Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Recent progress in silica aerogel Cherenkov radiator   In this paper, we present recent progress in the development of hydrophobic
silica aerogel as a Cherenkov radiator. In addition to the conventional method,
the recently developed pin-drying method for producing high-refractive-index
aerogels with high transparency was studied in detail. Optical qualities and
large tile handling for crack-free aerogels were investigated. Sufficient
photons were detected from high-performance aerogels in a beam test.

11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph