Theoretical design of a solid scintillation detector for tritium surface contamination measurement based on CaF2(Eu) sheet and self-coincidence technology of MCP-PMT

Yang Yang; Zhilin Chen; Caifeng Lai; Po Huang; Yu Li

doi:10.1016/j.apradiso.2024.111200

Theoretical design of a solid scintillation detector for tritium surface contamination measurement based on CaF₂(Eu) sheet and self-coincidence technology of MCP-PMT

Appl Radiat Isot. 2024 Apr:206:111200. doi: 10.1016/j.apradiso.2024.111200. Epub 2024 Jan 27.

Authors

Yang Yang¹, Zhilin Chen², Caifeng Lai¹, Po Huang¹, Yu Li¹

Affiliations

¹ Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, China.
² Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, China. Electronic address: chenzhilin@caep.cn.

PMID: 38324937
DOI: 10.1016/j.apradiso.2024.111200

Abstract

Measurement of tritium surface contamination is important for tritium related facilities, especially for fusion devices. A novel detector has been designed for tritium surface contamination measurements based on CaF₂(Eu) sheet and Microchannel plate photomultiplier tube (MCP-PMT). Self-coincidence technology has been introduced to obtain lower detection limit by diminishing the background noise caused by γ-rays and hot electrons. Performance of the detector was optimized by specifying the key parameters including the distance of the scintillator and sample, the thickness of light guide, the number of annular electrodes et al., using Monte Carlo method. Results indicate that detection efficiency of 49.4 % and the response deviations at different positions less than 0.5 % could be achieved. The detection limit of tritium under the simulation conditions is 0.09 Bq/cm² and 0.03 Bq/cm² when the counting time is 10 s and 60 s, respectively.

Keywords: MCP-PMT; Monte Carlo simulation; Self-coincidence; Tritium surface contamination.