Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Simulation study of a passive plasma beam dump using varying plasma
  density   A plasma beam dump uses the collective oscillations of plasma electrons to
absorb the kinetic energy of a particle beam. In this paper, a modified passive
plasma beam dump scheme is proposed using either a gradient or stepped plasma
profile to maintain a higher decelerating gradient compared to a uniform
plasma. The improvement is a result of the plasma wavelength change preventing
the re-acceleration of low energy particles. Particle-in-cell simulation
results show that both stepped and gradient plasma profiles can achieve
improved energy loss compared to a uniform plasma for an electron bunch of
parameters routinely achieved in laser wakefield acceleration.

19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an