Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evolution of clusters in energetic heavy ion bombarded amorphous
  graphite   Carbon clusters have been generated by a novel technique of energetic heavy
ion bombardment of amorphous graphite. The evolution of clusters and their
subsequent fragmentation under continuing ion bombardment is revealed by
detecting various clusters in the energy spectra of the direct recoils emitted
as a result of collision between ions and the surface constituents.

16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph