  During the recovery phase of a magnetic storm, fluxes of relativistic ($>1$
MeV) electrons in the inner magnetosphere ($3\le L \le 6$) increase to beyond
pre-storm levels, reaching a peak about 4 days after the initiation of the
storm. In order to account for the generation of these "killer electrons", a
model is presented primarily based on stochastic acceleration of electrons by
enhanced whistler-mode chorus. In terms of a quasi-linear formulation, a
kinetic (Fokker-Planck) equation for the electron energy distribution is
derived, comprising an energy diffusion coefficient based on gyroresonant
electron-whistler-mode wave interaction and parallel wave propagation; a source
term representing substorm-produced (lower energy) seed electrons; and a loss
term representing electron precipitation due to pitch-angle scattering by
whistler-mode waves and EMIC waves. Steady-state solutions for the electron
energy distribution are constructed, and fitted to an empirically-derived
relativistic Maxwellian distribution for the high energy "hard" electron
population at geosynchronous orbit. The mechanism is expected to be
particularly effective for the class of small and moderate storms possessing a
long-lasting recovery phase during which many substorms occur.
