Induced Emission of Gamma Radiation from Isomeric Nuclei

We study the possibility to influence the lifetime of nuclear isomeric states with the aid of incident fluxes of photons. We assume that a nucleus initially in an isomeric state |i> first absorbs an incident photon of energy E_{ni} to reach a higher intermediate state |n>, then the state |n> decays to a lower state |l>. In favorable cases the two-step induced emission rates become equal to the natural isomeric decay rates for incident power densities of the order of 10^{10} W cm^{-2}.