Institute of High Energy Physics,Academia Sinica,Beijing
Abstract:
This paper reports the study and production and the performance of 60 PWC's which were the first module of L3 hadron calorimeter.125 Volts plateau and 3.4%/100V plateau slope were obtained with the gas mixture of Ar:CO2=80:20.We also checked the dark current of some chambers and found that the dark current could be reduced by "cooking".The chambers worked well when they were assembled in a calorimeter module and tested by the beam of SPS at CERN.