Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Coulomb Expansion of Cold Non-Neutral Rubidium Plasma   We study the expansion of a cold, non-neutral ion plasma into the vacuum. The
plasma is made from cold rubidium atoms in a magneto-optical trap (MOT) and is
formed via ultraviolet photoionization. We employ time-delayed plasma
extraction and imaging onto a position- and time-sensitive micro-channel plate
detector to analyze the plasma. We report on the formation and persistence of
plasma shock shells, pair correlations in the plasma, and
external-field-induced plasma focusing effects. We also develop trajectory and
fluid descriptions to model the data and to gain further insight. The
simulations verify the formation of shock shells and correlations, and allow us
to model time- and position-dependent density, temperature, and Coulomb
coupling parameter, $\Gamma({\bf{r}},t)$. This analysis both reaffirms the
presence of shock shells and verifies that the experimental plasma is strongly
coupled.

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The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: stat
5
The categories of this paper are: gr-qc
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The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-th
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The categories of this paper are: math-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
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The categories of this paper are: nlin