Iron cosmogenic isotopes

Voshage H. and Hintenberger H. (1963) The cosmic-ray exposure ages of iron meteorites as derived from the isotopic composition of potassium and the production rates of cosmogenic nuclides in the past. In Radioactive Dating, International Atomic Energy Agency, Vienna, pp. 367-379. 

He) were able to show that some iron meteorites and lunar rocks also have cosmogenic W isotope anomalies that are superimposed on the radiogenic isotope effects. For the lunar rocks, these anomalies were shown to be due to the Ta(n,Y) a reaction, induced by cosmic radiation, whereby the short-lived isotope a (T = 114 days) subsequently decays to [141]. For the iron meteorites, cosmic ray-induced reactions lead to both the production and consumption of various W isotopes. As a result of these reactions, many samples of both magmatic and non-magmatic irons appear to have ratios that are... 

Markowski, A., Leya, 1., Quitte, G., Ammon, K., Halliday, A.N., and Wieler, R. (2006) Correlated heliiun-3 and tungsten isotopes in iron meteorites quantitative cosmogenic corrections and planetesimal formation times. Earth Planet. Sci. Lett., 250, 104-115. 

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