Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Travelling Wakefield Tube: THz Source Powered by Nonrelativistic
  Electron Beam   High peak power, tunable, narrowband terahertz emitters are becoming sought
after given their portability, efficiency, and ability to be deployed in the
field for industrial, medical, and military applications. The use of
accelerator systems producing THz frequencies via Cherenkov radiation,
generated by passing an electron beam through a slow-wave wakefield structure,
is a promising method to meet future THz requirements. To date, efforts have
been dedicated to analysis and design of sources utilizing laser seeded bunched
electron beam drivers with relativistic energies beyond 5 MeV. Presented here
is a wakefield THz generation scheme based on passing a long quasi-dc
nonrelativistic beam (200 keV) through a dielectric loaded travelling wave
structure. Reduced energy allows for compactness and portability of the
accelerator as the size and weight of the dielectric slow wave structure is
vanishingly small compared to the accelerator unit. The presented scheme can
serve as a tunable high peak power THz source operated between 0.4-1.6 THz and
produces power gain by a factor of five with an average efficiency of 6.8\%.

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The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-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: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ex