Technologie des aimants à tres haut champs et …...Desizing: Glassfibre mesh insulation is pulled over the wire, potato starch is used to lubricate. Before heat treatment the starch

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Technologie des aimants à tres haut champs et applications 1 GHz Dr. Rainer Kümmerle, Daniel Baumann

30ème Journée Utilisateurs RMN Bruker; Maison de la Chimie, Paris Mardi 29 Novembre 2016

1 GHz Aeon at NZN Bayreuth

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Niob-Titanium Wire Production

Cold extrusion from 1 m length to 20’000 m

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NbTi & Nb3Sn “wire” samples at intermediate drawing stage

NbTi, 36 Filaments Nb3Sn, 40,000 Filaments

NbTi, 8.670 Filaments

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(NbTaTi)3Sn wire with ~ 40.000 filaments

199 filament bundles

199 filaments in each bundle

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Low Temperature Superconductors (LTS)

NbTi:

Critical temperature TC : 9.6 K

Highest magnetic field: ~11 T

(useful up to fields of ~400 MHz)

Nb3Sn:

Critical temperature TC : 18 K

Highest magnetic field: ~23…26 T

(useful up to fields of ~1 GHz)

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Nb3Sn production and processing: cold extrusion

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Low Temperature Superconductors (LTS)

Niobum-Bronze wire, easy to bend/wind

Niobum-Bronze wire with glass fibre

insulation

Reacted (heat-treated) Nb3Sn wire,

brittle like ceramics

1.2 x 1.8 mm ~ 40’000 filaments

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Nb3Sn production & processing: winding & reaction process

• Copper (heatload, quench protection)

• Bronze; Cu with up to 16% Sn & 0.3 % Titanium

• Niobium

• Tantalum

• Glass fiber insulation

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Nb3Sn production & processing: winding & reaction process

Desizing:

Glassfibre mesh insulation is pulled over the wire, potato starch is used to lubricate.

Before heat treatment the starch needs to be removed. This is achieved by repeated heating

and vacuum pumping.

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Nb3Sn production & processing: winding & heat treatment process

• The wound Nb3Sn coils are heat treated in a ca. 2

weeks process

• The process takes place in a high vacuum oven

which transfers heat via internal radiation plates to

the wound coils

• Depending on the wire manufacturer, the wire

diameter and the shape of the wire the heat

treatment process needs to be adapted

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Mechanical forces on wires

• Copper

• Bronze

• Niobium

(Tensile strength: 125 MPa)

• Tantalum

(Tensile strength: 170…300 MPa)

• The different materials within the wire need to have very similar expansion coefficients

(from RT up to ~700°C and later from RT down to -269°C)

• Requires extremly robust coil former

• The coil former design is optimized to neither produce additional forces on wire nor to allow for

empty space

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Mechanical forces on wire

In a charged superconducting coil forces point in different

directions depending on position:

• Radial Force Diameter-dependent pressure/stress

(hoop-stress, up to 200 MPa)

• Axial Force transverse stress on wire

200 MPa = 2000 bar or ~1973 atm

(20400 m water column)

For comparison: 30 atm or 300 m is a typical lower dive level

for larger submarines

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16 17 18 19 20 21 22 23 24 250

100

200

300

400

T = 4.2K

T = 4.2K

T = 2.2K

16%Sn

16%Sn

14%Sn

(NbTaTi)3Sn

(NbTaTi)3Sn with high Sn content

(NbTaTi)3Sn with high Sn content T=2.2K

21T

Jc,o

vera

ll (

A/m

m2)

0H (Tesla)

700 800 900 1000

1 GHz

Proton Resonance Frequency (MHz)

Wire Technology: bronze wire with high Sn content

1.83x1.22 mm2

28000 Filaments

f Filaments = 4.8 m

Cu-16%Sn-Ti Bronze

Increased Sn content Higher Critical Current Jc

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Temperature T

T=const.

B=const.

max. jc(4.2K, 12T)

Magnetic field B

Critical Surface

Current density jc

4.2 K

12T

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Key Bruker UHF Magnet Technologies

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Active shielding (3rd generation)

Field coil Shielding coil

External Disturbance Suppression (EDS™)

Active refrigeration Aeon™ technology

2K cooling

Advanced LTS Superconductors

UHF Coil technology

Bo

Key UHF Technologies: High current designs and rectangular wire

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High current design

• rectangular wire • conductor area = 4 mm²

IM = 2 · Io

+ Bo

Low current design

+ Bo

IM = Io

• round wire • conductor area = 2 mm²

Advantages of Rectangular UHF LTS

• Higher current results in larger wire cross sections

• Better winding chamber filling factor

• Less insulation material in winding chamber

• Better control of forces

• Enables highest fields

• Enables smaller magnets

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NbTi-conductor (NbTaTi)3Sn-conductor

Nb

(NbTaTi)3Sn Bundle

2 mm

1 m

m

Cu

UltraStabilized™ 2 Kelvin sub-cooling: used today for 850 MHz to 1.2 GHz

• Long term stable magnet

• Highest field strengths

• Increased magnet stability

• Higher safety margins

• Lowest drift rates

• Easy helium refills

• Compatible with new Aeon™ & HTS technologies

• Patented technology

• Pioneered by Bruker

• Proven track record

• Over 230 systems installed

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UltraStabilized™ technology delivering

unique performance, stability and safety

Thermal Barrier

Joule-Thompson

Cooling Unit

Superconducting

Magnet Coil

Aeon Active-Refrigeration: no compromise on High-Resolution NMR Performance He-Re-Liquefaction for 2K sub-cooled magnets

• Sub-cooled LHe bath at same pressure of 1.05 bar as the 4.2K bath

• Low pressure (below 30 mbar) limited to the JT cooling unit maintained by pumping

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Subcooled helium gas

Sub-cooling Pump in BMPC II unit

Plo

w

Phig

h

He compressor

He g

as r

etu

rn lin

e

• He gas exhausted from the pump at room temperature and fed back to a PTC

• Recovered He gas re-liquefied by the PTC

• Thermal shield cooled by the 1st stage of the PTC (N2 free, no nitrogen vessel)

No Cryogen consumption during normal operation

J-T Unit

PTC

Bruker UHF Magnet Milestones

• 1992 First 750 MHz magnet

• 1995 First 800 MHz NMR magnet

• 1998 First 750 MHz wide bore magnet

• 2001 First 800 MHz actively shielded magnet

• 2004 First 850 MHz WB shielded magnet


• 2006 First 800 MHz single-story shielded magnet


• 2009 First 900 MHz WB shielded magnet

• 2009 First 850 MHz single-story shielded magnet

• 2009 First 1000 MHz magnet (unshielded)

• 2012 First Single-Story Aeon 800 MHz WB

• 2013 First Single-Story Aeon 900

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750

Bruker UHF Magnets Today- the state of the art: - Actively shielded (3rd generation) - Aeon closed loop cooling (LN2-free, no LHe boil-off) - Persistent, homogeneous, ultra-stabilized

Aeon 950 54mm single-story NMR magnet

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Aeon 1 GHz 54mm NMR Magnet

Aeon 21 T 11cm FTMS/MRI Magnet

Aeon 950 MHz 5mm TCI: Water Suppression

2mM Sucrose in H2O:D2O 90:10

Resolution: 11%

Hump: 8.3 / 29.8 Hz

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10 9 8 7 6 5 4 3 2 1 0 ppm

5.385.405.425.44 ppm

Aeon 950 MHz 5mm TCI: 15N detection

15N detected refocused INEPT

C/N-labeled ubiquitin

Adiabatic 13C (Chirp, 48 kHz sweep) CPD decoupling.

NS = 32, expt. Time 60 seconds

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105110115120125130 ppm

Aeon 950 MHz 5mm TCI


1H-15N sofast-HMQC

NS = 2

TD = 1k x 128

Expt. Time 18 seconds

Vertical projection: 15N detected INEPT

Horizontal projection: C & N decoupled excitation

sculpting

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ppm

7.27.47.67.88.08.28.48.68.89.09.29.49.69.8 ppm

105

110

115

120

125

130

Aeon 950 MHz 5mm TCI


3D (H)CCH-TOCSY 2D CH plane

NS = 4

TD = 3k x 256

Mixing = 9ms @ 12.5 kHz

Expt. Time 20 minutes

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ppm

-0.55.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 ppm

10

20

30

40

50

60

70



15N detected 3D CBCACON

NS = 16

TD = 2k x 64 x 80

D1 = 1s

Expt. Time: 30 hours

3D and NCO / NCaCb projections shown

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ppm

105110115120125130135140 ppm

15

20

25

30

35

40

45

50

55

60

65

70

ppm

105110115120125130135140 ppm

168

169

170

171

172

173

174

175

176

177

178

179

d(N)

d(CO)

d(N)

d(C)



15N detected 3D (h)CCCON

NS = 16

TD = 2k x 64 x 96

D1 = 1s

Expt. Time: 37 hours

3D and NCO / NCC projections shown

d(N)

d(N)

d(C)

d(CO)

28

ppm

105110115120125130135140 ppm

15

20

25

30

35

40

45

50

55

60

65

70

ppm

105110115120125130135140 ppm

168

169

170

171

172

173

174

175

176

177

178

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• Active shielding reduces space requirements by > one order of magnitude

• Aeon 1 GHz magnets leverage advanced BEST superconductors

• Active refrigeration eliminates LN2, reduces LHe boil-off essentially to zero

New GHz-class magnet, novel Cryoprobes, 111 kHz MAS probes, and new

NMR methods expand frontiers in structural biology, membrane protein and intrinsically disordered protein (IDP) research

ENC 2016 Announcement: World's first shielded Aeon 1 GHz System installed

Aeon 1 GHz at Research Center for Bio-Macromolecules at University of Bayreuth

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1 GHz 5mm TCI: Water Suppression


Resolution: 10%

Hump: 9.7 / 16.7 Hz

Composite pulse & crusher gradient presat

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10 9 8 7 6 5 4 3 2 1 0 ppm

5.395.405.415.42 ppm

1 GHz 5mm TCI: 13C RF power handling


1H-13C HSQC

NS = 2

TD 8k x 256

AQ 400ms

Adiabatic CPD decoupling

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ppm

3.53.63.73.83.94.04.14.24.3 ppm

60

62

64

66

68

70

72

74

76

78

80

82

1 GHz 5mm TCI: 13C RF power handling


1H-13C HSQC

AQ 400ms

Adiabatic CPD decoupling

2D HSQC 1H projection

1D 1H spectrum

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1 GHz 5mm TCI: CC-TOCSY


13C detected CC-TOCSY

NS = 16

TD = 4k x 128

Mixing = 20ms @ 13.5 kHz


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ppm

510152025303540455055606570 ppm

10

20

30

40

50

60

70

1 GHz relaxation-optimized 3D


3D BEST-HNCO

NS = 2

TD = 1k x 48 x 96

D1 = 100ms


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3D BEST-HNCO

NS = 2

TD = 1k x 48 x 96

D1 = 100ms

NUS 12.5% with CS processing

Expt. Time: 5 minutes!

(traditional sampling: 40 minutes)

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3D BEST-TROSY-HNCOCACB

NS = 2

TD = 1k x 64 x 256

D1 = 200ms

Expt. Time: 3 hours 46 minutes

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3D BEST-TROSY-HNCOCACB

NS = 2

TD = 1k x 64 x 256

D1 = 200ms

NUS: 12.5 % with CS processing

Expt. Time: 28 minutes

(traditional sampling: 3.75 hours)

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Acknowledgements

• Daniel Baumann

• Gerhard Roth

• Patrick Wikus • Ruedi Gaisser

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www.bruker.com

For research use only. Not for use in diagnostic procedures. Copyright © 2010 Bruker Daltonics. All rights reserved.

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Technologie des aimants à tres haut champs et …...Desizing: Glassfibre mesh insulation is pulled over the wire, potato starch is used to lubricate. Before heat treatment the starch