Development of Rn/Tn Compensated Gas Monitors for β Nuclides
作者单位：ALOKA Co. LTD. 6-22-1MureMitaka-shiTokyo181-8622Japan ALOKA Co. LTD. 6-22-1MureMitaka-shiTokyo181-8622Japan
会议名称：《The Second Asian and Oceanic Congress for Radiation Protection》
会议日期：2006年
学科分类：082803[工学-农业生物环境与能源工程] 08[工学] 0828[工学-农业工程] 0804[工学-仪器科学与技术]
关 键 词：Rn Tn gas monitor ionization chamber ventilation alpha particle exhaust gas
摘 要：A circuit was devised for removing the influence of Rn and Tn on an ionization chamber gas monitor for β rays. The circuit subtracted the current due to Rn and Tn from the gross current. A monitor installed the circuit canceled the concentration variation of Rn and Tn caused by ventilation condition. The background level of the gas monitor compensated the influence of Rn and Tn was reduced by 10%. The minimum detectable concentrations of the compensated monitor were lower than the legal concentration limits in exhaust gas of 8 radioisotopes used in life science research and nuclear medicine: 3H, 14C, 24Na, 51Cr, 67Ga, 75Se, , 89Sr, 99mTc, and 3 main radioisotopes discharged from the nuclear power plants: 85Kr , 41Ar and 133Xe.