skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Multiple ionization of He, Ne, and Ar by fast protons and antiprotons

Abstract

Single and multiple ionization of He, Ne, and Ar has been studied experimentally by impact of fast protons and antiprotons. The single-ionization cross sections obtained with protons and antiprotons are found to be the same. The double-ionization cross sections obtained with antiprotons, however, are much larger than those obtained with protons at equal velocity. This difference is found for all three gases but the effect is largest for He and Ne, where the difference is about a factor of 2 at 1 MeV/amu. The difference is discussed in terms of interference between two collision mechanisms which both result in double-electron escape. Experimental information on the magnitude of the interference term is obtained by inclusion of double-ionization data, partly obtained in this work, for fast electron and ..cap alpha..-particle impact. For triple ionization of Ne, we also find that antiprotons yield much larger cross sections than protons do. Identical cross sections, however, are found for triple ionization of Ar with protons and antiprotons. This is believed to be due to the fact that triple ionization of Ar is mainly a consequence of a single vacancy produced in an inner shell followed by electronic rearrangement. This observation supports the interpretation that themore » observed charge effect is due to an interference effect in the outermost shell.« less

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Institute of Physics, University of Aarhus, DK-8000 Aarhus C, Denmark
OSTI Identifier:
6015549
Resource Type:
Journal Article
Journal Name:
Phys. Rev. A; (United States)
Additional Journal Information:
Journal Volume: 36:8
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ARGON; ION-ATOM COLLISIONS; HELIUM; HYDROGEN IONS 1 PLUS; NEON; ANTIPROTONS; COMPARATIVE EVALUATIONS; CROSS SECTIONS; EXPERIMENTAL DATA; IONIZATION; KEV RANGE 100-1000; MEV RANGE 01-10; MULTICHARGED IONS; ANTIBARYONS; ANTIMATTER; ANTINUCLEI; ANTINUCLEONS; ANTIPARTICLES; ATOM COLLISIONS; BARYONS; CATIONS; CHARGED PARTICLES; COLLISIONS; DATA; ELEMENTARY PARTICLES; ELEMENTS; ENERGY RANGE; FERMIONS; FLUIDS; GASES; HADRONS; HYDROGEN IONS; INFORMATION; ION COLLISIONS; IONS; KEV RANGE; MEV RANGE; NONMETALS; NUCLEI; NUCLEONS; NUMERICAL DATA; RARE GASES; 640304* - Atomic, Molecular & Chemical Physics- Collision Phenomena

Citation Formats

Andersen, L H, Hvelplund, P, Knudsen, H, Moller, S P, Sorensen, A H, Elsener, K, Rensfelt, K, and Uggerhoj, E. Multiple ionization of He, Ne, and Ar by fast protons and antiprotons. United States: N. p., 1987. Web. doi:10.1103/PhysRevA.36.3612.
Andersen, L H, Hvelplund, P, Knudsen, H, Moller, S P, Sorensen, A H, Elsener, K, Rensfelt, K, & Uggerhoj, E. Multiple ionization of He, Ne, and Ar by fast protons and antiprotons. United States. https://doi.org/10.1103/PhysRevA.36.3612
Andersen, L H, Hvelplund, P, Knudsen, H, Moller, S P, Sorensen, A H, Elsener, K, Rensfelt, K, and Uggerhoj, E. Thu . "Multiple ionization of He, Ne, and Ar by fast protons and antiprotons". United States. https://doi.org/10.1103/PhysRevA.36.3612.
@article{osti_6015549,
title = {Multiple ionization of He, Ne, and Ar by fast protons and antiprotons},
author = {Andersen, L H and Hvelplund, P and Knudsen, H and Moller, S P and Sorensen, A H and Elsener, K and Rensfelt, K and Uggerhoj, E},
abstractNote = {Single and multiple ionization of He, Ne, and Ar has been studied experimentally by impact of fast protons and antiprotons. The single-ionization cross sections obtained with protons and antiprotons are found to be the same. The double-ionization cross sections obtained with antiprotons, however, are much larger than those obtained with protons at equal velocity. This difference is found for all three gases but the effect is largest for He and Ne, where the difference is about a factor of 2 at 1 MeV/amu. The difference is discussed in terms of interference between two collision mechanisms which both result in double-electron escape. Experimental information on the magnitude of the interference term is obtained by inclusion of double-ionization data, partly obtained in this work, for fast electron and ..cap alpha..-particle impact. For triple ionization of Ne, we also find that antiprotons yield much larger cross sections than protons do. Identical cross sections, however, are found for triple ionization of Ar with protons and antiprotons. This is believed to be due to the fact that triple ionization of Ar is mainly a consequence of a single vacancy produced in an inner shell followed by electronic rearrangement. This observation supports the interpretation that the observed charge effect is due to an interference effect in the outermost shell.},
doi = {10.1103/PhysRevA.36.3612},
url = {https://www.osti.gov/biblio/6015549}, journal = {Phys. Rev. A; (United States)},
number = ,
volume = 36:8,
place = {United States},
year = {1987},
month = {10}
}