Absolute electron impact emission cross section of the He+ 22P to 12S line at 304 AA produced by simultaneous ionisation-excitation

J. L. Forand, K. Becker, J. W. McConkey

Research output: Contribution to journalArticle

Abstract

A simple and straightforward approach to an absolute emission cross section measurement of the He+ 22P to 12S line at 304 AA following the simultaneous ionisation-excitation of He by electron impact is presented. The undispersed He and He+ impact radiation in the extreme ultraviolet (XUV) region (lambda ≤600 AA) is detected by a channel electron multiplier after passing through an XUV filter. A 304 AA emission cross section of (6.2±1.7)*10-19 cm2 at 200 eV impact energy is extracted utilising the known He cross sections, the measured He/He+ ratio and the wavelength-dependent transmission of the XUV filter and quantum yield of the photon detector. In the regime of high impact energies the emission cross section is found to be inversely proportional to the incident electron energy as expected for the optically forbidden two-electron simultaneous ionisation-excitation process.

Original languageEnglish (US)
Article number020
Pages (from-to)1409-1418
Number of pages10
JournalJournal of Physics B: Atomic and Molecular Physics
Volume18
Issue number7
DOIs
StatePublished - 1985

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electron impact
ionization
cross sections
excitation
filters
photomultiplier tubes
electron energy
energy
detectors
photons
radiation
wavelengths
electrons

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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Absolute electron impact emission cross section of the He+ 22P to 12S line at 304 AA produced by simultaneous ionisation-excitation. / Forand, J. L.; Becker, K.; McConkey, J. W.

In: Journal of Physics B: Atomic and Molecular Physics, Vol. 18, No. 7, 020, 1985, p. 1409-1418.

Research output: Contribution to journalArticle

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