BPM calibration information
From HallCWiki
Jump to navigationJump to search- The beam position monitors (BPMs) on the diagnostic girder in Hall C (IPM3H07A, IPM3H07B, and IPM3H07C) are calibrated by comparison with the Hall C superharps (IHA3H07A and IHA3H07B). Ideally, a "bulls-eye" scan is done which allows one to determine the BPM offsets and slopes. However, a single harp scan is sufficient to check the BPM offsets.
- If re-analyzing/revisiting BPM calibrations, make sure that the appropriate survey offsets are loaded into the harp analyzer tool
- Table of BPM calibration information. Offsets and slopes are from the "RAW" epics variables (no survey offsets applied).
| Date | Method | AXoff | BXoff | CXoff | AYoff | BYoff | CYoff | AXslope | BXslope | CXslope | AYslope | BYslope | CYslope | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/13/2018 | Calibration | -0.06 | 0.07 | -1.06 | -0.46 | 0.12 | 0.61 | -0.98 | -1.12 | -0.96 | 0.97 | 1.17 | 0.87 | 1st calibration |
| 8/29/2018 | Harp scan | 0.15 | 0.29 | -1.08 | -0.12 | 0.63 | 1.09 | - | - | - | - | - | - | - |
| 2/9/2019 | Harp scan | 0.25 | 0.46 | -1.01 | -0.08 | -0.04 | -0.11 | - | - | - | - | - | - | Radiator installed during January 2019 SAD |
| 6/23/2019 | Calibration | 0.11 | 0.17 | -1.07 | -0.40 | -0.18 | -0.40 | -0.97 | -1.11 | -0.95 | 0.95 | 1.15 | 0.85 | - |
| 12/8/2019 | Calibration | 0.14 | 0.22 | -1.13 | -0.06 | -0.29 | -0.78 | -0.96 | -1.09 | -0.96 | 0.95 | 1.16 | 0.85 | Polarized 3He running |
| 9/5/2021 | Harp scan | -0.35 | 0.17 | -0.83 | -0.35 | 0.19 | 0.47 | - | - | - | - | - | - | |
| 1/9/2022 | Harp scan | -0.08 | 0.32 | -0.67 | -0.40 | 0.20 | 0.43 | - | - | - | - | - | - | |
| 6/9/2022 | Harp scan | 0.16 | -0.22 | -0.54 | -0.18 | 0.02 | 0.39 | - | - | - | - | - | - | |
| 1/11/2023 | Harp scan | 0.06 | -0.35 | -0.69 | -0.20 | -0.03 | 0.38 | - | - | - | - | - | - |
- Beamline surveys
- Summary of survey information. The BPM offsets shown below should not be used for hcana offsets - they just give an indication of the changes to the girder position. The harp offsets should be used in the harp analyzer.
| Date | BPM AXoff | BPM BXoff | BPM CXoff | BPM AYoff | BPM BYoff | BPM CYoff | Harp AXoff | Harp BXoff | Harp AYoff | Harp BYoff | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 3/7/2017 | -2.84 | -2.88 | -3.27 | -0.21 | -0.20 | 0.05 | -2.88 | -3.07 | -0.13 | -0.04 | |
| 12/1/2017 | -0.01 | -0.01 | -0.17 | -0.27 | -0.22 | -0.16 | 0.01 | -0.12 | -0.12 | 0.02 | |
| 1/10/2018 | - | - | - | - | - | - | 0.01 | 0.11 | -0.12 | 0.08 | Harps only after wire repair |
| 8/17/2018 | 0.05 | 0.04 | -0.26 | -0.06 | -0.01 | 0.45 | 0.01 | 0.10 | 0.03 | 0.01 | |
| 2/17/2019 | 0.15 | 0.20 | -0.14 | -0.32 | -0.45 | -0.30 | 0.34 | 0.59 | -0.07 | -0.62 | After radiator installation |
| 7/17/2020 | -0.06 | 0.02 | -0.05 | -0.37 | -0.43 | 0.44 | 0.17 | 0.04 | -0.07 | -0.11 | During polarized 3He running |
| 8/17/2021 | -0.05 | 0.13 | 0.16 | 0.17 | 0.52 | -0.17 | -0.14 | -0.07 | 0.00 | -0.07 | First running after pol. 3He |
| 5/31/2022 | -0.03 | -0.79 | 0.30 | -0.18 | -0.45 | -0.54 | -0.15 | -0.64 | -0.08 | -0.64 | Cause of shifts not clear |
