Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Enhancement of Betatron radiation from laser-driven Ar clustering gas   Bright betatron x-ray has been generated using an Ar clustering gas jet
target irradiated with a 3 TW ultra-high contrast laser. The measured emission
flux with photon energy > 2.4 keV reaches 2\times10^8 photons/shot. It is
ten-fold enhancement comparing to the emission flux produced by using gas
target in the same laser parameters. Observation shows that much larger
electron beam charge and divergence angle lead to this improvement. Simulations
point to the existence of cluster in gas results in the increasing of electron
injection and much larger wiggling amplitude in wake-field, enriching the
betatron x-ray photons.

8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph