학술논문
A CsI hodoscope on CSHINE for Bremsstrahlung {\gamma}-rays in Heavy Ion Reactions
Document Type
Working Paper
Author
Qin, Yuhao; Guo, Dong; Xiao, Sheng; Wang, Yijie; Guan, Fenhai; Diao, Xinyue; Qin, Zhi; Si, Dawei; Zhang, Boyuan; Zhang, Yaopeng; Wei, Xianglun; Yang, Herun; Ma, Peng; Zou, Haichuan; Qiu, Tianli; Huang, Xinjie; Hu, Rongjiang; Duan, Limin; Duan, Fangfang; Hu, Qiang; Ma, Junbing; Xu, Shiwei; Bai, Zhen; Yang, Yanyun; Xiao, Zhigang
Source
Subject
Language
Abstract
Bremsstrahlung $\gamma$ production in heavy ion reactions at Fermi energies carries important physical information including the nuclear symmetry energy at supra-saturation densities. In order to detect the high energy Bremsstrahlung $\gamma$ rays, a hodoscope consisting of 15 CsI(Tl) crystal read out by photo multiplier tubes has been built, tested and operated in experiment. The resolution, efficiency and linear response of the units to $\gamma$ rays have been studied using radioactive source and $({\rm p},\gamma)$ reactions. The inherent energy resolution of $1.6\%+2\%/E_{\gamma}^{1/2}$ is obtained. Reconstruction method has been established through Geant 4 simulations, reproducing the experimental results where comparison can be made. Using the reconstruction method developed, the whole efficiency of the hodoscope is about $2.6\times 10^{-4}$ against the $4\pi$ emissions at the target position, exhibiting insignificant dependence on the energy of incident $\gamma$ rays above 20 MeV. The hodoscope is operated in the experiment of $^{86}$Kr + $^{124}$Sn at 25 MeV/u, and a full $\gamma$ energy spectrum up to 80 MeV has been obtained.
Comment: 9 pages, 19 figures
Comment: 9 pages, 19 figures