K. Kim <[email protected]> Experience with Recent High Field No-Insulation Magnets from the Test and User Viewpoint Kwanglok Kim and Seungyong Hahn Applied Superconductivity Center, National High Magnetic Field Laboratory, 2031 E. Paul Dirac Dr., Tallahassee, FL, 32310, USA Coated Conductors for Applications 2016, Aspen, CO September 12, 2016 Experience with Recent No-Insulation Magnets: IO-06 Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016) 1/32
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Experience with Recent High Field No-Insulation Magnets ... · K. Kim Experience with Recent High Field No-Insulation Magnets from the Test and User
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2. NI Coil wound with “Metallic Cladding” REBCO Tape
4. Summary
1. Introduction to No-Insulation (NI) REBCO Magnet
3. NI Coil wound with “Defect” REBCO Tape
2/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
1.1. REBCO coated conductor and NI winding technique 1.2. 40 T record high field from 9 T 14 mm superconducting insert coil in a background field 1.3. “Self-protecting” behavior of 26 T 35 mm multi-width NI all-REBCO magnet
2.1. Local current sharing and quench recovery up to 700 A/mm2
2.2. “Self-protecting” behavior after a thermal runaway quench at 700 ~ 820 A/mm2
2.3. “Long-term recovery” behavior after a thermal runaway quench at 820 A/mm2
3.1. NI coil incorporated with a “Defect Irrelevant Winding” (DIW) technique 3.2. “Defect irrelevant” behavior of a NI coil
Introduction to No-Insulation (NI) REBCO Magnet�n REBCO coated conductor ¨ In-field current carrying capacity and mechanical robustness ¨ The latest REBCO coated conductor carried 15 MA/cm2 in a 2.2 µm thick REBCO film at 30 K
under a 3 T c-axis parallel field*
* Reference: V. Selvamanickam, et al., “Critical current density above 15 MA cm-2 at 30 K, 3 T in 2.2 µm thick heavily-doped (Gd,Y)Ba2Cu3Ox superconductor tapes,” Supercond. Sci. Technol. Vol. 28, 072002 (2015)
n No-insulation (NI) winding technique ¨ “Self-protecting” against the event of a quench ¨ “Charging delay” of NI coil
“Self-protecting” of a No-Insulation (NI) REBCO Coil �n Unexpected event due to the thunder storm (Aug. 23) ¨ Power outage of the building during the 2nd charging test of a NI coil
(blackout)
¨ No coil damage was observed: “Self-protecting”
4/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
n Superconducting applications with the NI magnets ¨ 2 T 94 mm NI REBCO magnet for magnetic separation (2014, Korea U.) ¨ 4 kN 0.52 m × 0.42 m NI REBCO magnet for Maglev (2015, KRRI-SuNAM-CNU) ¨ 300 kW 1.2 m × 0.6 m MI REBCO magnet for induction heater (2017, CNU) ¨ 4 T quadruple MI REBCO magnet for rare isotope accelerator (2021, IBS-KERI)
n Selected NI-class REBCO Magnets - Completed
* MI: Metal-co-winding
¨ 0.4 T 40 m “multi-width” magnet with “bare” REBCO tapes (2011, MIT; first Magnet) ¨ 3 T 35 mm insert for 16.8 T (2011, KBSI-MIT; first LHe Operation; first LTS/HTS ) ¨ 4 T 240 mm 10-K cond. cooled magnet (2013, SuNAM-KPU; continuous use at SuNAM) ¨ 8.7 T 91 mm insert for 1.3 GHz LTS/HTS NMR (2013, MIT; first magnet level quench) ¨ 9 T 78 mm standalone magnet (2014, MIT; self-protecting at 900 A/mm2 ) ¨ 26.4 T 35 mm standalone magnet (2015, SuNAM/MIT/MagLab; record field from all-HTS) ¨ 3 T 100 mm all-REBCO “metallic cladding” magnet (2015, SuNAM/KBSI/MagLab, first MC) ¨ 9 T insert for 24 T operation (2015, IEE-CAS) ¨ 9 T 14 mm insert for 40 T operation (2016, MagLab, record field from supercond. inserts)
5/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
n Charging test results of a 9 T 14 mm all-REBCO insert ¨ Combined field of 40 T (9 T all-REBCO insert coil + 31 T resistive background magnet) ¨ Final coil temperature of 17 K (temperature limitation due to the He bubble) ¨ SuperPower’s new developed 30 µm substrate REBCO tapes
40 T Record High Field from Superconducting Inserts �
8/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
n Electromagnetic behavior of a 26 T 35 mm NI magnet at a quench moment ¨ The quench was initiated at DP18 and then a “fast electromagnetic” quench propagation was
observed to the adjacent neighbor double-pancake coils
Initial quench
DP18
DP17
DP16
DP19
DP15
¨ The magnet was “self-protecting” from the during the full field quench tests
“Quench Propagation” of a 26 T Multi-Width NI All-REBCO Magnet�
12/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
2. NI Coil wound with “Metallic Cladding” REBCO Tape 2.3. “Long-term recovery” behavior after a thermal runaway quench at 820 A/mm2 2.1. Local current sharing and quench recovery up to 700 A/mm2
2.2. “Self-protecting” behavior after a thermal runaway quench at 700 ~ 820 A/mm2
2.3. “Long-term recovery” behavior after a thermal runaway quench at 820 A/mm2
4. Summary
1.3. “Self-protecting” of 26 T multi-width NI all-REBCO magnet 1. Introduction to No-Insulation (NI) REBCO Magnet 1.1. REBCO coated conductor and NI winding technique 1.2. 9 T record high field from superconducting insert coil in a background field 1.3. “Self-protecting” of 26 T multi-width NI all-REBCO magnet
3. NI Coil wound with “Defect” REBCO Tape 3.1. NI coil incorporated with a “defect irrelevant” (DI) winding technique 3.2. Charging test of a DI coil in a bath of liquid nitrogen at 77 K
14/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
n Charging time comparison between NI and MC coils
Did It Work?: (1) Faster Charging; (2) Self-Protecting �
* Reference: J. Kim, S. Yoon, K. Cheon, K. H. Shin, S. Hahn, D. L. Kim, S. G. Lee, H. Lee, and S. H. Moon, “Effect of Resistive Metal Cladding of HTS Tape on the Characteristic of No-Insulation Coil,” IEEE Trans. Appl. Supercond. 26 (2016), 4601906
¨ ~ 4 times faster charging time showed at MC coil
Local Current Sharing and Quench Recovery of the MC Coil�n Electrical behavior of the MC coil ¨ Heater induced quench tests were performed at 4.2 K ¨ “Local current sharing” observed at 680 A/mm2
Current leads �
Hall sensor�
MC coil �
680 A/mm2
~4 µV�
~34 µV�
18/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
¨ “Self-protecting” of the MC coil was confirmed ¨ Current decreased from 336 A to 50 A within < 0.5 sec ¨ Starting heat diffusion as the heater was turned-on
< 0.5 sec ~1.5 sec
n Thermal runaway quench moment at 700 A/mm2
700 A/mm2
t = 1680 sec�
Heater�
t = ~1681.5 sec�t > ~1681.5 sec�
Thermal Runaway Quench of the MC Coil�
20/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
2. NI Coil wound with “Metallic Cladding” REBCO Tape 2.1. Local current sharing and quench recovery up to 700 A/mm2
2.2. “Self-protecting” behavior after a thermal runaway quench at 700 ~ 820 A/mm2
2.3. “Long-term recovery” behavior after a thermal runaway quench at 820 A/mm2
4. Summary
1. Introduction to No-Insulation (NI) REBCO Magnet 1.1. REBCO coated conductor and NI winding technique 1.2. 9 T record high field from superconducting insert coil in a background field 1.3. “Self-protecting” of 26 T multi-width NI all-REBCO magnet
3. NI Coil wound with “Defect” REBCO Tape 3.1. NI coil incorporated with a “defect irrelevant” (DI) winding technique 3.2. Charging test of a DI coil in a bath of liquid nitrogen at 77 K
24/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
NI Coil with “Defect Irrelevant Winding”�n “Defect Irrelevant Winding” (DIW) technique ¨ Concept: Portion of the coil current bypasses the defect spots ¨ DIW technique may enable…
* Reference: S. Hahn, et al., ““Defect irrelevant” Behavior of a no-insulation pancake coil wound with REBCO tape containing multiple defects,” Accepted in Supercond. Sci. Technol. (2016)
…the improvement of operational reliability of NI REBCO magnet on the partial damage of the REBCO coated conductor
…the construction cost reduction of high field NI REBCO magnets
25/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
Charging Test Result of a DI coil at 77 K�n Step charging of a DI coil in a bath of liquid nitrogen ¨ Ic criteria: 0.23 mV with 0.1 µV/cm; 2.3 mV with 1 µV/cm ¨ No substantial DC voltage measured during steady-state operations at < 60 A
28/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
n Comparison of the measured and expected Ic values of a DI coil ¨ Measured Ic value was 68 A (0.1 µV/cm criterion) ¨ Ic of “defect-free” coil was estimated to be 72 A (field angle: 67 °, field strength: 0.4 T)
Ic Measurement of a DI Coil�
30/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)
¨ 9 T 14 mm insert for 40 T: Current density of ~935 A/mm2
¨ The 26 T 35 mm multi-width NI magnet survived against two consecutive quenches
n Quench Behavior of a “Metallic Cladding” (MC) NI Coil ¨ Local current sharing and quench recovery of the MC coil was observed up to the current
density of 700 A/mm2
¨ The coil can operate “safely” at ≤ 680 A/mm2 without thermal runaway quench ¨ The coil survived against the multiple thermal runaway quenches at 700 ~ 820 A/mm2
¨ “Long-term recovery” behavior observed after a thermal runaway quench at 820 A/mm2
n Charging Test of a “Defect Irrelevant” (DI) NI Coil
¨ No substantial DC voltage measured during steady-state operations at < 60 A ¨ Expected to enable the magnet’s construction cost reduction and substantial improvement
the operational reliability upon the partial damage of the REBCO coated conductor
31/32 Experience with Recent No-Insulation Magnets: IO-06
Coated Conductor for Applications 2016, Aspen, CO (September 12, 2016)