Calibration of Tritium Microcalorimeter and Calorimetric Verification of Tritium Samples

• Published in: Tong wei su Vol. 36; no. 4; pp. 440 - 445
• Main Author: OUYANG Huiping;YUAN Xiaoming;HE Changshui;LI Zhuoxi;ZHANG Peixu;YANG Hongguang
• Format: Journal Article
• Language: Chinese
• Published: Editorial Board of Journal of Isotopes 01.08.2023
• Subjects: detection limit; microcalorimeter; tritium activity
• ISSN: 1000-7512
• DOI: 10.7538/tws.2022.youxian.023

Radioactive isotope decay gives off heat, which is an important basis for calculating the activity of radioactive isotope. In order to measure the heat emitted by tritium decay, the detection limit test, working curve calibration and tritium sample measurement verification of a low detection limit microcalorimeter of μW grade were carried out. The measurement results show that the detection limit of microcalorimeter is 1.28 μW, i.e. 38 mCi tritium. In this paper, the output thermoelectric potential U-input thermal power P of microcalorimeter was calibrated in the range of 165-5063 μW (5-50 Ci tritium), and the calibration relationship obtained is U（μV）=0.141P（μW）, corresponding to the relation between tritium activity and output thermoelectric potential A（Ci）=0.213U（μV）, and the liner correlation coefficient is greater than 0.999. The standard deviation of repeated measurement of tritium samples was 1.14%, and the deviation from PVT method was 2.45%. In order to ensure the consistency of measurement, the calo