PROPERTIES OF THE (150)(69)TM(81)6(-) BETA-DECAYING ISOMER

Decay experiments for Ho-148 6(-) and Tm-150 6(-) were carried out at the GSI On-line mass separator using 5 MeV/A Ni-58-beams on Mo-94 and Ru-96 targets. Gamma gamma-and gamma X-coincidences established the Tm -150 6(-) decay scheme, and e(-) gave firm I-pi assignments for Dy-148 and Er-150 levels fed in the decays. It was found that the previously unknown 6(1)(-) state in Er-150 receives significant beta-strength, w hich strongly suggests pi h(11/2)nu s(1/2)(-1) character for the Tm-15 0 1/2 6(-) isomer. The results are discussed in terms of the expected GT strength function. Shell mode calculations for the pi h(11/2)(4) yr ast states are presented.