Setting Up the Test Sector Hardware

Locate the NIM bins which contain the HV power supplies, BNC tail pulser, etc. and check the settings on the units in these racks.

• The BNC Tail Pulser settings should be:
  • External trigger
  • Single pulse
  • Maximum delay on 10 microsecond scale
  • Internal reference
  • + Polarity
  • 0.05 microsecond rise time
  • Maximum amplitude
  • 1000 microsecond fall time
  • No attenuation
• The drift-field voltage should be on for all data taking. Check it by plugging a DVM into the voltage monitor lemo jack of the peach-colored NIM HV unit (Chan. A); be sure you don't get the current monitor jack by mistake. The voltage will be displayed in kilovolts. If the voltage is unreasonable, be sure that the cable and connector are not damaged, giving an open circuit.
  • Outer sector: 1.389 kV
  • Inner sector: 1.584 kV
  If the HV supply is not on, set the vernier dial to 0 V and the toggle switch to ``auto reset;'' now, switch it on and set to ``trip hold.'' Raise the voltage slowly, being careful not to exceed the current limit (80Lock the vernier knob.
• The gating grid voltage supply should also be on for all data taking. It should be set to -90 volts for both outer and inner subsectors. Lock the vernier knob.
• The anode-wire voltage should be on only for cosmic-ray or laser runs. Check this on the red NIM HV unit (Chan. A) by plugging a DVM into the voltage monitor lemo jack; be sure you don't get the current monitor jack by mistake. The voltage will be displayed in kilovolts. If the voltage is unreasonable, be sure that the cable and connector are not damaged, giving an open circuit.
  • Outer sector: 1.450 kV
  • Inner sector: 1.171 kV
  If the HV supply is not on, set the vernier dial to 0 V and the toggle switch to ``auto reset;'' now, switch it on and set to ``trip hold.'' Raise the voltage slowly, being careful not to exceed the current limit (80Lock the vernier knob.
• On the Neslab chiller (large, yellowish, stand-alone unit): turn on the chiller with rocker switch, then check that the flow valve is open enough that the blue, interlocked, control-power lights on the low-voltage power supplies are illuminated. Increase the flow a bit past the point where they illuminate.
• There is one Kepco low-voltage power supply per readout board; the supplies are mounted in 19'' racks in groups of three. Supplies 1 and 2 are for the inner sector; units 3, 4, 5 and 6 are for the outer sector. Check the number on the power cable, if in doubt. Use Slow Controls to set the needed Kepco low-voltage power supplies to ``on;'' if necessary, one can also set them to ``local'' for manual control.
• For cosmic-ray runs, the HV PMT power supply at the top of the trigger rack must be set to -1700 V, with both power switches set to ``on.'' (Both pilot lights are dead; look at the HV meter (but even the HV meter has occasionally had problems!)
• For cosmic-ray runs, the two scintillator counters should be centered in the drift direction over the laser windows, visible at the top and bottom of the sector frame. Usually, the lower counter has 2 inches of lead over its sensitive area, so as to trigger only on high-momentum cosmics (200 MeV/c muons).
• The OR'ed busy from the Rosie's must be wired manually. All Rosie's enabled in the Run Control ``configuration'' window busies must be included in the OR, and only these. Check that it is wired correctly. The cables are labeled 1-6, the same as the Rosies. (Strictly speaking, no particular relationship is required between readout board and Rosie numbering.)

Procedures are different to set up a laser run.

Written: October 3, 1996 by R.Bossingham
Last modified: July 8, 1997 by R.Bossingham

Page maintenance:

Roy Bossingham, LBNL
RRBossingham@lbl.gov