Photoionization and Compton double ionization of helium from threshold to 20 keV

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.76.1220· OSTI ID:284524

Levin, J C; Armen, G B; Sellin, I A ^[1]

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1. Department of Physics, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States)

We report new measurements of He{sup ++}/He{sup +} ratios in three energy ranges. Near threshold, where only photoionization contributes, we find a ratio systematically lower than previously published measurements. From 2 to 6 keV, where Compton ionization gradually supplants photoionization as the dominant ionization mechanism, theory and experiment are in substantial agreement. Far above threshold where Compton ionization dominates, theories diverge markedly. Comparison with present results indicates asymptotic values have been established for photoionization but not Compton ionization. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 284524
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 8 Vol. 76; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COMPTON EFFECT
ENERGY DEPENDENCE
HELIUM
PHOTOIONIZATION