The performance of 16 and 64 channel photomultipliers coupled to
scintillating fibres has been tested. The devices are sensitive to single
photoelectrons, show little gain losses for magnetic fields up to 100 Gauss and
have moderate optical cross-talk. The maximum channel to channel gain
variations reach a factor two for the 16 channel version and a factor of four
for the 64 channel PM. The measurements and simulations indicate that the
photomultipliers are well suited for the light detection in fibre trackers.Comment: 11 pages, 9 picture
