Study of radiation background at the north crossing point of the BEPC in collision mode

Understanding the radiation background at the north crossing point （NCP） in the tunnel of BEPCII is crucial for the performance safety of the High Purity Germanium （HPGe） detector, and in turn of great significance for long-term stable running of the energy measurement system. Therefore, as the first step, a NaI（T1） detector is constructed to continuously measure the radiation level of photons as background for future experiments. Furthermore, gamma and neutron dosimeters are utilized to explore the radiation distribution in the vicinity of the NCP where the HPGe detector will be located. Synthesizing all obtained information, the shielding for neutron irradiation is studied based on model-dependent theoretical analysis.

Measurement of radiation dose at the north interaction point of BEPC Ⅱ

The technique details for measuring radiation dose are expounded. The results of gamma and neutron radiation levels are presented and the corresponding radiation shielding is discussed based on the simplified estimation. In addition, the photon radiation level move as background for future experiments is measured by a NaI（T1） detector.