Neutron capture on (180)Ta(m): clue for an s-process origin of nature's rarest isotope.
The neutron capture cross section of (180)Ta(m) has been measured in the keV range, yielding a stellar average of 1465+/-100 mb at kT = 30 keV. Though the sample contained only 6.7 mg (180)Ta(m) (at an enrichment of 5.5%), the few capture events could be separated from much larger backgrounds by a unique combination of high efficiency, good energy resolution, and high granularity of the Karlsruhe 4 pi BaF(2) detector. A detailed s-process analysis based on this first experimental value indicates that (180)Ta(m) is predominantly of s-process origin.
Wisshak
K
K
Forschungszentrum Karlsruhe, Institut für Kernphysik, Postfach 3640, D-76021 Karlsruhe, Germany. wisshak@ik3.fzk.de
Voss
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Arlandini
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Becvár
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Straniero
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Gallino
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Heil
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Käppeler
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Krticka
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Masera
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Reifarth
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Travaglio
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