The Role of a direct knock-out mechanism in the inclusive (p, α) reaction
Date
2008-03
Authors
Van Zyl, Johannes Jacobus
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : University of Stellenbosch
Abstract
Experimental double differential cross sections and analyzing powers for the inclusive
93 Nb(p,α) r and 93 Nb(p, 3He) r reactions have been measured at an incident energy of
160 MeV. The results of this experiment, for emission angles ranging from 15º to 60º as
well as previously measured data for 93 Nb(p,α) r at 100 MeV and 59Co(p,α) r at 100 and
160 MeV, have been compared with theoretical calculations based on a direct quasi-free α-
cluster knockout mechanism.
A computer code has been employed which calculates triple differential cross section and
analysing power values using the distorted wave impulse approximation (DWIA). Inclusive
double differential cross sections and analysing powers were calculated by integrating over
the solid angle of the unobserved proton.
It was found that the DWIA is limited in its ability to reproduce the experimental data. Some
slight agreements have been observed in the region of large emission energies and small
angles. This is consistent with the findings of previous studies based on a direct multi-step
analysis which indicated that the first step knock-out reaction dominates in this region.
Description
Thesis (MSc (Physics))--University of Stellenbosch, 2008.
Keywords
Direct knock-out, DWIA, Differential cross section, Analysing power, Nuclear reactions, Dissertations -- Physics, Theses -- Physics