D. J. Pullen

Spectroscopy of 22Na with the 20Ne(3He, p) and 20Ne(6Li, α) reactions

Abstract The 22 Na nucleus has been studied by means of the 20 Ne( 3 He, p) reaction at 15 MeV incident energy and the 20 Ne( 6 Li, α) reaction at 18 MeV bombarding energy. Levels up to 10 MeV of excitation were measured with energy resolutions of 25 keV in the ( 3 He, p) case and of 40 keV in the 6 Li induced reaction using the University of Pennsylvania tandem Van de Graaff and multi-angle spectrograph. The systematics of the proton and α-particle angular distribution shapes allow the assignment of values of the transferred angular momentum for a number of transitions, resulting in several new spin-parity assignments. Comparison of the proton and α-particle spectra reveals that T = 1 levels are extremely weakly excited in the ( 6 Li, α) reaction and this fact is used for assigning several T = 1 states. A distorted wave calculation of relative intensities was performed based on a description of the 22 Na levels in terms of pure two-particle Nilsson states with associated rotational bands. This analysis is consistent with the ground state K = 3 band and the K = 0, T = 1 band built on the first 0 + state having simple two-Nilsson-particle character whereas the properties of the second (1.93 MeV) 1 + state are inconsistent with such a description. It is concluded that the combination of ( 3 He, p) and ( 6 Li, α) reactions employed in the present study provides a powerful spectroscopic tool.

Study of 74As by the 73Ge(3He, d) reaction

Abstract The energy levels of 74As have been studied using the 73Ge(3He, d)74As reaction at an incident energy of 17 MeV. The overall energy resolution was 30 keV. Twenty-five levels in 74As were identified up to 2.2 MeV excitation energy and angular distributions were measured in the interval 3 3 4 ° to 86 1 4 ° . Spectroscopic strengths and lp values have been extracted for many of the transitions by means of a distorted-wave analysis of the differential cross sections. A comparison with the 75As(p, d) data suggests the presence of several unresolved doublets in 74As.

The (τ, p) reactions on Cr (II). 54Cr(τ, p)56Mn

Abstract The 54Cr(τ, p)56Mn reaction has been studied at 15 MeV incident energy using a multi-angle spectrograph. Ninety-seven transitions were identified up to 5.62 MeV excitation and many of the corresponding proton angular distributions were measured. The systematics of L = 0 angular distributions shapes is discussed in detail and criteria for distinguishing L = 0 and L = 0 + 2 transitions are derived. The implication of the present data for the nuclear structure of 56Mn is commented upon and the distribution of 1+ (τ, p) strength in 56Mn is discussed.

(h, p) Reactions on Cr: (I). 50Cr(h, p)52Mn

Abstract The reaction 50 Cr(h, p) 52 Mn has been studied at 16.5 MeV incident energy and with a resolution of ≈ 15 keV FWHM. Forty-nine transitions were observed up to 5.87 MeV of excitation and proton angular distributions were extracted. The distribution shapes in conjunction with DW calculations are used for assignments of spin and parity of many final states. The data are compared to previous information on 52 Mn and two states at 2.929 MeV and 5.491 MeV are assigned as isobaric analogues of the two lowest 0 + states in 52 Cr. The strength of the 0 + → 1 + excitations is commented upon.

(h,p) REACTIONS ON Cr. I.

Abstract The reaction 50 Cr(h, p) 52 Mn has been studied at 16.5 MeV incident energy and with a resolution of ≈ 15 keV FWHM. Forty-nine transitions were observed up to 5.87 MeV of excitation and proton angular distributions were extracted. The distribution shapes in conjunction with DW calculations are used for assignments of spin and parity of many final states. The data are compared to previous information on 52 Mn and two states at 2.929 MeV and 5.491 MeV are assigned as isobaric analogues of the two lowest 0 + states in 52 Cr. The strength of the 0 + → 1 + excitations is commented upon.

sup 50

Abstract The reaction 50 Cr(h, p) 52 Mn has been studied at 16.5 MeV incident energy and with a resolution of ≈ 15 keV FWHM. Forty-nine transitions were observed up to 5.87 MeV of excitation and proton angular distributions were extracted. The distribution shapes in conjunction with DW calculations are used for assignments of spin and parity of many final states. The data are compared to previous information on 52 Mn and two states at 2.929 MeV and 5.491 MeV are assigned as isobaric analogues of the two lowest 0 + states in 52 Cr. The strength of the 0 + → 1 + excitations is commented upon.