An analysis of the total neutron cross section of89Y between 0.3 and 9.0 MeV

Abstract

A measurement of the total neutron cross section of 89Y from 0.3 MeV to 9.0 MeV is presented. Values for the nuclear level density and average neutron total width of the levels in 90Y are deduced for excitation energies of 7.26, 7.86 and 9.61 MeV. The measurement is compared with the theoretical cross section derived from the generalised optical potential of Wilmore and Hodgson (1964) and also with an R-matrix calculation of Ramavataram et al. (1975). Fluctuations are observed in the cross section below 1.5 MeV. An analysis of the fluctuations indicates they can be explained by fluctuations in the widths and spacings of the levels in 90Y.