J.E. Kitching

The level structures of 85, 87Sr from (d, p) reactions

Abstract The reactions 84 Sr(d, p) 85 Sr and 86 Sr(d, p) 87 Sr have been studied at a bombarding energy of 12 MeV. Thirty-four levels below 4.5 MeV of excitation have been identified in 87 Sr and fifty-four levels below 3.5 MeV have been identified in 85 Sr. Transferred orbital angular momenta and spectroscopic information have been deduced from a DWBA analysis of the proton differential cross sections. It has been found that the lowest-lying excited states arise from 1g 9 2 , 2p 1 2 and 2p 3 2 configurations. The 1f 5 2 shell appears to be completely filled in these low-mass strontium isotopes.

Effective interaction among 1g92 and 2p12 neutrons in the strontium isotopes

Abstract In the seniority scheme an effective interaction shell-model calculation has been carried out for the low-lying structure of the strontium istopes. The model predictions are compared with existing experimental data and the quality of the seniority quantum number evaluated. Differences between effective neutron matrix elements have been determined and compared with the corresponding proton case. Comparisons of predicted two-neutron transfer cross sections with experimental data have been used to remove ambiguities in the sign of certain off-diagonal matrix elements.

EFFECTIVE INTERACTION AMONG 1g/sub 9/2/ AND 2p/sub 1/2/ NEUTRONS IN THE STRONTIUM ISOTOPES.

Abstract In the seniority scheme an effective interaction shell-model calculation has been carried out for the low-lying structure of the strontium istopes. The model predictions are compared with existing experimental data and the quality of the seniority quantum number evaluated. Differences between effective neutron matrix elements have been determined and compared with the corresponding proton case. Comparisons of predicted two-neutron transfer cross sections with experimental data have been used to remove ambiguities in the sign of certain off-diagonal matrix elements.

Levels excited in the reaction 58Ni (p,t) 56Ni

Abstract Angular distributions have been obtained for triton groups in the reaction 58Ni(p,t)56Ni corresponding to levels up to 8.5 MeV excitation. Spin assignments are presented and the level structure of 56Ni is discussed.

The conservation of seniority in the 1g92 neutron shell

Abstract The results of one- and two-neutron transfer reactions across the strontium isotopes are applied to a study of the conservation of seniority in the 1 g 9 2 neutron shell.

Proton stripping reactions populating levels in 95,97,101Tc

The structure of the low-lying levels of 95,97,101Tc was investigated with the proton stripping (3He,d) reaction. The experimental angular distributions were compared with distorted-wave Born-approximation calculations, and l-values and spectroscopic factors were extracted. The proton configurations of the target ground states were deduced. The systematics of transition strength distributions are discussed.

The (d, α) reaction viewed as a two-step process☆

Abstract The 98, 97, 94Mo(d, α)96, 95, 92Nb and 93Nb(d, α)91Zr reactions have been studied at 12 MeV bombarding energy. A DWBA analysis using one- and two-step processes has been carried out. The two-step process is found, in general, to dominate the one-step and together give rise to cross-section predictions within a factor of 10 of experiment. The angular distribution patterns are found to be best reproduced by DWBA predictions based on certain L-transfers (“parity violating”) associated with only the two-step process and which play but a minor role in their contribution to the overall cross section.

Study of low-lying states in 92Tc with the 92Mo(3He, t) reaction

Abstract States in 92 Tc have been studied by means of the 92 Mo( 3 He, t) reaction at 27.5 MeV. The Q -value for this reaction and the excitation energy of the isobaric ground state analogue of 92 Mo were determined to be −7.882 ± 0.030 MeV and 3.813 ± 0.030 MeV respectively. Strongly populated levels in 92 Tc appear to belong to configurations arising from the (1g 9 2 ) π (1g 9 2 ) ν −1 multiplet.

States of 87Sr populated by deuteron pick-up from 89Y

Abstract The reaction 89 Y(d, α) 87 Sr has been observed at a bombarding energy of 12 MeV. Angular distributions of the emitted α-groups were recorded over the angular range 10° to 160° lab and compared with a DWBA analysis. Many levels in 87 Sr appear to be populated by proton pickup from the 2 p 3 2 orbit. The levels of 87 Sr populated in this reaction correspond to those observed in the 87 Rb(p, n) 87 Sr reaction but differ to a large extent from those seen in neutron stripping and pick-up reactions.

(t,p)-reaction studies of the transitional nuclei-150Nd and 152Nd

Abstract The 0 + states observed in the reactions 148 Nd(t, p) 150 Nd and 150 Nd(t, p) 152 Nd are reported and discussed. Their properties suggest significant differences between the samarium and neodymium at the onset of nuclear deformation.