Statistical Properties of Excited Nuclei in the Mass Range 47≤A≤59

Abstract

Level densities and their energy dependences for nuclei in the mass range 47≤A≤59 have been determined from the measurements of neutron evaporation spectra in (p,n) reaction. Neutron spectra from (p,n) reaction on nuclei of 47Ti, 48Ti, 49Ti, 53Cr, 54Cr, 57Fe, 59Co have been measured at proton energies between 7 and 11 MeV. The measurements of neutron spectra were performed by time-of-flight fast neutron spectrometer on the pulsed tandem accelerator EGP-15 of IPPE. The high resolution and stability of time-of-flight spectrometer allowed identify reliably the discrete low-lying levels together with continuum part of neutron spectra. Analyses of the measured data have been carried out in the framework of statistical equilibrium and pre-equilibrium models of nuclear reactions. The calculations are done with use of the exact formalism of the statistical theory as given by Hauser-Feshbach with the generalized superfluid model of nucleus, the back-shifted Fermi-gas model and the composite formula of Gilbert-Cameron for nuclear level density. The nuclear level densities of 47V, 48V, 49V, 53Mn, 54Mn, 57Co, 59Ni and their energy dependences have been determined. The obtained results have been discussed in totality with existing experimental and model systematic data.