Decay of metastable xenon atoms Xe*(3P2) in a xenon afterglow

Using the light absorption technique, the decay constant for the density of metastable xenon atoms Xe*( 3 P 2 ) has been measured in a pure xenon afterglow at pressures between 4*10 -2 and 8 Torr. At a gas temperature at 300K the diffusion coefficients D 0 for the Xe*( 3 P 2 ) metastable atoms in the parent gas has been found to be 19+or-2 cm 2 Torr s -1 , the relaxation cross section sigma of the Xe*( 3 P 2 ) atoms in a two-body collision with a xenon atom has been determined to be (7.4+or-1)*10 -20 cm 2 and the coefficient of a three-body collision of the Xe*( 3 P 2 ) atoms with two xenon atoms A 2 was found to be (7.6+or-1)*10 -32 cm 6 atom -2 s -1 . At pressures above 4 Torr the authors have observed a repopulation of the metastable level resulting from the electron-Xe 2 * molecular ion recombination.