Mound Technical Solutions
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Tritium Beta Scintillation Detectors
The beta scintillation detector (BSD) is used to measure a photocurrent that is linearly proportional to the partial pressure of tritium. Figure 1 shows the BSD sensitivity versus gas pressure; the sensitivity is constant (within 1%) which is linear response for pressures up to 10 Torr
Fig. 1. BSD sensitivity versus sample pressure for HDT-He samples (n) and HDT-He with 10% N2 (s) samples.
When calibrated to give tritium partial pressure from a sensitivity, S(Volts/Torr-T2), the mole percentage of total tritium can be computed:

where [P- P0] is the total sample pressure. The gas measurement condition that is necessary for linear response of the BSD is low pressure (< 10 Torr) such that absorption of the beta energy by the gas is minimal (about 1% or less) or predictable.
Fig. 2.
A Basic Analytical System for BSD measurement of process tritium