A Study of the 42Ca(p,?)43Sc Reaction

Abstract

The 42Ca(p, y)43SC reaction has been studied below 2�75 MeV proton bombarding energy. Approximately 100 resonances have been identified and located in the range Ep = 2�00-2�75 MeV. Nine resonances at Ep = 1045, 1201, 1299, 1319, 2038, 2471, 2523, 2643 and 2714 keV for the 42Ca(p, y)43SC reaction were investigated with either a 54 or a 120 cm3 Ge(Li) detector. Single spectra were obtained at each of these resonances, and these were used to derive consistent y ray decay schemes and accurate level energies for the resonant and bound levels of 43Sc. Fifty-two bound levels up to an excitation energy of 4�47 MeV were observed, out of which seventeen new levels have been identified at 2�114,2� 796,2' 846,2' 860,2' 875,3 '160,3' 331,3' 374,3 '463,3;504,3' 645, 3'734,3'757,3'860,4'007,4'038 and 4�430 MeV. In addition, new results or results differing from earlier reports have been obtained for the decay properties of levels below 4�47 MeV in 43SC? The strengths of the nine resonances were measured relative to the reported strength at Ep = 2038 keV. The resonance at Ep = 2643 keV was shown for the first time to populate levels of spin> 7/2 via the proton capture reaction. A strong M1 (analogue to anti-analogue) transition from the resonance level to the level at 1� 931 MeV (9/2+) was observed. From measurements of y ray angular distributions, the following spin and parity assignments were made: 9/2+ at 7'514, 7/2+ at 4'371, >7/2 at 4'038 and 7/2 at 3�808 MeV. The resonance level at 7�514 MeV has possibly aT = 3/2 character. The low-lying excited states in 43SC are in reasonable agreement with the theoretical predictions of Johnstone (1968).