Gamma-ray laser operating with the assistance of the recoil of free nuclei

The concept of a γ-ray laser which makes use of the kinematic shift and the splitting of the spectral lines of radiative γ-transitions observed in an ensemble of free nuclei owing to recoil is considered. These effects form a prerequisite for the formation of hidden population inversion with no excess of the number of excited emitters over the number of unexcited ones, for implementation of a broadband unperturbing x-ray pump in an unconventional 'two-level' scheme, for the manifestation of anisotropic quantum amplification without any reflecting structures, etc. These attractive properties offer strong possibilities of staging an initial demonstration nuclear γ-ray laser experiment.