Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evolution of the electric fields induced in high intensity laser-matter
  interactions   Multi MeV protons \cite{snavely2000intense} and heavier ions are emitted by
thin foils irradiated by high-intensity lasers, due to the huge accelerating
fields, up to several teraelectronvolt per meter, at sub-picosecond timescale
\cite{dubois2014target}. The evolution of these huge fields is not well
understood till today. Here we report, for the first time, direct and
temporally resolved measurements of the electric fields produced by the
interaction of a short-pulse high-intensity laser with solid targets. The
results, obtained with a sub-$100$ fs temporal diagnostics, show that such
fields build-up in few hundreds of femtoseconds and lasts after several
picoseconds.

5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org