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Lawrence Berkeley National Laboratory Recent Work Title Beam Based Alignment of C-Shaped Quadrupole Magnets Permalink
| Content Provider | Semantic Scholar |
|---|---|
| Author | Portmann, Gregory |
| Copyright Year | 2013 |
| Abstract | Many storage rings have implemented a method of finding the positional offset between the electrical center of the bOeam position monitors (BPM) and the magnetic center of the adjacent quadrupole magnets. The algorithm for accomplishing this is usually based on modulating the current in the quadrupole magnet and finding the beam position that minimizes the orbit perturbation. When the quadrupole magnet is C-shaped, as it is for many light sources, the modulation method can produce an erroneous measurement of the magnetic center in the horizontal plane. When the current in a Cshaped quadrupole is changed, there is an additional dipole component in the vertical field. Due to nonlinearities in the hysteresis cycle of the C-magnet geometry, the beam-based alignment technique at the Advanced Light Source (ALS) deviated horizontally by .5 mm from the actual magnetic center. By modifying the technique, the offsets were measured to an accuracy of better than 50 J..l1Il. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://cloudfront.escholarship.org/dist/prd/content/qt3q30c96s/qt3q30c96s.pdf?t=p22aga |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
