New Data from Laser Interrogation of Electron-Atom Collisions Experiments

Abstract

Recent data from two methods in which high resolution laser radiation is used to assist in determining electron-atom collision parameters are presented. The electron superelastic method has yielded the first measurement of Stokes parameters for electron de-excitation of the 3²D_5/2–3²P_3/2,1/2 transition of atomic Na, the upper level having been optically prepared by resonant, stepwise excitation from the 3²S_1/2 ground level via the 3²P_3/2 level using two single mode lasers. As well, we report on the development of a model to determine the optical pumping parameters for superelastic scattering from the 3²P_3/2 level when it is prepared by two lasers exciting from the F = 1 and F = 2 states respectively of the 3²S_{1/ 2} ground level. Data are also presented for collision parameters for the excitation of the 6¹S_o–6¹ P_I transition of the I = 0 isotope of Hg by electrons of 50 eV incident energy. The technique employed for these measurements is the stepwise electron–laser excitation coincidence method, in which the electron excited atom is further excited by resonant laser radiation, and fluorescence photons emitted by relaxation from the laser excited state are detected in coincidence with the scattered electron.