Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modeling Accelerated Pick-up Ion Distributions at an Interplanetary
  Shock   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. The efficiency of injection of the pick-up ion component differs
from that of the solar wind, and is expected to be strongly enhanced at highly
oblique and quasi-perpendicular shock events, in accord with inferences from
{\it in situ} observations. This paper explores theoretical modeling of the
phase space distributions of accelerated ions obtained by the Ulysses mission
for the Day 292, 1991 shock associated with a corotating interaction region,
encountered before Ulysses' fly-by of Jupiter. A Monte Carlo simulation is used
to model the acceleration process, adapting a technique that has been
successfully tested on earlier IP shocks possessing minimal pick-up ion
presence. Phase space distributions from the simulation technique for various
low mass ions are compared with SWICS and HI-SCALE data to deduce values of a
``turbulence parameter'' that controls the efficiency of injection, and the
degree of cross-field diffusion. Acceptable fits are obtained for the $H^+$ and
$He^+$ populations using standard prescriptions for the pick-up ion
distribution; $He^{++}$ spectral data was only fit well for scenarios very
close to the Bohm diffusion limit. It is also found that the simulation
successfully accounts for the observation of energetic protons farther upstream
of the forward shock than lower energy pick-up protons, using the same
turbulence parameter that is required to achieve reasonable spectral fits.

0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn