The neutron energy-dependent angular distribution of γ rays from the Sn117(n,γ) reaction was measured with germanium detectors and a pulsed neutron beam. The angular distribution was clearly observed in γ-ray emissions with an energy of 9327 keV which corresponds to the transition from a neutron resonance of Sn117+n to the ground state of Sn118. The angular distribution causes an angular-dependent asymmetric resonance shape. An asymmetry ALH was defined as (NL-NH)/(NL+NH), where NL and NH are integrated values for lower- and higher-energy regions of a neutron resonance, respectively. We found that the ALH has the angular dependence of (Acosθγ+B), where θγ is the γ-ray emission angle with respect to the incident neutron momentum, with A=0.394±0.073 and B=0.118±0.029 in the 1.33 eV p-wave resonance.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics