Study on Residual Radioactivity Evaluation of ps Laser Beam Line of XG-Ⅲ Device

The PIC and Monte Carlo simulation methods were used to evaluate the dose of Xray source and neutron source driven by the ps laser beam line of the XGⅢ device. After using PIC to determine the highenergy electron source term, it was used as input data of Monte Carlo software FLUKA to obtain the residual radioactivity and the residual dose around different targets at different time after the experiment. The simulation results show that for the laserdriven bremsstrahlung Xray source, after the experiment is completed and cooled for 10 min, the residual dose rate at 1 cm from the target surface is about 4 mSv/h, and 15 μSv/h at 30 cm from target surface. For the photoneutron source generated by the laserdriven photonuclear reaction, the residual dose rate at 1 cm from the target surface is less than 10 μSv/h after the experiment is completed and cooled for 10 min. In addition to the type of target material, the variation of the residual dose rate around the target will also be affected by the thickness of the target. Therefore, in different irradiation environments, it is necessary to adopt different radiation protection schemes for targets with different materials and thicknesses. The results of this study can provide relevant reference for radiation risk analysis of protective measures of ultrashort ultraintense laser facility.