INGAS: Iranian Noble Gas Analyzing System for radioxenon measurement.

In this article, Iranian Noble Gas Analyzing System ( INGAS ) will be introduced. This system is based on beta–gamma coincidence technique and consists of a well-type NaI(Tl) as gamma or X radiation detector and a cylindrical plastic scintillator to detect beta or conversion electron. Standard NIM modules were utilized to detect coincidence events of detectors. Both the beta and gamma detectors were appropriately calibrated. The efficiency curve of gamma detector for volume geometry was obtained by comparing the results of gamma point sources measurements and simulations of GATE V7.0 Monte Carlo code. The performance of detection system was checked by injection of 222 Rn and 131m Xe gaseous source in the detection cell. The minimum detectable activity of the system for 133 Xe is 1.240±0.024 mBq for 24 h measurement time. [ABSTRACT FROM AUTHOR]