Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vertical pairing of identical particles suspended in the plasma sheath   It is shown experimentally that vertical pairing of two identical
microspheres suspended in the sheath of a radio-frequency (rf) discharge at low
gas pressures (a few Pa), appears at a well defined instability threshold of
the rf power. The transition is reversible, but with significant hysteresis on
the second stage. A simple model, which uses measured microsphere resonance
frequencies and takes into account besides Coulomb interaction between
negatively charged microspheres also their interaction with positive ion wake
charges, seems to explain the instability threshold quite well.

18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
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The categories of this paper are: solv-int
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The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
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The categories of this paper are: eess
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph