Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Magnetic Metrology of SOLEIL Synchrotron Storage Ring Multipoles A. Dael, P. Brunelle 1, C. Benabderrahmane, F. Marteau, A. Madur, P. Berteaud, L. Dubois, M. Girault, F. Paulin, J. Veteran, Magnetism & Insertions Group 1 Machine Physic Group Synchrotron SOLEIL, Saclay, FRANCE

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Quadrupoles Knowledge of harmonics content of magnetic field produced by the magnets Magnetic axis location inside +/- 25µm along x and z axis Magnetic roll angle determination inside +/- 0.1 mrad around s axis Defaults correction Sextupoles To check harmonic field measurement To check centering Machine Physicists needs Beam direction s x z Axis definition One solution : A high accuracy magnetic measurements tool SMB = S OLEIL M ultipolar M agnetic M easurements B ench

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Multipole S.R. General Parameters (1) Total number (short + long) / prototypes / spares160 ( ) / 2 / 2 Magnetic length (m) (short; long)0.32 m ; 0.46 m Bore diameter (mm)66 mm Max. Gradient (nominal point):short; long20 T/m ; 23 T/m Good field region (mm): H / V  35 mm /  12.5 mm Number of families10 Tolerances : Reproducibility from magnet to magnet (  Gdl/  Gdl) Alignment on the girder :  X =  Z (µm) ;   S (mrad) Alignment of the girder :  X =  Z (µm) ;   S (mrad) µm ; 0.1 mrad 100µm ; 0.2 mrad Homogeneity (  Bdl /  x = 30 mm: TolerancesDesign (short) Design (long) 12-poles* poles poles * Cancelled using 45° chamfer : 4.4mm width for short quadrupoles and 4.6mm width for long quadrupoles

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Number: compact/with ears for photon beamline/prototype/spare88 / 32 / 2 / 2 Magnetic length (m)0.16 m Bore diameter (mm)73 mm Good field region (mm) : H / V  35 mm /  12.5 mm Number of families10 Max. Strength: S(main field)320 T/m² Max. Field (T) for Dipolar correctors: Horiz. / Vert T / T Max. gradient for Skew Quadrupoles0.126 T/m Tolerances: Reproducibility from magnet to magnet (  S dl/  S dl) (main field) Alignment on the girder :  X =  Z (m) ;   S (rad) Alignment of the girder :  X =  Z (m) ;   S (rad) µm ; 0.3 mrad 100µm ; 0.2 mrad Homogeneity (  Bdl /  Bdl x = 32 mm: Sextupolar main fieldTolerancesDesign 18-poles± (after chamfer optimization) 30-poles± poles± poles± Multipole S.R. General Parameters (2)

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Measurement process Flux measurements data processing Field harmonics Positioning offset over x and z Angular offset around s :  s Choice of wedges

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Theory review (1) Some calculations * * [1]: W.G. Davies, “The theory of the measurement of magnetic multipole fields with rotating coil magnetometers,” Nuclear Instruments & Methods in physics research, vol. A311, pp. 399–436, July [2]: A.K. Jain, “Harmonics coils,” CERN Accelerator School on Measurements and Alignment of Accelerator and Detector magnets, vol , pp , April [3]: L. Bottura, “Standard analysis procedures for field quality measurements of the LHC magnets-Part I: Harmonics”, LHC-MTA-IN , revised on with How to find ? A A AA  10 =  (  1 )-  (  0 )=  1 -  0  21 =  (  2 )-  (  1 )=  2 -  1 …  0 M-1 =  (  0 )-  (  M-1 )=  0 -  M-1 Faraday’s law of electromagnetic induction

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Theory review (2) Magneto-geometrical quantities cyl. wedges rect. wedge x s z ; Cylindrical WedgesRectangular Wedges

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Design : SMB Synoptic Scheme

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Bench Design : Sensor positioning Many “V” shape versus cylinder interfaces are used for mechanical contacts Guarantees : * reproducibility of mechanical positioning * good transmission of angular position information Sensor positioning : Sensor = 64 mm diameter cylinder mechanical transmission of angle positioning information: Rotary encoder

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Bench Design : Angle mastering Angular reference ? Rotary Encoder Heidenhain : points per turn -> 10 µrad on angle determination Angular position ? Line/Dot/Plan Interface line dot plane Bubble level 20 µrad/div = mm It is now possible to measure mechanical angle position of the sensor.

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Sensor Design (1) Objectives : To get good rigidity for longitudinal flexion To get good rigidity for torsion Principle: To uncouple each objectives To avoid spurious harmonics To minimize error on angle

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Imperfections measurements (1) Multipolar permanent magnet references

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Results Imperfections measured :  x sensor = 60 µm ;  z sensor = 22 µm ;  sensor = mrad Measurements reproducibility:  p-p gradient = 4 µT.m  p-p harm =  p-p x = 1µm  p-p z = 0 µm  p-p  = 3 µrad Before centering: After centering: Vacuum chamber Gradient homogeneity in transverse plane

Magnetic Metrology of SOLEIL Synchrotron S.R. Multipoles IMMW 14, A. Madur Conclusion Very encouraging results were obtained at end of the 3 month mag. meas. campaign But it is important to note that only beam commissioning will validate our work THANK YOU