Deexcitation cross sections of Ar(3P2, 3P1, 3P, and 1P1) by CH4, SiH4, and GeH4

Abstract

Deexcitation cross sections of Ar(3P2), Ar(3P1), Ar(3P0), and Ar(1P1) by CH4, SiH4, and GeH4 have been measured. The cross section values obtained are largely dependent on both the electronic states of excited argon atoms and the target molecules. The magnitude of these values is discussed in terms of energy transfer mechanisms or interactions responsible for the deexcitation transition. In the deexcitation of the metastable atoms, Ar(3P2) and Ar(3P0), the magnitude of the cross sections is mainly ascribed to the adiabatic transition from the interaction potentials for Ar*–M (M=CH4, SiH4, and GeH4 ) to those for Ar–M* due to a long-range potential curve crossing, while in the deexcitation of the resonant atoms, Ar(3P1) and Ar(1P1), the magnitude is mainly ascribed to resonant energy transfer due to a long-range dipole–dipole interaction.