On the role of stimulated processes in annihilation line radiation of cosmic sources. 2

The influence of stimulated annihilation on the steady-radiation characteristics of a double-quantum system with a given power of the positron source is considered. The coherent-radiation conditions and criteria for gamma-laser realization, i.e. population inversion, are ascertained. The graser functioning as an amplifier of incident radiation is studied. In approximation of a specified electron and positron concentration the realization of a stationary annihilation gamma-Jlaser in the system is possible only if its size is sufficiently small. Otherwise an explosive instability takes place in the system and the intensity becomes so high within the finite time that the constant concentration approximation does not hold. Inversion of populations is possible only in the system with a sufficiently small length, the last restriction coinciding with the criterion of stationary gamma-laser realization in the approximation of particle constant concentration