Abstract
Neutron-capture rays from the Texas A&M research reactor have been used to excite one nuclear energy level each in , Cd, Sn, Hg, , and , and two in , in the 5-9-MeV region. Angular-distribution measurements of the scattered rays showed that the transitions were all consistent with dipole radiation. However, for various reasons, the data could also be reproduced in most cases by assuming a mixture of dipole and quadrupole radiation. Three further measurements were made for the , the , the , and one excitation: (1) an absolute differential cross-section measurement on the resonance scattering, (2) a resonance absorption measurement, and (3) a differential cross-section measurement at liquid-nitrogen temperature. From these data, values were found for (the excited level width for an electromagnetic transition to the ground state), (the excited level total electromagnetic width), and (the energy displacement between the neutron-capture -ray energy and the resonance energy). The values of (between 0.14 and 1.0 eV) were found to be about 10 times larger than the values usually found for -ray widths in this energy region as determined from neutron-capture reactions.
- Received 15 April 1968
DOI:https://doi.org/10.1103/PhysRev.179.1153
©1969 American Physical Society