hts r&d for high field magnets
Post on 13-Jan-2016
48 Views
Preview:
DESCRIPTION
TRANSCRIPT
03 Dec 2007Muon Collider Design Workshop 1Fermilab
HTS R&D for High Field Magnets
Michael Lamm
• Introduction
• Examples of Accelerator Magnet R&D with HTS
• High Field Magnet Design
• National Collaboration
With input from several people at the US National Labs
03 Dec 2007Muon Collider Design Workshop 2Fermilab
Colliding Ring/IR Magnets ~10 T, wide aperture/open midplane
Wide(?) aperture pulsed( ?) 20 T solenoids
HCC solenoid rings up to 20 T
Very High Field Solenoids
From MCTF End of year report
Interesting Magnets in Muon Colliders
“Low Emmitance” scenario…
03 Dec 2007Muon Collider Design Workshop 3Fermilab
Why consider HTS? Thermal Margin..
Superconducting state a function of Jc, Field and Temperature
IR and Collider ring and target magnets require high thermal margin at modest fields
>10 T on conductor calls for Nb3Sn or HTS materials
03 Dec 2007Muon Collider Design Workshop 4Fermilab
Magnets with fields on conductor ~>20T call for HTS
03 Dec 2007Muon Collider Design Workshop 5Fermilab
HTS Materials Used in Magnets
• Bi 2223 tape– Has been available in long piece lengths from American
Superconductor
– Stainless steel reinforced to improve tensile strength
– Significant Angular dependence to Jc (field)
• Bi 2212 Round wire– Available in long piece length from OST
– No angular dependence
– Better Je than Bi2223
– Can be made into a Rutherford cable
– Wind and react technology….(problems with treatment)
03 Dec 2007Muon Collider Design Workshop 6Fermilab
HTS Materials Used in Magnets II
• 2G YBCO Tape– Excellent tensile
strain sensitivity – Significant
improvement in Je over Bi 2223 tape
– Jc has strong angular dependence with external field.
– Used in 26T solenoid insert
– Relatively new…. Still being studied
From Drew Hazelton Presentation at MT 20
03 Dec 2007Muon Collider Design Workshop 7Fermilab
HTS Accelerator Magnet R&D in the US
• HEP National Labs study HTS applications in accelerator magnets as part of broader SC magnet R&D Program (Nb3Sn mostly)– BNL– LBNL– Fermilab– Muons Inc has worked with FNAL and BNL several
topics– Also work at LANL studying HTS materials
• Studies at the National High Magnetic Field Lab on high field solenoids have applicability to Muon Colliders
03 Dec 2007Muon Collider Design Workshop 8Fermilab
LBNL HTS Program
• Emphasis on Bi-2212 Wind and React Technology
• With SWCC Showa Cable Systems Co. Ltd.• Build HTS subscale racetrack coils from Bi
2212 Rutherford cables. R&D Issues with Bi-2212 W&R
– Reaction cycle (precise temperature control +/- 2 degrees at >800K)
– Insulation to withstand extreme temperatures
– Important new data on Bi “leakage” issues
• Status: 5 coils manufactured, 3 in progress
03 Dec 2007Muon Collider Design Workshop 9Fermilab
Observed at NHMFL as well as HTS vendor: problem not well understood
03 Dec 2007Muon Collider Design Workshop 10Fermilab
BNL Program
• Design/built/test prototype quadrupole for RIA projects
• Expected very high heat deposition (15 kW)
• Magnets built with Bi2223 tape from American Superconductor, with plans to build YBCO magnets
Racetrack coils during assembly
Completed 12 Coil magnet
03 Dec 2007Muon Collider Design Workshop 11Fermilab
BNL Program
• \
Their experience is well suited toward HTS applications in high radiation/energy deposition
03 Dec 2007Muon Collider Design Workshop 12Fermilab
New world record for superconducting magnet
26.9 T field,
>200 MPa hoop stress
03 Dec 2007Muon Collider Design Workshop 13Fermilab
03 Dec 2007Muon Collider Design Workshop 14Fermilab
FNAL Program
• Emphasis on HTS cable/strand analysis• Two Oxford Instrument Teslatron, capable of
testing up to 17 T solenoid field, from 1.9K to 70K
• Cabling machine• Tests performed on Bi 2212 round wire, Bi 2223
tape and YBCO tape• Data used in 50 T solenoid paper studies• Plans in FY08 to wind small solenoids for
Teslatron
03 Dec 2007Muon Collider Design Workshop 15Fermilab
E. Barzi, LTSW 2007, Oct. 29-31, 2007, South Lake Tahoe, CA 15
October 30, 2007
HTS and LTS Performance at 4.2 K
0
200
400
600
800
1000
1200
1400
1600
0 5 10 15 20 25 30
Applied Field, T
J E (
4.2
K, B
), A
/mm2 .
1.2 mc 2G SuperPower Parallel1.2 mc 2G SuperPower Perpendicular348 2G AMSC Parallel348 2G AMSC PerpendicularBSCCO-2212 Round Wire (OST)BSCCO-2223 Tape ParallelBSCCO-2223 Tape PerpendicularNb3Sn (High Jc RRP, OST)Nb3SnNbTi
03 Dec 2007Muon Collider Design Workshop 16Fermilab
Conductor Testing at Fermilab
B
SAMPLE
I
B c
b a
IB
Probe for Angular Measurements
Courtesy of E. Barzi
03 Dec 2007Muon Collider Design Workshop 17Fermilab
Example of Measurements Performed
4.2 K
1
2
3
4
5
6
7
-11.25 0 11.25 22.5 33.75 45 56.25 67.5 78.75 90 101.25
Angle, o
Ic /I
c(7
7K
,0T
)
0T
1T
2T
3T
4T
6T
8T
10T
12T
15T
Bi-2223 BSCCO-2223
0
100
200
300
400
500
600
700
800
0 2 4 6 8 10 12 14 16B, T
Ic, A
33K ┴
22K ┴
14K ┴
4.2K ┴
1.8K ┴
33K //
22K //
14K //
4.2 K //
Studies performed on Bi-2223 and YBCO tape (not shown) show Strong angular dependence
Studies performed over a wide range of angles, temperatures and fields
E. Barzi, SC R&D Lab
Supported by Muons Inc..
Also extensive temperature and field studies on Bi 2212 wire inc. effect of cabling on Jc (not shown)
03 Dec 2007Muon Collider Design Workshop 18Fermilab
E. Barzi, LTSW 2007, Oct. 29-31, 2007, South Lake Tahoe, CA
18
B and T Dependence of Anisotropy
1
2
3
4
5
6
7
8
0 3 6 9 12 15B, T
Icnorm
(Bpar)/ Ic
norm
(Bper
p )
T =33 K
T = 22 K
T = 14 K
T = 4.2 K
0
1
2
3
4
5
6
7
0 2 4 6 8 10 12 14 16B, T
Icnorm(B
par)/
Ic n
orm
(Bperp)
T = 33 KT = 22 KT = 14 KT = 4.2 K
Bi-2223
2G 348
PERPcPERPc
PARcPARc
TKIBI
TKIBI
)0,77(/)(
)0,77(/)(
The B dependence has a linear trend, where the slope value increases with T.
No observable T dependence. The ratio saturates at ~7.
03 Dec 2007Muon Collider Design Workshop 19Fermilab
E. Barzi, LTSW 2007, Oct. 29-31, 2007, South Lake Tahoe, CA
19
0
200
400
600
800
1000
1200
1400
0 2 4 6 8 10 12 14 16
B, T
Ic, A
.
33 K ┴
22 K ┴
14 K ┴
4.2 K ┴
33 K //
22 K //
14 K //
4.2 K //
Comparison with Super Power 2G
Ratio saturates, but decreases with temperature
0
1
2
3
4
5
0 2 4 6 8 10 12 14 16B, T
Icn
orm
(Bp
ar)/
Ic n
orm
(Bp
erp)
33 K22 K14 K4.2 K
Ic(77K, 0T)=1061 A
03 Dec 2007Muon Collider Design Workshop 20Fermilab
E. Barzi, LTSW 2007, Oct. 29-31, 2007, South Lake Tahoe, CA
20
Spectrum No. 1 2 3 Element At. % At. % At. % Ag (L) 0 100 0 Bi (M) 14.91 0 3.59 Sr (L) 9.04 0 2.21 Ca (K) 5.53 0 0.78 Cu (L) 11.49 0 5.80 Mg (K) 0 0 29.33 O (K) 59.03 0 58.28 Totals 100.00 100.00 100.00
SEM/EDS Cable Surface Analysis
The surface of all the cables after reaction showed black spots embedded in the silver coating.
Bi-2212?
Bi-2212+MgO?Caused by filament powder leaks
For all the cables, tested at self-fields of 0.1 to 0.3 T, an Ic degradation of about 50% was measured. This was much larger than the reduction found on the extracted strands.
03 Dec 2007Muon Collider Design Workshop 21Fermilab
High Field Magnets Under Study
• Helical Solenoid for Helical Cooling Channel– Demonstration Magnet in FY08
• 0.5 M diameter NbTi 6T on conductor
– Channel for Real HCC calls for high field solenoid
• Design Studies for 50 T Solenoids– Paper studies performed by Palmer/Kahn et al. and
Kashikhin/Zlobin et al• Published at Pac07/MT20
03 Dec 2007Muon Collider Design Workshop 22Fermilab
3.3kmSuperconducting cable length
20mmCoil section length along Z axis
4.4MJOperating stored energy
10kAOperational current
5.7TNbTi superconductor peak field
0.54T/mLongitudinal field gradient, Bz/z
-3.86TInitial field, Bz
0.07T/m2Quadrupole field gradient, 2B/r/z
-0.88T/mInitial quadrupole field, B/r
-0.17T/mDipole field gradient, B/z
1.25TInitial dipole field, B
0.255mRadius of beam reference orbit
1.6mHelix twist pitch
3.2mHelical Solenoid length
0.5mInner bore diameter
ValueUnitParameter
3.3kmSuperconducting cable length
20mmCoil section length along Z axis
4.4MJOperating stored energy
10kAOperational current
5.7TNbTi superconductor peak field
0.54T/mLongitudinal field gradient, Bz/z
-3.86TInitial field, Bz
0.07T/m2Quadrupole field gradient, 2B/r/z
-0.88T/mInitial quadrupole field, B/r
-0.17T/mDipole field gradient, B/z
1.25TInitial dipole field, B
0.255mRadius of beam reference orbit
1.6mHelix twist pitch
3.2mHelical Solenoid length
0.5mInner bore diameter
ValueUnitParameter
Helical Solenoid
The solenoid consists of a number of ring coils shifted in the transverse plane such that the coil centers follow the helical beam orbit. 1) NbTi 4-coil demo 2) MANX expt. 3) multi stage HCC in Muon accelerator (probably HTS in final stage)
PAC07 MOPAN117
Issues:•Mechanical Support•Required field quality (construction tolerances)•Cryostat•Powering and Quench Protection
03 Dec 2007Muon Collider Design Workshop 23Fermilab
High Field Solenoid
• Proposed for end of cooling channel for final emittances
• 30-50 T DC, 30-50 mm aperture, 1 m length
• Goals: Highest practical field, accelerator field quality, low manufacturing cost, low operating costs
• Superconducting for manageable power reqs– Existing very high field magnets are resistive or resistive/SC
hybrids Megawatt Power, one-of-a-kind, expensive to build/operate
– Engineering current density (Je) of HTS materials measured up to 45 T, have a mild dependence on B… however..
– Building this solenoid is beyond present capabilities, although 25-30T HTS solenoids are proposed, 25 T solenoid inserts demonstrated
03 Dec 2007Muon Collider Design Workshop 24Fermilab
High Field Solenoid Designs
• Two high field solenoid paper studies related have been performed in the last ~15 months.– Parameters
• Hybrid magnet with NbTi, Nb3Sn and HTS superconductor
• Utilize Bi-2223 tapes (steel reinforced, long lengths and reasonable Jc)
– Extrapolate Je to 45-50T using low field angular dependence
– Bi-2212 field Je vs. Field
• Bi-2212 wire is also possible, YBCO not considered (yet)
03 Dec 2007Muon Collider Design Workshop 25Fermilab
Design Study #1
From PAC07 MOPAN118 Kahn/Palmer et al
Inner diameter set by HTS min bend radius
Bi 2223 inner coil, co-wound with SS tape
SS thickness adjusted radial to compensate for hoop stress
45T Bore Field
03 Dec 2007Muon Collider Design Workshop 26Fermilab
Design Issues
Demonstrated feasibility of HTS/hybrid approach
Mitigation of hoop stress through SS tapeNeed to intercept axial forcesPlan to study new YBCO conductor
Quench Protection Issues explored:Internal Heaters unlikely to work Need sensitive quench detection circuitry, probably on every layer of coil, with separate extraction circuits for each layer
03 Dec 2007Muon Collider Design Workshop 27Fermilab
Fermilab based study
Va. Kashikhin et al…
Consider two cases: Minimum Volume/Minimum Cost
-Several concentric coils independently supported through SS innertube/outersupport structure. SS rings sized for expected forces
-Coil tension/compression limited to 150 MPa
-Requires bonding/no gaps between inner/outer tubes
03 Dec 2007Muon Collider Design Workshop 28Fermilab
Minimum Cost
HTS coils
Nb3Sn
NbTi
Note: “Minimum Radius” eliminates NbTi portion.
03 Dec 2007Muon Collider Design Workshop 29Fermilab
National Collaboration on HTS Magnet R&D
• There is little or no market for HTS materials relevant for high field scientific applications.
• From discussion with HTS Vendors, sustained support from magnet community is needed to make progress. Need effort comparable to successful Nb3Sn Conductor Program
• Proposal “White Paper” (David Larbalestier, Lance Cooley, Ken Marken and Alvin Tollestrup) to form collaboration among interested National Labs, Universities and HTS vendors to develop program
• Broad Collaboration of NMR, material science and HEP application interested in >23 T at 4 K and >10 T at 20 K
03 Dec 2007Muon Collider Design Workshop 30Fermilab
Collaboration Plans
• Ongoing discussions among the National Magnet Labs and University representatives to define collaboration•BNL, FNAL, LANL, LBNL, NHMFL, NIST, TAMU and others…•Identify common ground for conductor needs•Consolidate existing data on conductor tests•Identify facilities and resources•Near term and longer term plans for magnet related conductor development and testing, magnet development
• Proposal for DOE funding has been written
03 Dec 2007Muon Collider Design Workshop 31Fermilab
Conclusion
• Several interesting magnet will need to be designed/built at a reasonable cost– Need to start development of magnet list/specification– All reasonable options should be considered
• Active effort on high field magnets in National labs– Plans for a “National HTS Conductor Program”
analogous to the existing Nb3Sn program
• Paper studies show feasibility of HTS for 50T solenoids– Need to consider 2G-YBCO. Need more data on angular
dependence with field and strain/stress characteristics
top related