Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Accelerator Development at the FREIA Laboratory   The FREIA Laboratory at Uppsala University focuses on superconducting
technology and accelerator development. It actively supports the development of
the European Spallation Source, CERN, and MAX IV, among others. FREIA has
developed test facilities for superconducting accelerator technology such as a
double-cavity horizontal test cryostat, a vertical cryostat with a novel
magnetic field compensation scheme, and a test stand for short cryomodules.
Accelerating cavities have been tested in the horizontal cryostat,
crab-cavities in the vertical cryostat, and cryomodules for ESS on the
cryomodule test stand. High power radio-frequency amplifier prototypes based on
vacuum tube technology were developed for driving spoke cavities. Solid-state
amplifiers and power combiners are under development for future projects. We
present the status of the FREIA Laboratory complemented with results of recent
projects and future prospects.

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The categories of this paper are: math-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: hep-ex
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The categories of this paper are: q-fin
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The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
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The categories of this paper are: chem-ph
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The categories of this paper are: q-bio
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The categories of this paper are: math