Studies of afterglows in noble-gas mixtures: A model for energy transfer in He/Xe+

R. Shuker, Y. Binur, A. Szöke

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

Time-resolved spectroscopy of excited mediums following electrical discharges in helium/xenon mixtures, in which xenon is the minority constituent, show enhancement in the emission of all the ionic-xenon levels relative to that observed in pure-xenon discharges. The time characteristics depend on the helium pressure and the decay follows the molecular helium emission. The total pressure ranges between 20 and 300 Torr, of which the xenon pressure is up to 1 Torr. The discharge has a peak current density of 500 A/cm2 and it flows for about 100 nsec. It is suggested that helium plays an active role in the generation of excited xenon ions by transferring excitation energy to xenon. The acceptors can be Xe+ in its ground state and neutral Xe in its metastable state. In the investigated discharges both, Xe+ and metastable Xe* exist in high densities for up to 5-10 μsec into the early afterglow. During this period, atomic helium metastables and molecular helium states such as a u+3, A u+1, and B Πg1 are also highly populated and in fact constitute an energy store. The molecular states of helium can resonantly transfer energy through the bound-free transitions to ground-state Xe+ to form excited xenon ions Xe+* with an estimated cross section of 4 × 10-14 cm2-a resonable order of magnitude considering the large enhancement observed in Xeii emission. Penning ionization and charge transfer have only little effect on observed enhancement.

Original languageEnglish
Pages (from-to)515-521
Number of pages7
JournalPhysical Review A
Volume12
Issue number2
DOIs
StatePublished - 1 Jan 1975
Externally publishedYes

Fingerprint

Dive into the research topics of 'Studies of afterglows in noble-gas mixtures: A model for energy transfer in He/Xe+'. Together they form a unique fingerprint.

Cite this