Two-Particle States Excited by The (α, d) Reactions on s-d Shell Nuclei

Abstract

The (α, d) reactions in Mg²⁴, Si²⁸, S³² and Ca⁴⁰ have been studied by using 29.0 MeV alpha particles. The energy spectra of deuterons obtained were dominated by two or more strongly excited levels. Levels at 2.73, 3.64 4.06 and 4.79 MeV of Cl³⁴ are identified to be 2⁻, 5⁻, 3⁻ and 4⁻ states, respectively, which arise from a (d3⁄2 f7⁄2) configuration, by the use of the relation between the particle-particle and the particle-hole interaction energies, which is given by the shell theory. Levels at 3.60 MeV of Al²⁶ and 4.17 MeV of P³⁰ are identified to have the same (d3⁄2 f7⁄2) 5 configuration as the 3.64 MeV level of Cl³⁴ from their large spectroscopic amplitude, the similarity of their angular distribution and the relationship between their reaction Q values and the mass number of the residual nuclei. Levels at 7.11 MeV of P³⁰, 5.23 MeV of Cl³⁴ and 0.60 MeV of Sc⁴² are identified to have a (f7⁄2)²⁷ configuration from the reason mentioned above and the results of the DWBA calculation.