Nuclear structure studies with (n,d) reactions.

Abstract

The ²⁷AI(n,d)²⁶Mg and ⁵⁶Fe(n,d)⁵⁵Mn reactions have been studied at 22 MeV incident energy. The 6MV Van de Graaff facility at the National Accelerator Centre, Faure was used for the experimental aspects. An (n, charged particle) spectrometer was used to detect the energy and angle of the outgoing deuterons. The spectrometer allows for accumulation of particle discriminated data over an angular range of 80⁰. The intrinsic geometry of the spectrometer limits its' angular resolution to ~ 5⁰ (FWHM). The spectrometer has an energy resolution of ~ 0.7MeV(FWHM). A detailed study of the experimental system has been conducted and the proportional counters in particular were extensively investigated. A review of the relevant nuclear models for the target and residual nuclei is presented, together with a theoretical outline of the reaction mechanism for the (n,d) reaction. The distorted waves method approach is used in the analysis of the reaction cross sections. Optical potentials are used to simulate the incoming and outgoing distorted waves and thus generate the theoretical cross sections for the (n,d) reactions. The shapes of the angular distributions of the reaction cross sections for different orbital angular momentum transfers are compared to obtain a fit. Comparison of experimental and theoretical cross sections produce the spectroscopic factors which reveal the occupancy or vacany of level states and hence the single particle nature of these states. It was concluded from the study that the shell model of the nuclei under investigation gives a very good description of the results obtained for the (n,d) reactions.