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تسجيل مستخدم جديدNuclear level densities and gamma-ray strength functions in 44,45Sc
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The scandium isotopes 44,45Sc have been studied with the 45Sc(3He,alpha gamma)44Sc and 45Sc(3He,3He gamma)45Sc reactions, respectively. The nuclear level densities and gamma-ray strength functions have been extracted using the Oslo method. The experimental level densities are compared to calculated level densities obtained from a microscopic model based on BCS quasiparticles within the Nilsson level scheme. This model also gives information about the parity distribution and the number of broken Cooper pairs as a function of excitation energy. The experimental gamma-ray strength functions are compared to theoretical models of the E1, M1, and E2 strength, and to data from (gamma,n) and (gamma,p) experiments. The strength functions show an enhancement at low gamma energies that cannot be explained by the present, standard models.
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The $gamma$-ray strength function ($gamma$SF) and nuclear level density (NLD) have been extracted for the first time from inverse kinematic reactions with the Oslo Method. This novel technique allows measurements of these properties across a wide ran
ge of previously inaccessible nuclei. Proton-$gamma$ coincidence events from the $mathrm{d}(^{86}mathrm{Kr}, mathrm{p}gamma)^{87}mathrm{Kr}$ reaction were measured at iThemba LABS and the $gamma$SF and NLD in $^{87}mathrm{Kr}$ obtained. The low-energy region of the $gamma$SF is compared to Shell Model calculations which suggest this region to be dominated by M1 strength. The $gamma$SF and NLD are used as input parameters to Hauser-Feshbach calculations to constrain $(mathrm{n},gamma)$ cross sections of nuclei using the TALYS reaction code. These results are compared to $^{86}mathrm{Kr}(n,gamma)$ data from direct measurements.
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