The annihilation probability for the components of a primary F-H pair in thermally activated motion

Annihilation probabilities P_a have been calculated for the components of a primary F-H pair for various interaction functions E (r). It is shown that P_a is small for E (r)=0 but increases for E(r) < 0, being also a function of temperature, with a negative temperature coefficient for E(r) < 0.Translated from Izvestiya Vysskikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 41–44, October, 1977.