Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extitation of wakefield by a laser pulse in a metallic-density electron
  plasma   Since it is possible to form laser pulses with a frequency much larger than
the frequency of visible light, Prof. T.Tajima proposed using such pulse to
accelerate the particles at its injection into the crystal. Here, the wakefield
excitation in the metallic-density plasma and the electron acceleration by
laser pulse are simulated. The accelerating gradient has been ob-tained
approximately 3TV/m. It is shown that, as in ordinary plasma, with time
beam-plasma wakefield acceleration is added to laser wakefield acceleration.

33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph