Rhenium Osmium Chronometer

The rhenium osmium chronometer is a method of radiometric age determination .

The isotope ¹⁸⁷ Re ( rhenium ) has a half-life of 4.12 · 10 ¹⁰ years. This long half-life allows the nuclide pair ¹⁸⁷ Re and ¹⁸⁷ Os ( osmium ) to be used as a chronometer for the r-process . This idea originally came from DE Clayton . ¹⁸⁷ Re is generated exclusively in the r process, while ¹⁸⁷ Os is primarily generated exclusively in the S process . The S-process frequency of ¹⁸⁷ Os can be inferred from the neighboring ^{isotope 188} Os . The remaining ¹⁸⁷ Os must have been created by the decay of ¹⁸⁷ Re. The ratio of the frequencies of ¹⁸⁷ Re and the not primarily generated ¹⁸⁷ Os is then correlated with the beginning of r-process events in our galaxy and thus also with the age of our galaxy.

Individual evidence

↑ Smoliar, MI, Walker, RJ and Morgan, JW (1996). Re-Os ages of group IIA, IIIA, IVA, and IVB iron meteorites. Science 271, pp. 1099-1102
↑ Bosch: Observation of bound-state β- decay of fully ionized ¹⁸⁷ Re: ¹⁸⁷ Re- ¹⁸⁷ Os Cosmochronometry . In: Physical Review Letters . 77, No. 26, 1996, pp. 5190-5193. doi : 10.1103 / PhysRevLett.77.5190 .

[1] Smoliar, MI, Walker, RJ and Morgan, JW (1996). Re-Os ages of group IIA, IIIA, IVA, and IVB iron meteorites. Science 271, pp. 1099-1102

[Bosch1996-2] Bosch: Observation of bound-state β- decay of fully ionized ¹⁸⁷ Re: ¹⁸⁷ Re- ¹⁸⁷ Os Cosmochronometry . In: Physical Review Letters . 77, No. 26, 1996, pp. 5190-5193. doi : 10.1103 / PhysRevLett.77.5190 .