| 1. |
- Misra, Deepankar, et al.
(författare)
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Second-order interference in collisions of 4-MeV/u F9+ ions with H-2
- 2009
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 80:6, s. 62701-
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Tidskriftsartikel (refereegranskat)abstract
- Frequency doubling in interference oscillations in fast-ion-induced electron emission spectrum from H-2 is investigated. Experimentally observed oscillatory structure is well explained by a model calculation based on the rescattering of emitted electron from the second H center. The second-order contribution is found to be as large as 10%. The doubling of oscillation frequency is found out to be independent of angle of observation. Derived analytical expression for the double differential cross section ratio including the first- and second-order interference terms, fits the observed oscillatory structure quite well. The present analysis is in broad agreement with the earlier observations by Stolterfoht et al.
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| 2. |
- Misra, Deepankar, et al.
(författare)
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Two-Center Double-Capture Interference in Fast He2++H2 Collisions
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:15, s. 153201-
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Reinhed, Peter, et al.
(författare)
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Precision lifetime measurements of He- in a cryogenic electrostatic ion-beam trap
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:21, s. 213002-
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Tidskriftsartikel (refereegranskat)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 black-body radiation. We report the first correction free measurements of the lifetimes of the 1s2s2p 4PoJ state of 4He- and the high precision result 359.0±0.7 μs for the J=5/2 level. The lifetimes for the J=3/2 and J=1/2 levels are determined to be 12.3±0.5 and 7.8±1.0 μs, respectively.
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