Short introduction into the Superconductors Lab

for the exchange program between TE/MSC-SCD and TE/MSC-TF By Gerard Willering 11-05-2010

+ About 3 technical students + About 5 doctoral students + 1 fellow + External In total about 28

TE-MSC-SCD Activities

Superconducting materials and applications

Mandate Design, prototype and follow the production of superconducting wires, tapes and cables for magnets, and other electrical devices ( bus bars, switches, current leads, power transmission and energy management systems, instrumentation).

Experiments Characterize, test and analyze the performance of the materials developed and procured.

Test stations Operate, maintain and develop test and characterization capabilities for superconducting wires, tapes, cables.

Examples of current Research, Technologies and Competences in the section

HTS

LHC Current leads - BSSCO FRESCA II magnet insert - YBCO Superconducting LINK - MgB 2

Nb

3

Sn

Stability Cables FRESCA II magnet Wires ITER LHC magnet upgrade Chemical composition Cabling Busbar interconnections Heat transfer through insulation Precision thermometry Materials imaging with several tomography methods

NbTi

Fast Cycling Magnets LHC reception tests (past) Cabling

Station FReSCa (Facility for the Reception of Superconducting Cables) -Vertical double cryostat, height about 4 meter - Outer cryostat holds the dipole magnet (about 7 tonnes), always kept at LHe temperature - Inner cryostat (70 mm inner diameter) holds the sample. Warm-up 15 hours, cool-down 5 hours.

Flow scheme practical work

Industry and collaborations Materials and cabling lab Building 103 Preparation of cables HTS lab Building 288 Development and preparation of HTS cables and wires Superconductors lab Building 163 Characterization and reception tests Further collaboration Knownledge exchange Magnet production Material development

Superconductors Lab (163) Test stations 7 wire test stations Specifications - Up to 4 kA - Up to 15 T background field - Regulated temperature 1.8 and 4.3 K - Many types of sample holders Test capabilities - Ic - RRR - Quench propagation - Magnetization - Strain dependence - Heat flow experiments - Special tests FRESCA cable test station Specifications - 32 kA - 10 T background dipole magnet - 1.8 K to 4.3 K - Many types of sample holders - 2 meter long samples Test capabilities - Ic - RRR - Cable stability - Quench propagation - Strain dependence - Heat flow experiments - Special cable tests - Interconnection tests - Joint tests

Sample holder and sample specifications for NbTi and Nb 3 Sn tests.

Typical pressure up to 100 MPa are applied with screws.

Design of a new sample holder with only thermal contraction to apply the pressure > 200 MPa.

(necessary for Nb 3 Sn research)

Interesting current measurements by Michiel de Rapper on Nb 3 Sn - Critical current and Training 35

LARP 983 @ 4.3 K

30 25 20 15 10 5 0 0 1 2 Iq d direction Iq c direction Ic c direction Ic d direction Strand Ic 3 4 5 6 7 8 Effective field (T) 9 10 11 12 13 14 • • •

very little degradation vs. extracted strand (>1% on average) unstable behavior at low field.

long training (30 quenches)

20 15 10 5 Sample CERN 0 0 5 10 15 20 25 30 35 40 45 Quench number (#) 9

Interconnection sample with instrumentation New shunt and clamp design Interconnection sample with shunts