A trapped-electron experiment is used to study the total inelastic cross section in helium from threshold to 3 eV above threshold. By normalising to the positive ionisation cross section of Rapp and Englander-Golden (1965) the authors find the peak in the 2 3 S excitation cross section at 20.35 eV to be 6.2*10 -18 cm 2 +or-10%. The authors result is substantially larger than previous measurements but is in agreement with recent theoretical work. They discuss several systematic errors to which the trapped-electron method is subject and derive reasonable bounds for the magnitude of the errors.
No takes yet. Share an insight, caveat, or question.
Johnston et al. (1983) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: