| dc.description.abstract | In this thesis, the gamma strength functions (GSF) of \(^{44}\)Sc, \(^{50,51}\)V, and \(^{64}\)Zn have been studied using numerical shell model calculations with the software KSHELL. The scandium and vanadium calculations were compared to existing experimental Oslo method data. This work has a focus on the different contributions of \(E1\) and \(M1\) transitions to the GSFs with a particular emphasis on the low energy enhancement (LEE) part of the GSFs. The applicability of the generalised Brink-Axel (gBA) hypothesis has been studied for all of the nuclei, supplemented by a statistical analysis of the reduced transition probabilities (\(B\) values) from the calculations. The shell model and KSHELL have been pushed to the limit of what is computationally feasible to produce as high quality calculations as possible. In all cases, the shell model calculations of this work show that the LEE is caused by \(M1\) transitions, not \(E1\) transitions. The calculated GSFs fit well with the experimental data in the entire gamma energy range of \(E_{\gamma} = [0, 10]\) MeV, and the inclusion of \(E1\) transitions is generally necessary for a good fit. The GSFs of all nuclei seem to be approximately independent of angular momentum, supporting the validity of the gBA hypothesis for these calculations. The distribution of \(B\) values from different selections of excitation energies closely match the Porter-Thomas (\(\chi_{\nu = 1}^{2}\)) distribution for all nuclei, while in some cases the \(B\) distributions from selections of angular momenta show systematic deviations from the Porter-Thomas distribution, particularly for the \(E1\) transitions. Using a sufficient amount of levels (and hence \(B\) values) per \(j^{\pi}\) in the shell model calculations is important for the quality of the resulting GSFs, particularly at the highest gamma energies. A correspondence between where fluctuations in the GSF starts and where the accompanying level density stops rising exponentially is seen. The GSFs of \(^{50,51}\)V and \(^{64}\)Zn have to our knowledge for the first time been calculated with \(E1\) and \(M1\) transitions in the same framework. | eng |