Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Acceleration of solar wind ions to 1 MeV by electromagnetic structures
  upstream of the Earth's bow shock   We present measurements from the ESA/NASA Cluster mission that show in situ
acceleration of ions to energies of 1 MeV outside the bow shock. The observed
heating can be associated with the presence of electromagnetic structures with
strong spatial gradients of the electric field that lead to ion gyro-phase
breaking and to the onset of chaos in ion trajectories. It results in rapid,
stochastic acceleration of ions in the direction perpendicular to the ambient
magnetic field. The electric potential of the structures can be compared to a
field of moguls on a ski slope, capable of accelerating and ejecting the fast
running skiers out of piste. This mechanism may represent the universal
mechanism for perpendicular acceleration and heating of ions in the
magnetosphere, the solar corona and in astrophysical plasmas. This is also a
basic mechanism that can limit steepening of nonlinear electromagnetic
structures at shocks and foreshocks in collisionless plasmas.

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The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
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The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom