We are reporting preliminary results of studies of R59000-00-M16 and M64 tu
bes, manufactured by Hamamatsu Photonics, to he employed by the MINOS neutr
ino experiment. Our tests focused on anode response uniformity, gain, cross
-talk, and linearity for light illuminating PMTs through a 1.2mm diameter f
iber. (C) 2001 Elsevier Science B.V. All rights reserved.