Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Kinetic Electron and Ion Instability of the Lunar Wake Simulated at
  Physical Mass Ratio   The solar wind wake behind the moon is studied with 1D electrostatic
particle-in-cell (PIC) simulations using a physical ion to electron mass ratio
(unlike prior investigations); the simulations also apply more generally to
supersonic flow of dense magnetized plasma past non-magnetic objects. A hybrid
electrostatic Boltzmann electron treatment is first used to investigate the ion
stability in the absence of kinetic electron effects, showing that the ions are
two-stream unstable for downstream wake distances (in lunar radii) greater than
about three times the solar wind Mach number. Simulations with PIC electrons
are then used to show that kinetic electron effects can lead to disruption of
the ion beams at least three times closer to the moon than in the hybrid
simulations. This disruption occurs as the result of a novel wake phenomenon:
the non-linear growth of electron holes spawned from a narrow dimple in the
electron velocity distribution. Most of the holes arising from the dimple are
small and quickly leave the wake, approximately following the unperturbed
electron phase-space trajectories, but some holes originating near the center
of the wake remain and grow large enough to trigger disruption of the ion
beams. Non-linear kinetic-electron effects are therefore essential to a
comprehensive understanding of the 1D electrostatic stability of such wakes,
and possible observational signatures in ARTEMIS data from the lunar wake are
discussed.

22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio