Investigation of level density and Gama strength function for photoneutron reaction in medical linacs in Beamline.

Photoneutron reaction cross-sections of 197Au, 187Re, 186W, 181Ta, 94,95,96,97,98,100Mo isotopes were calculated through the TALYS 1.95 nuclear reaction code. The energy range of the incident photon chosen as 7 MeV-30 MeV corresponded to the range of the giant dipole resonance region, which is also an applicable energy range in radiotherapy for many commercial medical linear accelerators. Calculations were performed using three phenomenological level density models available in code, namely the Constant Temperature Fermi Gas Model, the Back-shifted Fermi Gas Model, and the Generalized Superfluid Model. The most convenient level density model for each reaction was chosen using relative variance calculations. The cross-section calculations were repeated using gamma strength function models, Kopecky-Uhl generalized Lorentzian model, Brink-Axel Lorentzian model, and Goriely's hybrid model and the best level density model was kept constant. The calculated data and the experimental data from the international Experimental Nuclear Reaction Data Library were analysed and compared graphically.

Investigation of level density parameter effects on (p,n) and (p,2n) reaction cross-sections for the fusion structural materials 48Ti, 63Cu and 90Zr.

The materials used in fusion reactor must be resistance to the harmful effects of radiation in the manner of material itself. Selection of the appropriate materials used in nuclear reactor has a crucial importance to achieve the maximum efficiency and security. Ti, Cu and Zr are known to be employed as first wall materials in fusion reactors. In this study, level density parameter effects on (p,n) and (p,2n) reaction cross-section calculations have been investigated by employing different level density models within TALYS 1.8 computer code for 48Ti, 63Cu and 90Zr selected as target materials. Also, for these isotopes (p,n) and (p,2n) reaction cross-section calculations have been done by using two different level density models of EMPIRE 3.2 code. For calculations; Constant Temperature Fermi Gas Model, Back Shifted Fermi Gas Model, Generalised Super Fluid Model and Microscopic level densities (temperature dependent Hartree Fock Bogolyubov, Gogny Force) from Hilaire's combinatorial tables have been used from TALYS 1.8. In addition, Generalised Superfluid Model and Hartree Fock Bogolyubov Model have been selected for calculations from EMPIRE 3.2 code. To appoint the best level density model, the relative variance analyses have been done. The cross-section calculations have been repeated via TALYS 1.8 level density models by changing the a parameter replacing with the obtained one from the best level density model result and value taken from the literature for each isotope. To analyze and comment about the outcomes of the study, a comparison of the results have been done with each other and the experimental data taken from the literature.