Chinese Journal of Radiological Health 2024;33(6):626-630

doi:10.13491/j.issn.1004-714X.2024.06.002

Design and test of proportional counter for measurement of tritium in air

Yang LYU 1 ; Baoji ZHU 1 ; Yuanqiao LI 1 ; Xiaoxia LYU 1 ; Heng ZHU 1 ; Lijun XU 1 ; Min LIN 1

Affiliations

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Keywords

Low-level tritium; Proportional counter; Direct measurement; Plateau curve; Detection efficiency

Country

China

Language

Chinese

Abstract

Objective Ionization chamber detector is commonly used for direct and continuous measurement of tritium concentration in the air. However, the measurement sensitivity is low due to the limitations of weak current measurement technology. It is necessary to develop a proportional counter for measuring tritium in the air. Methods This study involved the design of a proportional counter, considering various factors such as materials and structure. The stability, plateau curve, detection efficiency, and energy spectrum of the counter were tested. Results The coefficient of variation of the proportional counter was 3.14%, which met the standard requirement of being less than 15%. The plateau length was 260 V and the plateau slope was 0.80%/100V, which met the requirement of being less than 1%/100V. The tritium detection efficiency reached 68.02%. The energy spectrum measurement indicated a significant difference between tritium signal generated by the proportional counter and background signal, and the distribution of tritium in the energy spectrum was more concentrated. The background counting rate during tritium gas activity measurement could be reduced through energy spectrum measurement. Conclusion The proportional counter can provide a reference for the direct and continuous measurement of tritium in the air.