The Research On The Radiation Effects Induced By High-energy Proton

The research on the radiation effects of materials induced by high-energy proton irradiation is of important significance in many scientific fields, such as the single event effects of semiconductor components exposed on space, accelerator-driven nuclear energy generator, tritium production by accelerator, intense pulsed ion beam technology, proton radiography, etc. The effects and mechanisms of irradiation vary vastly for different energies and intensities of proton beams. This paper is mainly concerned with two aspects on the radiation effects of high-energy protons. One involves the radiation hardening technique of electronic devices aboard on spacecraft for extremely high energy protons with low flux existed in the environment of space; the other is related to the thermal-mechanical effects of materials under the exposure of high-energy intense-current proton beams. The radiation shielding and single event upset (SEU) of semiconductor components induced by high-energy low-flux and the thermal-mechanical effects of materials resulting from the high-energy intense-current proton irradiation are extensively studied, following conclusions are achieved:The characteristics of space radiation environment and the potential radiation effects are investigated systematically. The research uncovered the facts that, in the design of space vehicles, the single event effects induced by high-energy protons and iron ions in space must be taken into account seriously, the proper hardening measures must be taken to protect the electronic devices from disfunction. It is also suggested that, for the low-orbit satellites, the south Atlantic anominal zone should be avoided.The microscopic mechanisms of interaction of high-energy proton with material are studied in detail, including nuclear scattering, nuclear reaction and electronic stopping of protons. Nuclear scattering results in the displacement defects in material as well as the deflection of proton from its incident direction; Electronic stopping of protons acts as the most important factor in the degradation of incident proton energy, resulting in electronic effects such as single event upset. Nuclear reaction is the important mechanism for causing single event upset as well, especially for high-energy protons.All the formula needed for simulating proton-induced radiation effects are deduced. To bypass the obstacle of lacking nuclear reaction parameters of high-energy protons interacting with Silicon, the author successfully obtained the necessary nuclear reaction cross sections by combining an intranuclear cascade nuclear reaction model with Monte-Carlo simulation, which are applied to the calculation of SEU. The calculated results are compared with those given by-literatures, good agreements are achieved.In the calculation of radiation shielding and single event upset (SEU), several mono-energyproton beams have been considered. The energy depositions in materiel by protons are calculatedand compared for two cases with or without taking proton nuclear reactions into account. The calculated results show that, for low energy protons (energy less than several decade MeV), the contribution of proton nuclear reaction to energy deposition can be neglected; while for high energy protons (energy greater than several hundred MeV), the great difference appears for the above two cases. This gives us an indication that the contribution of proton nuclear reaction to the energy deposition must be concerned for high-energy protons.The propagation process in material of thermal shock wave induced by high-energy intense-current pulsed proton beam irradiation is calculated for several different proton energies. In the calculation, the energy deposited in aluminum by proton beams is first calculated by M-C simulation, then a 1-D elastic-plastic fluid model is used to simulate the following thermal shock wave process as a result of thermal-mechanical effect by proton irradiation. The shape of proton is taken as a rectangle pulse with a width of 0.1 microseconds, the en...