Measurement of 3H by β-excited X-ray emission in D2 gas loaded Ti

It is known that traces of 3H in D2 gas loaded targets could originate from 3H impurity in D2 gas which is obtained by electrolysis of heavy water. Measurement of trace amounts of 3H in D2 gas loaded Ti targets has been carried out by the detection of Ti K X-rays excited by β-particles emitted from 3H. Three targets of D2 gas loaded Ti were prepared in Isotope Group of BARC and nine other targets were obtained from Amersham (U.K.). These target were counted in an identical geometry by mounting at 1.5 cm from HP Ge detector (100 mm2 x 10 mm). Four tritium loaded Ti targets of known activities obtain from Isotope Group and Amersham were also counted in the same geometry to obtain a calibration factor for the measurement of 3H in D2 gas loaded Ti targets. The sensitivity of detection of 3H in Ti matrix has been calculated and found to be about 50 nanocurie. The activity of 3H in these targets was found to be in the range of 0.02 to 6.0 millicurie which is significantly higher than normally expected from the impurity of 3H and there is a wide variation of 3H activity of these targets for the same amount of D2 gas loaded in Ti. To understand the origin of 3H activity observed in these D2 gas loaded targets, experiments under controlled conditions are being pursued. (author). 3 refs., 1 tab., 4 figs