Studies of highly excited nuclear bound levels using neutron capture gamma rays

Nuclear resonant scattering from individual levels has been observed using the discrete energy gamma rays produced by thermal neutron capture. This permits a study of the highly excited nuclear levels near the particle threshold region. It was found that only levels in nuclei in closed-shell regions have ground-state transition probabilities large enough to be detected by this method. An extension of the technique is suggested which permits variation of the gamma energy seen by the nucleus by about ±8 eV, using a rotating target.