Collisional quenching of Ga(5p) atoms by H-2, D-2 and CH4

Abstract

Collisional quenching of Ga(5p) atoms by H-2, D-2 and CH4 has been studied. The gallium atoms were generated by photolysis of trimethyl gallium using a KrF laser. The Ga(5p) state was populated by two-photon excitation from the ground state and cascade fluorescence from Ga(5s) atoms was analyzed to extract quenching rate constants for Ga(5p) atoms. The apparent quenching rate constants for Ga(5p) atoms are (4.6 +/- 0.3)X 10(-10), (3.4 +/- 0.3)X 10(-10) and (7.8 +/- 0.2)X 10(-11) cm(3) molecule(-1) s(-1) by H-2,D-2 and CH4, respectively. It is found that the predominant process for the large quenching rate constants for Ga(5p) atoms by H-2 and D-2 is the energy transfer for Ga(5s) formation.