Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collisionless electrostatic shock formation and ion acceleration in
  intense laser interactions with near critical density plasmas   Laser-driven collisonless electrostatic shock formation and the subsequent
ion acceleration have been studied in near critical density plasmas.
Particle-in-cell simulations show that both the speed of laser-driven
collisionless electrostatic shock and the energies of shock-accelerated ions
can be greatly enhanced due to fast laser propagation in near critical density
plasmas. However, a response time longer than tens of laser wave cycles is
required before the shock formation in a near critical density plasma, in
contrast to the quick shock formation in a highly overdense target. More
important, we find that some ions can be reflected by the collisionless shock
even if the electrostatic potential jump across the shock is smaller than the
ion kinetic energy in the shock frame, which seems against the conventional
ion-reflection condition. These anomalous ion reflections are attributed to the
strongly time-oscillating electric field accompanying laser-driven
collisionless shock in a near critical density plasma.

14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph