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Probing Atomic ‘Quantum Grating’ by Collisions with Charged Particles. ATOMS 2022. [DOI: 10.3390/atoms10040125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The wave function of an atom, which passed through a diffraction grating, is characterized by a regular space structure. Correspondingly, the interaction of another particle with this atom can be viewed as scattering on an ‘atomic quantum grating’ made of just a single atom. Probing this ‘grating’ by collisions with a charged projectile reveals few-body interference phenomena caused by the coherent contributions of its ‘slits’ to the transition amplitude (the superposition principle) and quantum entanglement of the particles involved. In particular, the spectra of electrons emitted from the atom in collisions with swift ions exhibit a pronounced interference pattern whose shape can be extremely sensitive to the collision velocity.
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2
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A Wi-Fi FTM-Based Indoor Positioning Method with LOS/NLOS Identification. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10030956] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In recent years, many new technologies have been used in indoor positioning. In 2016, IEEE 802.11-2016 created a Wi-Fi fine timing measurement (FTM) protocol, making Wi-Fi ranging more robust and accurate, and providing meter-level positioning accuracy. However, the accuracy of positioning methods based on the new ranging technology is influenced by non-line-of-sight (NLOS) errors. To enhance the accuracy, a positioning method with LOS (line-of-sight)/NLOS identification is proposed in this paper. A Gaussian model has been established to identify NLOS signals. After identifying and discarding NLOS signals, the least square (LS) algorithm is used to calculate the location. The results of the numerical experiments indicate that our algorithm can identify and discard NLOS signals with a precision of 83.01% and a recall of 74.97%. Moreover, compared with the traditional algorithms, by all ranging results, the proposed method features more accurate and stable results for indoor positioning.
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Lamichhane BR, Arthanayaka T, Remolina J, Hasan A, Ciappina MF, Navarrete F, Barrachina RO, Lomsadze RA, Schulz M. Fully Differential Study of Capture with Vibrational Dissociation in p+H_{2} Collisions. PHYSICAL REVIEW LETTERS 2017; 119:083402. [PMID: 28952760 DOI: 10.1103/physrevlett.119.083402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Indexed: 06/07/2023]
Abstract
We have measured fully differential cross sections for electron capture in 75 keV p+H_{2} collisions with subsequent dissociation of the intermediate molecular H_{2}^{+} ion by vibrational excitation using different projectile coherence lengths. Data were obtained for two molecular orientations as a function of projectile scattering angle. Two types of interference, single- and molecular two-center interference, were identified. The two-center interference structure is phase shifted by π compared to what we expected. Furthermore, the presence of projectile coherence effects could be reconfirmed.
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Affiliation(s)
- B R Lamichhane
- Department of Physics and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - T Arthanayaka
- Department of Physics and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - J Remolina
- Department of Physics and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - A Hasan
- Department of Physics and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
- Department of Physics, UAE University, P.O. Box 15551, Al Ain, Abu Dhabi, United Arab Emirates
| | - M F Ciappina
- Institute of Physics of the ASCR, ELI-Beamlines, Na Slovance 2, 182 21 Prague, Czech Republic
| | - F Navarrete
- Centro Atómico Bariloche and Instituto Balseiro (Comisión Nacional de Energía Atómica and Universidad. Nacional. de Cuyo), Bariloche, 8400 Río Negro, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 2290 Caba, Argentina
| | - R O Barrachina
- Centro Atómico Bariloche and Instituto Balseiro (Comisión Nacional de Energía Atómica and Universidad. Nacional. de Cuyo), Bariloche, 8400 Río Negro, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 2290 Caba, Argentina
| | - R A Lomsadze
- Department of Physics and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
- Tbilisi State University, Tbilisi 0179, Georgia
| | - M Schulz
- Department of Physics and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
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4
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Imaging molecular geometry with electron momentum spectroscopy. Sci Rep 2016; 6:39351. [PMID: 28004794 PMCID: PMC5177885 DOI: 10.1038/srep39351] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 11/22/2016] [Indexed: 11/10/2022] Open
Abstract
Electron momentum spectroscopy is a unique tool for imaging orbital-specific electron density of molecule in momentum space. However, the molecular geometry information is usually veiled due to the single-centered character of momentum space wavefunction of molecular orbital (MO). Here we demonstrate the retrieval of interatomic distances from the multicenter interference effect revealed in the ratios of electron momentum profiles between two MOs with symmetric and anti-symmetric characters. A very sensitive dependence of the oscillation period on interatomic distance is observed, which is used to determine F-F distance in CF4 and O-O distance in CO2 with sub-Ångström precision. Thus, using one spectrometer, and in one measurement, the electron density distributions of MOs and the molecular geometry information can be obtained simultaneously. Our approach provides a new robust tool for imaging molecules with high precision and has potential to apply to ultrafast imaging of molecular dynamics if combined with ultrashort electron pulses in the future.
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von Hahn R, Becker A, Berg F, Blaum K, Breitenfeldt C, Fadil H, Fellenberger F, Froese M, George S, Göck J, Grieser M, Grussie F, Guerin EA, Heber O, Herwig P, Karthein J, Krantz C, Kreckel H, Lange M, Laux F, Lohmann S, Menk S, Meyer C, Mishra PM, Novotný O, O'Connor AP, Orlov DA, Rappaport ML, Repnow R, Saurabh S, Schippers S, Schröter CD, Schwalm D, Schweikhard L, Sieber T, Shornikov A, Spruck K, Sunil Kumar S, Ullrich J, Urbain X, Vogel S, Wilhelm P, Wolf A, Zajfman D. The cryogenic storage ring CSR. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:063115. [PMID: 27370434 DOI: 10.1063/1.4953888] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm(-3) is derived, equivalent to a room-temperature pressure below 10(-14) mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.
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Affiliation(s)
- R von Hahn
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - A Becker
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - F Berg
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - K Blaum
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - C Breitenfeldt
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - H Fadil
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - F Fellenberger
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - M Froese
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - S George
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - J Göck
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - M Grieser
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - F Grussie
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - E A Guerin
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - O Heber
- Weizmann Institute of Science, Rehovot 76100, Israel
| | - P Herwig
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - J Karthein
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - C Krantz
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - H Kreckel
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - M Lange
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - F Laux
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - S Lohmann
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - S Menk
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - C Meyer
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - P M Mishra
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - O Novotný
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - A P O'Connor
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - D A Orlov
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - M L Rappaport
- Weizmann Institute of Science, Rehovot 76100, Israel
| | - R Repnow
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - S Saurabh
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - S Schippers
- I. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392 Gießen, Germany
| | - C D Schröter
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - D Schwalm
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - L Schweikhard
- Institut für Physik, Ernst-Moritz-Arndt-Universität, 17487 Greifswald, Germany
| | - T Sieber
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - A Shornikov
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - K Spruck
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - S Sunil Kumar
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - J Ullrich
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - X Urbain
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - S Vogel
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - P Wilhelm
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - A Wolf
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - D Zajfman
- Weizmann Institute of Science, Rehovot 76100, Israel
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Zhang SF, Fischer D, Schulz M, Voitkiv AB, Senftleben A, Dorn A, Ullrich J, Ma X, Moshammer R. Two-center interferences in dielectronic transitions in H2(+) + He collisions. PHYSICAL REVIEW LETTERS 2014; 112:023201. [PMID: 24484006 DOI: 10.1103/physrevlett.112.023201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Indexed: 06/03/2023]
Abstract
Molecular two-center interferences in a collision induced excitation of H2(+) projectile ions, with simultaneous ionization of helium target atoms, are investigated in a kinematically complete experiment. In the process under investigation, the helium atom is singly ionized and simultaneously the molecular hydrogen ion is dissociated. Different collision mechanisms are identified and interference fringes emerging from a correlated first-order mechanism and from an independent second-order process are observed.
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Affiliation(s)
- S F Zhang
- Institute of Modern Physics, Chinese Academy of Sciences, 730000 Lanzhou, China and Max-Planck-Institute for Nuclear Physics, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - D Fischer
- Max-Planck-Institute for Nuclear Physics, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - M Schulz
- Max-Planck-Institute for Nuclear Physics, Saupfercheckweg 1, D-69117 Heidelberg, Germany and Physics Department and LAMOR, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
| | - A B Voitkiv
- Max-Planck-Institute for Nuclear Physics, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - A Senftleben
- Max-Planck-Institute for Nuclear Physics, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - A Dorn
- Max-Planck-Institute for Nuclear Physics, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - J Ullrich
- Max-Planck-Institute for Nuclear Physics, Saupfercheckweg 1, D-69117 Heidelberg, Germany and Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116, Braunschweig, Germany
| | - X Ma
- Institute of Modern Physics, Chinese Academy of Sciences, 730000 Lanzhou, China
| | - R Moshammer
- Max-Planck-Institute for Nuclear Physics, Saupfercheckweg 1, D-69117 Heidelberg, Germany
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7
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Schneider K, Schulz M, Wang X, Kelkar A, Grieser M, Krantz C, Ullrich J, Moshammer R, Fischer D. Role of projectile coherence in close heavy ion-atom collisions. PHYSICAL REVIEW LETTERS 2013; 110:113201. [PMID: 25166529 DOI: 10.1103/physrevlett.110.113201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Indexed: 06/03/2023]
Abstract
We have measured fully differential cross sections for single ionization and transfer ionization (TI) in 16 MeV O(7+)+He collisions. The impact parameters mostly contributing to single ionization are about an order of magnitude larger than for TI. Therefore, the projectile beam was much more coherent for the latter compared to the former process. The measured data suggest that, as a result, TI is significantly affected by interference effects which are not present in single ionization.
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Affiliation(s)
- K Schneider
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany and Extreme Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, D-64291 Darmstadt, Germany
| | - M Schulz
- Physics Department and LAMOR, Missouri University of Science and Technology, Rolla, Missouri 65409, USA and Institut für Kernphysik, Universität Frankfurt, Max-von-Laue Strasse 1, D-60438 Frankfurt, Germany
| | - X Wang
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany and Shanghai EBIT Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433, China
| | - A Kelkar
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany and Extreme Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, D-64291 Darmstadt, Germany
| | - M Grieser
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - C Krantz
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - J Ullrich
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany and Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig, Germany
| | - R Moshammer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - D Fischer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
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8
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Voitkiv AB, Najjari B, Fischer D, Artemyev AN, Surzhykov A. Young-type interference in projectile-electron loss in energetic ion-molecule collisions. PHYSICAL REVIEW LETTERS 2011; 106:233202. [PMID: 21770502 DOI: 10.1103/physrevlett.106.233202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Indexed: 05/31/2023]
Abstract
Under certain conditions an electron bound in a fast projectile ion, colliding with a molecule, interacts mainly with the nuclei and inner shell electrons of atoms forming the molecule. Because of their compact localization in space and distinct separation from each other, these molecular centers play in such collisions a role similar to that of optical slits in light scattering leading to pronounced interference in the spectra of the electron emitted from the projectile.
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Affiliation(s)
- A B Voitkiv
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
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9
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Thomas RD, Schmidt HT, Andler G, Björkhage M, Blom M, Brännholm L, Bäckström E, Danared H, Das S, Haag N, Halldén P, Hellberg F, Holm AIS, Johansson HAB, Källberg A, Källersjö G, Larsson M, Leontein S, Liljeby L, Löfgren P, Malm B, Mannervik S, Masuda M, Misra D, Orbán A, Paál A, Reinhed P, Rensfelt KG, Rosén S, Schmidt K, Seitz F, Simonsson A, Weimer J, Zettergren H, Cederquist H. The double electrostatic ion ring experiment: a unique cryogenic electrostatic storage ring for merged ion-beams studies. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:065112. [PMID: 21721735 DOI: 10.1063/1.3602928] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate "rings" and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.
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Affiliation(s)
- R D Thomas
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden.
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10
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Misra D, Schmidt HT, Gudmundsson M, Fischer D, Haag N, Johansson HAB, Källberg A, Najjari B, Reinhed P, Schuch R, Schöffler M, Simonsson A, Voitkiv AB, Cederquist H. Two-center double-capture interference in fast He2+ + H2 collisions. PHYSICAL REVIEW LETTERS 2009; 102:153201. [PMID: 19518629 DOI: 10.1103/physrevlett.102.153201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Indexed: 05/27/2023]
Abstract
We report the first observation of Young-type interference effects in a two-electron transfer process. These effects change strongly as the projectile velocity changes in fast (1.2 and 2.0 MeV) He(2+) + H(2) collisions as manifested in strong variations of the double-electron capture rates with the H(2) orientation. This is consistent with fully quantum mechanical calculations, which ignore sequential electron transfer, and a simple projectile de Broglie wave picture assuming that two-electron transfer probabilities are higher in collisions where the projectile passes close to either one of the H(2) nuclei.
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Affiliation(s)
- Deepankar Misra
- Department of Physics, Stockholm University, AlbaNova University Center, SE-106 91 Stockholm, Sweden
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