Cosmic ray gradients in the heliosphere based on isotope production rates in meteorites

Abstract

It is shown that the expected radial and latitudinal cosmic ray intensity gradients within the heliosphere produce significant changes in isotope production rates in meteorites over their orbital space. The variation in production rates has been estimated for seven short-lived isotopes ⁵²Mn, ⁴⁹V, ⁵¹Cr, ⁴⁶Sc, ⁵⁷Co, ⁵⁴Mn and ²²Na for five meteorites Pribram, Lost City, Dhajala, Innisfree and Mbale for which orbital parameters are known. A comparison with the measured activity levels imply that accurate measurements of short lived isotopes in meteorites of known orbital parameters can give useful information about cosmic ray gradients and their time variations.