Magnetic field dependence of cross sections for collisional disorientation of 6 2P1/2 cesium atoms

The magnetic field dependence of the cross sections for the disorientation of 6 2P1/2 cesium atoms, induced in Cs-He collisions, has been studied using Zeeman scanning techniques. A Cs-He mixture, contained in a fluorescence cell which was located in a magnetic field variable from 0 to 10 kG, was irradiated with the circularly polarized 8943-A component of cesium resonance radiation in a direction parallel to the field, and the polarization of the resonance fluorescence was monitored in the backward direction in relation to the helium pressure and to the magnetic field strength. The cross sections, which are in good agreement with the results obtained previously at high and low magnetic fields, exhibit a variation with the magnetic field, which is in accordance with theoretical predictions