A Re-Analysis of Secondary Gamma-Ray Spectra Produced in Liquid Nitrogen by 14 MeV Neutrons

摘要

Spectra of secondary gamma rays obtained in a 1969 integral measurement, using a 14 MeV neutron source in a large volume of liquid nitrogen, have been re-analyzed in the 4 to 10 MeV region of gamma energy. The original analysis revealed apparently Doppler-broadened gamma rays in the 5 to 9 MeV region that were not reported in the differential measurements. A re-analysis using improved unfolding techniques was undertaken to obtain more detailed information about the gamma rays. The present analysis employed the unfolding code MAZE2, a more accurate Ge(Li) response matrix and a direct unfolding of the data. The recent results reveal much additional structure in the continuum gamma spectra; the average continuum flux is higher; and the continuum drops off faster above 9 MeV gamma energy. (Author)