Double ionization of noble gases by positron impact

Journal Article · Fri Oct 01 04:00:00 EDT 1999 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.60.2940· OSTI ID:692508

Moxom, J; Xu, J; Hulett, L D ^[1]; Schrader, D M ^[2]; Laricchia, G ^[3]

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1. Division of Chemical and Analytical Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
2. Chemistry Department, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201-1881 (United States)
3. Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT (United Kingdom)

The cross sections for double ionization and the ratios of double to single ionization, including Ps formation for Ne, Ar, Kr, and Xe are presented from threshold to 100 eV. Within the energy region 6.8 eV below the second ionization potential, i.e., the second Ore gap, we find Ne to have a double-ionization cross section indistinguishable from zero, which is consistent with prior measurements. However, the total double-ionization cross sections for Ar, Kr, and Xe just below the thresholds for direct double ionization are around 7{endash}24&hthinsp;{percent} of the maximum cross-section value for each atom, all of which are of the order of 10{sup {minus}21}&hthinsp;m{sup 2} and occur around 70{endash}90 eV. In contrast to what has previously been found for He and Ne, this is direct evidence of a significant amount of transfer ionization for the three heavier noble gases in the second Ore gap, which is consistent with previous measurements for Ar and Xe. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 692508
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 4 Vol. 60; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ARGON
EV RANGE 01-10
EV RANGE 10-100
IONIZATION
KRYPTON
NEON
POSITRON-ATOM COLLISIONS
POSITRONIUM
XENON