Checklist for Switching DAQs

Neglecting some of these steps or doing them in the wrong order could result in damage to Hall A equipment.

Experts:   Ahmed Zafar, Dustin McNulty, Bob Michaels

updated May 4, 2010

Integrating HAPPEX DAQ to Counting Spectrometer DAQ

1. Preliminaries.   to do long before switching
   • Make sure spectrometer DAQ works (might need reboots).   Use the CODA guide if necessary.
   • Check cavities in integration mode and counting mode at high current.   Run analysis macros. Do they work ?
   • Check with spot++ that rastered size is approx 4 x 3 mm (whatever is our present norm.)
   • Check the beam position ("centered" to within 0.3 mm, using the production criterea, see white board).
2. Switching to Low-Current Counting Mode
   • Septum off
   • Take access.
   • Expert to do the switch of the detector signals to counting mode
   • Switch cavities to have amplifiers. Take out attenuator on BCM.   Note: Cannot exceed 2 uA with amplifiers in place.
   • Set up cavities pre-gain and phase using established values.
   • Septum on
3. Set Up Beam
   • Do the beam recovery procedure.
   • Establish 50 nA on Pb target (or whatever current on another target).   Normally with laser attenuator = 65 and slit = 13, and then some adjustment to get rates low.
4. Setting HV
   • Do NOT turn on scint or VDC HV yet !   Must establish rates first.
   • Info about detector HV
     • Turn on the HV for upper scint and S0 (if S0 is in place).
     • Adjust Quartz Detector HV for Counting mode.
   • VDC HV on (4 kV) if the T1/T5 rates are below 500 kHz.   If above 500 kHz do not turn on HV.
5. Take CODA run and analyze it as usual.

Counting Spectrometer DAQ to Integrating HAPPEX DAQ

1. Setting HV
   • VDC HV off.   This is important.
   • Scintillator HV off.   This is important.
   • Info about detector HV
   • Adjust Quartz Detector HV for Integrating mode.
2. Switching to High-Current Integrating Mode
   • Septum off
   • Take access.
   • Expert to do the switch of the detector signals to integrating mode
   • Cavities:   take out amplifiers. Put in attenuator on BCM.   This is important.
   • Set up cavities pre-gain and phase using established values.
   • Septum on
3. Set Up Beam
   • Do the beam recovery procedure
4. Take data !   Check all data including cavities.