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36 results on '"Dognon, J-P."'

1. Ionization parameters of Trimethylbismuth for high-energy photon detection

Author

Farradèche, M., Tauzin, G., Mols, J-Ph., Bard, J-P., Dognon, J-P., Weinheimer, C., Schäfers, K. P., Sharyy, V., and Yvon, D.

Subjects
Physics - Instrumentation and Detectors
Abstract

CaLIPSO is an innovative photon detector concept designed for high precision brain PET imaging. For the first time, liquid trimethylbismuth is used as sensitive medium. The detector operates as a time-projection chamber and detects both Cherenkov light and charge signal. Indeed, each 511-keV photon releases a single primary electron that triggers a Cherenkov radiation and ionizes the medium. As trimethylbismuth has never been studied before, we measured its free ion yield defined as the number of electron-ion pairs released by the primary electron. To this end, we developed a low-noise measuring system to determine the weak current induced by a 60Co source in the liquid with an accuracy better than 5 fA for an electric field up to 7kV/cm. We used tetramethylsilane as benchmark liquid to validate the apparatus and we measured a zero-field free ion yield of 0.53 +/- 0.03 in agreement with literature. However, we found a zero-field free ion yield of 0.083 +/- 0.003 for trimethylbismuth, which is a factor 7 lower than the typical values for similar dielectric liquids. Quantum chemistry computations on heavy atoms tend to demonstrate the high ability of trimethylbismuth to capture electrons, which could explain this weak value. This recombination mechanism marks a new step in understanding charge transport in liquid detectors. Finally, to verify the detectability of individual charge pulses, we developed a charge pulse measurement system which has been successfully validated with TMSi. Measurements with TMBi are ongoing., Comment: 15th Vienna Conference on Instrumentation (2019)

Published
2019
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2. Free ion yield of Trimethyl Bismuth used as sensitive medium for high-energy photon detection

Author

Farradèche, M., Tauzin, G., Mols, J-Ph., Dognon, J-P., Dauvois, V., Sharyy, V., Bard, J-P., Mancardi, X., Verrecchia, P., and Yvon, D.

Subjects
Physics - Instrumentation and Detectors
Abstract

The CaLIPSO project is an innovative high-energy photon detector concept using trimethylbismuth as sensitive medium in a liquid ionization chamber. The detector, designed for high precision brain PET imaging, works as a time-projection chamber and detects Cherenkov light and charge signal. We measured the free ion yield of trimethylbismuth, which represents the number of electron-ion pairs released by the incident photon. To do so, we developed a low-noise measuring system to determine the current induced by a 60Co source in the liquid with an accuracy better than 5 fA for an electric field up to 7 kV/cm. We used tetramethylsilane as benchmark liquid to validate the apparatus and we measured a zero-field free ion yield of 0.53 +/- 0.03 in agreement with measurements in literature. However, we found a zero-field free ion yield of 0.083 +/- 0.003 for trimethylbismuth, which is a factor 7 lower than the typical values for similar dielectric liquids. Quantum chemistry computations on heavy atoms tend to demonstrate a high capacity of trimethylbismuth to capture electrons which could explain the weak value. The consequences of a low free ion yield in terms of high-energy photon detection and brain PET imaging are finally discussed.

Published
2018
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7. Large Shape Staggering in Neutron-Deficient Bi Isotopes

Author

Barzakh, A., Andreyev, A. N., Raison, C., Cubiss, J. G., Van Duppen, P., Péru, S., Hilaire, S., Goriely, S., Andel, B., Antalic, S., Al Monthery, M., Berengut, J. C., Bieroifmmode nelse ń, J., Bissell, M. L., Borschevsky, A., Chrysalidis, K., Cocolios, T. E., Day Goodacre, T., Dognon, J.-P., Elantkowska, M., Eliav, E., Farooq-Smith, G. J., Fedorov, D. V., Fedosseev, V. N., Gaffney, L. P., Garcia Ruiz, R. F., Godefroid, M., Granados, C., Harding, R. D., Heinke, R., Huyse, M., Karls, J., Larmonier, P., Li, J. G., Lynch, K. M., Maison, D. E., Marsh, B. A., Molkanov, P., Mosat, P., Oleynichenko, A. V., Panteleev, V., Pyykkö, P., Reitsma, M. L., Rezynkina, K., Rossel, R. E., Rothe, S., Ruczkowski, J., Schiffmann, S., Seiffert, C., and Seliverstov, M. D.

Published
2021

8. Large Shape Staggering in Neutron-Deficient Bi Isotopes

Author

Barzakh, A., primary, Andreyev, A. N., additional, Raison, C., additional, Cubiss, J. G., additional, Van Duppen, P., additional, Péru, S., additional, Hilaire, S., additional, Goriely, S., additional, Andel, B., additional, Antalic, S., additional, Al Monthery, M., additional, Berengut, J. C., additional, Bieroń, J., additional, Bissell, M. L., additional, Borschevsky, A., additional, Chrysalidis, K., additional, Cocolios, T. E., additional, Day Goodacre, T., additional, Dognon, J.-P., additional, Elantkowska, M., additional, Eliav, E., additional, Farooq-Smith, G. J., additional, Fedorov, D. V., additional, Fedosseev, V. N., additional, Gaffney, L. P., additional, Garcia Ruiz, R. F., additional, Godefroid, M., additional, Granados, C., additional, Harding, R. D., additional, Heinke, R., additional, Huyse, M., additional, Karls, J., additional, Larmonier, P., additional, Li, J. G., additional, Lynch, K. M., additional, Maison, D. E., additional, Marsh, B. A., additional, Molkanov, P., additional, Mosat, P., additional, Oleynichenko, A. V., additional, Panteleev, V., additional, Pyykkö, P., additional, Reitsma, M. L., additional, Rezynkina, K., additional, Rossel, R. E., additional, Rothe, S., additional, Ruczkowski, J., additional, Schiffmann, S., additional, Seiffert, C., additional, Seliverstov, M. D., additional, Sels, S., additional, Skripnikov, L. V., additional, Stryjczyk, M., additional, Studer, D., additional, Verlinde, M., additional, Wilman, S., additional, and Zaitsevskii, A. V., additional

Published
2021
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9. Large Shape Staggering in Neutron-Deficient Bi Isotopes

Author

Barzakh, Anatoli A.E., Andreyev, Andrei, Raison, C., Cubiss, J.G., Van Duppen, Piet, Péru, S., Hilaire, Stéphane, Goriely, Stéphane, Andel, Boris, Antalic, S., Al Monthery, M., Berengut, J.C., Bieron, J., Bissell, M.L., Borschevsky, A., Chrysalidis, K., Cocolios, Thomas, Day Goodacre, T., Dognon, J.-P., Elantkowska, M., Eliav, E., Farooq-Smith, G.J., Fedorov, D.V., Fedosseev, Valentine V.N., Gaffney, L.P., Garcia Ruiz, R.F., Godefroid, Michel, Granados, C., Harding, R.D., Heinke, R., Huyse, Mark, Karls, Julia, Larmonier, P., Li, J.G., Lynch, K.M., Maison, D.E., Marsh, B. A., Molkanov, P., Mosat, P., Oleynichenko, A.V., Panteleev, V., Pyykkö, Pekka, Reitsma, M.L., Rezynkina, K., Rossel, R.E., Rothe, S., Ruczkowski, J., Schiffmann, Sacha, Seiffert, Christoph, Seliverstov, M.D., Sels, S., Skripnikov, L.V., Stryjczyk, M., Studer, D., Verlinde, M., Zaitsevskii, A.V., Barzakh, Anatoli A.E., Andreyev, Andrei, Raison, C., Cubiss, J.G., Van Duppen, Piet, Péru, S., Hilaire, Stéphane, Goriely, Stéphane, Andel, Boris, Antalic, S., Al Monthery, M., Berengut, J.C., Bieron, J., Bissell, M.L., Borschevsky, A., Chrysalidis, K., Cocolios, Thomas, Day Goodacre, T., Dognon, J.-P., Elantkowska, M., Eliav, E., Farooq-Smith, G.J., Fedorov, D.V., Fedosseev, Valentine V.N., Gaffney, L.P., Garcia Ruiz, R.F., Godefroid, Michel, Granados, C., Harding, R.D., Heinke, R., Huyse, Mark, Karls, Julia, Larmonier, P., Li, J.G., Lynch, K.M., Maison, D.E., Marsh, B. A., Molkanov, P., Mosat, P., Oleynichenko, A.V., Panteleev, V., Pyykkö, Pekka, Reitsma, M.L., Rezynkina, K., Rossel, R.E., Rothe, S., Ruczkowski, J., Schiffmann, Sacha, Seiffert, Christoph, Seliverstov, M.D., Sels, S., Skripnikov, L.V., Stryjczyk, M., Studer, D., Verlinde, M., and Zaitsevskii, A.V.

Abstract

The changes in the mean-square charge radius (relative to Bi209), magnetic dipole, and electric quadrupole moments of Bi187,188,189,191 were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in Bi187,188,189g, manifested by a sharp radius increase for the ground state of Bi188 relative to the neighboring Bi187,189g. A large isomer shift was also observed for Bi188m. Both effects happen at the same neutron number, N=105, where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2021

10. Modeling of uranyl cation-water clusters

Author

Clavaguera-Sarrio, C., Dognon, J.-P., Brenner, V., Hoyau, S., Marsden, C.J., and Millie, P.

Subjects
Charge transfer -- Analysis, Polarization (Electricity) -- Analysis, Cations -- Atomic properties, Chemicals, plastics and rubber industries
Abstract

The model potential for uranyl cation-water clusters, one including polarization effects explicitly and charge-transfer effects implicitly, and the other including these two effects explicitly are derived from ab initio calculations on [UO2(H2O)](super 2+). The model with the explicit charge-transfer term reproduces accurately the ab initio geometries and energies of small clusters with containing up to five water molecules.

Published
2003

12. Collision-induced dissociation by helium: a piecewise construction of the cross section

Author

Poisson, K., Pujo, P. de, Brenner, V., Dognon, J. -P., Mestdagh, J. -M., and Derepas, A. -L.

Subjects
Chemistry, Physical and theoretical -- Research, Dissociation -- Physiological aspects, Helium -- Physiological aspects, Molecular dynamics -- Analysis, Collisions (Physics) -- Analysis, Chemicals, plastics and rubber industries
Published
2002

15. Secondary structures of short peptide chains in the gas phase

Author

Chin, W., Dognon, J.-P., Dimicoli, Iliana, Piuzzi, F., Tardivel, B., Mons, M., Laboratoire Francis PERRIN (LFP - URA 2453), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Published
2005

17. Spectroscopie laser de molécules biologiques en jet supersonique

Author

Chin, W., Dognon, J.-P., Dimicoli, I., Piuzzi, F., Tardivel, B., Mons, M., Laboratoire Francis PERRIN (LFP - URA 2453), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Published
2005

20. Competition between local conformational preferences and secondary structures in gas-phase model tripeptides

Author

Chin, W., Mons, M., Dognon, J.-P., Piuzzi, F., Tardivel, B., Dimicoli, I., Laboratoire Francis PERRIN (LFP - URA 2453), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Abstract

The gas-phase model tripeptides N-acetyl-Phe-Pro-NH2 and N-acetyl-Pro-Phe-NH2 have been studied experimentally and theoretically in order to investigate the local conformational preferences of the peptide backbone and their competition with secondary structures under solvent-free conditions. The combination of UV and IR spectroscopies shows that, under supersonic beam conditions, only a reduced number of conformations are formed, indicating efficient conformational relaxation processes in these species. IR spectroscopy in the NH stretch spectral range combined with density functional theory calculations proves to be a very efficient tool to assign the structure of these species in terms of intramolecular H-bonding. Classical secondary structures of biology, like repeated -turns are observed as major conformations. Only one minor conformation of N-Ac-Phe-Pro-NH2 was assigned to a -turn structure. According to the nature of the main conformers, the backbone conformational trends on the phenylalanine (Phe) residue is shown to be very dependent upon the neighbouring residues: Phe adopts a conformation when alone (in N-acetyl-Phe-NH2) or when followed by a proline residue (in N-acetyl-Phe-Pro-NH2) but favours a L conformation when preceded by proline (in N-acetyl-Pro-Phe-NH2). These subtle preferences, resulting from a competition between weakly polar or dispersive interactions, constitute a very stringent test of the theoretical tools for protein modelling and simulation.

Published
2004

21. Intramolecular interactions in gas-phase peptides

Author

Piuzzi, F., Mons, M., Dimicoli, I., Chin, W., Tardivel, B., Dognon, J.-P., Laboratoire Francis PERRIN (LFP - URA 2453), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Published
2004

23. Coopérative effects in the photophysical properties of DNA oligomers

Author

Markovitsi, D., Bouvier, B., Dognon, J.-P., Gustavsson, T., Lavery, R., Lazzarotto, E., Marguet, Sylvie, Millie, P., Onidas, D., Sharonov, A., Zakrzewska, K., Laboratoire Francis PERRIN (LFP - URA 2453), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de biochimie théorique [Paris] (LBT (UPR_9080)), Institut de biologie physico-chimique (IBPC (FR_550)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique D'Orsay (LCPO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Chemistry Department, University of Pennsylvania, Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut de biologie physico-chimique (IBPC (FR_550)), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), University of Pennsylvania [Philadelphia], Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université Paris Diderot - Paris 7 (UPD7)-Institut de biologie physico-chimique (IBPC), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Published
2004

24. Secondary structures in gas-phase model peptides as revealed by IR/UV double resonance spectroscopy

Author

Mons, M., Chin, W., Canuel, C., Dognon, J.-P., Butz, P., Compagnon, I., Piuzzi, F., Tardivel, B., Dimicoli, I., Laboratoire Francis PERRIN (LFP - URA 2453), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), PTCL, University of Oxford, and University of Oxford [Oxford]

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Published
2004

25. Secondary structure of a peptide chain as revealed by gas phase IR/UV double resonance spectroscopy

Author

Chin, W., Dognon, J.-P., Compagnon, I., Meijer, G., von Helden, G., Canuel, C., Dimicoli, I., Piuzzi, F., Tardivel, B., Mons, M., Laboratoire Francis PERRIN (LFP - URA 2453), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), FOM Institute for Plasma Physics : Rijnhuizen, and Foundation for Fundamental Research on Matter

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Published
2004

26. Can we Understand the Different Coordinations and Structures of Closed-Shell Metal Cation-Water Clusters

Author

Derepas, A.-L., Soudan, J.-M., Brenner, V., Dognon, J.-P., Millie, P., Laboratoire Francis PERRIN (LFP - URA 2453), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique D'Orsay (LCPO), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, metal cation-water clusters, back polarization, ab initio calculations, model potential, first hydration sphere structure, Physics::Chemical Physics
Abstract

We present a model potential for studying Mq+(H2O)n=1,9 clusters where M stands for either Na+, Cs+, Ca2+, Ba2+, or La3+. The potential energy surfaces (PES) are explored by the Monte Carlo growth method. The results for the most significant equilibrium structures of the PES as well as for energetics are favorably compared to the best ab initio calculations found in the literature and to experimental results. Most of these complexes have a different coordination number in cluster compared to experimental results in solution or solid phase. An interpretation of the coordination number in clusters is given. In order to well describe the transition between the first hydration sphere and the second one we show that an autocoherent treatment of the electric field is necessary to correctly deal with polarization effects. We also explore the influence of the cation properties (charge, size, and polarizability) on both structures and coordination number in clusters, as well as the meaning of the second hydration sphere. Such an approach shows that the leading term in the interaction energy for a molecule in the second hydration sphere is an electrostatic attraction to the cation and not a hydrogen bond with the water molecules in the first hydration sphere.

Published
2002

36. Can we understand the different coordinations and structures of closed-shell metal cation-water clusters?

Author

Derepas AL, Soudan JM, Brenner V, Dognon JP, and Millié P

Abstract

We present a model potential for studying M(q+)(H(2)O)(n=1,9) clusters where M stands for either Na(+), Cs(+), Ca(2+), Ba(2+), or La(3+). The potential energy surfaces (PES) are explored by the Monte Carlo growth method. The results for the most significant equilibrium structures of the PES as well as for energetics are favorably compared to the best ab initio calculations found in the literature and to experimental results. Most of these complexes have a different coordination number in cluster compared to experimental results in solution or solid phase. An interpretation of the coordination number in clusters is given. In order to well describe the transition between the first hydration sphere and the second one we show that an autocoherent treatment of the electric field is necessary to correctly deal with polarization effects. We also explore the influence of the cation properties (charge, size, and polarizability) on both structures and coordination number in clusters, as well as the meaning of the second hydration sphere. Such an approach shows that the leading term in the interaction energy for a molecule in the second hydration sphere is an electrostatic attraction to the cation and not a hydrogen bond with the water molecules in the first hydration sphere., (Copyright 2002 Wiley Periodicals, Inc.)

Published
2002
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