897. 無機粉末螢光体による慣性核融合用DT充填システム中のトリチウム分圧の測定

抄録

A compact tritium sensor has been developed at Institute of Laser Engineering to measure the partial pressure of tritium in the deuterium-tritium (DT) fueling system for inertia confinement fusion target. The inside of tritium sensor is filled with fluorescent powder which is optically coupled to a light out put digitizer with a photomultiplier through an optical fiber.
Fluorescent powder of hexa-ZnS: Cu, cubic-ZnS: Cu, ZnS: Ag, ZnS: Cu: Al, ZnS: Au: Cu: AI, (Zn·Cd) S: Cu: Al, (Zn·Cd) S: Ag, Zn₂SiO₄: Mn, Y₂O₂S: Tb, Y₂SiO₅: Ce, Y₃Al₅O₁₂: Tb and Y₃Al₅ O₁₂: Ce were examined in the view point of sensitivity, 1inearity, signal to noise ratio, effect of particle size and radiation damage. Intensity of luminance emitted from each varieties of powder exposed by the DT mixture was in direct proportion to tritium partial pressure under total DT pressurer of 0.07 to 7 atm. Fluorescent powder of Zn₂SiO₄: Mn, cubic-ZnS: Cu and (Zn·Cd) S: Cu: Al gave sufficiently luminance to detect tritium in the low pressure line of the DT fueling system. Luminance from Zn₂SiO₄: Mn increased in good proportion to the partial pressure of tritium, The accuracy of this measurement was estimated to be±3%. The use of powder was very beneficial to reduce saturation of luminance intensity due to absorption of β-ray by DT gas.