PARTICLE-GAMMA-RAY ANGULAR-CORRELATION STUDY OF NI-57 IN REACTION NI-58(HE-3, ALPHAGAMMA)NI-57

The levels of Ni57 populated in the reaction Ni58(He3,α)Ni57 have been studied using the method of particle-γ-ray angular correlations. The α particles were detected at 0 ° with respect to the incident beam by a position-sensitive detector located at the focal point of a magnetic spectrometer. Four 7.6×10.2-cm NaI (Tl) crystals were used simultaneously to detect coincident γ rays at angles between 90 ° and 160 °. Using l values known from previous work, the following spin-parity assignments are made for the levels indicated: 0.78 MeV 52-, 1.11 MeV 12-(32-), 2.59MeV 72-, 3.24MeV 72-, 3.71 MeV (32), 3.85MeV(32,52), 4.23MeV(32,52,72), 4.56 MeV(≤72), 5.22 MeV 72-, 5.56 MeV 32+, 6.00MeV 32+, Branching ratios for the decays of these levels are presented, along with mixing rations for the stronger transitions. © 1969 The American Physical Society.