Marion L. Stelts

The (α, n) cross sections on 17O and 18O between 5 and 12.5 MeV

Abstract The excitation functions for the (α, n) reaction on 17 O and 18 O have been measured from 5 to 12 MeV using long counters. Also, the neutron differential cross sections were measured at 9.8, 11.6 and 12.2 MeV, using the Livermore neutron time-of-flight facility. Neutron spectra were obtained every 15° between 3° and 135° with gas targets of enriched 17 O and 18 O. The angular distributions are roughly symmetric about 90°. Small forward peaking is observed at the higher bombarding energies for some of the states, mainly for the ground and first excited states.

A neutron capture γ-ray spectrometer for use at an electron linac

Abstract A three-crystal, Ge(Li)NaI spectrometer has been developed to measure neutron capture γ-ray spectra at the Livermore 100 MeV electron linear accelerator. Design criteria are discussed. Circuits and techniques to optimize performance in an electron linac environment are presented. Some useful data analysis techniques for extraction of peak energies and intensities are given. A technique is discussed for using the simple response function of a three-crystal spectrometer to unfold unresolved data to find the incident gg-ray spectrum.