Accession Number:

AD0630074

Title:

AN INVESTIGATION OF ELECTRONIC RECOMBINATION IN HELIUM AND ARGON AFTERGLOW PLASMAS BY MEANS OF LASER INTERFEROMETRIC MEASUREMENTS,

Descriptive Note:

Corporate Author:

ILLINOIS UNIV URBANA GASEOUS ELECTRONICS LAB

Report Date:

1966-02-15

Pagination or Media Count:

118.0

Abstract:

Two helium-neon laser interferometers were used to obtain the electron and neutral atom densities in an afterglow plasma. The interferometric technique utilized allows one to obtain both the spatial and temporal dependence of the electron decay. The two gases studied were helium and argon at 2 - 8 Torr and 0.3 - 0.8 Torr respectively. The electron density was in the range of 2 x 10 to the 13th power Ne 10 to the 15th powercu cm and the electron temperature in the range 1000 Te 7000 K. The electron temperature was measured by comparing the relative atomic line intensities and by inference from the recombination coefficient. The electronic recombination in helium, argon, and helium -argon mixtures was found to follow closely the predictions of Bates, Kingston, and McWhirter for collisional-radiative recombination Proc. Phys. Soc. 8343, 1964. In the range of electron temperature and density studied the recombination coefficient exhibited an approximate T to the -92 power dependence. The electron temperature inferred from the measured recombination coefficient indicates a pronounced electron temperature gradient across the tube which is believed to be due to electron heating effects in the afterglow. Author

Subject Categories:

  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE