Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Construction of a Prototype Spark Chamber   A small demonstration spark chamber is to be built at the Cavendish
laboratory. A prototype chamber consisting of five 20x22.5cm plates has been
built and descriptions of its properties and construction are given, while a
second chamber with a somewhat novel design is nearly complete. A discussion of
the issues surrounding the final design is presented, and recommendations are
made in light of the results of this work.

32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin