  The acceleration of interstellar pick-up ions as well as solar wind species
has been observed at a multitude of interplanetary (IP) shocks by different
spacecraft. This paper expands upon previous work modeling the phase space
distributions of accelerated ions associated with the shock event encountered
on day 292 of 1991 by the Ulysses mission at 4.5 AU. A kinetic Monte Carlo
simulation is employed here to model the diffusive acceleration process. This
exposition presents recent developments pertaining to the incorporation into
the simulation of the diffusive characteristics incurred by field line
wandering (FLW), according to the work of Giacalone and Jokipii. For a pure
field-line wandering construct, it is determined that the upstream spatial ramp
scales are too short to accommodate the HI-SCALE flux increases for 200 keV
protons, and that the distribution function for H+ somewhat underpopulates the
combined SWICS/HI-SCALE spectra at the shock. This contrasts our earlier
theory/data comparison where it was demonstrated that diffusive transport in
highly turbulent fields according to kinetic theory can successfully account
for both the proton distributions and upstream ramp scales, using a single
turbulence parameter. The principal conclusion here is that, in a FLW scenario,
the transport of ions across the mean magnetic field is slightly less efficient
than is required to effectively trap energetic ions within a few Larmor radii
of the shock layer and thereby precipitate efficient acceleration. This
highlights the contrast between ion transport in highly turbulent shock
environs and remote, less-disturbed interplanetary regions.
