Investigations of mechanisms of particle production in proton-induced nuclear spallation
Author: Udai Singh
Supervisor: prof. Krzysztof Pysz
Auxilliary supervisor: dr Sushil Sharma
abstract
Defence year: 2021
Studies of the selected problems in understanding of nuclear spallation physics are undertaken. Among them are the description of the initial phase of proton - target nucleus collision and proceeding of the intranuclear cascade, isotropic emission of nuclear fragments of very broad mass spectrum, contribution of the nonequlibrium and equilibrium processes to the total production
cross-section and its dependence on the isotope isospin, variation of the total production cross-section related to the number and ratio of protons and neutrons of the emitted particle. New experimental distributions of the double differential production cross-sections (d^2sigma/dOmegadE) for p, d, t, pi+ and pi- in the p + Nb reaction at 3.5 GeV proton beam energy are provided. They have been measured by High Acceptance DiElectron Spectrometer (HADES) experiment. The measured energy range of hydrogen isotopes are significantly extended in comparison to the experimental data available in the literature. The new experimental spectra are confronted with the theoretical prediction of three models of intranuclear cascade - GiBUU, UrQMD, INCL++. Discrepancies of the experimental and theoretical distributions are noticed and discussed. Experimental data derived from the literature are
used for examination of nuclear mechanisms assigned to the nuclear deexcitation phenomena. The comparative analysis of the four model prediction (ABLA07, GEMINI++, GEM2, SMM) of the selected observables relevant to the isotropic nuclear fragment emission is performed. Disagreement of the model prediction and the experimental data is observed.
