W.R. Webber
     New Mexico State University, Las Cruces, New Mexcio, 88003, USA

We have used a Monte Carlo diffusion model to describe the propagation of cosmic ray particles in the galaxy. This model uses realistic dependences for the matter density, the size of the galactic halo, the diffusion coefficient, etc., to describe this motion. The results are similar in may respects to those of Leaky Box models, but interesting differences, subject to measurement by ACE and other high precision instruments are evident. In this paper we focus on these differences as they relate to: 1) The effect of the matter density on the spectra of nuclei from ~1-100 GeV and how it influences the determination of the primary spectral index of these nuclei; 2) The effect of the matter density and the halo size on the ³He/⁴He, B/C and sub Fe/Fe ratios; 3) The effect of all of these propagation parameters on the surviving fractions of the radioactive clock isotopes including ¹⁴C and on the secondary K-capture isotopes.