Monte Carlo Simulations of Thermal-Nonthermal Radiation from a Neutron Star Magnetospheric Accretion Shell

We discuss the space-and-time-dependent Monte Carlo code we have developed to simulate the relativistic radiation output from compact astrophysical objects, coupled to a Fokker-Planck code to determine the self-consistent lepton populations. We highlight some major recent results obtained with this code,. They are relevant to the emission from a magnetized neutron star accretion shell near the Alfvén radius, reprocessing the radiation from the neutron sar surface. We explore the parameter space defined by the accretion rate, stellar surface field and the level of wave turbulence in the shell.