BPM Calibration
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BPM pedestal run (20 minutes)
1. Ask MCC to set iocse10 to Forced gain = 0.
2. Take CODA run for both Right and Left arms.
- Use only clock triggers. T8=100
- Need about 100k events.
3. Ask MCC to set iocse10 to auto gain.
Pedestal run: Left arm: Run: 757 and 758 ( longer one) Right: Run: 90557 and 90558 (longer one)
BPM Calibrations (Bullseye Scan) [1-2 hours]
This calibration was done in the owl shift of 12/14.2017 using both arms DAQ, however the Right arm dipole wasn't enabled. Set Beam energy (MeV) : 6418.49 Current ~6.7 uA
| Relative position | LHRS CODA run | RHRS CODA run | Harp scan entry no. | HarpA time stamp | HarpB time stamp |
| (1.15,2.25) | 805 | 90595 | 3504092 | 12142017_01:55:06 | 12142017_01:58:24 |
| (2.15,3.25) | 806 | 90596 | 3504092 | 12142017_02:38:06 | 12142017_02:39:57 |
| (0.15,3.25) | 807 | 90597 | 3504130 | 12142017_02:49:00 | 12142017_02:52:45 |
| (0.15,1.25) | 808 | 90598 | 3504140 | 12142017_02:57:48 | 12142017_02:59:33 |
| (2.15,1.25) | 809 | 90598 | 3504146 | 12142017_03:04:43 | 12142017_03:08:13 |
| (1.15,2.25) | 810 | 90600 | 3504151 | 12142017_03:17:15 | 12142017_03:19:01 |
How to perform a bulls eye scan:
1. You need unrastered beam:
- This must be competed in phase 1!
- use single foil target.
2. Ask MCC to steer the beam to the nominal center of the target.
3. Wait until beam is stable and have MCC perform a harp scan for the two superharps near the target (1H04A and 1H04B) and take a CODA run for both the left and right spectrometers during the same time. Start the coda run first before asking MCC. Request MCC to make an ELOG entry with the Harp results, you should see all three harp wires. Record ELOG entry numbers and timestamps of both harpscans.
4. Ask MCC then to steer the beam to positions around the nominal center:
- cover at least the area the raster will cover: (2,2), (2,-2), (-2,-2), (-2,2), (3,3), (-3,-3), and repeat (0,0)
- repeat harp and CODA runs for each position
5. Record Harp scan run numbers and corresponding CODA run number for each beam position. As an example, see HALOG # 3324009.
6. Make a record of the harp scans and CODA runs in the HALOG.
How to analyze the bulls eye scan:
- detailed instructions can be found at the Analyzing BPMs website. - the shift crew is not expected to analyze the bulls eye scan.
Calibration
GMP completed a BPM calibration during their run time. The results of the Bull's eye scan can be found on the Halla LogBook.