Mound Technical Solutions
BSD
© 2011 Mound Technical Solutions
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