SBS BPM calibration
From Hall A Wiki
This section gives instructions to perform a Beam Position Monitor (BPM) calibration.
Performing a Bull's Eye Scan
Unrastered beam is required for this procedure
- Start a new CODA run with the description [BPM Calibration] Bull's Eye Scan
- Ask MCC to steer the beam to the nominal center of the target
- When the beam is stable, ask MCC to perform a HARP scan using the two SuperHARPs near the target, 1H04A and 1H04B. Request MCC to make an elog entry with the HARP scan results. All three HARP wires should be visible.
- Record the elog entry numbers for all HARP scans.
- Ask MCC to steer the beam to positions around the nominal center:
- (0,0), (2,2), (2,-2), (-2,-2), (2,-2), (3,3), (-3,-3), and repeat (0,0). Repeat HARP and CODA runs for each of these positions. Label and document the runs accordingly in a HALOG post (example).
Taking a BPM Pedestal Run
- Ask MCC to set iocse10 to Forced gain = 0.
- Take a CODA run and label as BPM Pedestal Run
- Use only clock triggers ( set presale for TX=XYZ )
- Need about 100k events.
- Ask MCC to set iocse10 to auto gain.