Strongly excited levels of39Ca in the40Ca(3He, α)39Ca reaction

Angular distributions of the α-particle groups in the40Ca(3He, α)39Ca reaction were measured atEL(3He)=24.4 MeV by the use of a broad range magnetic spectrograph. α-particle groups corresponding to excitation energies in39Ca of 0, 2.47±0.03, 2.80±0.03, 3.03±0.05, 3.95±0.03, 4.02±0.03, 5.07±0.05, 5.40±0.05, 5.70±0.1 and 6.05±0.05 MeV were observed. The DWBA analysis shows that the ground state and the first excited (2.47) state consist mainly of a (1d1/2)−1 and a (2s)−1-neutron hole state, respectively. The (1d5/2)−1 hole state is considered to split into the 5.07, 5.40 and 6.05 MeV levels with nearly equal fractions. The angular distribution corresponding to the 2.80 MeV level suggests anl=3 neutron pick-up, which is due to the configuration mixing with 1f7/2 neutron shell in the ground state of40Ca.