Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Injection to rapid diffusive shock acceleration at perpendicular shocks
  in partially ionized plasmas   We present a three-dimensional hybrid simulation of a collisionless
perpendicular shock in a partially ionized plasma for the first time. In this
simulation, the shock velocity and the upstream ionization fraction are Vsh ~
1333 km/s and fi ~ 0.5, that are typical values for isolated young supernova
remnants in the interstellar medium. We confirm previous two-dimensional
simulation results that downstream hydrogen atoms leak into the upstream
region, they are accelerated by the pickup process in the upstream region, and
large magnetic field fluctuations are generated both in the upstream and
downstream regions. In addition, we find that the magnetic field fluctuations
have three-dimensional structures and the leaking hydrogen atoms are injected
to the diffusive shock acceleration at the perpendicular shock after the pickup
process. The observed diffusive shock acceleration can be interpreted as the
shock drift acceleration with scattering. Particles are accelerated to v ~ 100
Vsh ~ 0.3c within ~ 100 gyroperiods in this simulation. The acceleration time
scale is faster than that of the diffusive shock acceleration in parallel
shocks. Our simulation results suggest that supernova remnants can accelerate
cosmic rays to 10^{15.5} eV (the knee) during the Sedov phase.

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The categories of this paper are: cond-mat
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The categories of this paper are: math
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The categories of this paper are: nlin
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The categories of this paper are: cs
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-alg
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The categories of this paper are: comp-gas
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ph