Moeller Measurement Checklist for HAPPEX

This file: ~moller/moll_proc.html, last updated: Sun, 22 Apr 1999
moller@jlab.org
This checklist must be executed by the shift leader. The significant dangers are: (1) High current on Moeller target would destroy it; (2) Incorrect configuration settings could lead to useless data.

Starting

The procedure to start a Moeller measurement includes items as follows.
  1. Ask MCC to shut the beam off and to mask the cryo target
  2. Start moving the target to the empty position
  3. Ask MCC to load the magnetic settings file called "Halla_3362_lousymol.snap" and cycle the magnets. This file was created by Jay Benesch for 3362MeV. It is good for the Moeller and Compton polarimeters.
  4. Ask MCC to put in the Moeller target called "BOTTOM" and turn it to 3 "degrees" (this is the name of the unit on the operator screen, though in fact one unit is about 1.75 degrees).
  5. Turn on HV for the Moeller detector (hac42, slot 4).
  6. Once all of the above is done ask MCC to send 0.5uA of CW beam. The current should be tuned using the slit, keeping the laser power high.
  7. Check the BPM position on IPM1H01 and IPM1H03A. They should be within 1mm from zero. The "target" ion chamber SLD1H03 reading should not be higher than 1000. If needed, ask MCC to tune the beam closer to zero in X and Y.
  8. Make sure that the target motion is not masked anymore.
  9. One may start the Moeller measurements.

Finishing

The procedure to finish the Moeller measurement includes items as follows:
  1. Ask MCC to:
  2. Start moving the cryo target in
  3. Run "spot" at 5 microamps to verify raster amplitude, and DO NOT run higher current on target before running "spot"
  4. Verify on scope that the helicity mode is random