Radiative Lifetimes and Collisional Cross Sections for Xe i and ii

Abstract

Radiative lifetimes have been measured for 17 excited states of Xe i and 6 excited states of Xe ii. Collision cross sections have been determined for 16 of the Xe i states. A discussion is given of the contribution to the population of these states due to cascade and collisional processes. Lifetimes for 46 of the excited states of the xenon atom have been calculated and compared with the measured values, where applicable, in order to test the validity of the assumption, sometimes used in the discussion of noble-gas lasers, that the energy-level structure is adequately described in terms of j-l coupling. For completeness, the lifetimes of 24 excited states of the xenon ion have been calculated, and excellent agreement obtained between measured and calculated values. Virtually no previously measured or calculated values for these parameters are available in the literature. The experimental apparatus has been tested by measuring the lifetime of the 51S, 31P, 31D, 41D, 43S, and 33D excited states of helium and comparing them with previously measured values. Four of these lifetimes have been measured with very high precision.