Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Temperature of the Source Plasma for Impulsive Solar Energetic Particles   The steep power-law dependence of element abundance enhancements on the
mass-to-charge ratios [A/Q] of the ions in impulsive solar energetic-particle
(SEP) events causes these enhancements to reflect the temperature-dependent
pattern of Q of the ions in the source plasma. We searched for SEP events from
coronal plasma that is hotter or cooler than the limited region of 2.5 - 3.2 MK
previously found to dominate 111 impulsive SEP events. Fifteen new events were
found, four (three) originated in 2-MK (4-MK) plasma, but none from outside
this temperature range. Although the impulsive SEP events are strongly
associated with flares, this result indicates that these ions are not
accelerated from flare-heated plasma, which can often exceed 10 MK. Evidently
the ions of 2 - 20 MeV/amu that we observe in space are accelerated from
active-region plasma on open magnetic-field lines near the flare, but not from
the closed loops of the flare. The power-law dependence of the abundance
enhancements on A/Q of the ions is expected from theoretical models of
acceleration from regions of magnetic reconnection.

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The categories of this paper are: nlin
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: cmp-lg
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The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: quant-ph
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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: bayes-an
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The categories of this paper are: hep-th