Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The effect of cavity length detuning on the output characteristics for
  the middle infrared FEL oscillator of FELiChEM
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th