New measurements of scintillating fibers coupled to multianode photomultipliers

The author measured some properties of the multianode photomultipliers H4139 and XP4702 pertaining to their operation in conjunction with fiber scintillators. In particular, the cross-talk between adjacent pads for the light from a single fiber was measured as a function of an external axial magnetic field. The gain variations in this field were also measured simultaneously. The results indicate that the H4139 has a larger cross-talk at low fields but improves significantly, while its gain decreases slowly. On the other hand, the XP4702 has a low cross-talk without field and the gain decreases dramatically with magnetic fields while the cross-talk improves only slightly. The timing properties of the array were determined for minimum ionization particles. The timing properties of both phototubes are similar, and both are very fast. The results indicate that such a system can be used as a tracking detector in high rate environments such as the SSC.<>