Depth-dependent fractionation of light solar wind noble gases in a Genesis target

We analyzed light noble gases in a bulk metallic glass (BMG) that was exposed to solar wind (SW) irradiation on Genesis for its total exposure time and all SW regimes [1]. The BMG was especially designed to look for a putative solar energetic particle (SEP) component, reported to be present in lunar soils [2], by using the closed system stepwise etching (CSSE) technique. Here we present the depth distribution of He and Ne isotopes and discuss different processes leading to the observed fractionation patterns. Moreover, this will be compared with measurements of Ar isotopes that are actually in progress.