Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasi-monoenergetic Electron Beams from Laser-plasma Acceleration by
  Ionization-induced Injection in Low- density Pure Nitrogen   We report a laser wakefield acceleration of electron beams up to 130 MeV from
laser-driven 4-mm long nitrogen gas jet. By using a moderate laser intensity
(3.5*10^18 W.cm^(-2)) and relatively low plasma densities (0.8*10^18 cm^(-3) to
2.7*10^18 cm^(-3)) we have achieved a stable regime for laser propagation and
consequently a stable generation of electron beams. We experimentally studied
the dependence of the drive laser energy on the laser-plasma channel and
electron beam parameters. The quality of the generated electron beams is
discussed within the framework of the ionization-induced injection mechanism.

28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
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
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int