Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variable Ion Compositions of Solar Energetic Particle Events in the
  Inner Heliosphere: A Field-line Braiding Model with Compound Injections   We propose a model for interpreting highly variable ion composition ratios in
solar energetic particles (SEP) events recently observed by Parker Solar Probe
(PSP) at $0.3 - 0.45$ astronomical unit. We use numerical simulations to
calculate SEP propagation in a turbulent interplanetary magnetic field with a
Kolmogorov power spectrum from large scale down to the gyration scale of
energetic particles. We show that when the source regions of different species
are offset by a distance comparable to the size of the source regions, the
observed energetic particle composition He/H can be strongly variable over more
than two orders of magnitude, even if the source ratio is at the nominal value.
Assuming a $^3$He/$^4$He source ratio of $10 \%$ in impulsive $^3$He-rich
events and the same spatial offset of the source regions, the $^3$He/$^4$He
ratio at observation sites also vary considerably. The variability of the ion
composition ratios depends on the radial distance, which can be tested by
observations made at different radial locations. We discuss the implication of
these results on the variability of ion composition of impulsive events and on
further PSP and Solar Orbiter observations close to the Sun.

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The categories of this paper are: q-bio
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ph
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The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
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The categories of this paper are: adap-org
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The categories of this paper are: econ
1
The categories of this paper are: cs
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The categories of this paper are: eess
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The categories of this paper are: math-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: solv-int
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The categories of this paper are: stat
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: q-alg