SPECTROSCOPIC STUDIES IN A=90 MASS REGION .I. (3HE,D) REACTION ON 88SR, 90ZR AND 92MO NUCLEI

The proton states in neutron closed shell nuclei (N = 50) were investigated using the (3He, d) reaction on 88Sr, 90Zr and 92Mo at 18 MeV incident energy. Angular distributions of several deuteron groups up to 5 MeV excitation energy were measured between 25 and 80 degrees and compared with the predictions of DWBA reaction theory through the code JULIE in order to extract spectroscopic factors. Only one l = 4 transition has been seen at low energy indicating a very small admixture of the 1g 9 2 state. The observed l = 1 transition shows a rapid filling of the 2p 3 2 and 2p 1 2 sub-shell from 88Sr to 90Zr and no appreciable change from 90Zr to 92Mo. A very strong l = 2 transition around 3.5 MeV, observed in each reaction, marks presumably the beginning of the next major proton shell. © 1969.