Properties of Cd-112 from the (n,n 'gamma) reaction: Levels and level densities - art. no. 024316

Levels in Cd-112 have been studied through the (n,n'gamma) reaction with mo noenergetic neutrons. An extended set of experiments that included excitati on functions. gamma -ray angular distributions, and gamma gamma coincidence measurements was performed. A total of 375 gamma rays were placed in a lev el scheme comprising 200 levels (of which 238 gamma -ray assignments and 58 levels are newly established) up to 4 MeV in excitation. No evidence to su pport the existence of 47 levels as suggested in previous studies was found , and these have been removed from the level scheme. From the results, a co mparison of the level density is made with the constant temperature and bac k-shifted Fermi gas models. The back-shifted Fermi gas model with the Gilbe rt-Cameron spin cutoff parameter provided the best overall fit. Without usi ng the neutron resonance information and only fitting the cumulative number of low-lying levels, the level density parameters extracted are a sensitiv e function of the maximum energy used in the fit.