Proton radiation effects on structural material properties at charged particle accelerators

Materials of structure elements of high-current proton accelerator and types of nuclear reactions on the protons lossed in the process of acceleration, are determined. The relative defect forming ability of protons calculated relatively to neutrons of thermonuclear reactor (14 MeV) and BOR-60 reactor for 13 metals from Be to U is almost linear with the growth of the element number in the periodic system and changes from 8 (for Be) to 200 (for U), in the surface range (or up to 60 for Esub(n)=14 MeV). Radiation change of Nb3Sn stoichiometric composition is found for protons only: starting from the fluence approximately 1024 prot/cm2 a noticeable formation of Nb6Sn5 phase is possible which brings about a considerable decrease of temperature of transition to a superconducting state (approximately up to 1 K) and the reject of the superconducting element