احمد محمدی اسلامی

Nuclear level density is considered one of the important quantities in nuclear physics, and so far many efforts have been made in the analyzing of in the field of nuclear level densities and its related parameters, which leads to models such as Fermi gas model, back shifted Fermi gas model and shell model. Each of these models has its own advantages and disadvantages. In each of these models have been entered a set of free parameters for the various models are different. In this thesis we have used the semiempirical nuclear level density where are two free parameters ?? and ?? , and excitation energy is defined, for the below and above of it, different relationships are used to match the experimental data. Level density parameters of 14 nuclei are calculated by using the experimental data and the fitting of its diagrams with experimental data has been investigated.