Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High Density Pulsed Molecular Beam for Cold Ion Chemistry   A recent expansion of cold and ultracold molecule applications has led to
renewed focus on molecular species preparation under ultrahigh vacuum
conditions. Meanwhile, molecular beams have been used to study gas phase
chemical reactions for decades. In this manuscript, we describe an apparatus
that uses pulsed molecular beam technology to achieve high local gas densities,
leading to faster reaction rates with cold trapped ions. We characterize the
beam's spatial profile using the trapped ions themselves. This apparatus could
be used for preparation of molecular species by reactions requiring excitation
of trapped ion precursors to states with short lifetimes or for obtaining a
high reaction rate with minimal increase of background chamber pressure.

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The categories of this paper are: hep-ex
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The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: cond-mat
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The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int
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The categories of this paper are: supr-con