Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Femtosecond resolved mega-gauss magnetic field evolution in an intense
  laser generated solid plasma   We report the first femtosecond resolved evolution of the giant magnetic
field in a solid plasma, produced by a 100 fs, 10^16 W cm^-2, 806 nm laser
field, using a pump-probe Faraday rotation technique.

7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph