Electro-Mechanical Characterization of HTS Tapes and Conductors for the Next Generation High-Field

Magnets

Federica PierroDepartment of Mechanical Engineering

Tufts University

Young Scientist Plenary Session

Wednesday, September 25th 2019

Federica Pierro

REBCO Conductors for Future Fusion Magnets

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HTS performance affected by mechanical strain!

Fusion can change the world producing CLEAN, SAFE and ABUNDANT energy!!!

High magnetic field

Higher performance

Higher current density

Compact design!!!!

Higher temperature operation

New cooling option

LTS HTS

https://doi.org/10.1016/j.fusengdes.2015.07.008https://www.iter.org/

~ 30 m ~ 6 m

4.2 K 20 K

B. Sorbom, Fri-Mo-PL6-01, MT26

Federica Pierro

Sources of strain from tape to magnet

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SCOPE: predicting the electrical behavior of cables in high field magnets usingmechanical and electrical properties of individual tapes

APPROACH

Critical current characterization of single REBCO tapes

Structural simulations of REBCO Cables

Cable-in-ConduitREBCO coated conductor Magnets

Federica Pierro

Electro-mechanical characterization of REBCO tapes: experiments

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SCS4030-AP

Applied Strain, e (%)

-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6

I c/Ic

o

0.85

0.90

0.95

1.00

1.05

40 K, 15 T

20 K, 15 T

4.2 K,15 T

U-spring bending device

CuNi3Si alloy https://doi.org/10.1063/1.1819384

Measure the strain dependence of Ic at different temperature and fields relevant to fusion magnets

Federica Pierro

Finite Element Analysis of HTS Cables

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Twisted Stacked-Tape Cable (TSTC) subject to electromagnetic Lorentz loads

Copper Core Copper Tube filled with Solder

Support Structure

1 channel40 tapes

200 mm twist pitch

Predict the stress in the stack to inform the conductor design process

There are techniques to improve the performance!

Solder Filled Tube

Copper Core

Federica Pierro

Critical current prediction in HTS cables

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Predict the cable electrical performance

0.98

ɛ = 0.55%

Loads varied between 100 and 1000 kN/m

Using experimental data on single tapes

1

40

Federica Pierro

In conclusion…

We use experimental techniques and FEA tools to predict the electromechanical behavior of HTS cables starting from single tapes

The results of the work are critical to develop a tool to improve HTS cable design, accelerating the design process and

implementation of HTS in future magnets

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Thank you for your attention!Come see me if you have more questions

A special thank to Prof. Luisa Chiesa and the all team!!!