Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A buffer gas beam source for short, intense and slow molecular pulses   Experiments with cold molecules usually begin with a molecular source. We
describe the construction and characteristics of a cryogenic buffer gas source
of CaF molecules. The source emits pulses with a typical duration of 240
$\mu$s, a mean speed of about 150 m/s, and a flux of $5\times 10^{10}$
molecules per steradian per pulse in a single rotational state.

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The categories of this paper are: cond-mat
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The categories of this paper are: bayes-an
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
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The categories of this paper are: hep-th
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
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The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
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The categories of this paper are: gr-qc