Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Measurement of Magnetic-Field Structures in a Laser-Wakefield
  Accelerator
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs