Effect of a finite angular resolution on the measurement of polarization correlation parameters in electron heavy-noble-gas collisions

K. E. Martus, K. Becker, D. H. Madison

Research output: Contribution to journalArticle

Abstract

We present the results of a simple model calculation that highlights the effect of the finite (i.e., nonzero) angular resolution of electrostatic energy analyzers on the measurement of polarization correlation parameters in electron-photon coincidence experiments. It is demonstrated that measurements can yield drastically reduced apparent parameters in cases where the coincidence parameters vary rapidly as a function of electron scattering angle. For example, a measurement of the P1 parameter for Ar(1P) excited by 100-eV electrons which are scattered in the forward direction and detected by an analyzer with an angular resolution (full width at half maximum) of 3°will yield an apparent P1 value of 0.83 compared to the nominal value of 1.00. Since the measurement of P1 in the forward direction reveals important information about the relative contributions of direct excitation and exchange excitation, it is imperative that an experiment can distinguish a P1 value truly smaller than unity from an apparent value which is reduced merely by instrumental effects.

Original languageEnglish (US)
Pages (from-to)4876-4879
Number of pages4
JournalPhysical Review A
Volume38
Issue number9
DOIs
StatePublished - 1988

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angular resolution
rare gases
collisions
polarization
analyzers
electrons
excitation
unity
electron scattering
electrostatics
photons
approximation
energy

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Atomic and Molecular Physics, and Optics

Cite this

Effect of a finite angular resolution on the measurement of polarization correlation parameters in electron heavy-noble-gas collisions. / Martus, K. E.; Becker, K.; Madison, D. H.

In: Physical Review A, Vol. 38, No. 9, 1988, p. 4876-4879.

Research output: Contribution to journalArticle

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