X-Ray Emission Following Nuclear Reactions

We have recorded and analyzed spectra of x rays following proton and $\alpha$-particle bombardment of heavy atoms. The normal $K$ x rays are accompanied by satellite peaks originating from nuclear reactions. The phenomenon is very intense in $\alpha$-induced reactions and it is correlated with $\alpha ,xn$ cross sections; in the case of proton bombardment the intensity of the phenomenon is surprisingly weak. It is presumed that the ionization is due to internal conversion of residual $\gamma$ rays.