The calibration and operation of CERN wire scanners
The calibration and operation of CERN wire scanners BI day 2016 10/03/2016 Emiliano Piselli
Outline Wirescanner calibration • PSB & PS type • SPS type Calibration reproducibility Wirescanners Operation New tool Conclusions 10/03/2016 Emiliano Piselli 2
Wirescanner calibration Wirescanner working principle 0 10/03/2016 Emiliano Piselli 3
Wirescanner calibration PS-PSB Wirescanner type Beam 10/03/2016 Emiliano Piselli 4
Wirescanner calibration PS-PSB Wirescanner Calibration needed to correlate the potentiometer values with the projected position 10/03/2016 Emiliano Piselli 5
Wirescanner calibration PSB Wirescanner calibration bench 10/03/2016 Emiliano Piselli 6
Wirescanner calibration PSB Wirescanner calibration bench Photodiode Wirescanner Laser Beam displacer Mirror Beam Splitter 10/03/2016 Emiliano Piselli 7
Wirescanner calibration PSB Wirescanner calibration bench Photodiode Wirescanner Laser Beam displacer Mirror Beam Splitter 10/03/2016 Emiliano Piselli 8
Wirescanner calibration PSB Wirescanner calibration bench PSB Vertical Scanner Photodiode Wirescanner Laser Beam displacer Mirror Beam Splitter 10/03/2016 Emiliano Piselli 9
Wirescanner calibration PSB Wirescanner calibration bench Fixed system Photodiode Wirescanner Laser Beam displacer Mirror Beam Splitter 10/03/2016 Emiliano Piselli 10
Wirescanner calibration PSB Wirescanner calibration bench Moving system (+/- 30 mm) Photodiode Wirescanner Laser Beam displacer Mirror Beam Splitter 10/03/2016 Emiliano Piselli 11
Wirescanner calibration PS Wirescanner calibration bench 10/03/2016 Emiliano Piselli 12
Wirescanner calibration PS Wirescanner calibration bench Laser Splitter Wirescanner 10/03/2016 Emiliano Piselli Combiner Photodiode 13
Wirescanner calibration PS Wirescanner calibration bench Fixed system Laser Splitter Wirescanner 10/03/2016 Emiliano Piselli Combiner Photodiode 14
Wirescanner calibration PS Wirescanner calibration bench Moving system (+/- 50 mm) Laser Splitter Wirescanner 10/03/2016 Emiliano Piselli Combiner Photodiode 15
Wirescanner calibration PS Wirescanner calibration bench Moving system (+/- 50 mm) Laser Splitter Wirescanner 10/03/2016 Emiliano Piselli Combiner Photodiode 16
Wirescanner calibration PS Wirescanner calibration bench Optical measurements & simulation: J. Sirvent Laser Splitter Wirescanner 10/03/2016 Emiliano Piselli Combiner Photodiode 17
Wirescanner calibration PSB & PS Wirescanner calibration procedure 1. We move the laser/photodiode system from -50 mm to +50 mm with fixed step. At each position we record the photodiode signal vs potentiometer values (angular position) while the WS moves. We repeat different measurements for each position. Bits (angular position) 10/03/2016 Emiliano Piselli 18
Wirescanner calibration PSB & PS Wirescanner calibration procedure 2. For each scanned position, we open the corresponding files, we find the center of the 2 peaks (in bit), we plot the average as function of the position and we fit it with polynomial function. Bits (angular position) 10/03/2016 Emiliano Piselli 19
Wirescanner calibration PSB & PS Wirescanner calibration procedure Residual (mm) 3. We evaluate the calibration checking the average residual, the residual RMS, the peaks difference (constant and known) and the peak difference RMS. Bits (angular position) 10/03/2016 Emiliano Piselli 20
Wirescanner calibration SPS Wirescanner <<calibration>> Calibration not needed, since the potentiometer is read directly on the motor axis. 10/03/2016 Emiliano Piselli 21
Wirescanner calibration SPS Wirescanner <<calibration>> Projection plane 519 Horizontal 211. 1⁰ In Beam 92. 5 mm 64. 2⁰ Projected position: Ho m e 115. 8⁰ Position 519. H 519. V 416. H 416. V 414. H 414. V Crossing angle [rad] 0. 480813 Total range [rad] 3. 684390 3. 433063 2. 315528 2. 317797 3. 672173 3. 677409 10/03/2016 Emiliano Piselli 22
Calibration reproducibility Calibration reliability can influence the determination of the wirescanner beam profile width measurement. Running several calibrations shows different levels of reproducibility depending on the wirescanner speed and movement. PS Wirescanner 10 m/s OUT Position difference (mm) 10 m/s IN Bits (angular position) Average absolute error 68µm 10/03/2016 Emiliano Piselli Bits (angular position) Average absolute error 79µm 23
Calibration reproducibility Calibration reliability can influence the determination of the wirescanner beam profile width measurement. Running several calibrations shows different levels of reproducibility depending on the wirescanner speed and movement. PS Wirescanner 15 m/s IN Bits (angular position) Average absolute error 90µm 10/03/2016 Emiliano Piselli 15 m/s OUT Bits (angular position) Average absolute error 75µm 24
Wirescanners operation AQN=500 KHz • 3 measurements/ring/plane @ extraction for nominal beam for each shift • Measurements for MD (many scans in short period) 10/03/2016 Emiliano Piselli 25
Wirescanners operation PSB PM studies LHCINDIV Ring 3 Hor. GAIN ‰ transmission 0. 20% 100 200 300 400 500 600 2. 33 700 2. 24 800 2. 333 900 2. 423 1000 2. 389 0. 50% 0. 07 0. 046 2. 304 2. 368 2. 366 2. 26 2. 302 2% 2. 451 2. 342 2. 358 2. 313 2. 345 2. 329 2. 364 2. 331 2. 366 2. 375 5% 2. 347 2. 282 2. 319 2. 369 2. 354 2. 339 2. 318 2. 332 2. 321 20% 2. 302 2. 312 2. 275 2. 15 2. 088 1. 979 1. 934 1. 899 1. 836 1. 816 0. 038 RMS 0. 024 0. 193 GAIN ‰ transmission 100 200 300 400 500 600 700 800 900 1000 0. 20% 0. 50% 2. 358 2. 322 2. 395 2. 344 2. 351 2% 2. 438 2. 283 2. 276 2. 327 2. 31 2. 364 2. 303 2. 346 5% 2. 318 2. 321 2. 369 2. 364 2. 315 2. 338 2. 363 2. 31 2. 347 2. 386 20% 2. 306 2. 258 2. 31 2. 277 2. 203 2. 174 2. 102 2. 051 1. 992 1. 951 2. 502 2. 422 2. 342 2. 491 2. 399 0. 066 0. 027 0. 049 0. 027 0. 1318 Better…lower Filter and higher GAIN… or higher filter with lower GAIN… RMS 10/03/2016 Emiliano Piselli 26
Wirescanners operation PS 5 BWS • 3 hor & 2 vert AQN=FRev 10 m/s-15 m/s • 3 measurements/flat top and 3 measurement/injection 3 bp • 3 measurements/flat top 2 bp • Measurements for MD (many scans in short period) 10/03/2016 Emiliano Piselli 27
Wirescanners operation SPS 10 BWS • 3 hor & 3 vert rot • 2 hor & 2 vert lin AQN=FRev 6 m/s 0. 6 -1 m/s Bunches selection • Measurements @ flat top before any LHC filling • Measurements @ flat bottom to compare emittance with PS • Measurements for MD (many scans in short period) 10/03/2016 Emiliano Piselli 28
New tool BI seminar 22. 02. 2015 Aleksander Cudny Emiliano Piselli https: //bws-web. cern. ch/bws-web/ 10/03/2016 Emiliano Piselli Ismael Posada Trobo IT-OIS-WLS Guillaume Baud 29
New tool Aleksander Cudny Emiliano Piselli https: //bws-web. cern. ch/bws-web/ 10/03/2016 Emiliano Piselli Ismael Posada Trobo IT-OIS-WLS Guillaume Baud 30
New tool • User friendly • Don‘t need to be logged @ CERN • Usefull to compare different scans profiles and data Aleksander Cudny Emiliano Piselli https: //bws-web. cern. ch/bws-web/ 10/03/2016 Emiliano Piselli Ismael Posada Trobo IT-OIS-WLS Guillaume Baud 31
Usage statistics 2015 #scans BWS PSB R 1 H PSB R 1 V PSB R 2 H PSB R 2 V PSB R 3 H PSB R 3 V PSB R 4 H PSB R 4 V PS 54 H PS 64 V PS 65 H PS 68 H PS 85 V 5948 4455 12180 9393 11766 4807 5959 5553 10706 5668 4914 1160 7451 #estim 10750 10750 20000 30000 5000 % 55 41 113 87 109 45 55 52 54 19 16 149 23 70000 #scans 60000 50000 40000 30000 20000 BWS SPS 414 H SPS 414 V SPS 416 H SPS 416 V SPS 517 H LIN SPS 517 V LIN SPS 519 H SPS 519 V SPS 521 H LIN SPS 521 V LIN LHC B 1 H 1 LHC B 1 H 2 LHC B 1 V 1 LHC B 1 V 2 LHC B 2 H 1 LHC B 2 H 2 LHC B 2 V 1 LHC B 2 V 2 #scans 0 0 4623 3509 2672 513 3401 2723 13 1824 391 81 4813 4214 5284 4594 55 125 10000 0 PSB PS LHC SPS 10/03/2016 Emiliano Piselli 32
Usage statistics #scans BWS 2015 PSB R 1 H PSB R 1 V PSB R 2 H PSB R 2 V PSB R 3 H PSB R 3 V PSB R 4 H PSB R 4 V PS 54 H PS 64 V PS 65 H PS 68 H PS 85 V 5948 4455 12180 9393 11766 4807 5959 5553 10706 5668 4914 1160 7451 2014 1318 630 1292 2133 1980 1788 684 531 3468 1548 1481 4705 173 #scans 2013 153 58 2004 2898 1562 1755 409 322 545 957 1062 88 142 2012 5581 3200 10853 8748 9012 6514 6691 4165 8564 10875 7746 2780 2310 BWS SPS 414 H SPS 414 V SPS 416 H SPS 416 V SPS 517 H LIN SPS 517 V LIN SPS 519 H SPS 519 V SPS 521 H LIN SPS 521 V LIN LHC B 1 H 1 LHC B 1 H 2 LHC B 1 V 1 LHC B 1 V 2 LHC B 2 H 1 LHC B 2 H 2 LHC B 2 V 1 LHC B 2 V 2 10/03/2016 Emiliano Piselli 2015 0 0 4623 3509 2672 513 3401 2723 13 1824 391 81 4813 4214 5284 4594 55 125 2014 0 0 324 339 0 1 655 755 0 0 0 1 0 0 0 2013 0 0 1327 5523 0 0 0 231 400 561 0 349 378 446 0 2012 0 0 9833 6046 0 0 0 1189 1377 2737 2297 957 1119 2850 2469 33
Conclusions 1. PSB & PS calibration system and principle have been presented 2. PSB & PS BWS calibrations reproducibility shows a limit of 100µm 3. PM/filters automatic settings adjustment should be determinate 4. New web tool has been presented and it could replace many scripts written for a fast diagnose in case of problems. Is it too difficult? ? 10/03/2016 Emiliano Piselli 34
GRAZIE! Thanks to Ana, Bernd, Jonathan & Jose 10/03/2016 Emiliano Piselli 35
Extra slides. . . 10/03/2016 Emiliano Piselli 36
New tool BI seminar 22. 02. 2015 Aleksander Cudny Emiliano Piselli https: //bws-web. cern. ch/bws-web/ 10/03/2016 Emiliano Piselli Ismael Posada Trobo IT-OIS-WLS Guillaume Baud 37
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