On the influence of the initial pitch angle distribution on relativistic electron beam dynamics

Simulations of the evolution of a relativistic electron beam injected into the Earth's magnetosphere are examined. It is found that the lifetime of be am particles strongly depends on the initial pitch angle distribution and t hat lifetimes similar to those found for the radiation belts are obtained f or nearly equatorially mirroring injections. It is concluded that the resul ts of our previous study on beam propagation [Khazanov et al.,1999], which only considered upper ionospheric injections, are consistent with other rel ativistic electron studies and should be regarded as an examination of the loss cone edge population, whether naturally occurring or artificially inje cted into near-Earth space.