Assessment of HTS for Fusion. Activities of EFDA Manel Sanmart - PowerPoint PPT Presentation

Assessment of HTS for Fusion. Activities of EFDA Manel Sanmartí (IREC) On behalf of EFDA-HTS Work Program AIME on Superconductivity, Ciemat, 27th-28th May 2013

CONTENTS • Introduction • HTS for Fusion activities before 2011 • Why HTS for Fusion • EFDA HTS WP2011 • Scope and objectives • Results EFDA WP2011 • EFDA HTS WP2012-2013 Associations summary report • Summary and Conclusions

REFRAME : HTS for Fusion??

INTRODUCTION HTS FROM DISCOVERY TO INDUSTRIAL APPLICATION HTS CABLE HTS TRANSFORMERS, FCL HTS GENERATORS AND MOTORS *source: Walter Fietz presentation 26/03/11

INTRODUCTION HTS for Fusion…? under evaluation since 2004 • 23rd SOFT Sept. 2004

INTRODUCTION Why HTS for fusion? • *source: Walter Fietz presentation 26/03/11

INTRODUCTION HTS for fusion. Advantages • *source: Walter Fietz presentation 26/03/11

INTRODUCTION HTS challenges and prospects for Fusion *source: Walter Fietz presentation 26/03/11

EFDA HTS WP2011 • HTS for Fusion: EFDA program (May 2007) *source: Walter Fietz presentation 26/03/11

EFDA HTS WP2011 • SCOPE AND OBJECTIVES 1.- Monitoring and characterizing HTS material. Mechanical, electrical stabilization and quench, and neutron irradiation on HTS samples and cables 2.- Developing fusion cable concepts for the KA range with low ac losses 3.- Fabrication of fusion cable prototypes 4.- Cooling requirement and concepts 5.- Joint fabrication 6.- Manufacturing of winding prototypes/trial coils

EFDA HTS WP2011 • Results: 3 years Working Program 2012 2013 2014 Test and construction of Rutherford cables Test and studies HTS samples Construction of cable demonstrator Tape characterization before and after Joint formation on SULTAN sample irradiation HTS jointing techniques Cable design and manufacture Fast neutron irradiation HTS samples Fast neutron irradiation HTS samples Test planning in SULTAN Preparation of the SULTAN facility Design and manufacturing of jointing fixture Planned not finished in the year Finished in the year Mechanical tests of the joints Not started in the year • HTS EFDA program has not been fully deployed and will be reviewed end 2013

EFDA HTS WP2012 • WP2012 TASKS T06.- Construction and test of DEMO-relevant HTS cables • Test of Roebel • Test of Coaxial • Construction and test of Rutherford T07.- Characterisation of HTS tape test samples following neutron irradiation • Reactor irradiation after neutron 2—10 22 • Tape caractheritzation before and after irradiation T08.- Study of the performance of HTS twisted stacked cable T09.- Study on the effect of transverse loads on RE-123 Roebel cables

EFDA HTS WP2012 • WP2012 TASKS T10.- Design, manufacturing and testing of HTS cable joining techniques • Evaluation of different solders • Evaluation of different techniques T11.- Mechanical tests of single YBCO tape joints under magnetic field Condition • Electrical resistance. Repeatability • Axial strength for HTS joint samples with/without magnetic field T12.- Measurement and modelling the AC losses of coaxial cables T13.- Ic (B,T,e) characterization in relevant window for HTS tape configurations and exploring transverse load sensitivity

EFDA HTS WP2013 • WP2013 TASKS T06.)Studies testing and development of HTS samples • Rutherford)Roebel Cables • Strain characterization of ReBCO tapes, joints and CORC Ic and AC loss • Twisted Stack Cables T07.)Development and testing of HTS jointing techniques • Manufacturing of new joints • Electrical characterization of the joints at 77 K and self)field • Mechanical characterization of the joints in terms of Ic magnetic behaviour • Mechanical modelling and analysis of the stresses distribution in the joints

EFDA HTS WP2013 • WP2013 TASKS T08.-Determination of HTS properties after fast neutron irradiation of HTS samples • Characterization of each HTS tape shall be carried out before and after irradiation • Critical Temperature (Tc), Critical Current (Ic), Homogeneity of super current flow by magnetoscan T09.-Preparation of the SULTAN facility •Design and supply of HTS Bus Bars •Design of counter flow heat exchanger

KIT Contribution WP2013 Measurements in FBI-facility Different cable approaches have been investigated in the FBI (force F, magnetic field B and current I) facility of KIT. A CORC cable provided by the company "Advanced Conductor Technologies" (D. van der Laan) was investigated Cable parameters are: • 1160 mm long,15 tapes in 5 layers • 4 mm wide copper stabilized SuperPower tapes • Twist pitch of 17 mm The results show the good performance of this type of cable. 8 T surface : CORC cable 1 µ V/cm criteria 7 4.2 K 10.0 K 6 12.5 K 15.2 K 18.1 K 5 21.4 K 25.0 K I c / kA 4 29.0 K Schematic drawing of the FBI test facility 33.5 K 3 for the characterization of 38.3 K 43.8 K superconductor cables at temperatures 2 from 4.2 K up to 80 K under magnetic field up to 12 T and current up to 10 kA.. 1 0 2 4 6 8 10 12 B / T

KIT Contribution Measurements in FBI-facility For a measurement of a ROEBEL assembled cable such a cable was sealed in G10 for mechanical support. The joints to the Cu contacts were very homogeneous, no degradation by handling was observed. During measurement a degradation by Lorentz force was observed under higher magnetic fields. However, external experiments at CERN demonstrated that currents even at 10 T are possible, but to cope with mechanical forces is the critical point for the ROEBEL cable. 5 10 10 strand Roebel - individually contacted tape1 RACC cable tape2 LN 2 (77 K), self-field 2 T - 20 K surface temp. tape3 4 8 tape4 R contact: tape5 overall: 48 n Ω tape6 6 3 tape7 tape8 µ V/cm) µ V/cm) tape9 tape10 4 2 µ E / ( µ µ µ µ E / ( µ overall 2 1 0 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 0 1 2 3 4 5 I / kA I / kA Individually measured voltage/current Overall voltage/current characteristic of the characteristic of the ROEBEL cable ROEBEL cable at 2 T and 20 K. KIT will test optimized ROEBEL cable and other cable approaches in 2013

University of Twente • Association Focus Activity: Strain, Stability & Cable AC loss Behaviour of I c /I c0 for SCS4050 tape during torsion test 1.1 1 0.9 Vtap1 0.8 Vtap2 I c /I c0 Vtap3 0.7 Vtap4 Transverse stress and torsion under Vtap5 0.6 Vtap1rev controlled axial tensile load on tape at Vtap2rev 0.5 Vtap3rev 0.4 Vtap4rev 77 K or 4.2 K with or without applied Vtap5rev 0 0.2 0.4 0.6 0.8 1 1.2 1.4 magnet field. ε [%] Ic vs axial strain, B & T

University of Twente University of Twente Calorimetric & PU-Coil AC loss measurements for fusion spectra on stacked tape wire from CRPP, (D. Uglietti), CORC cable samples, Advanced Conductors (D. van der Laan)

EPFL-CRPP Association Focus Activity: T06 - Twisted Stack Cables Bending Test Sample length = 500 mm Assembled Assembled strand after soldering strand OUTCOME: coated conductor tapes can be assembled in a At 0.6% bending strain (0.25 m bending radius): 2012 soldered stacked cable reversible reduction less than 2% 2013 CABLE 26 strands NEW, BIGGER STRAND I c = 80 kA at 15 T, 5 K Cu cross-section: 650 mm 2 6.2 mm Ø Expected I c : ~3000 A at 5 K, 15 T

EPFL-CRPP • Association Focus Activity: • WP2013 T09 - Preparation of the SULTAN facility 1 m Superconducting 4.5 K In SULTAN sample currents up to 100 kA are transformer supplied by a NbTi transformer, which has to be operated at a temperature close to 4.5 K . 0.4 m On the other hand, the region of interest for testing HTS bus bar the HTS sample is between 4.5 K and ~40 K . In this task, it has been proposed to limit the heat flux between transformer and HTS test conductor to a reasonably small value by means Variable of a High Temperature Superconducting (HTS) HTS conductor 4 m temperature: under test 5 K – 40 K bus bar , which is similar to the HTS module of an HTS current lead.

TU WIEN Radiation resistance of coated conductors ITER fluence: 10 22 Am -2 Gd-123 (Y,Dy)-123 unirr. 77 K H || c H || c 100 100 64 K 50 K 22 m -2 10 10 77 K I c (A) 10 I c (A) 64 K 50 K 1 22 m -2 in Gd-screen 10 77 K 1 64 K 0.1 50 K 0 2 4 6 8 10 12 14 16 0 2 4 6 8 10 12 14 16 µ 0 H (T) µ 0 H (T) ITER design fluence: no degradation of J c . Gadolinium might be problematic because of (n, γ )-reaction, which induces significant additional disorder. (Neutron energy distribution has to be known.) Future work: irradiation to DEMO relevant fluences (3-5·10 22 Am -2 ).

TU WIEN Strain dependence of the critical currents ITER fluence: 10 22 Am -2 Self-field I c at 77 K pull rod irr = 0.1 I c unirr I c irr = 0.76 I c unirr I c push rods carriage • YBCO/RABiTS: strain dependence hardly changes/sligthly increases after irradiation. • GdBCO/IBAD: strain dependence strongly increases at large level of disorder (change in T c !).

TU WIEN Flux penetration into model Roebel loops Time resolved Scanning Hall probe measurements. Supports modelling of coupling losses