Thermal Stress Analysis of Tungsten Collimators Heated by High-Energy Proton BEAMS

摘要

An analytical and numerical investigation of the effect of a large quantity of high-energy protons on a tungsten alloy collimator is presented. Three different modes of failure are analyzed: thermal stress, thermal shock, and temperature in excess of the maximum allowable. Three analyses are developed to study the first beam pulse at 1-mA beam current. A quasi-steady-state analysis is applied to study the effect of multiple beam pulses at 0.1-mA beam current. The results for a 1-mA beam indicate that the yield stress is exceeded after 200 mu s, but the ultimate stress is not reached during the first beam pulse. The analytical solution is found to give good results in the elastic range. The numerical solution for 0.1-mA beam current shows that the yield stress is reached after 0.23 s and the ultimate stress is exceeded after 0.48 s. (ERA citation 01:024303)