Element Percent Welght

A number of studies have analyzed the production rates of various particles and elemental species by planetary surfaces when bombarded with Galactic Cosmic Ray (GCR) fluxes, either theoretically [I-21 or by means of various transport codes [3-51 some of which have emphasized neutron fluxes [6-81. Here we report on the preliminary results of our Monte Carlo study of the production of neutrinos by the lunar surface using GEANT [9], developed and produced at CERN. The effects of charm [ lo] are not included, and will be the subject of later work. The model for the lunar surface was taken to be the chemical composition of average soils found at various lunar landing sites during the Apollo and Luna programs [11], and then averaging again over all landing sites in order to define a generic regolith for the present analysis. The resulting weight percentages by element were calculated and are given in Table 1. These were the 13 elemental abundances measured to be present on the Moon with more than a trace, having atomic number A and charge Z. The lunar surface model was assumed to have a mean density of 2.85 g cm-3 [12] and a negligible magnetic field