Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stochastic Acceleration of Electrons and Protons. I. Acceleration by
  Parallel Propagating Waves   Stochastic acceleration of electrons and protons by waves propagating
parallel to the large scale magnetic fields of magnetized plasmas is studied
with emphasis on the feasibility of accelerating particles from a thermal
background to relativistic energies and with the aim of determining the
relative acceleration of the two species in one source. In general, the
stochastic acceleration by these waves results in two distinct components in
the particle distributions, a quasi-thermal and a hard nonthermal, with the
nonthermal one being more prominent in hotter plasmas and/or with higher level
turbulence. This can explain many of the observed features of solar flares.
Regarding the proton to electron ratio, we include the effects of $^4$He in the
dispersion relation and the damping of the turbulent waves by the thermal
background plasma. The relative acceleration of protons and electrons is very
sensitive to the ratio of the electron plasma frequency to its gyro-frequency.
Protons are preferentially accelerated in weakly magnetized plasmas. The
formalism developed here is applicable to the acceleration of other ion species
and to other astrophysical systems.

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The categories of this paper are: econ
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The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: ao-sci
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The categories of this paper are: plasm-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: funct-an
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: cond-mat