Accession Number : AD0278563

Title :   COLLISION CROSS SECTION OF SLOW ELECTRONS AND IONS WITH CESIUM ATOMS

Corporate Author : ILLINOIS UNIV URBANA COORDINATED SCIENCE LAB

Personal Author(s) : CHEN,C.L. ; RAETHER,M.

Report Date : MAY 1962

Pagination or Media Count : 1

Abstract : Microwave interferometry is adopted to measure the effective collision cross section for momentum transfer Qm- of thermal electrons (of mean energies of 0.06 to 0.071 eV) with cesium atoms in the afterglow of pure cesium and heliumcesium discharges. The momentum transfer cross section Qm- is found to be best represented by 1.61 x 10-10 Te-1 - 9.63 x 10-12 Te-1/2 + 2.03 x 10-13 cm2 in the temperature range of approximately 450 to 550 K. The energy dependence of the elastic electron-cesium-atom collision probability for momentum transfer is determined to be Pm = 997 u-1 - 4810 u-1/2 + 7230 cm-1 where u is the energy of the electrons in electron volts. This shows a smooth tendency to join Brode's data at higher electron energies. Mobilities of Cs+ ions in helium and in cesium have been determined from the helium-c siu ixture experiments in the same temperature range. They are (Cs+ in He) = 18.5 ! 0.5 cm2/volt-sec, and (Cs+ in Cs) = 0.4 ! 0.05 cm2/volt- ec referred to standard gas density (i.e., 2.69 x 1019/cm3). (Author)

Descriptors :   (*CESIUM), (*ELASTIC SCATTERING), (*ELECTRONS), INTERFEROMETERS, MICROWAVE EQUIPMENT, IONS, PROBABILITY, ATOMS, HELIUM

Distribution Statement : APPROVED FOR PUBLIC RELEASE