Gaseous Tritium Activity Monitoring with Scintillators (GaTAMoS)

Abstract

We present a novel device for the inline activity monitoring of gaseous tritium, named Gaseous Tritium Activity Monitoring with Scintillators (GaTAMOS). Unlike established methods that often rely on liquid scintillation or plastic scintillators with limited chemical resistance, this system utilises a chemically inert, inorganic Terbium-activated Gadolinium Oxysulfide (Gd2O2S:Tb) ceramic. A specialised soldering technique was developed to join the ceramic scintillator to a stainless-steel flange, achieving a vacuum-tight seal fully compatible with high-purity tritium applications. The device was characterised using pure tritium gas, demonstrating a linear response and high sensitivity across a dynamic range from < 1 kBq to >10 GBq. A key advantage of the ceramic material over organic alternatives is its high tolerance to aggressive cleaning agents. We demonstrate that the inevitable tritium memory effect can be significantly mitigated by flushing the cell with ethanol, removing >95% of residual contamination within minutes. The proposed system offers a compact, robust, and cost-effective alternative to ionisation chambers or BIXS systems for process monitoring in tritium handling facilities.