Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Brilliant circularly polarized $\gamma$-ray sources via single-shot
  laser plasma interaction   Circularly polarized (CP) $\gamma$-ray sources are versatile for broad
applications in nuclear physics, high-energy physics and astrophysics. The
laser-plasma based particle accelerators provide accessibility for much higher
flux $\gamma$-ray sources than conventional approaches, in which, however, the
circular polarization properties of emitted $\gamma$-photons are used to be
neglected. In this letter, we show that brilliant CP $\gamma$-ray beams can be
generated via the combination of laser plasma wakefield acceleration and plasma
mirror techniques. In weakly nonlinear Compton scattering scheme with moderate
laser intensities, the helicity of the driving laser can be transferred to the
emitted $\gamma$-photons, and their average polarization degree can reach about
$\sim 37\%$ ($21\%$) with a peak brilliance of $\gtrsim 10^{21}~$photons/(s
$\cdot$ mm$^2 \cdot$ mrad$^2 \cdot$ 0.1% BW) around 1~MeV (100~MeV). Moreover,
our proposed method is easily feasible and robust with respect to the laser and
plasma parameters.

8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat