Qweak Commissioning 6-2010
Setting Timing
Before running beam we must determine the delay times due to cable length in order to set the latency int he VFAT chips.
These measurements should take place during the May 2010 installation.
Setting Thresholds
During the May install we can set a set of baseline thresholds when there is no beam going into the hall.
This will need to be redone during the commissioning run.
Steps:
1.) Turn GEM detector up to 3kV on both Drift and GEM. The voltage will be on but the detector will not be working
2.) Set thresholds so there are zero counts in the VFATs when running a random trigger. So we need the DAQ up and triggerable by a pulse generator.
3.) Turn the detector on and trigger the DAQ using GEM trig out.
4.) Check thresholds to see if you are getting hits. If not lower the thresholds.
5.) If you needed to lower the thresholds then turn the GEM detector back off by lower the drift HV so it equals the GEM HV.