Survey of the (. alpha. , sup 2 He) reaction on fp -shell nuclei

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.42.2375· OSTI ID:6098655

Fister, U; Jahn, R; von Neumann-Cosel, P; Schenk, P; Trelle, T K; Wenzel, D; Wienands, U ^[1]

---

1. Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, Bonn (Federal Republic of Germany)

The ({alpha},{sup 2}He) reaction has been investigated at bombarding energies around 56 MeV on targets of {sup 40,42,44,48}Ca, {sup 50,52,54}Cr, {sup 54,56,58}Fe, {sup 58,60,62,64}Ni, {sup 64,66}Zn, and {sup 70,72}Ge. The angular distributions of prominent two-neutron states were analyzed with the distorted-wave Born approximation. Preferential population of states with dominant ({ital f}{sub 5/2},{ital g}{sub 9/2}){sub 7{sup {minus}}}, ({ital g}{sub 9/2}){sub 8{sup +}}{sup 2}, and ({ital g}{sub 9/2},{ital d}{sub 5/2}){sub 6{sup +}} configurations was observed for all nuclei with a closed {ital f}{sub 7/2} neutron shell. The binding energies of the 7{sup {minus}}, 8{sup +}, and 6{sup +} states are linearly dependent on the mass number and the isospin and well described by the weak-coupling model. The extracted parameters agree with the averaged values of a similar analysis for {ital f}{sub 5/2}, {ital g}{sub 9/2}, and {ital d}{sub 5/2} single-particle states in the corresponding odd-even nuclei. The excitation energies of the high-spin states could be well reproduced by a simplified shell model where only pure configurations are considered and the residual interaction energy is neglected. The simple structure of the experimentally observed states is further tested by large-scale shell-model calculations. Two-body matrix elements are extracted from the data for the ({ital f}{sub 5/2},{ital g}{sub 9/2}){sub 7{sup {minus}}} and ({ital g}{sub 9/2}){sub 8{sup +}}{sup 2} configurations.

• OSTI ID: 6098655
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Journal Name: Physical Review, C (Nuclear Physics); (USA) Vol. 42:6; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651520* -- Nuclear Properties & Reactions
A=39-58
Experimental
651620 -- Nuclear Properties & Reactions
A=59-89
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALKALINE EARTH ISOTOPES
ALPHA REACTIONS
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
BINDING ENERGY
BORN APPROXIMATION
CALCIUM ISOTOPES
CHARGED-PARTICLE REACTIONS
CHROMIUM ISOTOPES
CROSS SECTIONS
DIRECT REACTIONS
DISTRIBUTION
DWBA
ENERGY
ENERGY LEVELS
ENERGY RANGE
GERMANIUM 70 TARGET
GERMANIUM 72 TARGET
HIGH SPIN STATES
IRON ISOTOPES
ISOSPIN
ISOTOPES
MATHEMATICAL MODELS
MEV RANGE
MEV RANGE 10-100
MULTI-NUCLEON TRANSFER REACTIONS
NICKEL ISOTOPES
NUCLEAR MODELS
NUCLEAR REACTIONS
PARITY
PARTICLE MODELS
PARTICLE PROPERTIES
SHELL MODELS
SINGLE-PARTICLE MODEL
SPIN
STRIPPING
TARGETS
TRANSFER REACTIONS
TWO-NUCLEON TRANSFER REACTIONS
ZINC 64 TARGET
ZINC 66 TARGET