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1. Detailed low-spin spectroscopy of 65Ni via neutron capture reaction

Author

F. Kandzia, S. Bottoni, C. Costache, Michele Sferrazza, A. Turturica, Takaharu Otsuka, Ulli Köster, Y.H. Kim, N. Cieplicka-Oryńczak, Ł. W. Iskra, C. Michelagnoli, B. Fornal, C. Porzio, S. Leoni, F. C. L. Crespi, Michael Jentschel, N. Marginean, C. Mihai, Yusuke Tsunoda, Paolo Mutti, Institut Laue-Langevin (ILL), and ILL

Subjects
Physics, Spins, 010308 nuclear & particles physics, Monte Carlo method, FOS: Physical sciences, Généralités, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 3. Good health, Neutron capture, Angular correlation, Excited state, 0103 physical sciences, Oblate spheroid, Nuclear Experiment (nucl-ex), Atomic physics, 010306 general physics, Spin (physics), Spectroscopy, Nuclear Experiment
Abstract

An extended investigation of the low-spin structure of the Ni65 nucleus was performed at the Institut Laue-Langevin, Grenoble, France, via the neutron capture reaction Ni64(n,γ)Ni65, using the Fission Product Prompt Gamma-Ray Spectrometer High-Purity Ge array. The level scheme of Ni65 was significantly expanded, with two new levels and 87 newly found transitions. Angular correlation analyses were also performed, allowing us to assign spins and parities for a number of states and to determine multipolarity mixing ratios for selected γ transitions. The low-energy part of the experimental level scheme (up to about 1.4 MeV) was compared with Monte Carlo shell-model calculations, which predict spherical shapes for all states, apart from the 9/2+ and the second excited 1/2- states of oblate deformation., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2020

2. γ spectroscopy of the Y96 isotope: Searching for the onset of shape coexistence before N=60

Author

Ulli Köster, Y.H. Kim, C. Porzio, J. Dudouet, A. Turturica, Cosmin Teodor Mihai, S. Bottoni, N. Marginean, N. Cieplicka-Oryńczak, D. Reygadas, E. Ruiz-Martinez, R. Lica, Michael Jentschel, S. Pascu, B. Fornal, C. Michelagnoli, Ł. W. Iskra, S. Leoni, R. E. Mihai, M. Barani, R. Mărginean, C. Costache, G. Colombi, F. C. L. Crespi, C. R. Nita, and F. Kandzia

Subjects
Physics, Nuclear fission product, Isotope, Spin states, 010308 nuclear & particles physics, Fission, 01 natural sciences, Spectral line, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Ground state, Spectroscopy
Abstract

Medium and high spin states of the Y96 nucleus, located in the shape-coexistence region near Z=40 and N=60, were populated in thermal-neutron-induced fission of U233 and U235 targets, diluted in a scintillator. γ rays were measured with the FIssion Product Prompt γ-ray Spectrometer (FIPPS) high-purity germanium (HPGe) detector array, using double and triple γ-ray coincidence techniques and taking advantage of the efficient fission tag provided by the scintillating target material. A complex level scheme, extending up to 5.2 MeV and including excitations above the 8+β-decaying isomer, was investigated, and firm spin and parity assignments were given to a number of states, on the basis of angular correlation analysis and considerations on the γ-decay patterns. While the structures built on the 0− ground state and the 8+ isomer show irregular patterns typical for spherical shapes, the (6+) isomeric state at 1655 keV [with half-life of 181(9) ns], and the rotational band built on it [with spin-parity values between (6+) and (9+)], can be explained by Hartree-Fock-Bogoliubov calculations, if an oblate deformation is assumed. This is the first observation of a deformed structure in an N=57 isotone, lying three neutrons away from the N=60 line. An important finding is also the 115-keV transition which connects the (6+) 181(9)-ns isomer to the β-decaying 8+ spherical isomer, allowing us to firmly place the latter at 1541 keV excitation energy. This may be relevant for calculations of electron and antineutrino spectra from fission of actinides, for which Y96 is a prominent product.

Published
2020

3. Shape Coexistence at Zero Spin in ^{64}Ni Driven by the Monopole Tensor Interaction

Author

N, Mărginean, D, Little, Y, Tsunoda, S, Leoni, R V F, Janssens, B, Fornal, T, Otsuka, C, Michelagnoli, L, Stan, F C L, Crespi, C, Costache, R, Lica, M, Sferrazza, A, Turturica, A D, Ayangeakaa, K, Auranen, M, Barani, P C, Bender, S, Bottoni, M, Boromiza, A, Bracco, S, Călinescu, C M, Campbell, M P, Carpenter, P, Chowdhury, M, Ciemała, N, Cieplicka-Oryǹczak, D, Cline, C, Clisu, H L, Crawford, I E, Dinescu, J, Dudouet, D, Filipescu, N, Florea, A M, Forney, S, Fracassetti, A, Gade, I, Gheorghe, A B, Hayes, I, Harca, J, Henderson, A, Ionescu, Ł W, Iskra, M, Jentschel, F, Kandzia, Y H, Kim, F G, Kondev, G, Korschinek, U, Köster, Krishichayan, M, Krzysiek, T, Lauritsen, J, Li, R, Mărginean, E A, Maugeri, C, Mihai, R E, Mihai, A, Mitu, P, Mutti, A, Negret, C R, Niţă, A, Olăcel, A, Oprea, S, Pascu, C, Petrone, C, Porzio, D, Rhodes, D, Seweryniak, D, Schumann, C, Sotty, S M, Stolze, R, Şuvăilă, S, Toma, S, Ujeniuc, W B, Walters, C Y, Wu, J, Wu, S, Zhu, and S, Ziliani

Abstract

The low-spin structure of the semimagic ^{64}Ni nucleus has been considerably expanded: combining four experiments, several 0^{+} and 2^{+} excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0^{+} excitation is located at a surprisingly high energy (3463 keV), with a collective 2^{+} state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N=40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.

Published
2020

4. GRIDSA: femtosecond lifetime measurements with germanium detector arrays

Author

C. Michelagnoli, Michael Jentschel, Y.H. Kim, F. C. L. Crespi, N. Cieplicka-Oryńczak, F. Kandzia, S. Ziliani, S. Leoni, Ulli Köster, Institut Laue-Langevin (ILL), and ILL

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, List mode, Measure (mathematics), Semiconductor detector, symbols.namesake, Recoil, 0103 physical sciences, Femtosecond, symbols, Nuclear fusion, Atomic physics, 010306 general physics, Doppler effect
Abstract

International audience; We demonstrate the possibility to extract nuclear state femtosecond lifetimes from two-step $\gamma $ ray cascades measured with a Ge-detector array. The technique is based on measuring the Doppler shift of a $\gamma $ ray, caused by the recoil of a preceding $\gamma $ ray emission. Since the two $\gamma $ rays are populating/de-populating the same state they form a start/stop signal, the delay of which is compared to the slowing down motion of the nucleus within the target material. A multi-detector array combined with digital acquisition electronics in list mode, allows to measure several angular combinations and two-step cascades efficiently and simultaneously within one single experiment. The concept was demonstrated with the FIPPS array for the $^{35}\hbox {Cl(n,}\gamma \hbox {)}^{36}\hbox {Cl}$ reaction, where we obtained good agreement with literature values showing the validity of the method.

Published
2020

6. Shape transition in the neutron-rich Y nuclei and its evolution across the isotopic chain

Author

S. Bottoni, C. Porzio, Łukasz W. Iskra, Michael Jentschel, Yung Hee Kim, C. Michelagnoli, Natalia Cieplicka‒ Oryńczak, S. Leoni, Ulli Köster, F. Kandzia, B. Fornal, Institut Laue-Langevin (ILL), and ILL

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Fission, QC1-999, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Gamma ray, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Semiconductor detector, Nuclear physics, medicine.anatomical_structure, 0103 physical sciences, medicine, Neutron, Gamma spectroscopy, 010306 general physics, Nuclear Experiment, Nucleus, Excitation
Abstract

The evolution of the deformation across the Y isotopic chain, in the vicinity of N = 60 boundary, has been studied using gamma spectroscopy methods. The nuclei of interest have been produced by neutron induced fission of 235U and 241Pu targets, during two experimental campaigns named EXILL and FIPPS at the Institute Laue-Langevin in Grenoble. The emitted gamma rays have been collected by HPGe and LaBr3 detectors providing the identification of the high-spin levels in the 94Y and 96Y isotopes up to 6 MeV excitation energy, as well as information about the half-lives of the in-band states in the 98Y nucleus. The obtained results shed new light on the onset of deformation in the neutron-rich Y isotopes and, in general, in the A ≈ 100 region.

Published
2019

7. Improved STEREO simulation with a new gamma ray spectrum of excited gadolinium isotopes using FIFRELIN

Author

Manfred Lindner, J. Haser, M. Vialat, D. Lhuillier, C. Roca, H. Almazan, Adrien Blanchet, I. El Atmani, Torsten Soldner, T. Materna, Christian Buck, J. S. Real, F. Kandzia, A. Chebboubi, A. Stutz, P. del Amo Sanchez, L. Thulliez, L. Labit, Stefan Schoppmann, A. Letourneau, S. Kox, V. Savu, Olivier Litaize, A. Bonhomme, J. Lamblin, A. Minotti, T. Salagnac, V. Sergeyeva, H. Pessard, L. Bernard, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Almazan, H, Bernard, L, Blanchet, A, Bonhomme, A, Buck, C, Chebboubi, A, del Amo Sanchez, P, El Atmani, I, Haser, J, Kandzia, F, Kox, S, Labit, L, Lamblin, J, Letourneau, A, Lhuillier, D, Lindner, M, Litaize, O, Materna, T, Minotti, A, Pessard, H, Real, J, Roca, C, Salagnac, T, Savu, V, Schoppmann, S, Sergeyeva, V, Soldner, T, Stutz, A, Thulliez, L, Vialat, M, and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Gadolinium, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, scintillation counter: liquid, FOS: Physical sciences, chemistry.chemical_element, antineutrino/e: energy spectrum, Scintillator, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], n: thermal, 01 natural sciences, 7. Clean energy, programming, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Positron, data compilation, gadolinium: admixture, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Neutron, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment (nucl-ex), n: capture, 010306 general physics, Nuclear Experiment, numerical calculations, Physics, 010308 nuclear & particles physics, Gamma ray, Instrumentation and Detectors (physics.ins-det), simulation, 3. Good health, Neutron capture, gamma ray: emission, chemistry, sterile neutrino, Inverse beta decay, nuclear reactor, Delayed neutron, gadolinium: nuclide, neutron capture
Abstract

The STEREO experiment measures the electron antineutrino spectrum emitted in a research reactor using the inverse beta decay reaction on H nuclei in a gadolinium loaded liquid scintillator. The detection is based on a signal coincidence of a prompt positron and a delayed neutron capture event. The simulated response of the neutron capture on gadolinium is crucial for the comparison with data, in particular in the case of the detection efficiency. Among all stable isotopes, $^{155}$Gd and $^{157}$Gd have the highest cross sections for thermal neutron capture. The excited nuclei after the neutron capture emit gamma rays with a total energy of about 8 MeV. The complex level schemes of $^{156}$Gd and $^{158}$Gd are a challenge for the modeling and prediction of the deexcitation spectrum, especially for compact detectors where gamma rays can escape the active volume. With a new description of the Gd(n,${\gamma}$) cascades obtained using the FIFRELIN code, the agreement between simulation and measurements with a neutron calibration source was significantly improved in the STEREO experiment. A database of ten millions of deexcitation cascades for each isotope has been generated and is now available for the user., Comment: 5 pages, 3 figures

Published
2019

8. Development of a gas filled magnet for FIPPS phase II

Author

T. Materna, Ulli Köster, Olivier Méplan, Grégoire Kessedjian, Abdelaziz Chebboubi, H. Schwab, E. Froidefond, Paolo Mutti, Y.H. Kim, E. Ruiz-Martinez, Michael Jentschel, M. Thomas, E. Lelièvre-Berna, C. Michelagnoli, G. S. Simpson, H. Faust, F. Kandzia, Institut Laue-Langevin (ILL), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, ILL, and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Physics, Nuclear and High Energy Physics, Nuclear fission product, Spectrometer, 010308 nuclear & particles physics, Fission, Nuclear Theory, Phase (waves), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Magnetic field, Nuclear physics, Magnet, 0103 physical sciences, Neutron, 010306 general physics, Spectroscopy, Nuclear Experiment, Instrumentation
Abstract

International audience; The Fission Product Prompt γ-ray Spectrometer (FIPPS) is a new instrument of the Institut Laue-Langevin (ILL) for the spectroscopy of nuclei produced after neutron induced reactions. The future upgrade of the instrument aims to explore the neutron-rich region of the nuclear chart with higher selectivity by identifying the fragments produced after neutron induced fission. The Gas-Filled-Magnet (GFM) technique has been chosen in order to obtain a good mass separation (50 msr and P/P > 10%). A GFM design consisting of a 1/r magnetic field index and Thales circle-shaped entrance and exit magnet edges is proposed. The characteristic of the magnet is presented with realistic magnetic field calculations and Monte-Carlo simulations.

Published
2018

9. Sterile Neutrino Constraints from the STEREO Experiment with 66 Days of Reactor-On Data

Author

T. Soldner, A. Bonhomme, T. Salagnac, A. Letourneau, S. Kox, S. Schoppmann, T. Materna, Christian Buck, D. Lhuillier, F. Kandzia, A. Minotti, A. Stutz, L. Manzanillas, V. Sergeyeva, J. Haser, L. Bernard, H. Pessard, J. S. Real, J. Favier, S. Zsoldos, P. Del Amo Sanchez, J. Lamblin, C. Roca, H. Almazan, Manfred Lindner, V. Helaine, A. Blanchet, François Montanet, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Laue-Langevin (ILL), ILL, STEREO, Almazan, H, Sanchez, P, Bernard, L, Blanchet, A, Bonhomme, A, Buck, C, Favier, J, Haser, J, Helaine, V, Kandzia, F, Kox, S, Lamblin, J, Letourneau, A, Lhuillier, D, Lindner, M, Manzanillas, L, Materna, T, Minotti, A, Montanet, F, Pessard, H, Real, J, Roca, C, Salagnac, T, Schoppmann, S, Sergeyeva, V, Soldner, T, Stutz, A, Zsoldos, S, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Normalization (statistics), Sterile neutrino, data analysis method, neutrino: mass difference, General Physics and Astronomy, FOS: Physical sciences, anomaly, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), statistical analysis, 0103 physical sciences, antineutrino: nuclear reactor, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Research reactor, 010306 general physics, nuclear reactor: particle source, Physics, 010308 nuclear & particles physics, Oscillation, Anomaly (natural sciences), Null (mathematics), Detector, antineutrino: energy spectrum, neutrino: sterile, neutrino: mixing angle, Pulse (physics), antineutrino: oscillation, 13. Climate action, sterile neutrino, S067NUS, Elementary Particles and Fields, experimental results
Abstract

International audience; The reactor antineutrino anomaly might be explained by the oscillation of reactor antineutrinos toward a sterile neutrino of eV mass. In order to explore this hypothesis, the STEREO experiment measures the antineutrino energy spectrum in six different detector cells covering baselines between 9 and 11 m from the compact core of the ILL research reactor. In this Letter, results from 66 days of reactor turned on and 138 days of reactor turned off are reported. A novel method to extract the antineutrino rates has been developed based on the distribution of the pulse shape discrimination parameter. The test of a new oscillation toward a sterile neutrino is performed by comparing ratios of cells, independent of absolute normalization and of the prediction of the reactor spectrum. The results are found to be compatible with the null oscillation hypothesis and the best fit of the reactor antineutrino anomaly is excluded at 97.5% C.L.

Published
2018

10. Search for light sterile neutrinos with the STEREO experiment

Author

Anne Stutz, Viktoriya Sergeyeva, A. Bonhomme, Christian Buck, Alain Letourneau, Ilham El Atmani, Manfred Lindner, J. Haser, Alessandro Minotti, Luis Manzanillas, T. Materna, J. Lamblin, F. Kandzia, S. Zsoldos, S. Kox, Victor Hélaine, David Lhuillier, H. Pessard, J. S. Real, C. Roca, Thomas Salagnac, H. Almazan, Jean Favier, Torsten Soldner, François Montanet, Adrien Blanchet, Laura Bernard, S. Schoppmann, Pablo del Amo Sanchez, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Laue-Langevin (ILL), STEREO, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), ILL, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)

Subjects
Sterile neutrino, QC1-999, anomaly, Cosmic ray, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, law.invention, Nuclear physics, law, 0103 physical sciences, antineutrino: nuclear reactor, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Neutron, Physics::Chemical Physics, 010306 general physics, Physics, 010308 nuclear & particles physics, Oscillation, background, antineutrino: propagation, n: cosmic radiation, Nuclear reactor, talk: Grenoble 2018/05/24, neutrino: sterile, antineutrino: oscillation, Amplitude, Anomaly (physics), experimental results
Abstract

The stereo experiment is searching for a non-standard oscillation in the propagation of anti-neutrinos produced by a nuclear reactor which could be the sign for the existence of a sterile state of eV mass and the origin of the reactor anti-neutrino anomaly. In this paper, results from 66 days of reactor turned on and 138 days of reactor turned off are reported excluding large amplitude oscillations. A special focus is put on the data analysis and studies of correlated backgrounds. In particular the origin of the correlated background measured in reactor turned off periods is discussed. This background mainly originates from neutrons produced by cosmic radiation.

Published
2019

11. Upscaling ground-based backpack gamma-ray spectrometry to spatial resolution of UAV-based gamma-ray spectrometry for system validation.

Author

Altfelder S, Preugschat B, Matos M, Kandzia F, Wiens B, Eshmuradov O, and Kunze C

Subjects
Spectrometry, Gamma, Uranium analysis, Radiation Monitoring methods, Soil Pollutants, Radioactive analysis
Abstract

Advances in the development of gamma-ray spectrometers have resulted in devices that are ideal for use in conjunction with the increasingly reliable systems of autonomously flying uncrewed aerial vehicles (UAVs) that have recently become available on the market. Airborne gamma-ray spectrometry (GRS) measurements have many different applications. Here, the technique is applied to a former uranium mining and processing site, which is characterized by relatively low specific activities and, hence, low count rates, requiring relatively large detectors and correspondingly big size UAVs. The future acceptance of the use of such UAV-based GRS systems for radionuclide mapping depends on their ability to measure absolute specific activities of natural radionuclides such as U-238 in near-surface soil that are consistent with the results of established and proven ground-based systems. To determine absolute specific activities on the ground, the gamma radiation data from airborne detectors must be corrected for attenuation caused by the flight altitude above ground. In recent years, mathematical procedures for altitude correction have been developed, that are specifically tailored to the working range of several tens of meters typical for UAVs. However, very limited experimental validation of these theoretical approaches is available. A very large dataset consisting of about 3000 UAV-based and 19,000 backpack-based measurements was collected at a low-grade uranium ore dump in Yangiabad, Uzbekistan. We applied different geostatistical interpolation methods to compare the data from both survey techniques by upscaling backpack data to airborne data. Compared to backpack systems, UAV-based systems have lower spatial resolution, so measurements average over larger areal units (or in geostatistical terminology: "spatial support"). Taking into account the change in spatial support, we illustrate that (1) the UAV-based measurements show good agreement with the upscaled backpack measurements and that (2) UAV surveys provide good delineation of contrasts of the relatively smooth U-238 specific activity distribution typical for former uranium mining and processing sites. We are able to show that the resolution of UAV-based systems is sufficient to map extended uranium waste facilities., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results. Sven Altfelder reports financial support was provided by German Federal Ministry of Education and Research (BMBF). Sven Altfelder reports financial support was provided by International Atomic Energy Agency Department of Nuclear Safety and Security., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Published
2024
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12. Shape Coexistence at Zero Spin in ^{64}Ni Driven by the Monopole Tensor Interaction.

Author

Mărginean N, Little D, Tsunoda Y, Leoni S, Janssens RVF, Fornal B, Otsuka T, Michelagnoli C, Stan L, Crespi FCL, Costache C, Lica R, Sferrazza M, Turturica A, Ayangeakaa AD, Auranen K, Barani M, Bender PC, Bottoni S, Boromiza M, Bracco A, Călinescu S, Campbell CM, Carpenter MP, Chowdhury P, Ciemała M, Cieplicka-Oryǹczak N, Cline D, Clisu C, Crawford HL, Dinescu IE, Dudouet J, Filipescu D, Florea N, Forney AM, Fracassetti S, Gade A, Gheorghe I, Hayes AB, Harca I, Henderson J, Ionescu A, Iskra ŁW, Jentschel M, Kandzia F, Kim YH, Kondev FG, Korschinek G, Köster U, Krishichayan, Krzysiek M, Lauritsen T, Li J, Mărginean R, Maugeri EA, Mihai C, Mihai RE, Mitu A, Mutti P, Negret A, Niţă CR, Olăcel A, Oprea A, Pascu S, Petrone C, Porzio C, Rhodes D, Seweryniak D, Schumann D, Sotty C, Stolze SM, Şuvăilă R, Toma S, Ujeniuc S, Walters WB, Wu CY, Wu J, Zhu S, and Ziliani S

Abstract

The low-spin structure of the semimagic ^{64}Ni nucleus has been considerably expanded: combining four experiments, several 0^{+} and 2^{+} excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0^{+} excitation is located at a surprisingly high energy (3463 keV), with a collective 2^{+} state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N=40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.

Published
2020
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13. Global Dynamics of Yeast Hsp90 Middle and C-Terminal Dimer Studied by Advanced Sampling Simulations.

Author

Kandzia F, Ostermeir K, and Zacharias M

Abstract

The Hsp90 protein complex is one of the most abundant molecular chaperone proteins that assists in folding of a variety of client proteins. During its functional cycle it undergoes large domain rearrangements coupled to the hydrolysis of ATP and association or dissociation of domain interfaces. In order to better understand the domain dynamics comparative Molecular Dynamics (MD) simulations of a sub-structure of Hsp90, the dimer formed by the middle (M) and C-terminal domain (C), were performed. Since this MC dimer lacks the ATP-binding N-domain it allows studying global motions decoupled from ATP binding and hydrolysis. Conventional (c)MD simulations starting from several different closed and open conformations resulted in only limited sampling of global motions. However, the application of a Hamiltonian Replica exchange (H-REMD) method based on the addition of a biasing potential extracted from a coarse-grained elastic network description of the system allowed much broader sampling of domain motions than the cMD simulations. With this multiscale approach it was possible to extract the main directions of global motions and to obtain insight into the molecular mechanism of the global structural transitions of the MC dimer., (Copyright © 2019 Kandzia, Ostermeir and Zacharias.)

Published
2019
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14. Sterile Neutrino Constraints from the STEREO Experiment with 66 Days of Reactor-On Data.

Author

Almazán H, Sanchez PDA, Bernard L, Blanchet A, Bonhomme A, Buck C, Favier J, Haser J, Hélaine V, Kandzia F, Kox S, Lamblin J, Letourneau A, Lhuillier D, Lindner M, Manzanillas L, Materna T, Minotti A, Montanet F, Pessard H, Real JS, Roca C, Salagnac T, Schoppmann S, Sergeyeva V, Soldner T, Stutz A, and Zsoldos S

Abstract

The reactor antineutrino anomaly might be explained by the oscillation of reactor antineutrinos toward a sterile neutrino of eV mass. In order to explore this hypothesis, the STEREO experiment measures the antineutrino energy spectrum in six different detector cells covering baselines between 9 and 11 m from the compact core of the ILL research reactor. In this Letter, results from 66 days of reactor turned on and 138 days of reactor turned off are reported. A novel method to extract the antineutrino rates has been developed based on the distribution of the pulse shape discrimination parameter. The test of a new oscillation toward a sterile neutrino is performed by comparing ratios of cells, independent of absolute normalization and of the prediction of the reactor spectrum. The results are found to be compatible with the null oscillation hypothesis and the best fit of the reactor antineutrino anomaly is excluded at 97.5% C.L.

Published
2018
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15. Multidomain structure and correlated dynamics determined by self-consistent FRET networks.

Author

Hellenkamp B, Wortmann P, Kandzia F, Zacharias M, and Hugel T

Subjects
Crystallography, X-Ray, HSP90 Heat-Shock Proteins metabolism, Models, Molecular, Protein Domains, Fluorescence Resonance Energy Transfer methods, HSP90 Heat-Shock Proteins chemistry, Molecular Dynamics Simulation
Abstract

We present an approach that enables us to simultaneously access structure and dynamics of a multidomain protein in solution. Dynamic domain arrangements are experimentally determined by combining self-consistent networks of distance distributions with known domain structures. Local structural dynamics are correlated with the global arrangements by analyzing networks of time-resolved single-molecule fluorescence parameters. The strength of this hybrid approach is shown by an application to the flexible multidomain protein Hsp90. The average solution structure of Hsp90's closed state resembles the known X-ray crystal structure with Angstrom precision. The open state is represented by an ensemble of conformations with interdomain fluctuations of up to 25 Å. The data reveal a state-specific suppression of the submillisecond fluctuations by dynamic protein-protein interaction. Finally, the method enables localization and functional characterization of dynamic elements and domain interfaces., Competing Interests: The authors declare no competing financial interests.

Published
2017
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16. Binaural measurement of bone conduction click evoked otoacoustic emissions in adults and infants.

Author

Kandzia F, Oswald J, and Janssen T

Subjects
Acoustic Stimulation, Adult, Age Factors, Analysis of Variance, Auditory Threshold, Equipment Design, Female, Humans, Infant, Infant, Newborn, Male, Miniaturization, Neonatal Screening instrumentation, Predictive Value of Tests, Reaction Time, Reproducibility of Results, Time Factors, Aging, Bone Conduction, Evoked Potentials, Auditory, Hearing Tests instrumentation, Neonatal Screening methods, Otoacoustic Emissions, Spontaneous
Abstract

Transient evoked otoacoustic emissions (TEOAEs) are usually evoked with air conduction (AC) stimuli. Only a few reports exist about OAEs where stimuli have been delivered using bone conduction (BC) by placing a bone conductor on the forehead or the mastoid. The aims of the present study were to improve the test performance of BC-TEOAEs by using a nonlinear stimulation protocol and to find out, whether this technique can be applied in newborn hearing screening. BC-TEOAEs were measured binaurally in ten normal hearing adults and in ten infants. For measurements in infants, miniaturized probes without loudspeakers were constructed to allow a complete insertion of the probe in the infant's ear canal. It could be shown that robust and valid BC-TEOAEs can be elicited using a nonlinear stimulation protocol. Findings in adults indicated that BC-TEOAEs can be measured with properties similar to AC-TEOAEs. However, mean BC-TEOAE levels were reduced by 0.8-3.7 dB depending on frequency. In view of test time, this is compensated by performing binaural recordings. Measurements in infants indicated that the screening performance of BC-TEOAEs and AC-TEOAEs may be comparable. Further studies have to investigate, whether BC-TEOAEs are more robust than AC-TEOAEs against small conductive hearing loss., (© 2011 Acoustical Society of America)

Published
2011
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17. Hearing threshold estimation using concurrent measurement of distortion product otoacoustic emissions and auditory steady-state responses.

Author

Rosner T, Kandzia F, Oswald JA, and Janssen T

Subjects
Acoustic Stimulation, Adult, Aged, Aged, 80 and over, Auditory Threshold, Case-Control Studies, Female, Hearing Loss, Sensorineural physiopathology, Humans, Male, Middle Aged, Predictive Value of Tests, Reproducibility of Results, Sound Spectrography, Young Adult, Audiometry, Pure-Tone, Auditory Perception, Cochlea physiopathology, Electroencephalography, Hearing Loss, Sensorineural diagnosis, Otoacoustic Emissions, Spontaneous, Perceptual Distortion
Abstract

Both distortion product otoacoustic emissions (DPOAEs) and auditory steady-state responses (ASSRs) provide frequency-specific assessment of hearing. However, each method suffers from some restrictions. Hearing losses above 50 dB HL are not quantifiable using DPOAEs and their performance at frequencies below 1 kHz is limited, but their recording time is short. In contrast, ASSRs are a time-consuming method but have the ability to determine hearing thresholds in a wider range of frequencies and hearing losses. Thus, recording DPOAEs and ASSRs simultaneously at their adequate frequencies and levels could decrease the overall test time considerably. The goal of the present study was to develop a parameter-setting and test-protocol to measure DPOAEs and ASSRs binaurally and simultaneously at multiple frequencies. Ten normal-hearing and 23 hearing-impaired subjects participated in the study. The interaction of both responses when stimulated simultaneously at frequencies between 0.25 and 6 kHz was examined. Two limiting factors need to be kept. Frequency distance between ASSR carrier frequency f(c) and DPOAE primary tone f(2) needs to be at least 1.5 octaves, and DPOAEs may not be measured if the ASSR stimulus level is 70 dB SPL or above. There was a significant correlation between pure-tone and DPOAE/ASSR-thresholds in sensorineural hearing loss ears.

Published
2011
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