Production of isomers in compound and transfer reactions with 4He ions

Production of isomers in compound and transfer reactions with 4He ions

A well-known island of nuclear isomerism appears near A=175–180 due to the deformation alignment of single-particle orbits at high angular momentum. This sometimes results in the formation of multi-quasiparticle states with record spin that are long-lived because of “K-hindrance”, i.e. symmetry re-a...

Full description

Saved in:
Bibliographic Details
Published in:Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 646; no. 1; pp. 87 - 94
Main Authors: Karamian, S.A., Carroll, J.J., Aksenov, N.V., Albin, Y.A., Bozhikov, G.A., Dmitriev, S.N., Starodub, G.Y., Vostokin, G.K.
Format: Journal Article
Language:English
Published: Elsevier B.V 01-08-2011
Subjects:
Compound nucleus
Gamma spectroscopy
Isomer-to-ground-state ratio
Transfer reactions
Compound nucleus
Isomer-to-ground-state ratio
Gamma spectroscopy
Transfer reactions
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A well-known island of nuclear isomerism appears near A=175–180 due to the deformation alignment of single-particle orbits at high angular momentum. This sometimes results in the formation of multi-quasiparticle states with record spin that are long-lived because of “K-hindrance”, i.e. symmetry re-arrangement. Production methods and spectroscopic studies of these isomers remain a challenge for modern nuclear reaction and nuclear structure physics. In the present work, activities were produced by irradiation of 176Yb (97.6% enriched) and natLu targets with 35 MeV 4He ions from the internal beam of the U-200 cyclotron. Induced activities were analyzed by applying the methods of radiochemistry and gamma spectroscopy. Yields of the compound and nucleon-transfer reactions were measured and the isomer-to-ground state ratios were deduced. Calculated results were obtained using standard procedures to reproduce the (α, xn) cross-sections, and the systematic behavior of the nucleon-transfer yields was established. The isomer-to-ground-state ratios for direct reactions with 4He ions were examined, resulting in a new characterization of the reaction mechanism.
ISSN:0168-9002
1872-9576
DOI:10.1016/j.nima.2011.03.010