Monte Carlo calculations of cosmic ray electron and nuclei diffusion in the galaxy—A comparison of data and predictions

Abstract

We have made detailed calculations of cosmic ray electron and nuclei spectra using a Monte Carlo program for diffusion and energy changes during propagation in the galaxy. A comparison of the results with data indicates that all of the secondary to primary ratios, 3 He 4 He , B C and ( Z=21–23) Fe can be fit with the same set of diffusion parameters. These parameters also reproduce well the measured electron spectrum. Instead of specifying a path length in g/cm 2 to fit the observation as required in leaky box propagation models, the Monte Carlo calculations require physical and observable parameters. For example the best fit parameters require the line integral of n, the total hydrogen column density perpendicular to the disk, to be ∼ 15 × 10 20 cm −2 which is close to the measured value.