Superconducting Magnet Division R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 1 LTSW LTSW ’ ’ 09 09 HTS Magnet Program at BNL Ramesh Gupta
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 1LTSWLTSW’’09 09
HTS
Magnet
Program
at BNL
Ramesh Gupta
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 2LTSWLTSW’’09 09
Outline• Magnet R&D at BNL using Bi2212, Bi2223, YBCO and MgB2
High field @ low temperature : Muon collider solenoid (PBL SBIR)
Medium field @ high temperature : FRIB/RIA quad
Recent results of MgB2 solenoid
• HTS conductor obtained/ordered (~4 mm tape equivalent)
So far : ~15+ km
Last 12 months: ~ 8 km (for FRIB quad and PBL solenoid)
• Program needs – The Magnet Pull
2G optimization for (a) high field, low temperature applications and (b) medium field, high temperature applications.
To encourage this development, conductor vendors could be motivated with added support.
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 3LTSWLTSW’’09 09
BNL HTS Magnet ProgramHigh Field and High Temperature Applications
• Quick summary of several (built and tested) HTS programs
• More details on select two
We are and have been optimistic about the viability of HTS in a variety of applications. It may be because of our longer (over a decade) and successful association with HTS coil and magnet R&D.
Next few slides:
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 4LTSWLTSW’’09 09
HTS Common Coil Dipole with Bi2212 R&W Rutherford Cable
Coil /Magnet
CableDescription
MagnetDescription
Ic
(A)Je(sf)[Je(5T)]
(A/mm2)Self-
field, TCC006
DCC0040.81 mm wire,
18 strands 560 60[31] 0.27
CC007DCC004
0.81 mm wire,18 strands
2 HTS coils,2 mm spacingCommon coilconfiguration 900 97
[54] 0.43
CC010DCC006
0.81 mm wire,2 HTS, 16 Ag 94 91
[41] 0.023
CC011DCC006
0.81 mm wire,2 HTS, 16 Ag
2 HTS coils (mixedstrand)
74 mm spacingCommon coil 182 177
[80] 0.045
CC012DCC008
0.81 mm wire,18 strands
Hybrid Design1 HTS, 2 Nb3Sn 1970 212
[129] 0.66
CC023DCC012
1 mm wire,20 strands
Hybrid Design1 HTS, 4 Nb3Sn 3370 215
[143] 0.95
CC026DCC014
0.81 mm wire,30 strands 4300 278
[219] 1.89
CC027DCC014
0.81 mm wire,30 strands
Hybrid CommonCoil Design
2 HTS, 4 Nb3Sncoils (total 6 coils) 4200 272
[212] 1.84
Coils and Magnets built at BNL with Rutherford Bi2212 Cable
Racetrack HTS coil with Bi2212
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0 1 2 3 4 5 6 7 8 9
HTS Coil Production No. I c
(4K
,sel
f fie
ld),
Am
ps
Ic
HTS cables can carry significant currents in magnet coils.
Earlier coils <1 kA (~2001)
Later coils 4.3 kA (2003)
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0 1 2 3 4 5 6 7 8 9
HTS Coil Production No. I c
(4K
,sel
f fie
ld),
Am
ps
Ic
HTS cables can carry significant currents in magnets.
Earlier coils <1 kA (~2001)
Later coils 4.3 kA (2003)
Bi2212 Rutherford cable
Bi2212 Rutherford cable
Record 4.3 kA in HTS coils
2T
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 5LTSWLTSW’’09 09
HTS Solenoid for the Proposed ERL (Electron Recovery Linac) at BNL
0.00.10.20.30.40.50.60.70.80.91.0
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Current (Amp)
Volta
ge G
radi
ent (
µV/c
m)
Main CoilBucking Coil
Main coil: layer woundBucking: double pancake
Design current ~34 A
• HTS solenoid provides a unique technical solution. • HTS solenoid magnet is placed over the bellows before the gate valve in cold to warm transition region (~20 K)
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 6LTSWLTSW’’09 09
HTS Solenoid
HTS Solenoid for LDRD on SRF Electron Gun
• No room for LTS solenoid in Liquid Helium (LHe)
• Temperature between the first set of baffles is ~20 K
• Copper solenoid would generate ~500 W heat as against the ~5 W heat load of the entire cryostat
• Copper solenoid outside the cryostat will be too far away and will not provide the desired focusing and will result in a large deterioration in performance
• HTS solenoid provided a technical solution that was not possible with either with copper or with conventional low temperature superconductors.
• Design current was achieved at 77 K itself. That made HTS solenoid option to be an overall cheaper solution (design + build + test) as well since testing at ~77 K is much cheaper than testing at ~4 K .
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 7LTSWLTSW’’09 09
MgB2 Solenoid made with Conductor from COLUMBUS SUPERCONDUCTORS SpA
MgB2 Solenoid with a double pancake coil
Coil i.d. = 100 mmCoil o.d. = 200 mm# of Turns = 80
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 8LTSWLTSW’’09 09
MgB2 SolenoidCritical Current as a Function of Temperature
Ic as a function of temperature in MgB2 coils
050
100150200250300350400450
0 5 10 15 20 25 30 35 40Temp (K)
Ic (A
mp)
Conductor courtesy: COLUMBUS SUPERCONDUCTORS SpA
• Top and bottom plates are conduction cooled with the helium gas• Helium flow is adjusted to vary the temperature. 100 A => ~0.31 T
~1.3 T peak field
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 9LTSWLTSW’’09 09
More Details on Select Two
(current major HTS programs at BNL)
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 10LTSWLTSW’’09 09
High Field Muon Collider Solenoid SBIR with PBL (Particle Beam Lasers)
• A forward looking collaborative SBIR program between PBL & BNL.
• PBL brings ideas with highly respected individuals (most working part time)
– Some of them are: Bob Weggel, Bob Palmer, Ron Scanlan (in magnets) and Al Garren, David Cline, Jim Kolonko (in accelerators)
• BNL contributes its staff, ideas, facilities and past experience with HTS and AP.
• There is not enough funding in one SBIR to build 35-40 T solenoid. So why not attempt to build it with several serial SBIRs. It provides a natural segmentation for Lorentz force purpose and allows lessons learnt from one to transfer to other.
• Currently there are two funded Phase 2 SBIR : (1) ~100-165 mm, ~10 T solenoid and (2) 25-95 mm ~12 T insert solenoid.
• There is also one important upcoming Phase 1 proposal for Nb3Sn > 165 mm outsert solenoid with hope that with Phase 1 this year and Phase 2 funding next year, all three will attempt to make a short 35-40 T superconducting solenoid.
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 11LTSWLTSW’’09 09
Unique Features of Phase 1 Nb3Sn Solenoid Proposal
• High field Nb3Sn solenoid have been primarily built with CICC technology.
• CICC is proven technology. However, it offers a relatively lower Jw
as compared to the Rutherford cables, used in accelerator magnets.
• Higher Jw offers many advantages. However, industry is more likely to use this technology after it is proven in solenoids.
• One purpose of this SBIR is to do just that - that will be a significant contribution to high field solenoid technology in itself.
• Another purpose of this SBIR is to build the outsert to build 35-40 T solenoid with other two segments coming from previous two SBIR.
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 12LTSWLTSW’’09 09
Status of HTS Solenoid
• High Ic conductor (~165 A, 77 K self-field, on average) and high field (advanced pinning) conductor purchased from SuperPower by PBL for the first year. Over 1 km has been delivered, and rest coming soon (making it 1.6 km ).
• Test results from the conductors (next slide).
• FRIB/RIA coils and MgB2 solenoid have already been built and tested for several key construction features.
• Solenoid winding with pancake coils to start soon.
• Conductor order (1. 4 km) placed for the second year.
• More conductor order for another Phase 2 started this year is tobe placed soon.
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 13LTSWLTSW’’09 09
Critical Current Measurements at 4K as a Function of B// in SuperPower Wire
500
600
700
800
900
1000
1100
1200
1300
0 2 4 6 8 10 12Field, T
Crit
ical
Cur
rent
, A SP-M3-638-2 #2SP-ME-594-1
But what happens to the angular dependence?How much is the difference in the minimum value?Some tapes got damaged during high field testing.
Two 2G wires from different timeVariation in ~46 mm pieces from the same spool
(SP-M3-638-2#2 May 2009)
0100200300400500600700800900
10001100120013001400
0 1 2 3 4 5 6 7 8 9 10 11 12Applied Field (T)
Ic, A
mp
(@1 µV
/cm
)
Series1Series2Series3Series4
Significant variation
Variation in ~46 mm pieces from the same spool(SP-M3-638-2#2 May 2009)
0100200300400500600700800900
10001100120013001400
0 1 2 3 4 5 6 7 8 9 10 11 12Applied Field (T)
Ic, A
mp
(@1 µV
/cm
)
Series1Series2Series3Series4
Significant variation
Variation in different 46 mm long samples(SP-M3-638-2#2 May 2009)
0100200300400500600700800900
10001100120013001400
0 1 2 3 4 5 6 7 8 9 10 11 12Applied Field (T)
Ic, A
(1 m
icro
Volt/
cm)
Lesser variation here
Variation in different 46 mm long samples(SP-M3-638-2#2 May 2009)
0100200300400500600700800900
10001100120013001400
0 1 2 3 4 5 6 7 8 9 10 11 12Applied Field (T)
Ic, A
(1 m
icro
Volt/
cm)
Lesser variation here
• Wire chemistry influences field dependence.• At this stage of the production, there could also be a significant variation along the length at higher fields even though there was small at lower fields.
~175 A (77 K, self field)
~100 A (77 K, self field)
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 14LTSWLTSW’’09 09
HTS Quadrupoles for RIA/FRIB
To create intense beams of rare isotopes, up to 400 kW of beam hits the target before the fragment separator.
Quadrupole triplet is exposed to very high level of radiation and heat loads (~15 kW in the first quadrupole itself).
HTS magnets could remove this more efficiently at 30-50 K than LTS at ~4 K.
X(c
m)
400
kW b
eam
from
LIN
AC
Quad Triplet
Courtesy: Al Zeller, NSCL
• These quads were identified as one of the most critical components of the machine.• We have successfully built and tested a large number of coils and magnets and have performed radiation damage and energy deposition experiments. RIA: Rare Isotope Accelerator
FRIB: Facility for Rare Isotope Beams
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 15LTSWLTSW’’09 09
6.67 A/K
0
50
100
150
200
250
60 65 70 75 80 85 90temperature, K
curr
ent,
A
83.4
11.3 A/K
86.7
∆Textrap = 3.3 K∆T1 amp = 3.1 K
irradiated
Impact of Large Irradiation on YBCO
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
0 25 50 75 100 125
Radiation Dose (µA.Hours)
I c (Ir
radi
ated
) / I c
(Ori
gina
l)
SuperPower Sample#1SuperPower Sample#2SuperPower AverageASC Sample#1ASC Sample#2ASC Average
100 µA.hr dose is ~ 3.4 X 1017 protons/cm2 (current and dose scale linearly)
Ic Measurements at 77 K, self field
Ic of all original (before irradiation) was ~100 Amp
Ramesh Gupta, BNL 3/2008
PRESENTED AT ASC2008(Greene, Sampson & Gupta, BNL)
Ic studyTc study
Bottom line – YBCO is robust against radiation damage: • Negligible impact on FRIB performance even after 10 years (Al Zeller, MSU).
Note: The following doses are order of magnitude more than what would be in FRIB
• These doses (~400 kW beam, ~15 kW in first <0.1 m long magnet) are significantly more than those in accelerator magnets, including muon colliders and LHC upgrade.
Caveat: 77 K, self field. Lower temp., in field next
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 16LTSWLTSW’’09 09
HTS Coils for RIA/FRIB Magnets
• RIA quad is made with 24 coils, each using ~200 meter of HTS. We have purchased over 5 km of 1G wire for this project (FRIB purchase of 2G wire is separate).• This gives a good opportunity to examine the reproducibility in coil performance. • Stainless steel tape serves as an insulator which is highly radiation resistant.
SS Tape
HTS Tape
RIA: Rare Isotope AcceleratorFRIB: Facility for Rare Isotope Beams
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 17LTSWLTSW’’09 09
LN2 (77 K) Test of 25 BSCCO 2223 Coils
010203040506070
1 2 3 4 5 6 7 8 9 10 11 12 13Coil No.
Cur
rent
(@0.
1 µV
/cm
) Single Coil TestDouble Coil Test
Note: A uniformity in performance of a large number of HTS coils.It shows that the HTS coil technology is now maturing !
13 Coils made earlier tape(Nominal 175 turns with 220 meters)
12 Coils made with newer tape (150 turns with 180 meters)
0
10
20
30
40
50
60
70
1 2 3 4 5 6 7 8 9 10 11 12
Double Coil Test
Coil performance generally tracked the conductor performance very well.
Coil No.
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 18LTSWLTSW’’09 09
Various Magnet Structures of RIA Quad(a part of step by step R&D program)
6 feet
1.3 m
Unique Features of RIA HTS Quad : • Large Aperture, Radiation Resistant
Mirror Iron
Return Yoke Iron Pole
HTS Coils in Structure
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 19LTSWLTSW’’09 09
RIA HTS Mirror Model Test Results (operation over a large temperature range)
A summary of the temperature dependence of the current in two, four, six and twelve coils in the magnetic mirror model. In each case voltage first appears on the coil that is closest to the pole tip. Magnetic field is approximately three times as great for six coils as it is for two coils.
More coils create more
field and hence would have lower
current carrying capacity
0
50
100
150
200
250
300
0 10 20 30 40 50 60 70 80 90 100Tempratue (K)
Cur
rent
@ 0
.1 µ
V/cm
(A)
Two CoilsFour CoilsSix CoilsTwelve Coils
Courtesy/ContributionsSampson
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 20LTSWLTSW’’09 09
Energy Deposition and Cryogenics Experiments
Copper sheets between HTS coils with copper rods and copper washers for conduction cooling• In conduction cooling mode, helium flows through top and bottom plates only.• In direct cooling mode, helium goes in all places between the top and bottom plates and comes in direct contact with coils.• Energy deposition in magnet worked well in both cases.
Stainless steel tape heaters for energy deposition experiments
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 21LTSWLTSW’’09 09
15
17
19
21
23
25
27
29
31
33
0 5 10 15 20 25 30 35 40
Time (min)
Tem
p (K
)
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0.22
Volta
ge G
radi
ent (
V/cm
)
Temperature in various thermometers between HTS coils
Voltage gradient across the whole coil package
Large Energy Deposition Experiment
Magnet operated in a stable fashion with large heat loads (25 W, 5kW/m3) at the design temperature (~30 K) at 140 A (design current is 125 A).
Stab
le o
pera
tion
for
~40
min
utes
Voltage spikes are related to the noise
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 22LTSWLTSW’’09 09
Status of FRIB HTS Quad Program
• Design field gradient increased by 50%
• Desired operating temperature increased from ~30 K to ~50 K
• Moved from 1G to 2G
• Moved from ~4 mm wide tape to ~12 mm wide tape (more current, less number of coils)
• Conductor order placed for 2 km of 12 mm 2G
• Radiation damage experiments move from 77 K self field to lower temperature in applied field
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 23LTSWLTSW’’09 09
Progress through Conductor PO
• Generally speaking, industry is more willing to talk if they see a purchase order coming. We try to use this as an incentive for them to listen to our needs.
• We just placed purchased orders from two vendors (better to have two).• This is for ~12 mm wide tape, 1 km from each vendor.• This encouraged ASC to now deliver ~12 mm wide tape as an standard product.• SuperPower is responding well to the needs of magnet program (enhancing in-
field performance and willing to sell that as standard product)• This is the first time that there is a specification for in-field, lower temperature
performance. This is more meaningful for magnet applications then past 77 K, self-field specification.
• We together (us and conductor vendors) worked hard to develop these specifications and view it is a significant progress. It should be seen as the commitment from the conductor vendor to the magnet application.
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 24LTSWLTSW’’09 09
HTS Open Midplane Dipole SBIR(Another BNL/PBL collaboration)
muon Decay Particles muon Decay Particles
• An ideal open midplane design will have no structure on the midplane.
• Use of HTS (a) will allow very high magnetic fields (20 T or above) and (b) can tolerate high heat loads). • Higher field will allow higher energy and/or higher luminosity.
• Significant progress was made during LARP funding
• A conceptual engineering design was developed which showed how to deal with Lorentz forces, assemble coils and magnet, remove large heat loads and obtain good field quality.
• This has been recognized as a topic of interest by muon collider collaboration and has been placed in DOE SBIR solicitation list.
• Phase 1 is to study this for muon collider and Phase 2 to test key issues.
Superconducting Magnet Division
R. Gupta, BNL, HTS Magnet Program at BNL, Monterey, CA, November 9-11, 2009 Slide No. 25LTSWLTSW’’09 09
SUMMARY
• There are a variety of magnet applications where HTS offers unique advantages. Conductor continues to make progress that is relevant to magnet applications.
• A more positive picture is emerging through the development of concepts and through actual demonstration of usefulness of HTS in R&D magnets.
• There are still many issues to be solved. As in past, they generally get solved when the best mind works on them and that happens when there is reasonable funding.