DECAY PROPERTIES OF TC-97M,TC-G

The half-life of Tc-97g was re-measured using the parental relations b etween Ru-97 and Tc-97m,Tc-g, and the isotope dilution method for dete rmining the number of atoms, and gamma and X-ray spectrometry for dete rmining the absolute disintegration rate. The proposed half-life is (4 .21 +/- 0.16) x 10(6) yr. The half life of Tc-97m and the EC-decay bra nching ratio of Tc-97m to Mo-97 were determined to be (91.4 +/- 0.8) d and (3.94 +/- 0.18)%, respectively. The EC decay branching ratio of R u-97 to Tc-97m was also re-determined to be (1.71 +/- 0.02) x 10(-4). (C) 1998 Elsevier Science B.V.