Abstract
Differential cross-section measurements for + reactions are presented in 100-keV steps between 2.4 and 8.5 MeV at 0° and in 200-keV steps between 3.4 and 7.4 MeV at 40° (lab). Fluctuations in the cross sections are observed at all energies, but they are superimposed upon a rapid rise in cross section for beam energies below 4 MeV due to the Coulomb barrier effects. Coulomb barrier effects are accounted for by calculating the average differential cross section from the Hauser-Feshbach formula in which the transmission coefficients are determined from an optical-model potential. The ratios of the observed-to-calculated cross sections fluctuate about an almost constant value. These ratios are analyzed in terms of the Ericson fluctuation theory from which the coherence width is estimated to be keV (c.m.). The average cross-section ratio for the reaction indicates a 30% violation of isobaric-spin conservation in the 3.4- to 6.0-MeV interval.
- Received 27 October 1966
DOI:https://doi.org/10.1103/PhysRev.158.977
©1967 American Physical Society