Performance of the CMS ECAL safety system for Super Modules

A prototype of the safety system for the electromagnetic calorimeter (ECAL) of the CMS detector at LHC has been implemented and tested in Super Modules SM0 and SM1 during the ECAL test-beam campaign in summer 2003. The aim was to examine the system performance thoroughly and to resolve several open issues regarding the final system design. The performed tests mainly focused on the readout system performance, its calibration and noise problems. Furthermore, irradiation tests of the readout electronics components with a 64MeV proton beam up to an equivalent cumulative dose of 200 kGy and 3.2! 1014 neutron cm"2 have been performed at the Paul Scherrer Institute in spring 2004. The results of all these tests are very promising, leading to the conclusion that the tested prototype offers an excellent basis for the development of the safety system for the entire CMS ECAL