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295 results on '"Honkimäki, V."'

1. Ion and Electron Momentum Distributions from Single and Double Ionization of Helium Induced by Compton Scattering

Author

Kircher, M., Trinter, F., Grundmann, S., Kastirke, G., Weller, M., Vela-Perez, I., Khan, A., Janke, C., Waitz, M., Zeller, S., Mletzko, T., Kirchner, D., Honkimäki, V., Houamer, S., Chuluunbaatar, O., Popov, Yu. V., Volobuev, I. P., Schöffler, M. S., Schmidt, L. Ph. H., Jahnke, T., and Dörner, R.

Subjects
Physics - Atomic Physics
Abstract

We present the momentum distributions of the nucleus and of the electrons from double ionization of the helium atom by Compton scattering of photons with $h\nu=40$ keV. We find that the doubly charged ion momentum distribution is very close to the Compton profile of the nucleus in the ground state of the helium atom, and the momentum distribution of the singly charged ion to give a precise image of the electron Compton profile. To reproduce these results, non-relativistic calculations require the use of highly correlated initial- and final-state wavefunctions., Comment: 5 pages, 3 figures

Published
2021
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2. Photon-momentum-induced molecular dynamics in photoionization of N$_2$ at $h\nu=40$ keV

Author

Kircher, M., Rist, J., Trinter, F., Grundmann, S., Waitz, M., Melzer, N., Vela-Perez, I., Mletzko, T., Pier, A., Strenger, N., Siebert, J., Janssen, R., Honkimäki, V., Drnec, J., Demekhin, Ph. V., Schmidt, L. Ph. H., Schöffler, M. S., Jahnke, T., and Dörner, R.

Subjects
Physics - Atomic Physics
Abstract

We investigate K-shell ionization of N$_2$ at 40 keV photon energy. Using a COLTRIMS reaction microscope we determine the vector momenta of the photoelectron, the Auger electron and both N$^+$ fragments. These fully differential data show that the dissociation process of the N$_2^{2+}$ ion is significantly modified not only by the recoil momentum of the photoelectron, but also by the photon momentum and the momentum of the emitted Auger electron. We find that the recoil energy introduced by the photon and the photoelectron momentum is partitioned with a ratio of approximately 30/70 between the Auger electron and fragment ion kinetic energies, respectively. We also observe that the photon momentum induces an additional rotation of the molecular ion., Comment: 5 pages, 2 figures

Published
2021
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9. Hydrogen-bond network distortion of water in the soft confinement of Nafion membrane.

Author

Plazanet, M., Morfin, I., Honkimäki, V., Buslaps, T., Petrillo, C., and Sacchetti, F.

Subjects
COMPTON imaging, ELECTRON kinetic energy, BINDING energy, NAFION, CHEMICAL bond lengths, FREEZING points, WATER distribution, FREEZING
Abstract

A Compton spectroscopy investigation is carried out in hydrated Nafion membranes, enabling identification of distortions in the hydrogen-bond distribution of the polymer hydrating water by means of the subtle changes reflected by the Compton profiles. Indeed, deformations of the Compton profiles are observed when varying hydration, and two different bonding kinds are associated with the water molecules: at low hydration, water surrounds the sulfonic groups, while on increasing hydration, water molecules occupy the interstitial cavities formed upon swelling of the membrane. The analysis is proposed in terms of averaged OH bond length variation. A sizable contraction of the OH distance is observed at low hydration (∼0.09 Å), while at higher hydration levels, the contraction is smaller (∼0.02 Å) and the OH bond length is closer to bulk water. An evaluation of the electron kinetic energy indicates that the spatial changes associated with the water distribution correspond to a consistent binding energy increase. Distinct temperature dependences of each water population are observed, which can be straightly related to water desorption into ice on cooling below the freezing point. [ABSTRACT FROM AUTHOR]

Published
2021
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16. Ion and Electron Momentum Distributions from Single and Double Ionization of Helium Induced by Compton Scattering

Author

Kircher, M., primary, Trinter, F., additional, Grundmann, S., additional, Kastirke, G., additional, Weller, M., additional, Vela-Perez, I., additional, Khan, A., additional, Janke, C., additional, Waitz, M., additional, Zeller, S., additional, Mletzko, T., additional, Kirchner, D., additional, Honkimäki, V., additional, Houamer, S., additional, Chuluunbaatar, O., additional, Popov, Yu. V., additional, Volobuev, I. P., additional, Schöffler, M. S., additional, Schmidt, L. Ph. H., additional, Jahnke, T., additional, and Dörner, R., additional

Published
2022
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26. Photon-Momentum-Induced Molecular Dynamics in Photoionization of N2 at hν = 40 keV

Author

Kircher, M., Rist, J., Trinter, F., Grundmann, S., Waitz, M., Melzer, N., Vela-Perez, I., Mletzko, T., Pier, A., Strenger, N., Siebert, J., Janssen, R., Honkimäki, V., Drnec, J., Demekhin, P., Schmidt, L., Schöffler, M., Jahnke, T., and Dörner, R.

Subjects
Physics::Instrumentation and Detectors, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, Nuclear Experiment
Abstract

We investigate K-shell ionization of N2 at 40 keV photon energy. Using a cold target recoil ion momentum spectroscopy reaction microscope, we determine the vector momenta of the photoelectron, the Auger electron, and both N+ fragments. These fully differential data show that the dissociation process of the N2+2 ion is significantly modified not only by the recoil momentum of the photoelectron but also by the photon momentum and the momentum of the emitted Auger electron. We find that the recoil energy introduced by the photon and the photoelectron momentum is partitioned with a ratio of approximately 30∶70 between the Auger electron and fragment ion kinetic energies, respectively. We also observe that the photon momentum induces an additional rotation of the molecular ion.

Published
2019

31. Photon-Momentum-Induced Molecular Dynamics in Photoionization of $N_{2}$ at hν = 40 keV

Author

Kircher, Max, Rist, J., Trinter, F., Grundmann, Sven, Waitz, M., Melzer, N., Vela-Perez, I., Mletzko, T., Pier, A., Strenger, N., Siebert, J., Janssen, R., Honkimäki, V., Drnec, J., Demekhin, Ph. V., Schmidt, L. Ph. H., Schöffler, M. S., Jahnke, Till, and Dörner, R.

Subjects
Physics::Instrumentation and Detectors, Physics::Atomic and Molecular Clusters, ddc:530, Physics::Atomic Physics, Nuclear Experiment
Abstract

Physical review letters 123(19), 193001 (2019). doi:10.1103/PhysRevLett.123.193001, We investigate K-shell ionization of N2 at 40 keV photon energy. Using a cold target recoil ionmomentum spectroscopy reaction microscope, we determine the vector momenta of the photoelectron, theAuger electron, and both Nþ fragments. These fully differential data show that the dissociation process ofthe N2þ2 ion is significantly modified not only by the recoil momentum of the photoelectron but also by thephoton momentum and the momentum of the emitted Auger electron. We find that the recoil energyintroduced by the photon and the photoelectron momentum is partitioned with a ratio of approximately30∶70 between the Auger electron and fragment ion kinetic energies, respectively.We also observe that thephoton momentum induces an additional rotation of the molecular ion., Published by APS, College Park, Md.

Published
2019
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33. Photon-Momentum-Induced Molecular Dynamics in Photoionization of N2 at hν=40keV

Author

Kircher, M., primary, Rist, J., additional, Trinter, F., additional, Grundmann, S., additional, Waitz, M., additional, Melzer, N., additional, Vela-Perez, I., additional, Mletzko, T., additional, Pier, A., additional, Strenger, N., additional, Siebert, J., additional, Janssen, R., additional, Honkimäki, V., additional, Drnec, J., additional, Demekhin, Ph. V., additional, Schmidt, L. Ph. H., additional, Schöffler, M. S., additional, Jahnke, T., additional, and Dörner, R., additional

Published
2019
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39. The structure of liquid carbon dioxide and carbon disulfide.

Author

Neuefeind, J., Fischer, H. E., Simonson, J. M., Idrissi, A., Schöps, A., and Honkimäki, V.

Subjects
LIQUID carbon dioxide, CARBON dioxide, LIQUEFIED gases, CARBON disulfide, CARBON compounds, INORGANIC compounds, AIR pollution
Abstract

We present neutron and x-ray scattering data (a 2N+X experiment) of liquid CO2 and CS2 at a density of about 10 molecules/nm3. Because the scattering length contrast of the carbon isotope is very small and, in fact, smaller than anticipated from standard scattering length tables, a direct partial structure factor determination via matrix inversion gives unconvincing results. Instead we search for the best representation of the three independent scattering data sets by a simulation of rigid molecules interacting via a 12-6-1 potential, furthermore restricting the pressure p, the density ρ, and the temperature T to the experimental values. We show that a 12-6-1 potential is completely adequate to describe the structure of CO2; for CS2 we find that the best 12-6-1 potential still slightly overestimates the height of the sulfur-sulfur pair-distribution function gSS. Orientational correlations reflect the similarities much more than the differences of the two molecular systems. The distinct differences in the atom-atom pair distribution functions of CO2 and CS2 do not mean that their structures are radically different and the comparison with the crystalline structures is somewhat deceptive. A linear transformation, wherein all the parameters describing the interaction and the geometry of CS2 are changed to those of CO2, allows us to point out the physical parameters which may be responsible for the differences or similarities in thermodynamic behavior (pressure) and structures (orientations) between the two liquids. [ABSTRACT FROM AUTHOR]

Published
2009
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40. Polarimetric performance of a Laue lens gamma-ray CdZnTe focal plane prototype.

Author

Curado da Silva, R. M., Caroli, E., Stephen, J. B., Pisa, A., Auricchio, N., Del Sordo, S., Frontera, F., Honkimäki, V., Schiavone, F., Donati, A., Trindade, A. M. F., and Ventura, G.

Subjects
POLARIMETRY, GAMMA rays, MONOCHROMATORS, CADMIUM, ZINC, TELLURIUM, CRYSTALS
Abstract

A gamma-ray telescope mission concept [gamma ray imager (GRI)] based on Laue focusing techniques has been proposed in reply to the European Space Agency call for mission ideas within the framework of the next decade planning (Cosmic Vision 2015–2025). In order to optimize the design of a focal plane for this satellite mission, a CdZnTe detector prototype has been tested at the European Synchrotron Radiation Facility under an ∼100% polarized gamma-ray beam. The spectroscopic, imaging, and timing performances were studied and in particular its potential as a polarimeter was evaluated. Polarization has been recognized as being a very important observational parameter in high energy astrophysics (>100 keV) and therefore this capability has been specifically included as part of the GRI mission proposal. The prototype detector tested was a 5 mm thick CdZnTe array with an 11×11 active pixel matrix (pixel area of 2.5×2.5 mm2). The detector was irradiated by a monochromatic linearly polarized beam with a spot diameter of about 0.5 mm over the energy range between 150 and 750 keV. Polarimetric Q factors of 0.35 and double event relative detection efficiency of 20% were obtained. Further measurements were performed with a copper Laue monochromator crystal placed between the beam and the detector prototype. In this configuration we have demonstrated that a polarized beam does not change its polarization level and direction after undergoing a small angle (<1°) Laue diffraction inside a crystal. [ABSTRACT FROM AUTHOR]

Published
2008
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41. In situ studies on the kinetics of formation and crystal structure of In4Sn3O12 using high-energy x-ray diffraction.

Author

González, G. B., Okasinski, J. S., Mason, T. O., Buslaps, T., and Honkimäki, V.

Subjects
CRYSTALS, X-ray diffraction, THERMAL expansion, ANNEALING of crystals, RIETVELD refinement
Abstract

High-energy x-ray diffraction was utilized to study in situ the formation temperature and crystal structure of the rhombohedral phase In4Sn3O12. The kinetics of In4Sn3O12 formation from bixbyite In2O3 and tetragonal SnO2 nanopowders were investigated during isothermal annealing treatments ranging from 1335 to 1400 °C. The transformation data exhibited two regimes, well described with a two-exponent kinetics model. The first regime followed a Johnson–Mehl–Avrami–Kolmogorov (JMAK) behavior until 75% of the In4Sn3O12 phase formed and was modeled with a modified JMAK equation. The formation of the first grains of In4Sn3O12 at 1345 °C was observed in situ using diffraction two-dimensional images. Structural results obtained from Rietveld analysis include atomic positions, phase analysis compositions of the samples, and lattice parameters during heating, cooling, and isothermal conditions. Linear and volume coefficients of thermal expansion were determined for the In4Sn3O12 phase. [ABSTRACT FROM AUTHOR]

Published
2008
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43. UMo/Al nuclear fuel quantitative analysis via high energy X-ray diffraction

Author

Bonnin, A., Palancher, H., Honkimäki, V., Tucoulou, R., Calzavara, Y., Colin, Claire, Bérar, Jean-François, Boudet, Nathalie, Rouquette, H., Raynal, J., Valot, C., Rodriguez-Carvajal, J., Colin, Claire, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Synchrotron Radiation Facility (ESRF), Institut Laue-Langevin (ILL), ILL, Matériaux, Rayonnements, Structure (MRS), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), CRG et Grands Instruments (CRG), Laboratoire de Modélisation Multi-échelles des Combustibles (LM2C), Service d'Etudes de Simulation du Comportement du combustibles (SESC), Département d'Etudes des Combustibles (DEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département d'Etudes des Combustibles (DEC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Matériaux, Rayonnements, Structure (NEEL - MRS), and CRG & Grands instruments (NEEL - CRG)

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2011

45. K -shell diagram and hypersatellite spectra of 4d transition elements

Author

Diamant, R., Huotari, S., Hämäläinen, K., Sharon, R., Kao, C. C., Honkimäki, V., Buslaps, T., Deutsch, M., and Accelerator Laboratory (Department of Physics) (-2009)

Subjects
114 Physical sciences
Abstract

The K-shell diagram (K alpha(1,2) and K beta(1,3)) and hypersatellite (HS) (K-h alpha(1,2)) spectra of Y, Zr, Mo, and Pd have been measured with high energy-resolution using photoexcitation by 90 keV synchrotron radiation. Comparison of the measured and ab initio calculated HS spectra demonstrates the importance of quantum electrodynamical (QED) effects for the HS spectra. Phenomenological fits of the measured spectra by Voigt functions yield accurate values for the shift of the HS from the diagram lines, the splitting of the HS lines, and their intensity ratio. Good agreement with theory was found for all quantities except for the intensity ratio, which is dominated by the intermediacy of the coupling of the angular momenta. The observed deviations imply that our current understanding of the variation of the coupling scheme from LS to jj across the periodic table may require some revision. The K-shell diagram (K alpha(1,2) and K beta(1,3)) and hypersatellite (HS) (K-h alpha(1,2)) spectra of Y, Zr, Mo, and Pd have been measured with high energy-resolution using photoexcitation by 90 keV synchrotron radiation. Comparison of the measured and ab initio calculated HS spectra demonstrates the importance of quantum electrodynamical (QED) effects for the HS spectra. Phenomenological fits of the measured spectra by Voigt functions yield accurate values for the shift of the HS from the diagram lines, the splitting of the HS lines, and their intensity ratio. Good agreement with theory was found for all quantities except for the intensity ratio, which is dominated by the intermediacy of the coupling of the angular momenta. The observed deviations imply that our current understanding of the variation of the coupling scheme from LS to jj across the periodic table may require some revision. The K-shell diagram (K alpha(1,2) and K beta(1,3)) and hypersatellite (HS) (K-h alpha(1,2)) spectra of Y, Zr, Mo, and Pd have been measured with high energy-resolution using photoexcitation by 90 keV synchrotron radiation. Comparison of the measured and ab initio calculated HS spectra demonstrates the importance of quantum electrodynamical (QED) effects for the HS spectra. Phenomenological fits of the measured spectra by Voigt functions yield accurate values for the shift of the HS from the diagram lines, the splitting of the HS lines, and their intensity ratio. Good agreement with theory was found for all quantities except for the intensity ratio, which is dominated by the intermediacy of the coupling of the angular momenta. The observed deviations imply that our current understanding of the variation of the coupling scheme from LS to jj across the periodic table may require some revision.

Published
2009

47. XFEL: The European X-Ray Free-Electron Laser - Technical Design Report

Author

Abela, R., Aghababyan, A., Altarelli, M., Altucci, C., Amatuni, G., Anfinrud, P., Audebert, P., Ayvazyan, V., Baboi, N., Baehr, J., Balandin, V., Bandelmann, R., Becker, J., Beutner, B., Blome, C., Bohnet, I., Bolzmann, A., Bostedt, C., Bozhko, Y., Brandt, A., Bratos, S., Bressler, C., Brovko, O., Brück, H., Carneiro, J.-P., Casalbuoni, S., Castellano, M., Castro, P., Catani, L., Cavalleri, A., Celik, S., Chapman, H., Charalambidis, D., Chen, J., Chergui, M., Choroba, S., Cianchi, A., Clausen, M., Collet, E., Danared, H., David, C., Decking, W., Dehler, M., Delsim-Hashemi, H., Dipirro, G., Dobson, B., Dohlus, M., Duesterer, S., Eckhardt, A., Eckoldt, H.-J., Edwards, H., Faatz, B., Fajardo, M., Fateev, A., Feldhaus, J., Filipov, Y., Floettmann, K., Follath, R., Fominykh, B., French, M., Frisch, J., Froehlich, L., Gadwinkel, E., García-Tabarés, L., Gareta, J. J., Garvey, T., Gel'mukhanov, F., Gensch, U., Gerth, C., Goerler, M., Golubeva, N., Graafsma, H., Graeff, W., Grimm, O., Griogoryan, B., Grübel, G., Gutt, C., Hacker, K., Haenisch, L., Hahn, U., Hajdu, J., Han, J. H., Hartrott, M., Havlicek, J., Hensler, O., Honkavaara, K., Honkimäki, V., Hott, T., Howells, M. R., Huening, M., Ihee, H., Ilday, F. Ö., Ischebeck, R., Jablonka, M., Jaeschke, E., Jensch, K., Jensen, J.-P., Johnson, S., Juha, L., Kaerntner, F., Kammering, R., Kapitza, H., Katalev, V., Keil, B., Khodyachykh, S., Kienberger, R., Kim, J.-W., Kim, Y., Klose, K., Kocharyan, V., Koehler, W., Koerfer, M., Kollewe, M., Kong, Q., Kook, W., Kostin, D., Kozlov, O., Kraemer, D., Krasilnikov, M., Krause, B., Krebs, O., Krzywinski, J., Kube, G., Kuhlmann, M., Laich, H., Lange, R., Larsson, M., Lee, R. W., Leuschner, A., Lierl, H., Lilje, L., Limberg, T., Lindenberg, A., Lipka, D., Loehl, F., Ludwig, K., Luong, M., Magne, C., Maquet, A., Marangos, J., Masciovecchio, C., Maslov, M., Matheisen, A., Matyushevskiy, E., Matzen, O., May, H.-J., McNulty, I., McCormick, D., Meulen, P., Meyners, N., Michelato, P., Mildner, N., Miltchev, V., Minty, M., Moeller, W.-D., Möller, T., Monaco, L., Nagl, M., Napoly, O., Neubauer, G., Nicolosi, P., Nienhaus, A., Noelle, D., Nunez, T., Obier, F., Oppelt, A., Pagani, C., Paparella, R., Pedersen, H. B., Petersen, B., Petrosyan, B., Petrosyan, L., Petrov, A., Pflueger, J., Piot, P., Plech, A., Ploenjes, E., Poletto, L., Pöplau, G., Prat, E., Prat, S., Prenting, J., Proch, D., Pugachov, D., Quack, H., Racky, B., Ramert, D., Redlin, H., Rehlich, K., Reininger, R., Remde, H., Reschke, D., Richter, D., Richter, M., Riemann, S., Riley, D., Robinson, I., Roensch, J., Rosmej, F., Ross, M., Rossbach, J., Rybnikov, V., Sachwitz, M., Saldin, E., Sandner, W., Schäfer, J., Schilcher, T., Schlarb, H., Schloesser, M., Schlott, V., Schmidt, B., Schmitz, M., Schmueser, P., Schneider, J., Schneidmiller, E., Schotte, F., Schrader, S., Schreiber, S., Schroer, C., Schuch, R., Schulte-Schrepping, H., Schwarz, A., Seidel, M., Sekutowicz, J., Seller, P., Sellmann, D., Senf, F., Sertore, D., Shabunov, A., Simrock, S., Singer, W., Sinn, H., Smith, R., Sombrowski, E., Sorokin, A. A., Springate, E., Staack, M., Staykov, L., Steffen, B., Stephenson, B., Stephan, F., Stulle, F., Syresin, E., Sytchev, K., Sytchev, V., Tallents, G., Techert, S., Tesch, N., Thom, H., Tiedtke, K., Tischer, M., Tolan, M., Toleikis, S., Toral, F., Treusch, R., Trines, D., Tsakanov, V., Tsakov, I., Tschentscher, T., Ullrich, F.-R., van Rienen, U., Variola, A., Vartaniants, I., Vogel, E., Vogel, J., Vuilleumier, R., Wabnitz, H., Wanzenberg, R., Wark, J. S., Weddig, H., Weiland, T., Weise, H., Wendt, M., Wenndorff, R., Wichmann, R., Will, I., Winter, A., Witte, K., Wittenburg, K., Wochner, P., Wohlenberg, T., Wojtkiewicz, J., Wolf, A., Wulff, M., Yurkov, M., Zagorodnov, I., Zambolin, P., Zapfe, K., Zeitoun, P., Ziemann, V., Zolotov, A., Brinkmann, R., and Grabosch, H.-J.

Subjects
Physics
Abstract

This report contains a comprehensive technical description of a new international research infrastructure, the European X-Ray Free-Electron Laser (XFEL) Facility. It was written between October 2005 and June 2006 and provides a realistic cost estimate and a compelling assessment of the scientific pay-off. The report has been prepared with the contribution of hundreds of people from many laboratories in Europe and even beyond. Their contributions have been harmonised and merged by many editors, and the whole effort has been coordinated by the European Project Team, generously supported and hosted by the Deutsches Elektronen-Synchrotron (DESY) laboratory.

Published
2006
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