Gamma-rays from the Reaction Al²⁷ (p, γ)Si²⁸

抄録

Gamma-rays from the reaction Al²⁷ (p, γ)Si²⁸ have been studied at the four resonances occurring at E_p=226, 294, 326, and 405 kev by the use of a large NaI crystal scintillation spectrometer. The gamma-ray transitions from the resonance states to the levels in Si²⁸ at 1.78 Mev(1st), 4.62 Mev(2nd), 6.91 Mev, and 8.58 Mev were observed. Spins and parities of these levels and some of the resonance levels are deduced from the anisotropies of gamma-rays as follows: 4.62 Mev, J=4⁽⁺⁾; 6.91 Mev, J=2^± or 4⁺; 8.58 Mev, J=3⁺; 11.90 Mev, J=4⁽⁻⁾; 11.98 Mev, J=4⁻. J=4⁽⁺⁾ for the second excited state suggests the collective nature of this excited v level which has been expected from the other evidences found in neighbouring nuclei. The gamma-ray yield and the branching ratios of each resonance level are also given.