Pair Creation in the Pulsar Magnetosphere

We present numerical simulations of the electron-positron plasma creationprocess in a simple neutron star magnetosphere. We have developed a set ofcascade `kernels', which represent the endpoint of the pair cascades resultingfrom monoenergetic photon seeds. We explore two popular models by convolvingthese kernels with the seed photon distributions produced by curvatureradiation and by inverse Compton scattering. We find that the pair plasma ineither case is well-described in its rest frame by a relativistic Maxwelliandistribution with temperature near mc^2/k_B. We present cascade multiplicitiesand efficiencies for a range of seed particle energies and stellar magneticfields. We find that the efficiencies and multiplicities of pair creation areoften lower than has been assumed in previous work.Comment: 38 pages, including 11 figures and 5 tables. To appear in the Astrophysical Journal. Uses the aastex macro