A High Resolution Study of Proton Resonances in 51Mn

Abstract

High-resolution measurements of the differential cross sections of the 50Cr(p,p0) and 50Cr(p,p1) reactions were performed over the energy range E[subscript p]=1.8045–3.5011 MeV at five different scattering angles. This experiment was performed at the High Resolution Laboratory (HRL) at Triangle Universities Nuclear Laboratory (TUNL); the system is capable of measuring proton-scattering data with an energy resolution of ~250 eV. The goal of this work is to improve the purity and completeness of the 51Mn level sequences in order to investigate average level properties. The observed cross sections were fit using the multi-level, multi-channel, R-matrix code MULTI, and resonance parameters were extracted from the data. Many resonances were observed for the first time, and several others were reassigned different quantum numbers compared to previous work. A total of 185 resonances were observed, 64 of which had not been observed in previous studies. Statistical analyses based on predictions of random matrix theory were performed on the nearest-neighbor spacing distributions and the reduced-width distributions, with mixed results. The s-wave resonance sequences are in good agreement with GOE predictions, while the p-wave resonance analyses show evidence of missing and misassigned levels. Separation of the d-wave, f-wave, and g-wave resonances into pure sequences is not feasible due to ambiguity in J assignments for these levels. Strength functions and level densities were determined for both the pure and mixed sequences.

Description

Keywords

level densities, nuclear resonance spectroscopy, statistical tests

Citation

Degree

PhD

Discipline

Physics

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