Abstract
The () reactions on targets of , , , and were studied using -particle beams of 40.1, 46.0, 45.4, and 44.5 MeV, respectively. Angular distributions were obtained. States where the captured protonneutron pair is in the configuration coupled to an unperturbed target core are located and possible spin assignments are suggested. These states are , 13.03 MeV (), 11.95 MeV (); , 5.75 MeV (5+); , 7.74 MeV (), 9.14 MeV (); , 1.528 MeV (5+). Separated isotopes , , , and were used as targets to study the () reaction with a 50-MeV -particle beam. States with a probable configuration of were located. These states are , 9.47 MeV; , 8.92 MeV; , 6.79 MeV; , 5.99 MeV; , 4.75 MeV; , 4.57 MeV; , 2.99 MeV; , 2.88 MeV; , 2.88 MeV. The residual-interaction energies between the proton and neutron in the configurations , , and were derived from the excitation energies determined in the present work and previous work on and states. For nuclides, an "interactionmodel" method was proposed to extract the residual-interaction energy. The mean values of the residualinteraction energies are about -3.9, -3.0, and -2.2 MeV, respectively, for the three mentioned configurations. There is a slight decrease of residual-interaction energy with increasing . These results are reproduced satisfactorily by conventional shell-model calculations. Both the interaction-model method and Talmi's shell-model calculation method were used to calculate the excitation energies of states with the configuration. In general, the former method gives better agreement with the experimental results.
- Received 19 May 1969
DOI:https://doi.org/10.1103/PhysRev.186.1086
©1969 American Physical Society