Spectral neutrons yields from thick deuterium, beryllium and tantalum targets irradiated by 15.8 MeV protons and 14 MeV

The spectral density of the title neutrons from a deuterium target was measured by the shadow-bar method in an open (non-collimated) geometry. The spectral density of the neutrons from the reaction on a tantalum target was also determined in order to specify the effect of collimation of the incident beam on the shape of the neutron spectra. For a deuteron energy of 17.8 MeV, the spectrum was measured for the reaction d + Be serving as a yield standard for neutron generators based on medium energy accelerators 1 fig., 4 refs.