Abstract
Interactions of neutrons with silicon have been studied by measuring -ray production cross sections. For incident mean neutron energies MeV, spectra were obtained for a natural silicon sample. The rays were detected using a coaxial Ge(Li) detector of 30- active volume. Data were obtained for -ray scattering angles of 55 and 90° for all , of 35° for MeV, and of 75° for MeV. Time of flight was used with the detector to discriminate against pulses due to neutrons and background radiation. Data were also obtained at MeV, for a sample of enriched to 95% in , and for a similarly enriched sample of . These data have been studied to obtain absolute cross sections for production of rays for the incident neutron energies quoted above. The cross sections have been compared, where possible, with previously measured values; agreement was fair.
The spectra were studied for rays which could be associated with deexcitation of nuclear levels having unknown decay modes. For , rays were found having energies appropriate for decay of levels at excitation energies MeV. For , rays were found for decay of levels at excitation energies MeV. The spin of the 4.826-MeV state in is reasonably limited to 2, 3, or 4. No previously unknown transitions were found for or ; for , the evidence suggests that the 1.624-MeV level is a doublet of 3-keV separation.
- Received 13 February 1970
DOI:https://doi.org/10.1103/PhysRevC.2.990
©1970 American Physical Society
