2 nd ILSF School on Synchrotron Radiation and Its Applications

Transcription

1 2 nd ILSF School on Synchrotron Radiation s Otb October 9-12, 2012 Magnets, Design and fabrication Prepared by: Samira Fatehi,Mohammadreza Khabbazi, Prepared by: Samira Fatehi,Mohammad reza Khabbazi, Mechanic Group,Magnet section, Ititute for Research in Fundamental Sciences ILSF

2 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Rf References D. Einfeld, ed, Magnets,,CELLS SCAS, Frascati, Nov Th.Zickler, CERN Accelerator School, Specialized Course on Magnets, Bruges, Belgium, June Jack Tanab, Iron Dominated Electromagnets Design, Fabrication, Assembly and Measurements, January 6, G.E.Fisher, Iron Dominated Magnets, Stanford Linear Accelerator Center, H. Wiedemann, Particle Accelerator Physics I, Springer, K.Wille, The physics of Particle Accelerators, Oxford University,

3 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n ILSF Mechanic group Light sources and magnets Magnet types Dipoles Quadrupoles Sextupoles Combined magnets Special magnets Design Procedure Prototype magnets Fabrication Procedure OutLine

4 Mechanic c Group,ILSF 2 n nd ILSF Sch hool on Synchrotronn Radiation

5 2nnd ILSF Sch chool on Syynchrotron n Radiation on and Its A Application Light g t sou sources ces aand d magnets ag ets Storage ring Booster LTB Linac BTS Diamond Accelerator Complex

6 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Magnet types ALBA,TPS, PAL, SLS, CERN Brazilian light source Use in medium energy light sources ( 3 GEV), magnetic field 2 T Use in high h energy light sources (>3 GEV), magnetic field > 2 T Rarely used because of high prices, aging & etc

7 Magnet types 2 n nd ILSF Sch hool on Synchrotronn Radiation

8 2 nd ILSF Sch hool on Sy ynchrotron n Radiation Each magnet has 2 main parts : 1. Iron yoke( includes back leg, pole root, pole, ) 2. Coils

9 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Dipole magnet(bending magnet) Has 2 poles,2 coils Bends the electro in a single curved trajectory. Injection of particles into the accelerator Ejection of particles from the accelerator Production of synchrotron radiation Dipole main parameters B (magnetic field at center) L (length) h (half gap height) GFR (good field region), B y ( x) = cot Pole profile eq.: y=h By x

10 C core Standard Dipole Geometries H type Window frame High ampere turn 2 n nd ILSF Sch hool on Synchrotronn Radiation

11 Application n and Its A n Radiation ynchrotron hool on Sy nd ILSF Sch 2 n Normal Conducting Dipole Magnet 2 1 B magnetic flux h (gap height) ht) µo air permeability

12 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Magnetic g length Coming from, B increases towards the magnet center (stray flux) Magnetic length > iron length Magnetic length: magnetic B 0 L + B dz = For a dipole: L magnetic = Liron + 2 *(2 h) * K 2h: gap height k: geometry specific cotant ( 0.56) K gets smaller in case of: Pole width < gap height Beam direction Saturation

13 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Quadrupole magnet 4 poles, 4 coils Focus the beam and prevent deviating Zero field in center Strong gradient g (T/m) Placed in straight sectio between bending magnets Pole profile eq.: 2 R xy = 2 g (magnetic gradient field ) Quadrupole main L ( length) parameters R (Aperture) GFR (good field region) By B y ( x) = g x x

14 Standard Quadrupole Geometries 2 n nd ILSF Sch hool on Synchrotronn Radiation

15 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Normal lconducting Quadrupole Magnet integration path split in 3 sectio field defined by gradient g along s1: along s3: & g field gradient ra Aperture µoair permeability

16 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Magnetic length > iron length Magnetic length For a Quadrupole: Lmagnetic = Liron + 2RK Magnetic length R: Aperture k: geometry specific cotant ( 0.45) Beam direction

17 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Sextupole magnet Sextupole magnet correct chromatic aberration due to focusing errors on particles with different energy Sextupole main parameters B (Sextupole component) L ( length) R (Aperture) GFR (good field region) Pole profile: B y ( x) = 1 B x yx y = R x 0 0

18 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Normal Conducting Sextupole Magnet same procedure like the other magnets B Sextupole component R Aperture µ٠air permeability

19 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Combined magnets Functio generated by pole shape (sum a scalar potentials): Amplitudes cannot be varied independently Dipole + quadrupole h y = 1 + Dipole + quadrupole + sextupole Quadrupole + sextupole y = 1 + ( 0 ) gx B 0 h ( 0 ) 2 gx B x + B 0 2 B y gxy + B ( x y ) = cte. 3

20 Combined magnets Functio generated by ierting specified asymmetries in magnets : 2 n nd ILSF Sch hool on Synchrotronn Radiation

21 Application n and Its A 2 nd ILSF Sch hool on Sy ynchrotron n Radiation Combined magnets Functio generated by ierting auxiliary windings in magnets : Horizontal steering vertical steering SQ Quadrupole field

22 Special magnets 2 n nd ILSF Sch hool on Synchrotronn Radiation

23 Summary Bend the electron beam focuse the electron beam correct chromatic aberration 2 n nd ILSF Sch hool on Synchrotronn Radiation

24 Magnet design 2 n nd ILSF Sch hool on Synchrotronn Radiation

25 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Magnet Design Procedure a) obtain the needed current from the defined parameters Define Specificatio ( by beam dynamics) Perform computer design b) choosing material for the yoke c) profile designing and pole d) Saturation test e) Checking field optimization tolerances in the good field region Electrical and Cooling Design Mechanical Design

26 Application n and Its A n Radiation ynchrotron hool on Sy nd ILSF Sch 2 n 2D design: (Poisson Superfish,FEMM, Opera2D ) Use pre processor or modeler to build geometry Profit from symmetries to reduce number of elements

27 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Yoke materials Today s standard: cold rolled, non oriented electro steel sheets Massive iron only for dc magnets Magnetic and mechanical properties can be adjusted by final annealing in decarbonized atmosphere the smaller carbon content results in better magnetic properties (Increase in permeability Decrease in hysteresis loss and aging) Magnetic properties (permeability, coercivity) should be within small tolerances Homogeneity and reproducibility among the magnets of a series can be enh anced by selection, sorting or shuffling Organic or inorganic coating for iulation and bonding Material is usually cheaper, but laminated yokes are commonly used esp. in Booster rings. Packing factor should be kept bellow 98% Common used materials: AISI1010 (max 0.1 % carbon content & max 0.3% silicon content ) A(less than 0.003% carbon content & less than 1.3% silicon content) M400-50A( 0.02% carbon content & 2.4 % silicon content)

28 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Sheet thickness: 0.3 t 1.5 mm Specific weight: 7.60 δ 7.85 g/cm3 Coercivity: Hc< 70 (±10) A/m Electrical t i l resistivity 20 C: 0.16 (low Si) ρ 0.61 μωm (high h Si)

29 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Pole Optimization Rising the amount of these multipoles leads to BAD field quality i.e. more than 0.1% SHIMMING is needed

30 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Pole Optimization-Shimming process Pole Optimization is an iteration process & should be continued till one reaches the desire field quality i.e. < 10-4

31 ILSF Dipole, Quadrupole & Sextupole shims Dipole Sextupole Quadrupole nd ILSF Sch hool on Synchrotronn Radiation 2 n

32 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Dipole B = cot 0 B(x) Field Quality Calculatio central field ΔB = B B B B 0 0 Quadrupole B = 0 g0x Is the field at each point calculated by simulation Sextupole B = 1 B x

33 X[mm] nd ILSF Sch hool on Synchrotronn Radiation ΔB'/B' ΔB/B X (mm) 2 n

34 Saturation test 2 n nd ILSF Sch hool on Synchrotronn Radiation

35 Harmunic analysis 2 n nd ILSF Sch hool on Synchrotronn Radiation

36 2 nd ILSF Sch hool on Sy ynchrotron n Radiation 3D design:(radia,tosca,mermaid,flux3d ) 3D designis is necessary to study : The longitudinal field distribution End effects in the yoke End effects from coils Magnets where the aperture is large compared to the length Unlike 2D, in 3D: all regio with current deity have to be modeled completely

37 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Longitudinal shimming i (Chamfering) Dipoles: Rogowsky roll off or angular cut Depth D h and angle adjusted d using 3D codes or measurements Quadrupoles: Angular cut at the end Sextupoles: Usually not chamfered Chamfer should be chosen in such a way that maintain magnetic length cotant across the good field region

38 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Parameter Field Magnetic Length Gap height Good Field Region Parameter Field Magnetic Length Gap height Good Field Region Parameter Field Gradient Magnetic Length Aperture radius Good Field Region Prototype Magnets Value 0.5 T 50 cm 34 mm ±20mm Value 1.42 T 50 cm 32 mm ±15mm Value 23T/m 26 cm 30 mm ±18mm H Type DipoleMagnet C Type Dipole Magnet Quadrupole Magnet

39 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n prototype H Type dipole magnet Main Objectives: To compare the measurement results with design data. To develop fbi fabrication i procedures and techniques. To find if the available low carbon steel is capable of using as magnetic steel. Magneticspecificatio of material Magnet specificatio Parameter Unit H. Prototype Field B 0 T 0.5 Gradient B' T/m Gap mm 34 Good Field Region mm ±20 B/B - < Mechanical Length mm 500 Chemical components of steel C Si Mn P S 0.03 % 0.01 % 0.24 % % %

40 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n Physical design and main dimeio 2D magnetic design FEMM 3D magnetic and chamfer design RADIA Main dimeio

41 2 nd ILSF Sch hool on Sy ynchrotron n Radiation Electrical and cooling design Parameter Design Value Unit Total ampere tur per coil 6900 A Operating current 101 A Number of turn per coil 68 Number of pancakes per coil 2 Number of turn per pancake 34 Conductor height 4.05 mm Conductor width 8.66 mm Cooling channel height 1.81 mm Cooling channel width 6.42 mm Copper area mm 2 Specific resistance Ohm mm 2 /m Resistance per coil 0.08 Ohm Current Deity 4.33 A/mm 2 Voltage drop per coil 7.79 V Power per coil W Number of water circuit per coil 2 Water temperature rise 8 C Cooling water speed 1.02 m/s Pressure drop per circuit i 10 bar Reynolds number 1776

42 Stacking fixture Winding fixture 2 nd ILSF Sch hool on Synchrotronn Radiation

43 Laser cutting of laminatio Washed and dried laminatio mixing the two components of resin 2 n nd ILSF Sch hool on Synchrotronn Radiation

44 Coating procedure has been done by use of brush, and the packing factor is measured by measuring the length of packed laminatio 2 n nd ILSF Sch hool on Synchrotronn Radiation

45 Theyokehasbeencuredinanaircirculating oven with temperature of homogeneity (±2 C) for 12 hours 2 n nd ILSF Sch hool on Synchrotronn Radiation

46 In order to have two ends of the coil in the outer side the coil should wind from the middle for each layers and we need to have even layers 2 n nd ILSF Sch hool on Synchrotronn Radiation

47 2 nd ILSF Sch hool on Sy ynchrotron n Radiation The machining procedure is done in a way to prevent delamination and to use the common reference point on both yokes to reach to defined tolerances

48 2 nd ILSF Sch hool on Synchrotronn Radiation

49 2 nd ILSF Sch hool on Synchrotronn Radiation

50 2 nd ILSF Sch hool on Synchrotronn Radiation

51 nd ILSF Sch hool on Sy ynchrotron n Radiation 2 n STATUS REPORT ON THE IRANIAN LIGHT SOURCE FACILITY PROJECT The Iranian Light Source Facility Project (ILSF) is a3rd generation light source with energy of 3 GeV, a full energy injector and a 150 MeV linac as preinjector. This is the first large scale accelerator which will be built in Iran. For storage ring, booster synchrotron and linac including the trafer lines, a draft design will be completed soon. The storage ring has an emittance of 3.3nmrad, a circumference of meters with an overall of 32 straight sectio of different lengths. The booster synchrotron has a circumference of 192 meters and emittance of 35nm-rad. For the booster synchrotron a new lattice is proposed. The linac is a conventional 150 MeV accelerator.

52 IRANIAN LIGHT SOURCE FACILITY STORAGE RING MAGNETS 2 n nd ILSF Sch hool on Synchrotronn Radiation

53 2 nd ILSF Sch hool on Sy ynchrotron n Radiation EFFECTS OFMULTIPOLES ON DYNAMIC APERTURE OF THE ILSF STORAGE RING

54 2nnd ILSF Sch chool on Syynchrotron n Radiation on and Its A Application Thanks for your nice attention