Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the Electromagnetic Design of a Beta_g= 0.61, 650 MHz Superconducting
  Radiofrequency Cavity
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin