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- Gwinner, G., et al.
(författare)
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Influence of magnetic fields on electron-ion recombination at very low energies
- 2000
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 84:21, s. 4822-4825
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Tidskriftsartikel (refereegranskat)abstract
- Radiative recombination (inverse photoionization) is believed to be well understood since the beginning of quantum mechanics. Still, modern experiments consistently reveal excess recombination rates at very low electron-ion center-of-mass energies. In a detailed study on recombination of F and C ions with magnetically guided electrons we explored the yet unexplained rate enhancement, its dependence on the magnetic field B, the electron density n(e), and the beam temperatures T-perpendicular to and T-parallel to. The excess scales as T-perpendicular to(-1/2) and, surprisingly, as T-parallel to(-1/2), increases strongly with B, and is insensitive to n(e). This puts strong constraints on explanations of the enhancement.
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2. |
- Hoffknecht, A, et al.
(författare)
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Recombination of F6+ with free electrons at very low energies
- 1999
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Ingår i: Physica Scripta. Topical Issues. ; T80B, s. 298-300
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Tidskriftsartikel (refereegranskat)abstract
- Radiative and dielectronic recombination of F6+ have been studied at the heavy ion storage ring TSR in Heidelberg. For a detailed investigation of rate enhancement effects at very low electron-ion center-of-mass energies experimental parameters such as the magnetic guiding field, the electron density and the adiabatic expansion factor of the electron beam have been varied systematically. Whereas measurements at different electron densities show no influence on the enhancement and while a variation of the expansion factor evokes the predicted behaviour, we see an increase of the enhancement with increasing axial magnetic field between 20 mT and 70 mT.
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3. |
- Tokman, M, et al.
(författare)
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Dielectronic recombination resonances in F6
- 2002
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Ingår i: Physical Review A - Atomic, Molecular, and Optical Physics. - 1050-2947. ; 66:1, s. 012703/1-012703/13
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Tidskriftsartikel (refereegranskat)abstract
- Electron-ion recombination spectra of the Li-like ion F6+ in the energy range 0.0-0.6 eV from two different ion storage rings are presented, showing excellent agreement. The experimental results are compared with a calculated spectrum, obtained by combination of relativistic many-body methods and complex rotation, and the agreement is found to be very good. The recombination spectrum in the studied energy region is determined by the 2p6l dielectronic recombination resonances. The lowest-energy resonances are found around 10 meV, and include one broad resonance overlapping the threshold. The recombination rate coefficients are, even in this region, very well accounted for by the calculation. It is further shown that the nonrelativistically allowed resonances contribute to less than 60% of the integrated rate coefficients in the specified energy range.
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