Neutron-Physical Characteristics of a Neutron Source for the Production of Radioactive Isotopes Based on the Interaction of Electrons with Liquid Gallium

The nuclear-physical characteristics obtained for a gallium target in a series of experiments using the time-of-flight method, the method of threshold indicators and a spectrometer based on a 3 He proportional counter on the IREN setup (JINR, Dubna) are presented. The absolute values of the energy spectra of leakage neutrons in the energy range from 10 keV to 15 MeV were measured. The activation method was used to measure the neutron flux density on the surface of a gallium target: (2.882 ± 0.098) · 10 8 sec –1 · cm –2 . The integral yield of neutrons obtained from the gallium target on the basis of these data was 1.54 · 10 14 sec –1 with average current 4 mA. The time dependence of the activation level of the gallium target was measured. It was shown as a result of the analysis that the background level is reached on the surface of the irradiated gallium target in 5 days.