Mr Lew Classen (ECAP, University of Erlangen)
Three companies are developing new types of 3 inch photomultiplier tubes (PMTs) for the KM3NeT project. The first PMT samples have been delivered from Hamamatsu (R6233mod type) and ET Enterprises (D783KFLA type) and tested. The results of these tests are presented. PMTs of these two types have been ordered to build the the first KM3NeT developmental optical modules. MELZ have produced new 82mm-diameter PMTs, which are under internal tests in the company. First delivery from MELZ is expected in October 2011. Hamamatsu have started the development of new versions of PMTs, with better timing parameters and a larger photocathode. The delivery of the first samples of this new Hamamatsu type is expected in the Fall of 2011.