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First results on radiation damage in PbWO4 crystals exposed to a 20 GeV/c proton beam

M. Huhtinen·P. Lecomte·D. Luckey·F. Nessi-Tedaldi
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Abstract

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.

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M. Huhtinen, P. Lecomte, D. Luckey, F. Nessi-Tedaldi. 2003-12-09. First results on radiation damage in PbWO4 crystals exposed to a 20 GeV/c proton beam. https://doi.org/10.1142/9789812702708_0096

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