Superconducting magnet systems of Budker INP for generation of synchrotron radiation

Transcription

1 Superconducting magnet systems of Budker INP for generation of synchrotron radiation Mezentsev Nikolai Budker INP, Novosibirsk, Russia /1/2003 1

2 Contents: Superconducting Wave Length Shifters Superconducting multipole wigglers Superconducting bending magnet Superbend 7/1/2003 2

3 There are several reasons to install wigglers or shifters on a storage ring: to shift a spectrum to the harder X-ray region by using a higher magnetic field of the wiggler (shifter) to increase a photon flux due to many poles ( multipole wiggler); to obtain new feature of radiation like polarization to obtain a flexibility for experiments, due to a possibility to change the wiggler field during the experiment; to decrease or increase the emittance of the storage ring; to decrease the polarization time of an electron (positron) beam.

4 Table of main parameters Superconducting wigglers designed and produced at Budker INP Installed at: Year Magnetic field, T Max/normal Number of poles (Main + Side) Magnetic gap, mm Main Pole length, mm Magnetic length, mm Vertical aperture, mm Radiatio n power, kwatt Electron energy, GeV Beam current, A VEPP-3 (Budker INP) Helical undulator (Budker INP) VEPP-2 (Budker INP) Wiggler Siberia-1 (Moscow) 1985 PLS (Korea) 1995 LSU-CAMD (USA) 1998 SPring-8 (Japan) 2000 WLS (BESSY-II) 2000 PSF-WLS (BESSY-II) 2001 HMI- (BESSY-II) 2002 ELETTRA (Italy) (4.5) 7.68 (7.5) 7.55 (7.0) 10.3 (10.0) 7.5 (7.0) 7.5 (7.0) 7.67 (7.0) 3.7 (3.5) /1/2003 4

5 Superconducting Wave Length Shifters: 3 pole 10 Tesla WLS for SPring-8 3 pole 7 Tesla WLSs with fixed orbit at central pole for BESSY-2 7/1/2003 5

6 10 Tesla 3 pole WLS for Spring-8 M.G.Fedurin, G.N. Kulipanov,N.A. Mezentsev},V.A. Shkaruba, A.N. Skrinsky Budker INP, Novosibirsk, Russia Ando,S. Date, M.Hara, H. Kamitsubo, N. Kumagai, Y. Miyahara, T. Nakamura, H.Ohkuma, K. Soutome, M. Takao, H. Tanaka Spring-8, Japan 10 Tesla WLS for Spring-8 Slow Positron Source 7/1/2003 6

7 High energy of electron in SPring-8 gives a possibility to obtain wide spectrum of synchrotron radiation and hard part of the spectrum rich of MeV region. Critical energy of synchrotron radiation for electron energy of 8 GeV and magnetic field in central pole of the wiggler of 10 Tesla is equal to 450 kev. 7/1/2003 7

8 WLS magnetic system Pole number 3 Magnetic field in central pole (median plane) 10 Tesla (10.3 Tesla maximum) Magnetic field in side poles (median plane) 1.9 Tesla Stored energy at 10 Tesla field ~400 kj Weight of wiggler cold part ~1000 kg Windings of the central pole Nb 3 S Rectangular wire by the size 0.85х1.2 мм 2 Nb-Ti Round wire by a diameter 0.92 мм Full length of the magnet 1000 mm Pole gap 42 mm The size of the electron vacuum chamber 100x20 mm 2 The iron yoke of the wiggler is intended to mechanically support the superconducting windings and the whole magnetic system as well as to reinforce of magnetic field in the orbit and to close the magnetic flux. In this case, the iron yoke is designed to completely close in it the magnetic flux and to exclude influence of stray magnetic fields upon the electron beam of the storage ring outside the superconductive wiggler. The core is made of a magnetically soft material (ARMCO) to diminish influence of the residual magnetic fields. 7/1/2003 8

9 The central pole is a three-section winding, reeled up on a core of a magnetically soft metal with high magnetic permeability ( the ARMCO grade). Electric contacts between the sections are taken outward and connected to each other with a rectangular superconducting tie. To be reeled up, the coil is placed in a special technological mandrel. The inner section of the central pole is manufactured by the "dry reeling" method from a rectangular Nb-Sn tie 1.4x0.87 mm in size. Nb-Sn coil disassembled after baking out ½ of central pole of 10 Tesla WLS 7/1/2003 9

10 Magnetic field distribution Wiggler magnetic field is sign alternating magnetic system so as longitudinal field integral is equal to zero (- first field integral). Besides the magnetic field is symmetrical relative of the magnet center with high accuracy, that provides zero integral of a field for both halves of the magnet in a longitudinal direction (- second field integral). The measurement of magnetic map inside of the wiggler was made by Hall probes calibrated with help of special installed NMR probes Magnetic field(gs)incenral pole versus horizontal cross coordinate Magnetic field (Gs) in central pole versus verticzl coordinate Magnetic field, Gs Mag ne tic fie ld, Gs Horizontal cross coordinate, mm Vertical coordinate, mm 7/1/

11 Results of magnetic field measurements of 10 Tesla WLS for Spring-8 Comparison calculations and measurements Central pole Side poles 7/1/

12 10 Tesla WLS installed on SPrimg-8 7/1/

13 7 Tesla 3 pole WLS with fixed point of radiation 7/1/

14 7 Tesla WLS for BESSY-2 SC WLS General view Side view e- Correctors Top view 7/1/

15 Magnetic field distribution 7 Longitudinal magnetic field distribution along staight section for different field levels: 2.3, 4, 6, 7 Tesla Focusing K1-values for horizontal and vertical directions for E=1.9 GeV, B=7 Tesla horizontal vertical Magnetic field, Tesla Focusing K-value, 1/m^ Longitudinal distance, mm K2-value along the straight section for E=1.9 GeV, B=7 Tesla Longitudinal distance, mm K2 value, 1/m^ Longitudinal distance, mm 7/1/

16 Focusing property 1.5 Focusing K1-values for horizontal and vertical directions for E=1.9 GeV, B=7 Tesla 10 K2-value along the straight section for E=1.9 GeV, B=7 Tesla Focusing K-value, 1/m^ horizontal vertical K2 value, 1/m^ Longitudinal distance, mm Longitudinal distance, mm 7/1/

17 Orbit distortion inside 3 pole WLS Orbit angle deviation, mrad Orbit angle deviation in straight section at beam energy of 1.9 GeV for different field levels: 2.3,4, 6, 7 Tesla Longitudinal distance, mm Orbit displacement, mm Orbit displacement in straight section at 1.9 GeV for different field levels: 2.3, 4, 6, 7 Tesla Longitudinal distance, mm 7/1/

18 Phase diagram of photon beam from 3 pole WLS Central pole B=7 Tesla Side pole B=1.4 Tesla Correctors B=0.4 Tesla angle, rad x' kl x kl s kl mm mm x' kl 0 m x' kl + mm coordinate, mm 7/1/

19 Superconducting multipole wigglers: 7 Tesla 17 pole wiggler for HMI-BESSY Tesla 49 pole wiggler for ELETTRA 7/1/

20 7 Tesla 17 pole wiggler for BESSY-2 D. Berger - Hahn-Meitner-Institut, Glienicker Straße 100, Berlin, Germany F. Schaefers, M. Scheer, E. Weihreter - BESSY, Einsteinstraße 15, Berlin, Germany, M. Fedurin, M. Mezentsev, V.Shkaruba, V.Repkov, E.Miginsky, S.Khruschev - BINP, Acad. Lavrentiev prospect 11, Novosibirsk, Russia, 7/1/

21 Main parameters of the 17-poles wiggler for BESSY-HMI Number of poles (main+side) Vertical aperture, mm Magnetic gap, mm Period length (main pole length), mm Maximum magnetic field, T Currents for 7 T magnetic field, A First current Beam current, A Second current Electron energy, GeV Radiation power, kwatt (74) 7.45 (7.0) Zero field integral currents Two power supplies are used to energized wiggler field. Each coil consists of two windings. Such connection gives a possibility to control the field integral to zero with required accuracy. 7/1/

22 Radiation property of Superconducting multipole wiggler for BESSY-II - HMI Photo phase-space reduced to center of the wiggler 30 Photon flux, phot/sec/mrad/0.1%bw N0 ij N1 ij Tesla 17 pole wiggler 7 Tesla WLS E=1.9 GeV I=0.5A B=7 Tesla ε ij 200 Photon energy, kev α /1/2003 iα Power, Watt Angle, mrad P iα x' io ( x io s io x' io ) mm Coordinate, mm Radiation Power distribution E=1.9 GeV I=0.5A B=7 Tesla E=1.9 GeV B=7 Tesla Horizontal angle, mrad

23 Magnet system of 17-poles superconducting wiggler Copper liner into helium vessel vacuum tube Stainless steel LHe vessel 4 K Copper liner Wiggler magnet system Prototype magnet system 7/1/

24 Calculation results Transversal beam deviation along longitudinal coordinate (Beam trajectory) -Magnetic field distribution along longitudinal coordinate -Beam trajectory angle distribution along longitudinal coordinate -Transversal beam deviation along longitudinal coordinate (Beam trajectory) Measurement results Magnetic field distribution along longitudinal coordinate -Magnetic field distribution along longitudinal coordinate -Beam trajectory angle distribution along longitudinal coordinate Beam trajectory angle distribution along longitudinal coordinate -Transversal beam deviation along longitudinal coordinate (Beam trajectory) 7/1/

25 A superconducting 3.5 T 49-pole wiggler for ELETTRA storage ring A.Batrakov Batrakov,, S.Khrushchev, G.Kulipanov Kulipanov,, E.Kuper Kuper,, M.Kuzin, V.Lev, A.Medvedko Medvedko,, N.Mezentsev, E.Miginsky Miginsky,, V.Shkaruba Shkaruba,, V.Tsukanov Tsukanov, V.Zhurba BINP, Novosibirsk, Russia D.Zagrando Zagrando,, B.Diviacco Diviacco,, C.Knapic ELETTRA, ST, Trieste, Italy R.P.Walker Diamond Light Source Ltd., RAL, Chilton, Dicot,, U.K. 7/1/

26 Main wiggler parameters Field direction Field structure Main poles working magnetic field achived field number of poles ¾ poles: magnetic field number of poles ¼ poles: magnetic field number of poles Transverse field homogeneity Pole gap Period length Stored energy Working temperature Total mass of cooled parts Crytical photon energy (2 GeV) Total radiated power (E=2GeV, I=200 ma) Vertical 1/4, -3/4, 1, -1,... 1, -3/4, 1/4 3.5 T 3.66 T T T 2 B/B < at x=±1 cm 16.5 mm 64 mm 240 kj 4.2 K ~1000 kg 9.3 kev 8.5 kw 7/1/

27 Superconducting coils Sketch of ½ pole of magnet SC Wire characteristics Diameter, mm 0.87 (0.92) Ratio of NbTi : Cu 0.43 Critical current, Amp 380 (at 7 T) Number of filaments 8600 Photo of ½ pole of the magnet Cross section of the coil Wire packing ~88% 7/1/

28 Two halves of magnet before assembling Array of poles Prestressing system 7/1/

29 Prepressing of the superconducting coils inside of yoke is realized by four bronze stads. Assembled magnet Iron yoke Magnet arrays 7/1/ The length of the magnet yoke is 1700 mm

30 Wiggler assembling at ELETTRA site 7/1/

31 Longitudinal behavior of vertical magnetic field component for calculated c and measured data. 4 _ C a l c u l a t e d _ M e a s u r e d 2 B,Tesla L o n g i t u d i n a l c o o r d i n a t e, m m Remanent magnetic field in the wiggler after slow decreasing of currents to zero. Remanent magnetic field in the wiggler after quench B,Tesla B, Tesla londitudinal coordinate,mm Longitudinal coordinate, mm 7/1/

32 Photon phase-space reduced to center of the wiggler Synchrotron radiation from 3.5 T 49-pole wiggler and usual 1.5 T bending magnet (2 GeV,, 200 ma) x' io ph/sec/mr^2/(0.1%bw) x io s io mm mm x' L io+ mm x' io Radiation Power angle distribution Ýíåðãèÿ (êýâ) Power, Watt/mrad P iα /1/ α iα Horizontal angle, mrad

33 ELETTRA site Test quench (B=3.66 Tesla) Transportation to the ring Wiggler on the ring 7/1/

34 9 Tesla superbend for BESSY-2 S.Khrushchev, V.Lev, N.Mezentsev Mezentsev,, E.Miginsky Miginsky,, V.Shkaruba Shkaruba,, V.Syrovatin Syrovatin, V.Tsukanov Tsukanov,, V.Zhurba Zhurba, BINP, Novosibirsk,, Russia D.Kraemer - BESSY, Einsteinstraße e 15, Berlin, Germany 7/1/

35 Table of parameters Main parameters of SuperBend Maximum Field (required /reached), T 9.0 / 9.38 Magnetic gap, mm 46 Beam vacuum chamber: Vertical, mm Horizontal, mm Current in superconducting coils, A 300 Storage energy, kj 220 Cold mass, kg ~1300 Liquid helium consumption, l/h <1 Ramping time to 9 T ~15 min Bending angle, degree Bending radius, m m Edge angle, degree 1.3 Effective magnetic length, m Distance from flange to flange, m /1/

36 View of superbend position on BESSY-2 ring Equilibrium orbit cryostat Superbend magnet Magnetic elements of BESSY-2 ring 7/1/

37 Superbend cross -section in median plane External housing 20K shield Iron yoke 60K shield coils Beam orbit Room temperature cacuum chamber Liquid helium vessel 7/1/

38 Superconducting coil design of superbend NMR probes Bandage-stainless steel ring Liquid helium vessel tube 7/1/

39 Coil Sections Fabrication of superconducting coils of 9T SuperBend Wire Type Parameters of coils Number of layers Number of turns Total Turns Current density in coil, A/mm 2 1 Nb 3 Sn (80%), 10 77, d=1.24mm 2 Nb 3 Sn (50%), 10 77, d=1.24mm 3 Nb-Ti, , d=0.92 mm 4 (correction) Nb-Ti, 4 105, d=0.92 mm 5 (bandage) Stainless steel, d=1 mm 4 95, Fields at wire, T 7/1/

40 Magnetic system of superbend coils Iron yoke 7/1/

41 Final Assembling of SuperBend magnetic system 7/1/

42 Bath cryostat test of 9 Tesla superbend magnet prototype Quenching SuperBend prototype in bath cryostat (June 2003) T Maximum field 9.38 T was achieved in BINP (Novosibirsk) Magnetic Field, T New power supply Old power supply Quench Number uperbend magnet assembled with test ron yoke Superbend preparing for Bath cryostat test 7/1/

43 Longitudinal magnetic field distribution y, cm x, cm Magnetic field measurements were done 7/1/2003 in bath cryostat with Hall probe array at 4.2 K temperature. 43

44 Upper cryostat General view of the Cryostat cryocoolers Lower cryostat Beam pipe support Ion pump 7/1/

45 Thanks for attention 7/1/