The (p, n) charge-exchange reaction on ⁹⁰Zr at intermediate energies
type: CreativeWork
description: Using the Time-of-Flight facility at the National Accelerator Centre at Faure, the (p, n) charge-exchange reaction has been studied at intermediate energies of 120, 160 and 200 MeV, and at angles of 0°, 2° and 4°. In this work the data collected for the ⁹⁰Zr target will be presented. The influence on the data from slow neutrons due to previous pulses is discussed and the best manner of removing them from the spectra is recommended. It is shown how the background cosmic rays can be utilised to measure the intrinsic resolution of the detectors and to obtain an estimate of the neutron energy threshold. The differential cross-sections for the states corresponding to Fermi and Gamow-Teller transitions were extracted from the time spectra. The sum of the strength of all the discrete Gamow-Teller states was determined and compared to the Ikeda Sum Rule. It was found that only 50% of the sum could be accounted for in the discrete states. An overview of the theory that has been developed to extract Gamow-Teller strengths from the (p, n) cross-sections is given. Some of the theoretical models that have been used to describe the ⁹⁰Zr(p, n)⁹⁰ Nb reaction and account for the missing Gamow-Teller strength are briefly discussed.
abstract: Using the Time-of-Flight facility at the National Accelerator Centre at Faure, the (p, n) charge-exchange reaction has been studied at intermediate energies of 120, 160 and 200 MeV, and at angles of 0°, 2° and 4°. In this work the data collected for the ⁹⁰Zr target will be presented. The influence on the data from slow neutrons due to previous pulses is discussed and the best manner of removing them from the spectra is recommended. It is shown how the background cosmic rays can be utilised to measure the intrinsic resolution of the detectors and to obtain an estimate of the neutron energy threshold. The differential cross-sections for the states corresponding to Fermi and Gamow-Teller transitions were extracted from the time spectra. The sum of the strength of all the discrete Gamow-Teller states was determined and compared to the Ikeda Sum Rule. It was found that only 50% of the sum could be accounted for in the discrete states. An overview of the theory that has been developed to extract Gamow-Teller strengths from the (p, n) cross-sections is given. Some of the theoretical models that have been used to describe the ⁹⁰Zr(p, n)⁹⁰ Nb reaction and account for the missing Gamow-Teller strength are briefly discussed.
author: Kabutz, Rudolf T
language: eng
date published: 1992
date modified: 2026-07-22T22:23:19Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Physics

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/17385