Belle ACC FMPMT Base

Preamplifier Base Assemblies

• Schematic diagram of base.

• Schematic diagram of preamplifier.

• Note on Preamplifier Gains.

• Diagram on grounding and shielding of the preamplifier/base assembly.

• Note on preamplifier/base aging tests. The results of the study thus far can be found here. The gain of an FMPMT relative the other PMTs in the same group of twelve is plotted. The small variations can be ignored. The only significant failure occurred for PMT D10 on DAY 2 of the tests.

  The tests ran for approximately 5 months without any significant gain changes.

• Preamplifier noise measurement. With some effort it is possible to reduce the pickup noise of the preamplifiers to a low value. The scope trace (eps) shown here illustrates the result. The preamplifier in question has a gain of 10 and is attached to a 3" FMPMT. The upper trace is a Fourier transform of the preamplifier output. The lower trace is a sample trace. Note that apart from the weak structure at 103 MHz, there is little evidence that FM radio stations are being picked up.