Energetic-neutron spectrometry. Progress report, 1 April 1974--31 May 1975

During the past year, the capability of the neutron spectrometer was extended to measure two-parameters and it was used to measure omni-directional neutron spectra in the energy region from about 5 to 150 MeV. Several electronic modules, not commercially available, were designed and constructed to meet the specific requirements for the two-parameter version. The response of the new scintillator, NE-228A, to protons was calibrated at the Ohio University Accelerator Laboratory. The two-parameter spectrometer was tested and calibrated at different stages of the spectrometer development by measuring neutron spectra at 00 from 83.7 MeV deuteron and 100.2 MeV proton bombardment of thick beryllium targets at the University of Maryland cyclotron. A most beneficial fallout revealed by these tests is the ability of the two-parameter spectrometer to measure unidirectional neutrons in a more stringent background environment or at particle accelerators with a lower duty cycle than is possible with the one-parameter version. To demonstrate the feasibility of utilizing a two-parameter spectrometer to measure omnidirectional neutrons, the neutron skyshine and the skyshine source spectra from the Brookhaven Alternating Gradient Synchrotron were measured. (U.S.)