Monitoring of tritium in diluted gases by detecting bremsstrahlung X-rays

For developing an alternative mean for on-line and real-time tritium monitoring, the method of detecting bremsstrahlung X-rays was examined by measuring the counting rate of bremsstrahlung X-rays as a function of pressure in two mixed tritium gases diluted with hydrogen or helium. At a constant tritium partial-pressure ratio of 0.010, the relationship between the counting rate of bremsstrahlung X-rays, X (cpm) and the total pressure, P (Pa) can be expressed as X = 4.1 × 105 (1 − e−4.0 P/100,000). The counting rate depends only on tritium partial-pressure and the total pressure if the mixed gases contain no other species but hydrogen isotopes and helium isotopes. In addition, the relation between X and P can be simplified to a linear function in the low-pressure region of P ≪ 2.5 × 104 Pa.