A Sensitive Detector, System for the Continuous Monitoring of Tritium in the Air

A new design of a flow cell type of scintillation detector system suitable for continuous monitoring of tritium in the ambient air has been developed. The detector records 2500 counts per second with a single photomultiplier tvhbe type EMI 9514S for 1 MPC level of tritium activity release at 50 coutnts per second background and 2.5% coutnting efficiency. Possibility of designing detectors with an efficiency, comparable to that of liquid scintillators, has been discussed. The cell, filled with plastic scintillator powder, does not show any background build up over long periods of operation and has a low gamma response. The performance of the detector has been studied in detail and a complete tritiutm monitoring set up has been described.