Radiation shielding for the first optics enclosure at the High Energy Photon Source beamlines

The High Energy Photon Source (HEPS) is currently under construction in China and will be the brightest synchrotron radiation facility in the world. To solve the gas bremsstrahlung and synchrotron radiation hazard at HEPS beamlines, a comprehensive radiation study is performed. The Monte Carlo method is used to analyze the radiation field in the first optics enclosure at HEPS beamlines. First, the radiation sources including gas bremsstrahlung and synchrotron radiation are estimated. Then, the distribution of the radiation field in the hutch is calculated. Conservative parameters and a typical beamline geometry are used in the calculations. Finally, the shielding recommendations are summarized. In this paper, the considerations and bulk shielding design of the first optics enclosure at HEPS beamlines are described. The design satisfies the requirements of the radiation safety principles.