Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collisions of Slow Highly Charged Ions with Surfaces   Progress in the study of collisions of multiply charged ions with surfaces is
reviewed with the help of a few recent examples. They range from fundamental
quasi-one electron processes to highly complex ablation and material
modification processes. Open questions and possible future directions will be
discussed.

18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
21
The categories of this paper are: adap-org