# Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2014, Vol. 25 ›› Issue (5): 050101

• SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS •

### Dose rate distribution of photoneutrons in an ID beamline of SSRF: simulations and measurements

XU Jia-Qiang,1 XIA Xiao-Bin,1 SHENG Yin-Xiang-Zi,1 SHEN Wei-Zu,1 XU Xun-Jiang1

1. 1Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
• Contact: XIA Xiao-Bin E-mail:xiaxiaobin@sinap.ac.cn
XU Jia-Qiang, XIA Xiao-Bin, SHENG Yin-Xiang-Zi, SHEN Wei-Zu, XU Xun-Jiang. Dose rate distribution of photoneutrons in an ID beamline of SSRF: simulations and measurements.Nuclear Science and Techniques, 2014, 25(5): 050101

Abstract:

Photoneutrons, emitted by means of photonuclear interactions when gas bremsstrahlung interacts with beamline components, can be another potential radiation source needed to be considered for shielding design and dose assessment of beamline. In this paper, simulations and measurements of photoneutrons dose rate at beamline BL09U are carried out when Shanghai Synchrotron Radiation Facility (SSRF) running at Top-up mode (3.5 GeV, 235 mA). A geometry model is constructed for the beamline BL09U with considerations of the scattering process of the major optical components. The model is compiled into Monte Carlo simulation code FLUKA to calculate photoneutron dose distribution. Measurements of the photoneutrons dose rate were performed by using Environmental Neutron Monitor (ENM). Observation points were arranged uniformly along the inside and outside of the optical enclosure (OE) of BL09U. The calculation results agree with experiments within the measurements uncertainties. It is verified that photoneutrons dose simulation is reliable. The simulation and measurement methods can be applied to evaluate the neutron dose level of other beamline stations, and provide references for the shielding design of the beamlines at SSRF in the near future.