1 / 4

AR1 BPM Calibration (for new electronics)

AR1 BPM Calibration (for new electronics). Before any TOA measurements we attempted to look at the BPM calibration (AR2-BPM-03) Turn off quads (Q1,Q2) and sextupole and vertical corrector in first half of AR1. The beam doesn’t seem to blow up.

angeni
Download Presentation

AR1 BPM Calibration (for new electronics)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. AR1 BPM Calibration (for new electronics) • Before any TOA measurements we attempted to look at the BPM calibration (AR2-BPM-03) • Turn off quads (Q1,Q2) and sextupole and vertical corrector in first half of AR1. • The beam doesn’t seem to blow up. • Then steer with AR1-DIP-01 to calibrate AR2-BPM-03 AR1-OTR2 all AR1 magnets ON AR1-OTR2 with AR1-Q1,Q2, SEXT VCOR-01 OFF

  2. AR1 BPM Calibration • Change in AR1-DIP-01 current predicts poistion change at AR1-BPM-03 • L_dipole = 510 mm,  = 60°, 0= L_dipole/60° = 490 mm, z (distance AR1-DIP-01 exit to AR1-BPM-02) = 2.300 m • Thus [x/I/I0]predicted = 2.24 m

  3. AR1 BPM Calibration • A nominal calibration is entered 20mm *(((A-P1)+(D-P2))-((B-P2)+(C-P1)))/ ((A-P1)+(B-P2)+(C-P1)+(D-P2))20 • Bunch position varies over train (used 5 μsec train arbitrarily) • Can look at BPM calibration for each bunch first bunch last bunch Distribution of calibrations for all the bunches. Varies by about 8%. Expected value is -2240 (20% different to measured)

  4. Additional Info • If we plot the calibration factor vs bunch number, rather than just a histogram of calibration values, we see a clear correlation. • So this suggests the spread in calibrations is not statistical but systematic. • Perhaps the best calibration value to take is around bunch # 70-80 where the bunch position begins to plateau • These bunches also give the best symmetrical range of x positions around x = 0. For the first dipole setting, x ~ - 7 ; for the last dipole setting, x ~ + 9 • So if we take -1950 to be the measured calibration factor, and the real calibration should be -2240, then the calibration factor in the software should be changed from 20 mm to 23 mm.

More Related