Proton Impact of Bimolecular Targets

Abstract

Article HistoryFor a better control and understanding of the effects of radiation damage in living tissues by using the irradiation of biological systems by energetic ion beams have multiple applications in medical physics and space radiation health, such as hadron therapy for cancer treatment and it is necessary to advance an accurate description of the energy loss from the ion beam to the target. In the present work the dielectric formalism like Drude has been used to calculate the probability for an energetic proton and to produce electronic excitations in five targets of high biological interest, namely, liquid water, DNA, PMMA, Adenine and Guanine. Also, the effects of ionization fraction on the mean excitation energy, average energy and Inelastic mean free path studied taking in to consideration electronic excitation in the target. Good agreement achieved with previous work. Contribution/ Originality:This study document an empirical method of obtaining the energy loss function which is the key quantity to study the energy deposited in targets of biological interest by swift projectiles such as protons, so it contains all the information about the electron excitation spectrum of the target.,. The model used through (ELF), namely the extended-Drude ELF. Each term in the sum of Drude-type functions has three adjustable parameters. The parameters a, b and c can be obtained by a fit of Eq. (1) to the ELF for compounds. The energy delivered by a swift proton beam in materials of interest to hadron therapy in 5 compounds is investigated.