Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First results on radiation damage in PbWO4 crystals exposed to a 20
  GeV/c proton beam   We have exposed seven full length production quality crystals of the
electromagnetic calorimeter (ECAL) of the CMS detector to a 20 GeV/c proton
beam at the CERN PS accelerator. The exposure was done at fluxes of 10**12
p/cm**2/h and 10**13 p/cm**2/h and integral fluences of 10**12 p/cm**2 and
10**13 p/cm**2 were reached at both rates. The light transmission of the
crystals was measured after irradiation and suitable cooling time for induced
radioactivity to decrease to a safe level. First results of these measurements
are shown. The possible damage mechanisms are discussed and simulations based
on one possible model are presented. The implications for long-term operation
of CMS are discussed and it is shown that in the whole barrel and at least most
of the ECAL endcap hadron damage alone - even if cumulative - should not cause
the crystals to fail the CMS specification of an induced absorption coefficient
muIND < 1.5 /m during the first 10 years of LHC operation.

16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg