Population of states in 15O following the 16O(γ,n) reaction

Annand, J.R.M. et al. (1997) Population of states in 15O following the 16O(γ,n) reaction. Project Report. University of Lund. (Unpublished)

Abstract

This measurement forms part of a series of experiments designed to resolve the nature of the reaction mechanism involved between high-energy photons and the nucleus. Of the several theoretical models currently available, microscopic calculations, such as those of Gari and Hebach, and more recently Ryckebusch seem to better describe the experimental observations. These models include multi-particle effects by specific reference to short range correlations between the nucleons, meson-exchange effects and ground state correlations. Measurement of the population of excited residual states following photonuclear reactions, severely constrains the model parameters. This is particularly true for residual states with configurations involving terms with multiple holes. A study of the population of residual states in 11B following the 12C(γ,p) reaction, has provided compelling data that has helped to refine the model parameters. This measurement exploited a technique where γ-rays from residual excited states are used to provide better resolution of the relative population of these states. This de-excitation γ-ray technique is used in the present experiment, so as to provide a measure of the population strength to the +ve-parity doublet of states in 15O near 5.2 MeV. These states have a predominant 2p-lh structure, and hence provide an important test of the theoretical models. Without access to the de-excitation γ-ray spectrum it would not be possible to resolve population of these states from the -ve parity state at 6.2 MeV.

• Item Type: Research Reports or Papers (Project Report)
• Additional Information: MaxLab Activity Report 1997
• Status: Unpublished
• Glasgow Author(s) Enlighten ID: McGeorge, Dr John and MacGregor, Professor Douglas and Livingston, Dr Kenneth and Owens, Professor Robert and Ireland, Professor David and Annand, Dr John
• Authors: Annand, J.R.M., Crawford, G.I., Ireland, D.G., Livingston, K., MacGregor, I.J.D., McGeorge, J.C., Owens, R.O., Adler, J.O., Hansen, K., Lundin, M., Isaksson, L., Nilsson, B., Sandell, A., Schroeder, B., Boland, M.J., Rasool, R.P., and Thompson, M.N.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Publisher: University of Lund
• Copyright Holders: MAXLAB