Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Development of Fundamental Power Coupler for C-ADS Superconducting
  Elliptical cavities   5-cell elliptical cavities are chosen for the main linac of China Accelerator
Driven sub-critical System in the medium energy section. Each cavity is driven
by one fundamental power coupler delivering RF power up to 150 kW. A single
window, coaxial type coupler satisfying high power requirements, class 10 clean
room assembly with cavity and low heat load simultaneously was designed. This
paper gives the details of RF design, external Q calculation and thermal
analysis as well as multipacting simulations of the coupler.

33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph