa, C. Malbrunot, I. C. Tietje, Marco Prevedelli, N. Zurlo, P. Yzombard, D. Krasnický, P. Nedelec, Z. Mazzotta, V. Petracek, G. Testera, P. Lebrun, J. Fesel, Fabrizio Castelli, L. Di Noto, Johann Zmeskal, G. Bonomi, E. Widmann, Rafael Ferragut, Claude Amsler, D. Pagano, S. Haider, V. Lagomarsino, A. Gligorova, S.R. Müller, Marco Giammarchi, S. Aghion, J. Robert, Romualdo Santoro, S. Mariazzi, Nicola Pacifico, Luca Penasa, A. Demetrio, C. Zimmer, C. Evans, Giovanni Cerchiari, Ruggero Caravita, P. Lansonneur, Markus K. Oberthaler, B. Rienaecker, A. Hinterberger, L. Smestad, A. Fontana, M. Doser, Sebastian Gerber, V. N. Matveev, F. Guatieri, A. Rotondi, Doser, M., Aghion, S., Amsler, C., Bonomi, G., Brusa, R.S., Caccia, M., Caravita, R., Castelli, F., Cerchiari, G., Comparat, D., Consolati, G., Demetrio, A., Di Noto, L., Evans, C., Fanì, M., Ferragut, R., Fesel, J., Fontana, A., Gerber, S., Giammarchi, M., Gligorova, A., Guatieri, F., Haider, S., Hinterberger, A., Holmestad, H., Kellerbauer, A., Khalidova, O., Krasnický, D., Lagomarsino, V., Lansonneur, P., Lebrun, P., Malbrunot, C., Mariazzi, S., Marton, J., Matveev, V., Mazzotta, Z., Müller, S.R., Nebbia, G., Nedelec, P., Oberthaler, M., Pacifico, N., Pagano, D., Penasa, L., Petracek, V., Prelz, F., Prevedelli, M., Rienaecker, B., Robert, J., Røhne, O.M., Rotondi, A., Sandaker, H., Santoro, R., Smestad, L., Sorrentino, F., Testera, G., Tietje, I.C., Widmann, E., Yzombard, P., Zimmer, C., Zmeskal, J., Zurlo, N., Laboratoire Aimé Cotton (LAC), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
General Physics and Astronomy, Antiproton, magnetic field, Positronium, 01 natural sciences, 010305 fluids & plasmas, antihydrogen: formation, antimatter, Physics::Atomic Physics, Physics, antihydrogen, antiprotons, positrons, positronium, Large Hadron Collider, atom, General Engineering, Articles, antihydrogen, antiprotons, positronium, positrons, charge exchange, pulsed, anti-p, Antimatter, force: gravitation, gravitation: acceleration, Rydberg formula, symbols, Physics::General Physics, CERN Lab, General Mathematics, interferometer, Positron, antihydrogen: beam, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear physics, symbols.namesake, 0103 physical sciences, Physics::Atomic and Molecular Clusters, positronium: excited state, 010306 general physics, Antihydrogen, detector: position sensitive, gravitation: interaction, antihydrogen: production, ground state: hyperfine structure, Antiproton Decelerator, Automatic Keywords, Beam (structure)
Abstract

The efficient production of cold antihydrogen atoms in particle traps at CERN’s Antiproton Decelerator has opened up the possibility of performing direct measurements of the Earth’s gravitational acceleration on purely antimatter bodies. The goal of the AEgIS collaboration is to measure the value of g for antimatter using a pulsed source of cold antihydrogen and a Moiré deflectometer/Talbot–Lau interferometer. The same antihydrogen beam is also very well suited to measuring precisely the ground-state hyperfine splitting of the anti-atom. The antihydrogen formation mechanism chosen by AEgIS is resonant charge exchange between cold antiprotons and Rydberg positronium. A series of technical developments regarding positrons and positronium (Ps formation in a dedicated room-temperature target, spectroscopy of the n =1–3 and n =3–15 transitions in Ps, Ps formation in a target at 10 K inside the 1 T magnetic field of the experiment) as well as antiprotons (high-efficiency trapping of , radial compression to sub-millimetre radii of mixed plasmas in 1 T field, high-efficiency transfer of to the antihydrogen production trap using an in-flight launch and recapture procedure) were successfully implemented. Two further critical steps that are germane mainly to charge exchange formation of antihydrogen—cooling of antiprotons and formation of a beam of antihydrogen—are being addressed in parallel. The coming of ELENA will allow, in the very near future, the number of trappable antiprotons to be increased by more than a factor of 50. For the antihydrogen production scheme chosen by AEgIS, this will be reflected in a corresponding increase of produced antihydrogen atoms, leading to a significant reduction of measurement times and providing a path towards high-precision measurements. This article is part of the Theo Murphy meeting issue ‘Antiproton physics in the ELENA era’.

Published
2018
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43. Compression of a mixed antiproton and electron non-neutral plasma to high densities

Author

E. Widmann, Rafael Ferragut, Marco Giammarchi, M. Doser, A. Gligorova, J. Marton, S. Haider, Z. Mazzotta, P. Lansonneur, A. Hinterberger, Nicola Pacifico, Giovanni Consolati, Ole Røhne, A. Fontana, Markus K. Oberthaler, B. Rienaecker, O. Khalidova, P. Lebrun, L. Smestad, J. Fesel, V. Petracek, R. S. Brusa, D. Krasnický, P. Nedelec, J. Robert, Ruggero Caravita, Heidi Sandaker, Johann Zmeskal, H. Holmestad, D. Pagano, V. Lagomarsino, Claude Amsler, C. Malbrunot, S.R. Müller, N. Zurlo, Lea Di Noto, P. Yzombard, S. Aghion, C. Zimmer, Romualdo Santoro, S. Mariazzi, G. Testera, M. Fanì, Fabrizio Castelli, Marco Prevedelli, M. Antonello, G. Nebbia, Daniel Comparat, I. C. Tietje, F. Sorrentino, F. Prelz, Luca Penasa, A. Kellerbauer, Sebastian Gerber, V. N. Matveev, F. Guatieri, Giovanni Cerchiari, A. Rotondi, A. Demetrio, C. Evans, G. Bonomi, Massimo Caccia, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Aghion, Stefano, Amsler, Claude, Bonomi, Germano, Brusa, Roberto S., Caccia, Massimo, Caravita, Ruggero, Castelli, Fabrizio, Cerchiari, Giovanni, Comparat, Daniel, Consolati, Giovanni, Demetrio, Andrea, Di Noto, Lea, Doser, Michael, Evans, Craig, Fanì, Mattia, Ferragut, Rafael, Fesel, Julian, Fontana, Andrea, Gerber, Sebastian, Giammarchi, Marco, Gligorova, Angela, Guatieri, Francesco, Haider, Stefan, Hinterberger, Alexander, Holmestad, Helga, Kellerbauer, Alban, Khalidova, Olga, Krasnický, Daniel, Lagomarsino, Vittorio, Lansonneur, Pierre, Lebrun, Patrice, Malbrunot, Chloé, Mariazzi, Sebastiano, Marton, Johann, Matveev, Victor, Mazzotta, Zeudi, Müller, Simon R., Nebbia, Giancarlo, Nedelec, Patrick, Oberthaler, Marku, Pacifico, Nicola, Pagano, Davide, Penasa, Luca, Petracek, Vojtech, Prelz, Francesco, Prevedelli, Marco, Rienaecker, Benjamin, Robert, Jacque, Røhne, Ole M., Rotondi, Alberto, Sandaker, Heidi, Santoro, Romualdo, Smestad, Lillian, Sorrentino, Fiodor, Testera, Gemma, Tietje, Ingmari C., Widmann, Eberhard, Yzombard, Pauline, Zimmer, Christian, Zmeskal, Johann, Zurlo, Nicola, Antonello, Massimiliano, École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Electron density, Antiparticle, experimental methods, CERN Lab, Penning trap, Context (language use), Electron, gravity, antimatter, trapped particles, 01 natural sciences, electron: density, 010305 fluids & plasmas, antiproton trapping, Penning–Malmberg trap, Nuclear physics, anti-p: density, density: spatial distribution, Physics in General, Atomic and Molecular Physics, 0103 physical sciences, Physics::Atomic Physics, 010306 general physics, Antihydrogen, Nuclear Experiment, Physics, Plasma Physics, antihydrogen: production, electron: cloud, imaging, Plasma, electron: plasma, Atomic and Molecular Physics, and Optics, anti-p: plasma, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Antiproton, efficiency, Antimatter, Physics::Accelerator Physics, High Energy Physics::Experiment, and Optics
Abstract

Abstract We describe a multi-step “rotating wall” compression of a mixed cold antiproton–electron non-neutral plasma in a 4.46 T Penning–Malmberg trap developed in the context of the AEḡIS experiment at CERN. Such traps are routinely used for the preparation of cold antiprotons suitable for antihydrogen production. A tenfold antiproton radius compression has been achieved, with a minimum antiproton radius of only 0.17 mm. We describe the experimental conditions necessary to perform such a compression: minimizing the tails of the electron density distribution is paramount to ensure that the antiproton density distribution follows that of the electrons. Such electron density tails are remnants of rotating wall compression and in many cases can remain unnoticed. We observe that the compression dynamics for a pure electron plasma behaves the same way as that of a mixed antiproton and electron plasma. Thanks to this optimized compression method and the high single shot antiproton catching efficiency, we observe for the first time cold and dense non-neutral antiproton plasmas with particle densities n ≥ 1013 m−3, which pave the way for an efficient pulsed antihydrogen production in AEḡIS. Graphical abstract

Published
2018

44. AEgIS ¯ latest results

Author

B. Rienaecker, P. Nedelec, G. Nebbia, J. Robert, A. Hinterberger, M. Caccia, L. Smestad, V. Petráček, Fabrizio Castelli, Daniel Comparat, Chloé Malbrunot, Michael Doser, Sebastiano Mariazzi, S. Haider, Alberto Rotondi, N. Pacifico, Claude Amsler, M. Oberthaler, L. Di Noto, Luca Penasa, Stefano Aghion, R. S. Brusa, G. Testera, Angela Gligorova, P. Lebrun, Z. Mazzotta, Eberhard Widmann, F. Prelz, M. C. Simon, D. Krasnický, V. Lagomarsino, Felice Sorrentino, A. Demetrio, G. Angela, H. Holmestad, Ruggero Caravita, Alban Kellerbauer, P. Yzombard, Johann Zmeskal, C. Evans, Giovanni Consolati, Germano Bonomi, Sebastian Gerber, Giovanni Cerchiari, R. Santoro, V. A. Matveev, F. Guatieri, M. Fanì, Rafael Ferragut, P. Lansonneur, Heidi Sandaker, Andrea Fontana, O.M. Rhne., Marco Giammarchi, S.R. Müller, Davide Pagano, C. Zimmer, M. Sacerdoti, Marco Prevedelli, I. C. Tietje, Nicola Zurlo, and J. Fesel

Subjects
Physics, Large Hadron Collider, 010308 nuclear & particles physics, General relativity, QC1-999, 01 natural sciences, 7. Clean energy, Positronium, Antiproton Decelerator, Nuclear physics, Interferometry, Antiproton, Antimatter, 0103 physical sciences, 010306 general physics, Beam (structure)
Abstract

The validity of the Weak Equivalence Principle (WEP) as predicted by General Relativity has been tested up to astounding precision using ordinary matter. The lack hitherto of a stable source of a probe being at the same time electrically neutral, cold and stable enough to be measured has prevented highaccuracy testing of the WEP on anti-matter. The AEg̅IS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) experiment located at CERN's AD (Antiproton Decelerator) facility aims at producing such a probe in the form of a pulsed beam of cold anti-hydrogen, and at measuring by means of a moiré deflectometer the gravitational force that Earth's mass exerts on it. Low temperature and abundance of the H̅ are paramount to attain a high precision measurement. A technique employing a charge-exchange reaction between antiprotons coming from the AD and excited positronium atoms is being developed at AEg̅IS and will be presented hereafter, alongside an overview of the experimental apparatus and the current status of the experiment

Published
2018

45. Photodetachment and Doppler laser cooling of anionic molecules

Author

Daniel Comparat, J. Fesel, Sebastian Gerber, Michael Doser, Laboratoire Aimé Cotton (LAC), and École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, General Physics and Astronomy, 02 engineering and technology, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], symbols.namesake, Physics in General, Laser cooling, 0103 physical sciences, symbols, Physics::Atomic and Molecular Clusters, Molecule, Physics::Atomic Physics, Atomic physics, Physics::Chemical Physics, 010306 general physics, 0210 nano-technology, Doppler effect
Abstract

International audience; We propose to extend laser-cooling techniques, so far only achieved for neutral molecules, to molecular anions. A detailed computational study is performed for $C_{\bar{2}}$ molecules stored in Penning traps using GPU based Monte Carlo simulations. Two cooling schemes—Doppler laser cooling and photodetachment cooling—are investigated. The sympathetic cooling of antiprotons is studied for the Doppler cooling scheme, where it is shown that cooling of antiprotons to subKelvin temperatures could becomes feasible, with impacts on the field of antimatter physics. The presented cooling schemes also have applications for the generation of cold, negatively charged particle sources and for the sympathetic cooling of other molecular anions.

Published
2018

46. AEgIS experiment: Towards antihydrogen beam production for antimatter gravity measurements

Author

James William Storey, Claude Amsler, Vojtech Petracek, S. D. Hogan, L. Dassa, Chloé Malbrunot, Akitaka Ariga, G. Nebbia, Giovanni Cerchiari, Martin A. Subieta Vasquez, Cristina Riccardi, F. Prelz, Heidi Sandaker, Marco Prevedelli, Rafael Ferragut, Alban Kellerbauer, Sebastiano Mariazzi, Renzo Vaccarone, Ole Røhne, Markus K. Oberthaler, Lea Di Noto, G. Testera, Sergio Di Domizio, Angela Gligorova, Sandra Zavatarelli, Daniel Comparat, Tomoko Ariga, Frédéric Merkt, Sebastian Lehner, Eberhard Widmann, Alexey Dudarev, Antonio Ereditato, V. Lagomarsino, Louis Cabaret, Patrick Nedelec, Giovanni Consolati, Pablo Genova, Simone Cialdi, Lars V. Jørgensen, Johann Zmeskal, Fabrizio Castelli, Germano Bonomi, M. Kimura, P. Bräunig, M. Spacek, Alberto Rotondi, E. Jordan, C. Pistillo, Michael Doser, F. Moia, Ruggero Caravita, S. Haider, A. S. Belov, C. Regenfus, Fabio Villa, S. Gninenko, Jiro Kawada, D. Krasnický, Marco Giammarchi, Andreas Knecht, T. Kaltenbacher, J. Bremer, Roberto S. Brusa, Viktor Matveev, Stefano Aghion, Jan Hendrik Derking, Adriano Fontana, N. Pacifico, Carlo Canali, Paola Scampoli, Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), AEGIS, Sebastiano, Mariazzi, Stefano, Aghion, Claude, Amsler, Akitaka, Ariga, Tomoko, Ariga, Alexandre S., Belov, Germano, Bonomi, Philippe, Br?unig, Roberto S., Brusa, Johan, Bremer, Louis, Cabaret, Carlo, Canali, Ruggero, Caravita, Fabrizio, Castelli, Giovanni, Cerchiari, Simone, Cialdi, Daniel, Comparat, Giovanni, Consolati, Luca, Dassa, Jan Hendrik, Derking, Sergio Di, Domizio, Lea Di, Noto, Michael, Doser, Alexey, Dudarev, Antonio, Ereditato, Rafael, Ferragut, Andrea, Fontana, Pablo, Genova, Marco, Giammarchi, Angela, Gligorova, Sergei N., Gninenko, Stephen D., Hogan, Stefan, Haider, Elena, Jordan, Lars V., J?rgensen, Thomas, Kaltenbacher, Jiro, Kawada, Alban, Kellerbauer, Mitsuhiro, Kimura, Andreas, Knecht, Daniel, Krasnick?, Vittorio, Lagomarsino, Sebastian, Lehner, Chloe, Malbrunot, Viktor A., Matveev, Frederic, Merkt, Fabio, Moia, Giancarlo, Nebbia, Patrick, N?d?lec, Markus K., Oberthaler, Nicola, Pacifico, Vojtech, Petr??ek, Ciro, Pistillo, Francesco, Prelz, Marco, Prevedelli, Christian, Regenfu, Cristina, Riccardi, Ole, R?hne, Alberto, Rotondi, Heidi, Sandaker, Scampoli, Paola, James, Storey, Martin A., Subieta Vasquez, Michal, ?pa?ek, Gemma, Testera, Renzo, Vaccarone, Fabio, Villa, Eberhard, Widmann, Sandra, Zavatarelli, Johann, Zmeskal, Sebastiano Mariazzi, Stefano Aghion, Claude Amsler, Akitaka Ariga, Tomoko Ariga, Alexandre S. Belov, Germano Bonomi, Philippe Braeunig, Roberto S. Brusa, Johan Bremer, Louis Cabaret, Carlo Canali, Ruggero Caravita, Fabrizio Castelli, Giovanni Cerchiari, Simone Cialdi, Daniel Comparat, Giovanni Consolati, Luca Dassa, Jan Hendrik Derking, Sergio Di Domizio, Lea Di Noto, Michael Doser, Alexey Dudarev, Antonio Ereditato, Rafael Ferragut, Andrea Fontana, Pablo Genova, Marco Giammarchi, Angela Gligorova, Sergei N. Gninenko, Stephen D. Hogan, Stefan Haider, Elena Jordan, Lars V. J?rgensen, Thomas Kaltenbacher, Jiro Kawada, Alban Kellerbauer, Mitsuhiro Kimura, Andreas Knecht, Daniel Krasnick?, Vittorio Lagomarsino, Sebastian Lehner, Chloe Malbrunot, Viktor A. Matveev, Frederic Merkt, Fabio Moia, Giancarlo Nebbia, Patrick N?d?lec, Markus K. Oberthaler, Nicola Pacifico, Vojtech Petr??ek, Ciro Pistillo, Francesco Prelz, Marco Prevedelli, Christian Regenfu, Cristina Riccardi, Ole R?hne, Alberto Rotondi, Heidi Sandaker, Paola Scampoli, James Storey, Martin A. Subieta Vasquez, Michal ?pa?ek, Gemma Testera, Renzo Vaccarone, Fabio Villa, Eberhard Widmann, Sandra Zavatarelli, and Johann Zmeskal

Subjects
Physics, Physics::General Physics, 530 Physics, GRAVITATION, Gravitational acceleration, Penning trap, Atomic and Molecular Physics, and Optics, Positronium, Nuclear physics, symbols.namesake, Antiproton, Antimatter, Physics::Atomic and Molecular Clusters, Rydberg formula, symbols, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], PARTICLE PHYSICS, Physics::Accelerator Physics, Physics::Atomic Physics, Atomic physics, Antihydrogen, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Beam (structure), ComputingMilieux_MISCELLANEOUS
Abstract

AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is an experiment that aims to perform the first direct measurement of the gravitational acceleration g of antihydrogen in the Earth’s field. A cold antihydrogen beam will be produced by charge exchange reaction between cold antiprotons and positronium excited in Rydberg states. Rydberg positronium (with quantum number n between 20 and 30) will be produced by a two steps laser excitation. The antihydrogen beam, after being accelerated by Stark effect, will fly through the gratings of a moir´e deflectometer. The deflection of the horizontal beam due to its free fall will be measured by a position sensitive detector. It is estimated that the detection of about 103 antihydrogen atoms is required to determine the gravitational acceleration with a precision of 1%. In this report an overview of the AEgIS experiment is presented and its current status is described. Details on the production of slow positronium and its excitation with lasers are discussed.

Published
2014

47. Towards the first measurement of matter-antimatter gravitational interaction

Author

Giovanni Consolati, Heidi Sandaker, A. Kellerbauer, D. Krasnický, S. Haider, L. Di Noto, Z. Mazzotta, P. Lebrun, Giovanni Cerchiari, Daniel Comparat, Markus K. Oberthaler, Massimo Caccia, P. Nedelec, E. Widmann, Rafael Ferragut, G. Testera, G. Bonomi, B. Rienaecker, A. Fontana, C. Malbrunot, L. Ravelli, I. C. Tietje, V. Lagomarsino, Fabrizio Castelli, C. Zimmer, G. Nebbia, F. Sorrentino, Sebastian Gerber, S.R. Müller, O. Khalidova, Luca Penasa, Ruggero Caravita, V. N. Matveev, M. Doser, S. Aghion, Marco Prevedelli, F. Guatieri, R. S. Brusa, Claude Amsler, Marco Giammarchi, A. Hinterberger, Romualdo Santoro, S. Mariazzi, A. Demetrio, C. Evans, J. Fesel, P. Lansonneur, F. Prelz, M. Fanì, L. Smestad, J. Robert, A. Rotondi, A. Gligorova, H. Holmestad, N. Zurlo, P. Yzombard, Nicola Pacifico, J. Marton, Ole Røhne, V. Petracek, Johann Zmeskal, D. Pagano, Laboratoire Aimé Cotton (LAC), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Physics::General Physics, experimental methods, geometry, CERN Lab, electric field: gradient, QC1-999, deflection, 02 engineering and technology, Gravitational acceleration, 7. Clean energy, 01 natural sciences, antihydrogen: acceleration, Nuclear physics, Gravitation, Physics and Astronomy (all), Gravitational field, 0103 physical sciences, Physics::Atomic and Molecular Clusters, antimatter, Physics::Atomic Physics, Equivalence principle, positronium: excited state, 010306 general physics, Antihydrogen, Physics, General Relativity and Cosmology, detector: position sensitive, atom, gravitation: interaction, 021001 nanoscience & nanotechnology, charge exchange, anti-p, experimental equipment, Deflection (physics), equivalence principle, Antiproton, Antimatter, gravitation: acceleration, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], 0210 nano-technology, experimental results
Abstract

International audience; The AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is a CERN based experiment with the central aim to measure directly the gravitational acceleration of antihydrogen. Antihydrogen atoms will be produced via charge exchange reactions which will consist of Rydberg-excited positronium atoms sent to cooled antiprotons within an electromagnetic trap. The resulting Rydberg antihydrogen atoms will then be horizontally accelerated by an electric field gradient (Stark effect), they will then pass through a moiré deflectometer. The vertical deflection caused by the Earth's gravitational field will test for the first time the Weak Equivalence Principle for antimatter. Detection will be undertaken via a position sensitive detector. Around $10^3$ antihydrogen atoms are needed for the gravitational measurement to be completed. The present status, current achievements and results will be presented, with special attention toward the laser excitation of positronium (Ps) to the $n=3$ state and the production of Ps atoms in the transmission geometry.

Published
2017

48. Field ionization of Rydberg atoms for high-brightness electron and ion beams

Author

Rory W. Speirs, Benjamin Sparkes, Daniel Comparat, Jens Grimmel, Robert E. Scholten, and A. J. McCulloch

Subjects
Physics, Thermal ionization, 02 engineering and technology, Molar ionization energies of the elements, 021001 nanoscience & nanotechnology, 01 natural sciences, Ion source, Atmospheric-pressure laser ionization, Field desorption, Ionization, 0103 physical sciences, Rydberg atom, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, Atomic physics, 010306 general physics, 0210 nano-technology, Electron ionization
Abstract

We present an ionization mechanism for use in a cold atom electron source with the goal of producing highly monochromatic electron beams. We experimentally produce a map of the Stark states of $^{85}\mathrm{Rb}$ below the ionization threshold and identify states that undergo selective field ionization. The properties of an electron beam produced by field-assisted ionization of such states are quantified. A theoretical framework is established to predict the improvement to beam quality when ionization is conducted above the ionization threshold, where ionization conditions are typically more favorable than below the threshold. Calculations suggest that selective ionization of Rydberg states may offer a pathway to the production of high-brightness, highly monochromatic ion and electron beams.

Published
2017

49. Forced field ionization of Rydberg states for the production of monochromatic beams

Author

Y. J. Picard, Elias Moufarej, Daniel Comparat, Francis Robicheaux, G. Khalili, M. Vielle-Grosjean, and A. J. McCulloch

Subjects
Physics, 02 engineering and technology, Electron, 021001 nanoscience & nanotechnology, 01 natural sciences, Ion, symbols.namesake, Electric field, Ionization, Field desorption, 0103 physical sciences, Rydberg formula, symbols, Physics::Atomic Physics, Atomic physics, 010306 general physics, 0210 nano-technology, Excitation, Voltage
Abstract

We study Rydberg ionization in an electric field in order to produce monochromatic ion and electron beams. We present an experimental study of the photoexcitation and ionization of high quantum-defect states, using excitation from the $7s$ state in cesium to Rydberg states in the presence of a uniform electric field. Such states can exhibit complex ionization behavior, for instance, highly localized growth in the ionization rate due to interference effects. The data are well reproduced by the WKB quantum-defect and frame transformation methods with no adjustable parameters. This indicates that large changes in the Rydberg ionization rate from small changes in electric field are possible when a nearly stable state crosses a more unstable state. A fast variation of the ionization rate with electric field allows for the production of beams with very low energy dispersion. We develop a simple two-level model to predict the voltage and spatial resolution that would occur when atoms are prepared in a state with such sharp ionization in electric field. This confirms that Rydberg forced ionization in an electric field presents a pathway for the production of high-brightness, highly monochromatic ion and electron beams.

Published
2017

50. The AEgIS experiment at CERN: Measuring antihydrogen free-fall in earth's gravitational field to test WEP with antimatter

Author

Daniel Comparat, P. Lebrun, Heidi Sandaker, L. Ravelli, Davide Pagano, Alberto Rotondi, G. Testera, S. Haider, Tomoko Ariga, Antonio Ereditato, F. Prelz, Rafael Ferragut, Fabrizio Castelli, Michael Doser, Sebastian Gerber, Paola Scampoli, F. Guatieri, Claude Amsler, H. Holmestad, P. Lansonneur, Felice Sorrentino, Giovanni Consolati, Germano Bonomi, M. Oberthaler, M. Sacerdoti, Angela Gligorova, Marco Prevedelli, P. Yzombard, I. C. Tietje, Nicola Zurlo, L. Cabaret, Patrick Nedelec, Johann Zmeskal, T. Huse, G. Nebbia, Adriano Fontana, Sebastiano Mariazzi, B. Rienaecker, N. Pacifico, Luca Penasa, Roberto S. Brusa, S. Vamosi, V. Petracek, C. Pistillo, Ruggero Caravita, Marco Giammarchi, Z. Mazzotta, Alban Kellerbauer, V. A. Matveev, Eberhard Widmann, V. Lagomarsino, L. Di Noto, Massimo Caccia, I. M. Strojek, Ole Røhne, Giovanni Cerchiari, P. Bräunig, D. Krasnický, A. Demetrio, C. Evans, J. Fesel, Chloé Malbrunot, L. Smestad, Romualdo Santoro, Brusa, R. S, Amsler, C, Ariga, T, Bonomi, G, Bräunig, P, Cabaret, L, Caccia, M, Caravita, R, Castelli, F, Cerchiari, G, Comparat, D, Consolati, G, Demetrio, A., Di Noto, L, Doser, M, Ereditato, A, Evans, C, Ferragut, R, Fesel, J, Fontana, A, Gerber, S, Giammarchi, M, Gligorova, A, Guatieri, F, Haider, S, Holmestad, H, Huse, T, Kellerbauer, A, Krasnický, D, Lagomarsino, V, Lansonneur, P, Lebrun, P, Malbrunot, C, Mariazzi, S, Matveev, V, Mazzotta, Z, Nebbia, G, Nedelec, P, Oberthaler, M, Pacifico, N, Pagano, D, Penasa, L, Petracek, V, Pistillo, C, Prelz, F, Prevedelli, M, Ravelli, L, Rienaecker, B, Røhne, O. M, Rotondi, A, Sacerdoti, M, Sandaker, H, Santoro, R, Scampoli, Paola, Smestad, L, Sorrentino, F, Strojek, I. M, Testera, G, Tietje, I. C, Vamosi, S, Widmann, E, Yzombard, P, Zmeskal, J, Zurlo, N., Brusa, R S, Røhne, O M, Scampoli, P, Strojek, I M, Tietje, I C, Zurlo, N, Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Aimé Cotton (LAC), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan)

Subjects
History, Physics::General Physics, CERN Lab, 530 Physics, deflection, [PHYS.PHYS.PHYS-ACC-PH]Physics [physics]/Physics [physics]/Accelerator Physics [physics.acc-ph], antihydrogen: beam, 7. Clean energy, 01 natural sciences, Education, Nuclear physics, Physics and Astronomy (all), Gravitational field, positron: capture, anti-p: capture, 0103 physical sciences, excited state, antimatter, Physics::Atomic Physics, Equivalence principle, 010306 general physics, Antihydrogen, Physics, Large Hadron Collider, 010308 nuclear & particles physics, charge exchange, Computer Science Applications, Antiproton Decelerator, Deflection (physics), equivalence principle, Antiproton, gravitation, Antimatter, Physics::Accelerator Physics, High Energy Physics::Experiment, gravity, antihydrogen
Abstract

International audience; The AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) experiment is designed with the objective to test the weak equivalence principle with antimatter by studying the free fall of antihydrogen in the Earth’s gravitational field. A pulsed cold beam of antihydrogen will be produced by charge exchange between cold Ps excited in Rydberg state and cold antiprotons. Finally the free fall will be measured by a classical moiré deflectometer. The apparatus being assembled at the Antiproton Decelerator at CERN will be described, then the advancements of the experiment will be reported: positrons and antiprotons trapping measurements, Ps two-step excitation and a test-measurement of antiprotons deflection with a small scale moiré deflectometer.

Published
2017

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