Spallation production of 3He, 21Ne,and 38Ar from target elements in the Bruderheim chondrite

The concentrations of noble gas isotopes of He, Ne and Ar have been measured in eight mineral separates of the Bruderheim chondrite. The cosmic-ray-produced nuclides ²¹Ne and ³⁸Ar were correlated by a computer least-squares fitting program with the elemental composition in each separate of potential targets for nuclear production yielding the following production equations: ${}^{21}\text{Ne, 10}{}^{\mathrm{?8}}\text{cm}{}^3\text{/g] = k(0.45Mg] + 0.085Si] + 0.060S] + 0.017Ca] + 0.0044Fe + Ni])}$; ${}^{38}\text{Ar, 10}{}^{\mathrm{?8}}\text{cm}{}^3\text{/g] = k(2.6K] + 0.37Ca] + 0.08Ti + Cr + Mn] + 0.021Fe + Ni])}$ with elemental concentrations in weight per cent and k equal to the reciprocal of the cosmic-ray exposure age of Bruderheim. The P(S)/P(Cr + Mn + Fe + Ni) weight production ratio for ³He was determined to be 1.53; relative productions of ³He from O, Mg and Si and ²¹Ne from Al proved to be incalculable.