Upgrade of the monitoring system of LHCb ECAL
Résumé
In order to improve the stability of the LHCb ECAL monitoring system, the light guides transporting LED light to PMTs have been replaced by radiation hard quartz fibers. The behavior of transparency of the selected fibers under moderate radiation doses, up to few kGy, was studied in detail. The performance of the upgraded version of the LHCb ECAL monitoring system is also discussed.