Relaxation of electronic excitations in Kr-2(+) ions in cold krypton plasma

Abstract

Reaction rate constants have been calculated for electronic transitions in Kr+ 2 ions and for their decay as induced by collisions with krypton atoms and/or spontaneous radiation processes. The rate constants have then been used in a series of modelings of electronic relaxation in the ions in cold krypton plasmas with the main focus on relaxation times and final states. It has been shown that the collision-induced (non-radiative) relaxation is much faster than the radiative one and completely dominates with typical relaxation times ranging between nanoseconds and microseconds. The relaxation always ends up in the Kr+ 2 electronic ground state, high electronic excitations survive for longer times than lower excitations due to spin-orbit coupling effects.