Stephan Russenschuck CERNATMEL Progress Report from the Magnet

Stephan Russenschuck, CERN-AT-MEL Progress Report from the Magnet Polarity Coordinator Stephan Russenschuck CERN AT-MEL-EM 1211 Geneva 23 1

Instead of an Overview Share with me è The confusion about the Magnet Polarity Conventions. è The doubts about the Polarity of the Main Quadrupole. Stephan Russenschuck, CERN-AT-MEL è The worries about the continuity of the Spool-piece Busbars. è The passion for the following question: 9: 00 or 3: 00? 2

Stephan Russenschuck, CERN-AT-MEL LHC Magnet Polarities EDMS: 90042 3

Polarity Conventions Θ Center of machine Stephan Russenschuck, CERN-AT-MEL (Convention) Θ Convention: Beam 1 Convention: Looking downstream of Beam 1 4

MAD Frame Positive Dipole Stephan Russenschuck, CERN-AT-MEL Θ Θ Positive Quadrupole Focusing Proton Beam on the Horizontal Plane 5

Stephan Russenschuck, CERN-AT-MEL LHC Magnet Polarities EDMS: 90042 mad 6

Dipole in MAD and MAG Frame Θ B 2 mad = - B 2 mag Stephan Russenschuck, CERN-AT-MEL DKN(. , 0, 0, 0) = B 1 mad = B 1 mag Θ 7

Page 5 of EDMS 90042 Document Stephan Russenschuck, CERN-AT-MEL mad 8

Skew Dipole and Quadrupole in Both Frames B 1 mag → A 1 mag B 2 mag → A 2 mag Θ Θ Stephan Russenschuck, CERN-AT-MEL A 1 mad = A 1 mag A 2 mad = - A 2 mag Θ B 1 mad → A 1 mad Θ B 2 mad → A 2 mad 9

Skew Dipole and Quadrupole in Both Frames B 1 mag → A 1 mag B 2 mag → A 2 mag Θ Θ Stephan Russenschuck, CERN-AT-MEL - A 1 mad = A 1 mag - A 2 mad = - A 2 mag Θ B 1 mad → - A 1 mad Θ + B 2 mad → - A 2 mad 10

Page 5 of EDMS 90042 Document Stephan Russenschuck, CERN-AT-MEL - mad 11

Stephan Russenschuck, CERN-AT-MEL LHC Magnet Polarities EDMS: 90042 Dipole Quadrupole 12

Conversion Table: Dipoles (and B 3, B 5, . . ) MAD Deflecting H Kicker V Kicker B 1 A 1 tilt clockwise out up in down up in EDMS Negative Positive 90042 dipole skew dipole A 1 -A 1 Stephan Russenschuck, CERN-AT-MEL Beam 1 (Polarity) Meas. dipole - B 1 -A 1 B 1 Mag. Frame 13

Conversion Table: Quadrupoles (and B 4, B 6, …) MAD B 2 A 2 tilt clockwise Focusing Q 1 + Q 1 - Focusing in horizontal Q 2 - Q 2 + in horizontal plane Stephan Russenschuck, CERN-AT-MEL A 2 plane EDMS Positive Negative Positivite 90042 Quadrupole skew quadrupole - A 2 (Polarity) Meas. - B 2 Mag. Frame 14

MAD Conventions for the Double Ring Measured in Stephan Russenschuck, CERN-AT-MEL Aperture 1 Beam 1 in outer ring Beam 1 in inner ring Current into A Current into B Ap. 1 Ap. 2 B 1 + + B 1 + - - + b 2 + B 2 + - b 2 - + b 3 + B 3 + + b 4 + B 4 + - b 4 + - a 1 + A 1 + - a 1 - + a 2 + A 2 + + a 3 + A 3 + - a 3 - + a 4 + A 4 + + a 4 + + How to parse this chart: Whatever the powering of the main dipole, the relative b 2 is always measured negative in Ap. 1. A negative b 2 gives +B 2 (focusing in the h-plane) in MAD for beam 1 in the inner ring (Ap. 2), sectors 2 -3, 3 -4, 4 -5, 8 -1. In these sectors the current enters terminal B of the dipole magnet. This creates a +B 2 in Ap 2. A sign reversal of b 2 is needed. 15

Stephan Russenschuck, CERN-AT-MEL Dipole Busbar Routing (LHC-DCB-ES-0001) 16

LHCMQ_DS 0020 Stephan Russenschuck, CERN-AT-MEL P 4 fl (A Terminal) 17

LHCMQ_ DS 0021 (LHCMQ__S 0018) Stephan Russenschuck, CERN-AT-MEL P 4 FL (A Terminal) P 1 FL (A Terminal) 18

Stephan Russenschuck, CERN-AT-MEL LHCDCQAA 0002 19

Stephan Russenschuck, CERN-AT-MEL LHCLQMBP 0002 (Version VAB 18. 06. 98 Approved) Wrong polarity 20

Stephan Russenschuck, CERN-AT-MEL LHCLQM_S 0004 (Production Drawing 2002) o. k. 21

Stephan Russenschuck, CERN-AT-MEL LQMTK (F Busbar, Diode-Type A) 22

Stephan Russenschuck, CERN-AT-MEL Concern: Spool-piece Busbar Routing 23

Stephan Russenschuck, CERN-AT-MEL Spool-piece Busbar Routing in the SSS 24

Continuity Testing of Spool Piece Busbars From: Budinger [mailto: ralf. budinger@accel-ssl. com] Sent: jeudi, 19. août 2004 07: 07 To: schirm karl (E-Mail) Cc: Burgmer. Rolf (E-Mail); Schellong Bernd (E-Mail) Subject: Busbar Stephan Russenschuck, CERN-AT-MEL Hallo Hr Schirm, nur kurz zusammengefasst: Beim Testen der Busbars gestern waren an Set 111 die spool 2+3 vertauscht und an Set 105 die spools 11+12, sowie 16+17 gegeneinander vertauscht. mfg Ralf Budinger Three labeling or cross-over errors in a batch of 10 tested SSS busbar sets 25

Stephan Russenschuck, CERN-AT-MEL Continuity Checker 26

Instead of a Conclusion: Mandate of the Magnet Polarity Coordinator è To ensure the coherence in the definition of the magnet polarities among MAD input files, the LHC reference database, field computations, field measurements, interconnection works and the powering of electrical circuits. è To define the base-line for the verification of magnet polarities from magnet production to powering in the machine. Stephan Russenschuck, CERN-AT-MEL è To establish, in consultation with the project engineers and magnet coordinators the rules and templates for the documentation and treatment of powering non-conformities. è To gather and re-distribute relevant documentation. To ensure adequate flow of information and filtering of MTF data for the electrical quality assurance in the tunnel. 27