论文信息 - Search for the decay of 180Tam.

Search for the decay of 180Tam.

A sample of Ta/sub 2/O/sub 5/ containing 151 mg of Ta enriched to 5.47% in /sup 180/Ta/sup m/ was counted in a well-type high-purity Ge detector. This was enclosed in a large NaI(Tl) detector operated in anticoincidence to reduce the cosmic-ray continuum background. Several runs of approx.100 days each were made under different conditions to search for ..gamma..-ray singles or summing peaks that would follow the electron capture decay of /sup 180/Ta/sup m/ to /sup 180/Hf or the ..beta../sup -/ decay to /sup 180/W. Lower limits derived were T/sub 1/2/>3.0 x 10/sup 15/ yr, logf/sub 0/t>22.9 for electron capture decay and T/sub 1/2/>1.9 x 10/sup 15/ yr, logf/sub 0/t>21.3 for ..beta../sup -/ decay. The total half-life of /sup 180/Ta/sup m/ is therefore T/sub 1/2/>1.2 x 10/sup 15/yr.

Cumming | Alburger

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