Nuclear field shift effect as a possible cause of Te isotopic anomalies in the early solar system-An alternative explanation of Fehr et al. (2006 and 2009)

作者：Moynier Frederic^*; Fujii Toshiyuki; Albarede Francis

来源：Meteoritics & Planetary Science, 2009, 44(11): 1735-1742.

DOI：10.1111/j.1945-5100.2009.tb01203.x

We explore the possibility that Te isotopic anomalies measured in Ca-Al-rich inclusions (Fehr et al. 2009) and in leachates of carbonaceous chondrites (Fehr et al. 2006) may be due to mass-independent effects controlled by nuclear field shift rather than to nucleosynthetic processes. Fehr et al.'s spectrum of mass-independent anomalies of Te isotopes shows a smooth correlation with mass number and nuclear charge distribution. Ratios of even to odd isotopes, as file (125)Te/(126)Te ratio used by these authors for normalization are particularly prone to nuclear Field shift effects. We show that the alternative normalization of isotopic ratios to (130)Te/(126)Te strongly reduces the trend of isotopic fractionation with mass number, leaving only (125)Te as truly anomalous.
For both normalizations ((125)Te/(126)Te and (130)Te/(126)Te), Fehr et al.'s results fit the theory of Bigelcisen (1996), which Suggests that the nuclear field shift effect call potentially account for the observed Te isotope abundances, as all alternative to nucleosynthetic processes.
We propose that these mass-independent effects may be acquired during accretion of sulfides from the solar nebula.

• 出版日期2009-11