Multipole expansion of the atomic radiation relaxation operator

A closed-form expression is derived in this work for the atomic relaxation operator containing all yield effects with the radiation of spontaneous photons. It is shown that these effects lead to the following: 1) interference in the probabilities of transitions having different multipole order and identical parity, 2) polarization of atomic states with even multipole orders, and 3) anisotropic diffusion of atoms in momentum space.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 30–40, October, 1987.