arXiv 0907.01262009-07-01nucl-ex

Search for long-lived isomeric states in neutron-deficient thorium isotopes

J. Lachner, I. Dillmann, T. Faestermann, G. Korschinek, M. Poutivtsev, G. Rugel

备注：: 3 pages, 1 figure
发表信息：: Phys.Rev.C78:064313,2008
DOI：: 10.1103/PhysRevC.78.064313

英文摘要：

The discovery of naturally occurring long-lived isomeric states (t_1/2 > 10^8 yr) in the neutron-deficient isotopes 211,213,217,218Th [A. Marinov et al., Phys. Rev. C 76, 021303(R) (2007)] was reexamined using accelerator mass spectrometry (AMS). Because AMS does not suffer from molecular isobaric background in the detection system, it is an extremely sensitive technique. Despite our up to two orders of magnitude higher sensitivity we cannot confirm the discoveries of neutron-deficient thorium isotopes and provide upper limits for their abundances.

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