Excitation of core coupled states in 87Sr and 89Sr via two-step processes in the 88Sr(p, d) and 88Sr(d, p) reactions

Gamma-ray spectroscopy of87Y

“…Studies of 89Sr 1-1, 2], SVSr [1,2], , and 89y [4,5] indicate that the weak-coupling model is a useful tool for describing low-lying excitations in nuclei near the N=50 closed-shell nucleus 8SSr. A comparison of the SSSr(p,t) S6Sr and 89y(p,t) 87y reactions [6] suggests that this description can be extended to the structure of 87y.…”

Neutron single-particle strength outside theN=50core

“…Some weak population of states via = 1 and 3 transfer was observed, which has previously been attributed to incomplete filling of the fp shell, for example in Ref. [9].…”

“…In 91 Zr, it is difficult to connect states populated at 2.625, 2.690, 2.813, and 3.917 MeV to previously observed states at similar excitation energies. The state at 2.131 MeV is also populated in an = 4 transition in the 92 Zr(p,d) reaction [9] and this state has a previous 9/2 + attribution that was based on evidence from (n, n γ ) excitation functions [41]. In the current work, the population in the (d,p) reaction is weak, the angular distribution is inconclusive and it is not observed in the (α, 3 He) reaction.…”

“…Contamination was a problem for the 88 Sr and 90 Zr targets, so additional angles of 10 • and 22.5 • were used for the α-induced reaction to reveal all states for at least one angle. Angular-momentum assignments for the majority of the states populated have been made in previous work [7][8][9][10][11][12][13][14][15][16][17][18][19]; these were checked using measured angular distributions and information gained by a comparison of cross sections from the two different reactions used.…”

“…The (d,p) reaction on N = 50 targets has been studied previously [7][8][9][10][11][12][13][14][15][16][17][18]. However, different experimental techniques and beam energies have been used for each target.…”