Atomic Energy Science and Technology ›› 2020, Vol. 54 ›› Issue (3): 385-393.

### Measurement of Beam Profile of CSNS Back-n

HAN Changcai;OUYANG Xiaoping;ZHANG Xianpeng;SONG Zhaohui;BAO Jie;YAN Weipeng

1. Northwest Institute of Nuclear Technology, Xi’an 710024, China;China Institute of Atomic Energy, Beijing 102413, China
• Online:2020-03-20 Published:2020-03-20

### 中国散裂中子源反角白光中子束斑测量

1. 西北核技术研究院，陕西 西安710024；中国原子能科学研究院，北京102413

Abstract:

The measurement of neutron beam profile will provide fundamental data for subsequent nuclear data measurements and other physical experiments. A high performance intensified CMOS camera based on neutron energy resolved imaging system with time-of-flight technique was developed at China Spallation Neutron Source, and its spatial resolution is less than 1 mm. Some typical characteristic parameters of the neutron beam, such as beam profile, beam size and non-uniformity were obtained and analyzed. At ES1 and ES2 (experiment station 1 and 2), which are about 55 and 75 m away from the target respectively, the FWHMs of neutron beam profile are 55 and 63 mm respectively, and the full widths of 75% maximum are 50 and 60 mm respectively, and the beam profile is well-defined and step like. The results show that the beam profile, size and non-uniformity are not dependent on neutron energy, even the non uniformity in the center of the beam profile is less than 10%. With the well-defined contour and elegant non-uniformity of the beam profile, the nuclear data can be measured successfully.