First results from 8-stage PMTs
1. ADC spectra
2. Efficiency
PMT high voltage was set at the nominal value (1750 and 1500 for
10-stage and 8-stage tubes respectively). Trigger is based
on 4 PMTs in two short trigger paddles (TOF tubes are not in the trigger).
Discriminator threshold was set at 30mV. Linear fan-in/fan-out was used
to split the signal between ADC and TDC. The table below shows the
percentage of triggered events with good hits in TOF PMTs.
|
Left
|
Right
|
10-stage PMT
|
97.2%
|
98.3%
|
8-stage PMT
|
79.8%
|
79.9%
|
3. Timing resolution
In progress....