Laser fast neutron measured by bubble detector
Authors: Zhao Lei  , Xu Miao-Hua  , Zhang Yi-Hang  , Zhang Zhe  , Zhu Bao-Jun  , Jiang Wei-Man  , Zhang Xiao-Peng  , Zhao Xu  , Tong Bo-Wei  , He Shu-Kai  , Lu Feng  , Wu Yu-Chi  , Zhou Wei-Min  , Zhang Fa-Qiang  , Zhou Kai-Nan  , Xie Na  , Huang Zheng  , Zhong Jia-Yong  , Gu Yu-Qiu  , Li Yu-Tong  , Li Ying-Jun  ,   State Key Laboratory for GeoMechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing 100083, China;,   Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;,   School of Physical Sciences, University of Chinese Academy of Science, Beijing 100049, China;,   Collaborative Innovation Center of IFSA(CICIFSA, Shanghai Jiao Tong University, Shanghai 200240, China;,   School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China;,   Department of Astronomy, Beijing Normal University, Beijing 100875, China;,   Science and Technology on Plasma Physics Laboratory, Research Center of Laser Fusion, CAEP, Mianyang, 621900, China
Published: December 2020

Neutron source has broad application prospects in crystallography, neutron irradiation, neutron therapy for cancer, and so on. As a new scheme to produce bright pulsed neutron source, the laser-driven neutron has attracted wide interest. In recent years, laser driven neutron sources have been extensively studied and the great progress has been made. Short pulsed laser driven neutron sources could be a compact and relatively cheap way to produce quasi-monoenergetic neutrons. The yields and the angular distributions of the laser-driven neutron sources are important in the research of laser-driven neutron sources and relevant applications. We conduct experimental investigation of this respect by using the XingGuang-Ⅲ high intense laser facility, which delivers synchronized picosecond and nanosecond laser pulses. The picosecond laser energy is 100 J, the pulse width is 1 ps, and the focusing spot diameter is 20 μm. At this time, the corresponding laser power density reaches 3×1019 W/cm2. A high-energy deuterium ion beam is produced by focusing the picosecond laser on a deuterated polyethylene foil, and the deuterium ion beam is incident on a secondary deuterated polyethylene planar target to activate the D-D reaction to obtain the neutron beam. In the experiment, the neutron yield and its angular distribution are measured by the different-sensitivity BD-PND bubble detectors, which are placed in the target chamber around the target. The emission of the neutron beam is found to be non-uniform. A maximum intensity of 5.13×107 n/sr is observed in the forward direction. The angular distribution of the neutron beam is theoretically calculated by taking into account the energy-angle cross section, the angular and energy distribution of the incident deuterium ion beam. The probability of the neutron energy-angle distribution in the laboratory system is obtained by the coordinate transformation from the probability in the center of mass frame. The results show good agreement with the experimental measurements. This experiment has a certain reference value in the practical application of D-D reaction neutron source.