Quality control of TPS magnet

Transcription

1 Quality control of TPS magnet Jyh-Chyuan Jan On behalf of magnet group, NSRRC IMMW19, Oct 29, 2015, Hsinchu, Taiwan.

2 Outline Introduction Magnet inspect procedure Mechanical error of magnet Field performance of magnet Crosstalk issue of magnet Permeability inspect of BR vacuum chamber Field distortion from the permeability chamber Summary 2

3 Milestone of TPS magnet 2005 Preliminary design of the magnet 2007 TPS project approved 2009 Magnet prototype constructed and examined in house 2011 One-section prototype (23 magnets) finished 2012 Mass production of magnet was begun 2013 Oct. All magnets completed 2014 Aug. Accelerator install completed 2014 mid-dec. Hardware testing and improvement completed 2014 Dec. 31 First synchrotron light at 3 GeV was observed (no correction applied) 2015 April-July Seven IU and three EPU were installed 2015 Sep. ID commissioning and Vacuum clearing 3

4 Magnet parameter SR magnet Dipole Quadrupole short/long Sextupole A/B/C Quantity / / 48 / 24 Magnetic length (m) / Field strength (T,T/m,T/m 2 ) / Magnetic gap height/diameter (mm) Number of turns / pole / Conductor dimension (mm 2 ) / Coolant hole diameter (mm) 7 4 / BR magnet Dipole Quadrupole Sextupole BD/BH QF/Q1/Q2/QM S1/S2 Magnet quantity 42 / / 12 / 12 / Magnet length (m) 1.6 / Bore diameter or gap (mm) 21.4~ Number of turns / pole / 18 / 12 / 6 18 Normal field (T, T/m,T/m 2 ) 0.819,-1.72, ,25.8/14.3/-9.1/ Conductor dimension(mm 2 ) Coolant hole diameter(mm) Pole profile is machined by the Computer Numerical Control Machine (CNC) Pole profile is machined by the Wire Electrical Discharge Machine (WEDM) Ref: C. S. Hwang et. al., Status of accelerator lattice magnets design of TPS project, Proceedings of PAC 09, Canada (2009). 4

5 Magnetic field specification-sr/br Storage ring (GFR= 25mm) SR-dipole (SR-DM) SR-quadrupole (SR-QM) SR-sextupole (SR-SM) n B n L/B 1 L [ 10-4 ] n B n L/B 1 L [ 10-4 ] A n L/B 1 L [ 10-4 ] n B n L/B 2 L [ 10-4 ] A n L/B 2 L [ 10-4 ] ±15 ±10 1 ±3 2 ±2 ± ±3 3 ±2 ±1 3 ±2 ±2 3 ±2 4 ±0.5 ±0.3 4 ±3 ±1 4 ±3 5 ±0.8 ± ±0.5 ± ±0.3 ±0.3 8 ±0.5 ±0.3 9 ±0.3 ±0.3 9 ±0.3 ± ±0.3 ± ±0.3 ±0.3 b 0 /b ±0.3 ±0.3 b 0 L/b 0 L ±0.3 ±0.3 Symbol bn (an) bn/bn bnl/bnl BnL/BmL (AnL/BmL) Index n=0 is dipole term Definition normal (skew) multipole strength homogeneity of central field strength homogeneity of integral field strength normalized integral normal (skew) multipole error Booster ring (GFR= 15mm) BR-dipole (BR-BD/BH) BR-Pure quadrupole (BR-QP) BR-combined quadrupole (BR-QF) BR-sextupole (BR-SM) n B n L/B 1 L n B n L/B 1 L A n L/B 1 L n B n L/B 1 L A n L/B 1 L n B n L/B 2 L A n L/B 2 L [ 10-4 ] [ 10-4 ] [ 10-4 ] [ 10-4 ] [ 10-4 ] [ 10-4 ] [ 10-4 ] ± ±4 ± ±4 ±2 3 ±4 ±2 3 ±15 ±6 3 ±3 4 ±1 ±1.5 4 ±4 ±1 4 ±9 ±6 5 ±3 ±0.5 5 ±2 ± ±3 ±1.5 b 1 L/b 0 L ±1 ± ±1 ±0.3 8 ±10 ±1.5 b 2 L/b 0 L ±0.5 ±0.5 8 ±5 ± ±3 ±1.5 9 ±4 ±0.5 9 ±2 ± ±6 ± ±0.5 ± ±4 ± ±3 ± ±1.5 ± ±0.3 ± ±0.5 ± ±2 ± ±1.7 ± ±0.5 ± ±0.3 ± ±0.3 ± ±0.5 ± ±0.3 ±0.3 5

6 Magnet quantity Magnet type Symbol installation (+spare) SR-dipole SR-DM 48 (+2) SR-short quadrupole SR-short-QM 192 (+3) SR-long quadrupole SR-long-QM 48 (+2) SR-sextupole SR-SM 168 (+6) BR-BD dipole BR-BD 42 (+1) BR-BH dipole BR-BH 12 (+1) BR-pure quadrupole BR-QP 36 (+5) BR-combined quadrupole BR-QF 48 (+1) BR-sextupole BR-SM 24 (+2) Double mini quadrupole-q465 SR-Q465 6 (+1) Double mini quadrupole-q565 SR-Q565 3 (+1) Transfer line magnet (LTB/BTS) BTS-QM BTS-DM LTB-DM/QM 7 (1) 2 (1) 1 (1)/11 (2) Corrector CV/CH and FFC 134 and 100 Buckley System Ltd. (New Zealand) Gongin Co., Ltd. (Taiwan) Danfysik A/S (Denmark) 96.2% of fabricated magnets are installed (include prototype magnet). Only 3.8% of fabricated magnets for the spare. No more choice for the magnet installation 6

7 Magnet alignment Field measurement in the Lab The mechanical center and tilt of the magnets were adjusted by using 3D-coordinate measuring machine (CMM) and then inspected with the rotating-coil measurement system (RCS). Magnet install on the girder Horizontal block Vertical block Magnet install on the girder Dimension of measurement bench is same to girder 7

8 Field correction method Feet-shim Yoke-shim A feet-shim method was used to shim the mechanical and magnetic centers of quadrupole and sextupole magnet close to the ideal center. A yoke-shim method was used to reduce the octupole error (B 3 L/B 1 L) of initial several longquadrupole magnets because the pole profile inaccurately. The pole-shim method was used to correct the multipole error of sextupole magnet. Pole-shim Ref: J. C. Jan, et. al., Multipole errors and methods of correction for TPS lattice magnets, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, V24, NO. 3, (2014). 8

9 Magnet inspect procedure BSL (Vender site) BR/SR-Magnets manufacture Iron laminate Iron cutting Coil winding Assembly CMM*1 - mechanical precise check (Mechanical center shimming within 0.03mm) QM/SM: field fail SM: pole shim Field quality pre-check RCS*2 - magnetic field pre-check (NSRRC staff and equipment) HPS*1 - magnetic field pre-check (vender s staff and equipment) Shipping NSRRC (vendee site) Storage Field measurement HPS*2 - For dipole magnet RCS*2 - Full field quality check (Field center offset < 0.02mm) I-B curve measurement SR-QM/SM Field center offset > 0.02 mm Mechanical shimming CMM*1 - Mechanical center shimming within 0.01mm CMM: 3D coordinate measuring machine RCS: Rotating coil measurement system HPS: Hall probe measurement system 9

10 RCS-Field center measurement Marks A and B of feet label the distinct sides of the magnet. The procedures of the two-sided method: First step, installing the magnet on the normal side of the bench and recording data. The normal-side installation keeps the feet at the left side of the trough wall (Nor. side). Field center is X n in the normal side. Second step, the rotation of the magnet 180 o along a vertical axis (horizontal rotation) keeps the feet at the right side of the trough wall (Opp. side). ). Field center is X o in the opposite side. Real field center X=( X n - X 0 )/2 Terminal side Terminal side Opp. side B A A Nor. side A B Nor. side Opp. side 10

11 Field measurement precision HPS RCS NMR Dipole magnet Dipole field Hall sensor for DM HPS: The absolute field strength of Hall sensor has been calibrated by the Nuclear magnetic resonance & electron spin resonance system (NMR) B < 0.3 G The repeatable of field strength is better than 0.01%. RCS: The absolute field strength of RCS has been corrected by the HPS. The repeatable of main field strength of RCS is better than 0.01%. The repeatable of normalized multipoles of RCS is better than (n>2 is better than ) The repeatable and resolution of field center offset measurement is better than 0.01 mm. 11

12 Mechanical error of magnet Pole profile Design (mm) Measure (mean sd, mm) Measure - Design (mm) Dipole magnet h Quadrupole magnet SQd SQg Sextupole magnet Sd 78 * - Sg Yoke length Dipole Quadrupole 265/ / / Sextupole * No CMM date measured after pole-shim The difference between the designed and machined values of the gap / bore diameter is better than mm. The difference between designed and machined value of the pole gap is better than mm. The deviation of the laminate yoke length was controlled to be smaller than 0.15 % of the yoke length or one-piece thickness of lamina. Note: SR 12 (BR) laminated by 1 mm (0.5mm) silicon steel.

13 Field performance of Spec. Measure (mean sd) SR-dipole b 0 L (0.07%) Short SR-quadrupole b 1 L (0.16%) B 2 L/B 1 L B 3 L/B 1 L B 5 L/B 1 L Long SR-quadrupole b 1 L (0.09%) B 2 L/B 1 L B 3 L/B 1 L B 5 L/B 1 L SR-sextupole b 2 L (0.25%) B 3 L/B 2 L B 4 L/B 2 L B 8 L/B 2 L BR-dipole (BD/ BH) b 0 L / b 1 L / b 2 L / BR-quadrupole (Q1) b 1 L Q1: B 2 L/B 1 L B 3 L/B 1 L B 5 L/B 1 L Unit: b 0 L (T m), b 1 L (T), b 2 L (T/m), B n L/B m L ( 10-4 ) The index n=0 is dipole term, n=1 is quadrupole term. The dispersion of the field strength is generally dominated by the error of bore diameter and the yoke length. The multipole errors are dominated by the asymmetric or machining error of the pole profile. The field quality of magnet is much better than the specifications. The SR and BR magnets have a great quality of the field because of the strict mechanical machining. Ref: J. C. Jan et. al., SUMMARY OF FIELD QUALITY OF TPS LATTICE MAGNETS, Proceedings of International 13Particle Accelerator Conference, Dresden, Germany (2014).

14 Magnet center measurement result + Feet-shim Measurement (mean value sd) short SR-quad. long SR-quad. SR-sext. Mechanical center offset vertical (mm) horizontal (mm) Magnetic center offset vertical (mm) horizontal (mm) Mechanical tilt (deg.) Magnetic tilt (deg.) The mechanical center offset was shimmed better than 0.01 mm in both vertical and horizontal directions. The field center offset was detected better than 0.02 mm in both vertical and horizontal directions after feet-shim. 14 The mechanical and field tilt of magnet is better than 0.01 o after feet-shim.

15 Without any corrector applied Closed Orbit of TPS Storage Ring r.m.s. = 1.78 mm r.m.s. = 1.04 mm The closed orbit distortion (COD) measurement without any corrector: 1.78 mm (rms) horizontal and 1.04 mm (rms) vertical after the LOCO and BBA. The COD results demonstrate very high quality of magnets and the girder alignments. Ref: in the C. C. TPS. Kuo et. al., Commissioning of the Taiwan Photon Source, TUXC3, IPAC T. C. Tseng et. al., The Auto-Alignment Girder System of TPS Storage Ring, THYB2, IPAC2015.

16 Magnet cross talk Crosstalk effect measurement by RCS QM-FFC (90mm): Iron effect: Integral field strength reduced -0.85% in the QM. Current effect: Integral field strength variation of QM < 0.01% between FFC charged 0A and 10A (DC). SM-FFC (140mm): Integral sextupole field strength reduced -0.06% in SM CVCH-Double mini QM (115mm): Integral field strength reduced -0.17% in QM SM-FFC QM-FFC CVCH-QM in double mini section 16

17 TPS commission The electron beam is difficult to survive in the booster ring 2014 Nov. 13: The vacuum chamber have the permeability 2014 Dec. 10: Heat treatment all of vacuum chamber and reinstallation 2014 Dec. 31: Beam storage in storage ring 17

18 Chamber permeability studies of Booster ring Storage ring (Al chamber,518.4m) Booster ring (SUS elliptical chamber,496.8m) SUS elliptical chamber 35 mm (H) 20 mm (V) and thickness 0.7 mm Elliptical chambers are cold-drawn from circular tube of stainless steel (SUS304). The relative permeability ( r ) of the vacuum chamber appeared after the drawing process. An annealing process was used to eliminate the permeability of the BR chamber. Ref: I. C. Sheng et. al., Demagnetized Booster Chambers in TPS, WEPHA049, IPAC

19 Chamber permeability inspection (1) quickly scan of chamber Corrector magnet (dipole field) NbFeB magnet will be attached on the un-annealed chamber Elliptical chamber HPS (2) permeability magnitude measurement Annealed chamber A two-step test of the chamber permeability: (1) a quickly scan of the chamber by the NbFeB permanent magnet and (2) the magnitude measurement by the HPS. The permeability of the chamber is easily to check with NbFeB magnet for r > NbFeB permanent magnet: 6 mm(d) 2 mm(t) 2 g(w) with 0.25 T field strength. 19 The relative permeability of the BR chamber is less than after annealing.

20 Field distortion from the un-annealed chamber b0/b0 (%) b1/b1 (%) Un-annealed chamber Annealed chamber BR combined-function chamber Un-annealed chamber HPS Current (A) A un-annealed chamber was measured to understand the field distortion in the BR dipole (combined-function) magnet. The field distortion increases with decreasing excitation current in the un-annealed chambert indicates that the orbit of electron beam at low energy will be perturbed seriously due to the effect of un-annealed chamber in the BR. 20

21 Summary (I) The machining error of the pole profile of a TPS magnet is better than 0.02 mm as manufactured with the CNC and WEDM techniques. The multipole errors of these magnets thereby conform to the strict requirements of the spec. A precise mechanical and magnetic center was shimmed and detected with the CMM and RCS. The mechanical center offset of magnet was shimmed better than 0.01 mm in both vertical and horizontal directions. The magnetic center offset of magnet was detected better than 0.02 mm in both vertical and horizontal directions after feet-shim. The mechanical and magnetic tilt of magnet is better than 0.01 o after feetshim. The crosstalk of QM-FFC, SM-FFC and double mini QM-CVCH are %, -0.06% and -0.17%, respectively. 21

22 Summary (II) The permeability of the BR chamber appeared after cold drawing of stainless steel (SUS304). The permeability of the BR chamber was quickly inspected with a NbFeB permanent magnet and HPS. The permeability of the BR chamber was less than after heat treatment. A serious distortion of the field from the un-annealed chamber was observed, indicates that the of electron beam at low energy will be perturbed seriously due to the effect of un-annealed chamber in the BR. 22

23 Thanks for your attention 23