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Johansson HAB, Zettergren H, Holm AIS, Haag N, Nielsen SB, Wyer JA, Kirketerp MBS, Støchkel K, Hvelplund P, Schmidt HT, Cederquist H. Unimolecular dissociation of anthracene and acridine cations: The importance of isomerization barriers for the C2H2 loss and HCN loss channels. J Chem Phys 2011; 135:084304. [DOI: 10.1063/1.3626792] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Seitz F, Holm AIS, Zettergren H, Johansson HAB, Rosén S, Schmidt HT, Ławicki A, Rangama J, Rousseau P, Capron M, Maisonny R, Domaracka A, Adoui L, Méry A, Manil B, Huber BA, Cederquist H. Polycyclic aromatic hydrocarbon-isomer fragmentation pathways: Case study for pyrene and fluoranthene molecules and clusters. J Chem Phys 2011; 135:064302. [DOI: 10.1063/1.3622589] [Citation(s) in RCA: 20] [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: 11/14/2022] Open
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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. Rev Sci Instrum 2011; 82:065112. [PMID: 21721735 DOI: 10.1063/1.3602928] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Holm AIS, Johansson HAB, Cederquist H, Zettergren H. Dissociation and multiple ionization energies for five polycyclic aromatic hydrocarbon molecules. J Chem Phys 2011; 134:044301. [DOI: 10.1063/1.3541252] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Haag N, Holm AIS, Johansson HAB, Zettergren H, Schmidt HT, Nielsen SB, Hvelplund P, Cederquist H. Electron capture induced dissociation of doubly protonated pentapeptides: Dependence on molecular structure and charge separation. J Chem Phys 2011; 134:035102. [DOI: 10.1063/1.3533952] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Holm AIS, Zettergren H, Johansson HAB, Seitz F, Rosén S, Schmidt HT, Lawicki A, Rangama J, Rousseau P, Capron M, Maisonny R, Adoui L, Méry A, Manil B, Huber BA, Cederquist H. Ions colliding with cold polycyclic aromatic hydrocarbon clusters. Phys Rev Lett 2010; 105:213401. [PMID: 21231303 DOI: 10.1103/physrevlett.105.213401] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Indexed: 05/26/2023]
Abstract
We report the first experimental study of ions interacting with clusters of polycyclic aromatic hydrocarbon (PAH) molecules. Collisions between 11.25 keV 3He+ or 360 keV 129Xe20+ and weakly bound clusters of one of the smallest PAH molecules, anthracene, show that C14H10 clusters have much higher tendencies to fragment in ion collisions than other weakly bound clusters. The ionization is dominated by peripheral collisions in which the clusters, very surprisingly, are more strongly heated by Xe20+ collisions than by He+ collisions. The appearance size is k=15 for [C ₁₄H₁₀](k)2+.
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Affiliation(s)
- A I S Holm
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden
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Zettergren H, Johansson HAB, Schmidt HT, Jensen J, Hvelplund P, Tomita S, Wang Y, Martín F, Alcamí M, Manil B, Maunoury L, Huber BA, Cederquist H. Magic and hot giant fullerenes formed inside ion irradiated weakly bound C60 clusters. J Chem Phys 2010; 133:104301. [DOI: 10.1063/1.3479584] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Reinhed P, Orbán A, Werner J, Rosén S, Thomas RD, Kashperka I, Johansson HAB, Misra D, Brännholm L, Björkhage M, Cederquist H, Schmidt HT. Precision lifetime measurements of He(-) in a cryogenic electrostatic ion-beam trap. Phys Rev Lett 2009; 103:213002. [PMID: 20366032 DOI: 10.1103/physrevlett.103.213002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Indexed: 05/29/2023]
Abstract
We have developed a small purely electrostatic ion-beam trap which may be operated in thermal equilibrium at precisely controlled temperatures down to 10 K. Thus, we avoid magnetic field induced mixing of quantum states and may effectively eliminate any influence from absorption of photons from blackbody radiation. We report the first correction-free measurement of the lifetime of the 1s2s2p {4}P{5/2}{0} level of 4He(-) yielding the high-precision result 359.0 +/- 0.7 micros. This result is an essential proof-of-principle for cryogenic electrostatic storage rings and traps for atomic and molecular physics.
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Affiliation(s)
- P Reinhed
- Department of Physics, Stockholm University, AlbaNova University Center, 10691 Stockholm, Sweden
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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. Phys Rev Lett 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Schmidt HT, Fischer D, Berenyi Z, Cocke CL, Gudmundsson M, Haag N, Johansson HAB, Källberg A, Levin SB, Reinhed P, Sassenberg U, Schuch R, Simonsson A, Støchkel K, Cederquist H. Evidence of wave-particle duality for single fast hydrogen atoms. Phys Rev Lett 2008; 101:083201. [PMID: 18764612 DOI: 10.1103/physrevlett.101.083201] [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] [Received: 01/17/2008] [Indexed: 05/26/2023]
Abstract
We report the direct observation of interference effects in a Young's double-slit experiment where the interfering waves are two spatially separated components of the de Broglie wave of single 1.3 MeV hydrogen atoms formed close to either target nucleus in H++H2 electron-transfer collisions. Quantum interference strongly influences the results even though the hydrogen atoms have a de Broglie wavelength, lambda_{dB}, as small as 25 fm.
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Affiliation(s)
- H T Schmidt
- Department of Physics, Stockholm University, AlbaNova University Center, S-10691 Stockholm, Sweden.
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