Accession Number : AD0716684

Title :   Electron Density and Temperature Decay in Mercury Afterglows,

Corporate Author : TRENT UNIV PETERBOROUGH (ONTARIO) DEPT OF PHYSICS

Personal Author(s) : Surgawara,M. ; Gregory,B. C.

Report Date : 02 MAR 1970

Pagination or Media Count : 10

Abstract : Average electron number density and electron-temperature measurements are presented for the mercury vapor afterglow in a hot-cathode cylindrical discharge tube at a pressure range where ambipolar diffusion predominates. The average electron number density is measured using cylindrical microwave cavities in the TM010 and dipole resonance modes. The electron temperature is measured by means of a time-resolving 3.0-GHz radiometer. Three pressure regions are identified. The initially rapid electron-temperature decay occurring during the first 0.5 msec of the afterglow is pressure independent and is well explained by electron-ion elastic collisions. The slow electron temperature decay after 0.5 msec which occurs in the second pressure region is pressure dependent and is explained by a balance between energy gain from collisions of the second kind in the reaction e + triplet P(2) to triplet P(1) +e and losses due to electron-ion elastic collisions. A complete discussion of these processes is given and the neglect of other mechanisms justified. (Author)

Descriptors :   (*MERCURY, *AFTERGLOWS), IONS, PLASMA MEDIUM, ELECTRON DENSITY, TEMPERATURE, CANADA

Subject Categories : Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE