Radiation Safety Systems Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085, India.
Technical Physics Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085, India.
Radiat Prot Dosimetry. 2020 Sep 16;190(3):307-319. doi: 10.1093/rpd/ncaa103.
A single stage vacuum-type proton recoil neutron telescope (PRT) was used for accurate measurement of 14.57 MeV neutron fluence rate from an indigenously developed D-T neutron generator at Purnima, BARC. The telescope consists of a polyethylene radiator having 4 cm diameter and CsI (Tl) scintillation crystal having thickness 1.5 mm and 4 cm diameter separated by 20.5 cm kept in a vacuum chamber. The neutron detection efficiency of the telescope for 14.57 MeV neutrons was calculated analytically using n-p scattering cross section data from Evaluated Nuclear Data File VII and also evaluated using fluka simulation. The relativistic transformation of n-p differential scattering cross section from centre-of-mass to laboratory system was used for calculating the efficiency of PRT. The 14.57 MeV neutron fluence rate was also measured using copper foils. The comparison of fluence rate measured using PRT and copper foil activation techniques is presented in this paper. The total uncertainty in measurement using PRT and copper foil activation technique is found to be 3.93 and 6.97%, respectively.
一个单级真空型质子反冲中子望远镜（PRT）被用于在 Purnima，BARC 上对源自印度的 D-T 中子发生器的 14.57 MeV 中子注量率进行精确测量。望远镜由一个直径为 4 厘米的聚乙烯辐射器和一个厚度为 1.5 毫米、直径为 4 厘米的 CsI（Tl）闪烁晶体组成，两者之间用 20.5 厘米的距离隔开，放置在一个真空室内。使用从评价核数据库第七版获得的 n-p 散射截面数据，通过分析计算了望远镜对 14.57 MeV 中子的探测效率，也通过 fluka 模拟进行了评估。使用质心系到实验室坐标系的 n-p 微分散射截面的相对论变换，计算了 PRT 的效率。本文还介绍了使用 PRT 和铜箔活化技术测量 14.57 MeV 中子注量率的比较。使用 PRT 和铜箔活化技术测量的总不确定度分别为 3.93%和 6.97%。
