Polarization and angular correlation measurements following the 40Ar(p, nγ) 40K reaction

Abstract

Gamma-ray angular distributions and polarization correlations have been measured using the reaction 40Ar(p, nγ) 40K. All the experiments were carried out with bombarding energies close to threshold for the states under investigation. Comparison with compound nuclear predictions has yielded the following spin assignments to states in 40K; 1.959(2 +), 2.047(2 −), 2.070(3 −), 2.103(1 −), 2.261(3 +), 2.290(1 +), 2.291(4, (3)), 2.419(2,3), 2.575(2,4) and 2.625(0 −). Multiple mixing ratios together with the gamma-ray branching ratios have been determined for all these levels. A short theoretical treatment of the polarization of gamma rays from aligned nuclei using the phase-consistent formalism of Brink and Rose is included.