Abstract: The Shanghai HIgh repetition rate XFEL aNd Extreme light facility (SHINE) under construction is located at Zhangjiang Hi-Tech Park, Shanghai. The SHINE facility consists of an 8 GeV continuous-wave (CW) superconducting linear accelerator, a 100 PW laser system, three undulator lines, and ten experimental end-stations at phase-I. The SHINE facility will be built in a tunnel 29 meters underground, with a total length of 3 km. In the tunnel of No.2 shaft, there are many beam collimators for scraping off electrons with a relatively large opening angle at the periphery of the beam halo, and the beam loss rate of the beam collimator is 1/10,000. In this paper, the Monte Carlo program FLUKA is used to simulate the Gaussian distribution of the electron beam outside 3 σ_beam with its SOURCE program. The model to simulate the loss of electrons at the beam collimator is called the beam ring-type Gaussian model. The main material of the beam collimator adopts tungsten to attenuate the strong radiation caused by the electron electromagnetic shower. The model was used to analyze the activation of the beam collimator. The results show that the Gaussian distribution model can more realistically reproduce the loss of electrons in the beam collimator. Gaussian distribution model was used to analyze the activation and the results prove that the disposal of tungsten radioactive waste is not difficult.

Key words: Shanghai hard X-ray free electron laser device, SHINE, beam collimator, Monte Carlo code, FLUKA, the beam ring-type Gaussian model, activation analysis