Phys. Rev. Lett. 93, 172501 (2004) [4 pages]New Half-Life Measurement of 182Hf: Improved Chronometer for the Early Solar SystemReceived 27 May 2004; published 20 October 2004 The decay of 182Hf, now extinct, into stable 182W has developed into an important chronometer for studying early solar system processes such as the accretion and differentiation of planetesimals and the formation of the Earth and the Moon. The only 182Hf half-life measurements available were performed 40 years ago and resulted in an imprecise half-life of (9±2)×106 yr. We redetermined the half-life by measuring the specific activity of 182Hf based on two independent methods, resulting in a value of t1/2(182Hf)=(8.90±0.09)×106 yr, in good agreement with the previous value, but with a 20 times smaller uncertainty. The greatly improved precision of this half-life now permits very precise intercalibration of the 182Hf–182W isotopic system with other chronometers. © 2004 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.93.172501
DOI:
10.1103/PhysRevLett.93.172501
PACS:
21.10.Tg, 27.70.+q, 91.35.Nm, 96.35.Cp
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.