K. Ogino

The 2+2 and 4+1 states of the even isotopes 78–86Kr excited in the inelastic scattering of 51.9 MeV protons

Abstract The 2 + 2 and 4 + 1 states of the even isotopes 78–86 Kr have been studied by the inelastic scattering of protons. The B (E2;0 + g → 2 + 2 ) values of these isotopes are roughly equal, where as the B (E4; + g → 4 + 1 ) values decrease to a minimum at 82 Kr and then increase with neutron number. Comparison of the experimental results with current theoretical models implies an abrupt change of structure between 78–82 Kr and 84–86 Kr.

Systematics of low-lying octupole states in the doubly-even nuclei from Ge to Sr

Abstract Low-lying octupole states of doubly-even 78–86Kr isotopes have been studied with inelastic scattering of 51.9 MeV protons. It is shown that in the doubly-even nuclei from Ge to Sr with N = 42–50, the lowest octupole vibrational energies of nuclei with equal neutron excess are almost the same. The transition strengths of these states increase with Z.

Systematic study of the (d, p) reaction with 56 MeV polarized deuterons

Abstract Differential cross sections and vector analyzing powers were measured for the (d, p) reaction with 56 MeV polarized deuterons. The investigation covered the transitions to the single-particle states of the 1p. 2s, 1d. 2p, 1f, 3s, 2d and 1g shells. The analyzing powers showed a j -dependence which depended on the number of nodes in the radial wave function of the transferred neutron. DWBA and adiabatic model calculations were carried out. The DWBA calculations reproduced the experimental cross sections and analyzing powers for the stripping to the j > states. The adiabatic model did not necessarily improve the fits to the data for these transitions. As for the j transitions, on the other hand, the DWBA calculations could not reproduce the experimental angular distributions, while the adiabatic model calculations improved the agreement with the experimental data.

Splitting of low-lying octupole vibrational strength in 76,78,80,82Kr

Abstract Two low-lying octupole states of 78,80,82Kr, which were previously observed in inelastic proton scattering to share the low-lying octupole vibrational strength, were found to be strongly excited in the (p,t) reaction. Characteristics of these states and a comparison with the IBM model strongly suggest that the splittings in the lighter isotopes 76,78,80,82Kr are due to a coupling of the octupole vibration to the quadrupole degree of freedom.

High spin states of 2s-1d shell nuclei excited by (α, d) reactions

Abstract High spin states in the 2s-1d shell nuclei of 18F, 20F, 22Na, 24Na, 26Al, and 30P have been investigated by (α, d) reactions at incident energies of 64.3–65.3 MeV. The ( f 7 2 ) 2 7 + states in 20F, 22Na and 24Na, and the ( f 7 2 d 5 2 )6 − states in 20F and 24Na are proposed. The systematic dependenc of the Q-value and intensity on the mass number for the (α, d) reaction leading to the 5+, 6−, and 7+ states is obtained. For the 7+ states, the dependence of the Q-values on the mass number in the mass region below 26 deviates from the line expected from the results of heavier 2s-1d shell nuclei. The excitation energies of the ( f 7 2 ) 2 7 + states expected from a crude shell-model calculation are in good agreement with the experimental data. Using the Q-values for the 7+ states and empirical binding energies for the single-particle f 7 2 shell orbit, a mass dependency of the p-n interaction energies for the ( f 7 2 ) 2 7 + configuration has been found to be E[( f 7 2 ) 2 7 + ] = − 100 A of these 2s-1d shell nuclei.

A study of the (p, d) reactions on A = 12–94 nuclei by 65 MeV polarized protons

Abstract Differential cross sections and analyzing powers have been measured for (p, d) reactions on 1p, 2s, 1d, 2p, 1g and 2d shell nuclei with 65 MeV polarized protons. The analyzing powers clearly show a j -dependence which depends on the numbers of nodes in the radial wave function of the neutron. The shapes of the angular distributions of the analyzing powers can be classified into five types for simple neutron pickup reactions from the 1p−2d shells. The pickup from the 1 p 1 2 shell is singular.The DWBA calculations have been carried out on these (p, d) reactions in order to interpret the j -dependence. Adiabatic deuteron optical potentials can describe the data better than those derived from the deuteron elastic scattering except for the pickup from the 1 p 1 2 shell. The analyzing powers for the 1 p 1 2 shell neutron pickup can be reproduced only when large values of the radius and diffuseness parameters are used in the bound-state potential.

Study of the (3He, t) reaction on 48Ca at 82 MeV

Abstract The reactions ( 3 He, t), ( 3 He, 3 He), ( 3 He, α) and ( 3 He, d) on 48 Ca have been studied at an incident energy of 82 MeV. The obtained angular distributions for the ( 3 He, t) reaction have been analyzed in terms of second-order DWBA theory, using a zero-range approximation. The relative ratio of the cross sections for the excitation of the f in 7 2 f 7 2 −1 multiplets of 48 Sc could not be explained consistently by the one-step charge-exchange process only. However, the ratio was reproduced in order of magnitude by second-order DWBA calculations including the effect of two-step processes, such as ( 3 He-α-t) and ( 3 He-d-t) channels. The effects of the d- and α-channels on the elastic scattering of 3 He from 48 Ca were also examined in the framework of second-order full finite-range DWBA.

Inelastic scattering of 65 MeV protons from 12C, 24Mg, 28Si, and 32S.

Measurements of angular distributions of the cross sections and analyzing powers for the elastic and inelastic scatterings of 65 MeV polarized protons from /sup 12/C, /sup 24/Mg, /sup 28/Si, and /sup 32/S are reported. Coupled channels analyses of the scattering data are presented assuming the 0/sub 1//sup +/, 2/sub 1//sup +/, and 4/sub 1//sup +/ states to be members of the ground band, the 0/sub 2//sup +/ state to begin the

Fragmentation of low-lying hexadecapole states in even 74–82Se and a RPA calculation

Abstract The level schemes of the even 74–82 Se up to E x = 5.0 MeV have been investigated with high-resolution inelastic proton scattering at E p = 64.8 MeV. Several 4 + states with comparable strengths were found at E X = 2.0–5.0 MeV in all isotopes studied. The energy weighted sum-rule fraction of the 4 + states in this region increases with decreasing neutron number from 82 Se (1.0%) up to 76 Se (3.7%), and then decreases in 74 Se (2.6%). A RPA calculation with a pairing plus hexa-decapole-hexadecapole interaction can well reproduce the distribution of the excitation energies and transition strengths for the hexadecapole states.

(6Li, d) reactions on 24Mg and 26Mg at 73 MeV

Abstract The 24, 26 Mg( 6 Li, d) 28, 30 Si reactions have been studied at 73 MeV bombarding energy. The angular distributions were analyzed with exact finite-range distorted wave Born approximation calculations assuming a direct α-cluster transfer. Extracted spectroscopic strengths leading to low-lying levels of 28 Si and relative spectroscopic strengths between transitions to 28 Si and 30 Si ground states are consistent with those previously obtained by several α-transfer reactions. Many strongly populated levels have been observed at E x ≳ 10 MeV for 28 Si. A marked similarity was found between the deuteron spectrum and the 24 Mg(α, α) 24 Mg excitation function in this excitation energy region. A brief comparison of the present α-transfer results with previous two-nucleon transfer data leading to 28,30 Si is also presented.