Design of a Compton-Suppression Spectrometer and Its Application to the Study of High-Spin Yrast States

摘要

Detailed gamma -ray spectroscopy of high-spin states is hampered by transitions with low intensity on a high gamma -ray background. An approach to enhance weak peaks in a spectrum in the reduction of the Compton background by means of a Compton-suppression spectrometer (CSS). Optimization of a CSS by means of Monte Carlo calculations is described. The investigation of high-spin states in the sd-shell nucleus exp 38 Ar with a Compton-suppression spectrometer is reported. With previously described techniques, in combination with p- gamma coincidence measurements to establish an unambiguous level scheme, states up to Jsup( pi ) = 11 exp - could be identified and investigated. A gamma-gamma coincidence experiment on the nuclei exp 167 exp 168 Hf is described with two Compton-suppression spectrometers. Yrast bands are followed, beyond the region of the first backbending, up to spin J = 37/2 and J = 28 for exp 167 Hf and exp 168 Hf, respectively. (Atomindex citation 12:614233)