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Rajput J, Garg D, Cassimi A, Fléchard X, Rangama J, Safvan CP. Addressing three-body fragmentation of methane dication using "native frames": Evidence of internal excitation in fragments. J Chem Phys 2023; 159:184303. [PMID: 37955322 DOI: 10.1063/5.0171881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/23/2023] [Indexed: 11/14/2023] Open
Abstract
The three body fragmentation of methane dication has been studied using the technique of cold target recoil ion momentum spectroscopy. The process is initiated by impact of energetic Ar9+ ions on neutral methane and the data is subsequently collected in coincidence with Ar8+ projectile. By analysing the dissociation channels leading to (H + H+ + CH2+) and (H + H2+ + CH+) fragments, it is concluded that these fragments are formed in a sequential manner via formation of molecular intermediates CH3+ and CH2+ respectively. It is shown that these molecular intermediates carry a few eVs as their internal energies, part of which is released when they emit an H-atom with the open possibility that the final detected fragments may still be internally excited. This was accomplished by analysing the two-steps of the sequential process in their own native frames. For a molecular system having three-dimensional structure, our results prove to be an ideal example to highlight the importance of using native frames for correct interpretation of the obtained results. Our results indicate that the dissociation of methane dication can be a major source of production of H-atoms in addition to H+ fragments with the probability of the two being of similar order.
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Affiliation(s)
- Jyoti Rajput
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
| | - Diksha Garg
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
| | - A Cassimi
- CIMAP, CEA-CNRS-ENSICAEN-UNICAEN, Normandie Université, F-14050 Caen Cedex 04, France
| | - X Fléchard
- Université de Caen Normandie, ENSICAEN, CNRS/IN2P3, LPC Caen UMR6534, F-14000 Caen, France
| | - J Rangama
- CIMAP, CEA-CNRS-ENSICAEN-UNICAEN, Normandie Université, F-14050 Caen Cedex 04, France
| | - C P Safvan
- Inter-University Accelerator Centre, New Delhi 110067, India
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2
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Ji M, Bernard J, Chen L, Brédy R, Ortéga C, Joblin C, Cassimi A, Martin S. Cooling of isolated anthracene cations probed with photons of different wavelengths in the Mini-Ring. J Chem Phys 2017; 146:044301. [PMID: 28147509 DOI: 10.1063/1.4973651] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report on a direct measurement of the Internal Energy Distribution (IED) shift rate of an initially hot polycyclic aromatic hydrocarbon (PAH) molecular ensemble, anthracene cations (C14H10+). The ions were produced in an electron cyclotron resonance (ECR) ion source and stored in an electrostatic ion storage ring, the Mini-Ring. Laser pulses of two wavelengths were sent successively to merge the stored ion bunch at different storage times to enhance the neutral fragment yield due to fast laser induced dissociation. Using this technique, we have been able to determine directly the energy shift rate of the IED, without involving any theoretical simulation or any assumption on dissociation rates, cooling rates, or the initial IED. Theoretical energy shift rates have been estimated from the evolution of simulated IEDs by taking into account the effects of the unimolecular dissociation and two radiative decay mechanisms: the Poincaré fluorescence and the infrared vibrational emission. The comparison between the experimental results and the model provides new evidence of the important role of the Poincaré fluorescence in the overall cooling process of anthracene cations. Although in the short time range the commonly accepted intuition says that the cooling would result mostly from the dissociation of the hottest ions (depletion cooling), we demonstrate that the Poincaré fluorescence is the dominant contribution (about 85%) to the net cooling effect.
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Affiliation(s)
- M Ji
- Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Cedex Villeurbanne, France
| | - J Bernard
- Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Cedex Villeurbanne, France
| | - L Chen
- Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Cedex Villeurbanne, France
| | - R Brédy
- Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Cedex Villeurbanne, France
| | - C Ortéga
- Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Cedex Villeurbanne, France
| | - C Joblin
- Université de Toulouse; UPS-OMP; IRAP; Toulouse, France
| | - A Cassimi
- CIMAP, CEA/CNRS/ENSICAEN/UNICAEN, Bd H. Becquerel, BP 5133, F-14070 Caen, France
| | - S Martin
- Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Cedex Villeurbanne, France
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Guillous S, Bourin C, Ban D'Etat B, Benyagoub A, Cassimi A, Feierstein C, Gardés E, Giglio E, Girard S, Grygiel C, Houel A, Lebius H, Méry A, Monnet I, Ramillon JM, Rangama J, Ropars F, Verzeroli E, Viteau M, Delobbe A. A new setup for localized implantation and live-characterization of keV energy multiply charged ions at the nanoscale. Rev Sci Instrum 2016; 87:113901. [PMID: 27910696 DOI: 10.1063/1.4966675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An innovative experimental setup, PELIICAEN, allowing the modification of materials and the study of the effects induced by multiply charged ion beams at the nanoscale is presented. This ultra-high vacuum (below 5 × 10-10 mbar) apparatus is equipped with a focused ion beam column using multiply charged ions and a scanning electron microscope developed by Orsay Physics, as well as a scanning probe microscope. The dual beam approach coupled to the scanning probe microscope achieves nanometer scale in situ topological analysis of the surface modifications induced by the ion beams. Preliminary results using the different on-line characterization techniques to study the formation of nano-hillocks on silicon and mica substrates are presented to illustrate the performances of the setup.
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Affiliation(s)
- S Guillous
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - C Bourin
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - B Ban D'Etat
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - A Benyagoub
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - A Cassimi
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - C Feierstein
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - E Gardés
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - E Giglio
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - S Girard
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - C Grygiel
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - A Houel
- Orsay Physics (Tescan-Orsay Holding), 95 Avenue des Monts Auréliens, ZA Saint-Charles F-13710, Fuveau, France
| | - H Lebius
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - A Méry
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - I Monnet
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - J-M Ramillon
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - J Rangama
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - F Ropars
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - E Verzeroli
- Orsay Physics (Tescan-Orsay Holding), 95 Avenue des Monts Auréliens, ZA Saint-Charles F-13710, Fuveau, France
| | - M Viteau
- Orsay Physics (Tescan-Orsay Holding), 95 Avenue des Monts Auréliens, ZA Saint-Charles F-13710, Fuveau, France
| | - A Delobbe
- Orsay Physics (Tescan-Orsay Holding), 95 Avenue des Monts Auréliens, ZA Saint-Charles F-13710, Fuveau, France
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Martin S, Chen L, Brédy R, Bernard J, Cassimi A. Fragmentation of doubly charged HDO, H2O, and D2O molecules induced by proton and monocharged fluorine beam impact at 3 keV. J Chem Phys 2015; 142:094306. [PMID: 25747080 DOI: 10.1063/1.4913398] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Doubly charged ions HDO(2+), H2O(2+), and D2O(2+) were prepared selectively to triplet or singlet excited states in collisions with F(+) or H(+) projectiles at 3 keV. Excitation energies of dications following two-body or three-body dissociation channels were measured and compared with recent calculations using ab initio multi-reference configuration interaction method [Gervais et al., J. Chem. Phys. 131, 024302 (2009)]. For HDO(2+), preferential cleavage of O-H rather than O-D bond has been observed and the ratio between the populations of the fragmentation channels OD(+)_H(+) and OH(+)_D(+) were measured. The kinetic energy release has been measured and compared with previous experiments.
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Affiliation(s)
- S Martin
- Institut Lumière Matière, UMR5306 Université Claude Bernard Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex, France
| | - L Chen
- Institut Lumière Matière, UMR5306 Université Claude Bernard Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex, France
| | - R Brédy
- Institut Lumière Matière, UMR5306 Université Claude Bernard Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex, France
| | - J Bernard
- Institut Lumière Matière, UMR5306 Université Claude Bernard Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex, France
| | - A Cassimi
- CIMAP, GANIL Université de CAEN, Bd. H. Becquerel, Caen, France
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5
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Iskandar W, Matsumoto J, Leredde A, Fléchard X, Gervais B, Guillous S, Hennecart D, Méry A, Rangama J, Zhou CL, Shiromaru H, Cassimi A. Interatomic Coulombic decay as a new source of low energy electrons in slow ion-dimer collisions. Phys Rev Lett 2015; 114:033201. [PMID: 25658997 DOI: 10.1103/physrevlett.114.033201] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Indexed: 06/04/2023]
Abstract
We provide the experimental evidence that the single electron capture process in slow collisions between O^{3+} ions and neon dimer targets leads to an unexpected production of low-energy electrons. This production results from the interatomic Coulombic decay process, subsequent to inner-shell single electron capture from one site of the neon dimer. Although pure one-electron capture from the inner shell is expected to be negligible in the low collision energy regime investigated here, the electron production due to this process overtakes by 1 order of magnitude the emission of Auger electrons by the scattered projectiles after double-electron capture. This feature is specific to low charge states of the projectile: similar studies with Xe^{20+} and Ar^{9+} projectiles show no evidence of inner-shell single-electron capture. The dependence of the process on the projectile charge state is interpreted using simple calculations based on the classical over the barrier model.
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Affiliation(s)
- W Iskandar
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - J Matsumoto
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - A Leredde
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - X Fléchard
- LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, 14050 Caen Cedex 04, France
| | - B Gervais
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - S Guillous
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - D Hennecart
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - A Méry
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - J Rangama
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - C L Zhou
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - H Shiromaru
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - A Cassimi
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
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6
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Iskandar W, Matsumoto J, Leredde A, Fléchard X, Gervais B, Guillous S, Hennecart D, Méry A, Rangama J, Zhou CL, Shiromaru H, Cassimi A. Atomic site-sensitive processes in low energy ion-dimer collisions. Phys Rev Lett 2014; 113:143201. [PMID: 25325640 DOI: 10.1103/physrevlett.113.143201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Indexed: 06/04/2023]
Abstract
Electron capture processes for low energy Ar(9+) ions colliding with Ar(2) dimer targets are investigated, focusing attention on charge sharing between the two Ar atoms as a function of the molecular orientation and the impact parameter. A preference for charge-asymmetric dissociation channels is observed, with a strong correlation between the projectile scattering angle and the molecular ion orientation. The measurements here provide clear evidence that projectiles distinguish each atom in the target and that electron capture from near-site atoms is favored. Monte Carlo calculations based on the classical over-the-barrier model, with dimer targets represented as two independent atoms, are compared to the data. They give new insight into the dynamics of the collision by providing, for the different electron capture channels, the two-dimensional probability maps p(b), where b is the impact parameter vector in the molecular frame.
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Affiliation(s)
- W Iskandar
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - J Matsumoto
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - A Leredde
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - X Fléchard
- LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, 14050 Caen Cedex 04, France
| | - B Gervais
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - S Guillous
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - D Hennecart
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - A Méry
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - J Rangama
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - C L Zhou
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - H Shiromaru
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - A Cassimi
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
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7
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Leredde A, Fléchard X, Cassimi A, Hennecart D, Pons B. High-resolution probe of coherence in low-energy charge exchange collisions with oriented targets. Phys Rev Lett 2013; 111:133201. [PMID: 24116777 DOI: 10.1103/physrevlett.111.133201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 08/09/2013] [Indexed: 06/02/2023]
Abstract
The trapping lasers of a magneto-optical trap have been used to bring Rb atoms into well defined oriented states. Coupled to recoil-ion-momentum spectroscopy, this provided a unique MOTRIMS setup which was able to probe scattering dynamics, including the coherence features, with unprecedented resolution. The technique was applied to the low-energy charge exchange reactions Na+ + Rb(5p±1)→Na(3p,4s)+Rb+. The measurements revealed detailed features of the collisional interaction which were employed to improve the theoretical description. As such, it was possible to ascertain the validity of the intuitive models used to predict the most likely capture transitions.
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Affiliation(s)
- A Leredde
- LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, F-14070 Caen, France
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8
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Couratin C, Velten P, Fléchard X, Liénard E, Ban G, Cassimi A, Delahaye P, Durand D, Hennecart D, Mauger F, Méry A, Naviliat-Cuncic O, Patyk Z, Rodríguez D, Siegień-Iwaniuk K, Thomas JC. First measurement of pure electron shakeoff in the β decay of trapped 6He+ ions. Phys Rev Lett 2012; 108:243201. [PMID: 23004268 DOI: 10.1103/physrevlett.108.243201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Indexed: 06/01/2023]
Abstract
The electron shakeoff probability of 6Li2+ ions resulting from the β- decay of 6He+ ions has been measured with high precision using a specially designed recoil ion spectrometer. This is the first measurement of a pure electron shakeoff following nuclear β decay, not affected by multielectron processes such as Auger cascades. In this ideal textbook case for the application of the sudden approximation, the experimental ionization probability was found to be P(so)(exp)=0.02339(36) in perfect agreement with simple quantum mechanical calculations.
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Affiliation(s)
- C Couratin
- LPC Caen, ENSICAEN, Université de Caen Basse Normandie, CNRS/IN2P3-ENSI, Caen, France
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9
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Matsumoto J, Leredde A, Flechard X, Hayakawa K, Shiromaru H, Rangama J, Zhou CL, Guillous S, Hennecart D, Muranaka T, Mery A, Gervais B, Cassimi A. Asymmetry in multiple-electron capture revealed by radiative charge transfer in Ar dimers. Phys Rev Lett 2010; 105:263202. [PMID: 21231656 DOI: 10.1103/physrevlett.105.263202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Indexed: 05/30/2023]
Abstract
We measured kinetic energies of the fragment ions of argon dimers multiply ionized by low-energy Ar(9+) collisions. For (Ar2)(4+) dissociation, the asymmetric channel (Ar(3+) + Ar(+)) yield is found unexpectedly higher than the symmetric channel (Ar(2+) + Ar(2+)) yield in contrast with previous observation for covalent molecules or clusters. For the dissociation channel (Ar2)(2+)→Ar(+) + Ar(+), two well-separated peaks were observed, clearly evidencing that the direct Coulombic dissociation and the radiative charge transfer followed by ionic dissociation alternatively occur for the dicationic dimers. The respective intensity of these two peaks provides a direct mean to unravel the respective proportion of one-site and two-site double-electron capture, which are found equal for this collision system.
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Affiliation(s)
- J Matsumoto
- Department of Chemistry, Tokyo Metropolitan University, Tokyo, Japan
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Gervais B, Giglio E, Adoui L, Cassimi A, Duflot D, Galassi ME. The H2O2+ potential energy surfaces dissociating into H+/OH+: Theoretical analysis of the isotopic effect. J Chem Phys 2009; 131:024302. [DOI: 10.1063/1.3157164] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Blieck J, Fléchard X, Cassimi A, Gilles H, Girard S, Hennecart D. A new MOTRIMS apparatus for high resolution measurements in ion-atom collisions and trapped atoms studies. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/163/1/012070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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12
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Blieck J, Fléchard X, Cassimi A, Gilles H, Girard S, Hennecart D. A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus for ion-atom collisions and trapped atom studies. Rev Sci Instrum 2008; 79:103102. [PMID: 19044697 DOI: 10.1063/1.2994151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus has been built and tested at the LPC-CAEN. Dedicated to ion-atom collisions studies and excited fraction measurements, the setup combines a projectile ion beam line, a target of cold rubidium atoms provided by a magneto-optical trap (MOT), and a recoil ion momentum spectrometer. In a test experiment using a beam of Na(+) projectiles, we demonstrate its capability to measure, with a very high signal over background ratio, fully differential cross sections in scattering angle, initial state, and final state of the system. We detail, in this work, features that had not been described previously in the literature: an extraction of the recoil ions transverse to the ion beam axis, and a fast switch for the MOT magnetic field. Advantages of transverse versus longitudinal extraction are discussed, and future possibilities for the setup are presented.
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Affiliation(s)
- J Blieck
- LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, Caen 14050, France
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13
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Liu XJ, Fukuzawa H, Teranishi T, De Fanis A, Takahashi M, Yoshida H, Cassimi A, Czasch A, Schmidt L, Dörner R, Wang K, Zimmermann B, McKoy V, Koyano I, Saito N, Ueda K. Breakdown of the two-step model in K-shell photoemission and subsequent decay probed by the molecular-frame photoelectron angular distributions of CO2. Phys Rev Lett 2008; 101:083001. [PMID: 18764609 DOI: 10.1103/physrevlett.101.083001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Indexed: 05/26/2023]
Abstract
We report results of measurements and of Hartree-Fock level calculations of molecular-frame photoelectron angular distributions (MFPADs) for C 1s photoemission from CO2. The agreement between the measured and calculated MFPADs is on average reasonable. The measured MFPADs display a weak but definite asymmetry with respect to the O+ and CO+ fragment ions at certain energies, providing evidence for an overlap of gerade and ungerade final ionic states giving rise to a partial breakdown of the two-step model of core-level photoionization and its subsequent Auger decay.
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Affiliation(s)
- X-J Liu
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
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14
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Liu XJ, Fukuzawa H, Teranishi T, De Fanis A, Takahashi M, Yoshida H, Cassimi A, Czasch A, Schmidt L, Dörner R, Koyano I, Saito N, Ueda K. Internal inelastic scattering satellite probed by molecular-frame photoelectron angular distributions from CO2. Phys Rev Lett 2008; 101:023001. [PMID: 18764178 DOI: 10.1103/physrevlett.101.023001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Indexed: 05/26/2023]
Abstract
The molecular-frame photoelectron angular distribution (MFPAD) of the satellite accompanying the C 1s photoline of the CO2 molecule has been measured at the C 1s(2sigmag)-->4sigmau* shape resonance, using electron-ion multicoincidence momentum spectroscopy. The observed MFPAD indicates that the conjugate satellite is excited by internal inelastic scattering. In this scenario, a photoelectron is ejected from the C 1s(2sigmag) orbital along the molecular axis and collides with an O lone-pair electron in the highest occupied molecular orbital 1pig. Then one of the colliding electrons is trapped to the lowest unoccupied molecular orbital 2piu*, while the other is emitted as a satellite photoelectron of sigmag symmetry, losing the information of the original photoelectron emission direction and parity.
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Affiliation(s)
- X-J Liu
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
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Adoui L, Legendre S, Tarisien M, Cassimi A, Galassi ME, Giglio E, Gervais B. High LET highly charged ion-induced ionization and fragmentation of water molecules and clusters. ACTA ACUST UNITED AC 2007. [DOI: 10.1088/1742-6596/88/1/012023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Laurent G, Fernández J, Legendre S, Tarisien M, Adoui L, Cassimi A, Fléchard X, Frémont F, Gervais B, Giglio E, Grandin JP, Martín F. Kinematically complete study of dissociative ionization of by ion impact. Phys Rev Lett 2006; 96:173201. [PMID: 16712294 DOI: 10.1103/physrevlett.96.173201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Indexed: 05/09/2023]
Abstract
We present a kinematically complete study of dissociative ionization of D(2) by 13.6 MeV/u S(15+) ions. The experiment allows us to unravel the competing mechanisms, namely, direct single ionization, autoionization of doubly excited states, ionization excitation, and double ionization, and to analyze the corresponding electron angular distribution from fixed-in-space molecules. The conclusions are supported by theoretical calculations in which the correlated motion of all electrons and nuclei and the interferences between them are described from first principles.
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Affiliation(s)
- G Laurent
- Centre Interdisciplinaire de Recherche Ions Lasers (CIRIL)-CEA-CNRS-ENSICaen, France
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Ueda K, De Fanis A, Saito N, Machida M, Kubozuka K, Chiba H, Muramatu Y, Sato Y, Czasch A, Jaguzki O, Dörner R, Cassimi A, Kitajima M, Furuta T, Tanaka H, Sorensen S, Okada K, Tanimoto S, Ikejiri K, Tamenori Y, Ohashi H, Koyano I. Nuclear motion and symmetry breaking of the B 1s-excited BF3 molecule. Chem Phys 2003. [DOI: 10.1016/s0301-0104(02)00903-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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18
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De Fanis A, Saito N, Pavlychev AA, Ladonin DY, Machida M, Kubozuka K, Koyano I, Okada K, Ikejiri K, Cassimi A, Czasch A, Dörner R, Chiba H, Sato Y, Ueda K. Symmetry-dependent multielectron excitations near the C 1s ionization threshold and distortion of the shape resonance in CO(2). Phys Rev Lett 2002; 89:023006. [PMID: 12096995 DOI: 10.1103/physrevlett.89.023006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2002] [Indexed: 05/23/2023]
Abstract
Satellite bands accompanying the C 1s photoline for the CO2 molecule parallel to the electric vector of the incident radiation E are found to be more intense than those for CO2 perpendicular to E in the shape resonance region. This indicates that multielectron excitations are caused in part by the interaction of the outgoing C 1s photoelectron with the valence electrons. The photoelectron-impact valence excitations couple with the C 1s single-hole ionization and distort the shape resonance significantly. We assign the broad resonance at approximately 312 eV to a distorted Sigma(u) shape resonance.
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Affiliation(s)
- A De Fanis
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
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Landers A, Weber T, Ali I, Cassimi A, Hattass M, Jagutzki O, Nauert A, Osipov T, Staudte A, Prior MH, Schmidt-Böcking H, Cocke CL, Dörner R. Photoelectron diffraction mapping: molecules illuminated from within. Phys Rev Lett 2001; 87:013002. [PMID: 11461463 DOI: 10.1103/physrevlett.87.013002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2001] [Indexed: 05/23/2023]
Abstract
We demonstrate the use of a multiparticle coincidence technique to image the diffraction of an electron wave whose source is placed at a specific site in a free molecule. Core-level photoelectrons are used to illuminate the molecule from within. By measuring the vector momenta of two molecular fragments and the photoelectron, a richly structured electron diffraction pattern is obtained in a body-fixed frame of the randomly oriented molecule in the gas phase. We illustrate this technique for CO, creating a photoelectron from the C(1s) shell and scanning its energy from zero to 30 eV.
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Affiliation(s)
- A Landers
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA.
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Abstract
We have studied the fragmentation of water vapour molecules induced by collision with a Xe44+ beam at 6.7 MeV/u. From the measurement of the fragment time of flight, we show that the amount of fragmentation due to multiple ionization is very large. In the case of single ionization, we are able to reproduce accurately the experimental cross sections by calculating for each molecular level the single-ionization cross section in the framework of the CDW-EIS theory and with a diagram of dissociation modified with respect to the diagram obtained in the case of dipolar ionization. By using qualitative arguments based on the ability of the medium to neutralize a charged species, we tentatively extend our result to liquid water. From our analysis, we show that ionizations involving three or more ejected electrons could enhance the oxygen production. For the physicochemical phase we estimate that the rate of oxygen production by multiple ionization represents approximately 18% of the OH rate produced by single ionization.
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Cassimi A, Duponchel S, Flechard X, Jardin P, Sortais P, Hennecart D, Olson RE. State-selective electron capture in low velocity multiply charged ion, helium collisions. Phys Rev Lett 1996; 76:3679-3682. [PMID: 10061082 DOI: 10.1103/physrevlett.76.3679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Rothard H, Caraby C, Cassimi A, Gervais B, Grandin JP, Jardin P, Jung M, Billebaud A, Chevallier M, Groeneveld KO, Maier R. Target-thickness-dependent electron emission from carbon foils bombarded with swift highly charged heavy ions. Phys Rev A 1995; 51:3066-3078. [PMID: 9911943 DOI: 10.1103/physreva.51.3066] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Gosselin A, Boduch P, Hennecart D, Hicham S, Husson X, Lecler D, Lepoutre A, Cassimi A, Grandin JP. Test of a recoil ion source at GANIL medium energy facility. ACTA ACUST UNITED AC 1994. [DOI: 10.1051/jp3:1994239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Jardin P, Grandin JP, Cassimi A, Lemoigne JP, Gosselin A, Husson X, Hennecart D, Lepoutre A. Recoil ion kinetics. ACTA ACUST UNITED AC 1993. [DOI: 10.1063/1.43758] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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25
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Gibbons JP, Elston SB, Kimura K, DeSerio R, Sellin IA, Burgdörfer J, Grandin JP, Cassimi A, Husson X, Liljeby L, Druetta M. Observation of rapid evolution of convoy electron angular distributions. Phys Rev Lett 1991; 67:481-484. [PMID: 10044905 DOI: 10.1103/physrevlett.67.481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Cassimi A, Grandin JP, Suraud MG. Charge state distributions of 44 MeV/amu129Xe44+ and 29 MeV/amu208Pb56+ after various solid targets. ACTA ACUST UNITED AC 1991. [DOI: 10.1007/bf01426343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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