Measurement of cross sections for 22Na, 20-22Ne and 36-42Ar in the spallation of Mg, Al, Si, Ca and Fe. Production ratios of some cosmogenic nuclides in meteorites

2014 We measured the cross sections of 22Na, 20,21,22Ne and 36,38,39,42Ar in nuclear reactions induced by the proton bombardment of Mg, Al, Si, Ca and Fe at several energies between 0.059 and 24 GeV using highsensitivy mass-spectrometry for noble gases and 03B3-counting for 22Na. We then evaluated the cross section ratio versus energy for the 22Na/22Ne, 26Al/21Ne, 39Ar/38Ar and 36Cl/36Ar radioactive-stable pairs of isotopes, which are useful for measuring the exposure age of meteorites. From the results alone, we can set some limits to the corresponding production ratios in iron meteorites, but not in stony objects because a knowledge of chemical abundances of Na, Mg, Al, Si, S, K, Ca, Fe, and shielding conditions are required. J. Physique 45 (1984) 855-861 MAl 1984,