Institute of Electrical Engineering

contacts: Eugen SEILER, Fedor GÖMÖRY

IFAST WP9 kick-off meeting 5 May 2021

of Slovak Academy of Sciences

IEE ≈ 100 employees

Bratislava, Slovakia

Dept. of Superconductors ≈ 15 empl.

~ 55 years of superconductivity research

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Institute of Electrical Engineering (IEE)

Electromagnetic characterisationDC&AC transport, DC&AC magnetization/susceptibility,

AC losses, Magnetic mapping

Numerical modeling and sc theoryFlux penetration and AC loses, Large coils,

SC/FM composites

Applications R&DSuperconducting Cables, Coils, Motors,

Fault current limiters, Magnetic cloak

Dept. of Superconductors:

Multifilamentary composite sc wiresDevelopment of MgB2 wires and tapes at present

Dealing mostly with

REBCO coated

conductors,

SC tapes3

ARIES

– field of first flux penetration (entry) Hen (~Hc1)

IFAST

on ‘small samples’

– critical temperature Tc

participation

DC superconducting characterisation

Commercial PPMS system (with He re-liquefier)

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● DC magnetisation measurements using Vibrating Sample Magnetometer

● Small planar samples (~ 2x2 mm – cutting)

m[e

mu

]

Hdc [Oe]VSM sample holders

per

pen

dic

ula

r H

par

alle

l H

small sample

cutting phase (disk saw)

virgin curve + magnetisation loop

● AC susceptibility – temperature scans

Determining Tc’s of different films in Multilayer and SIS samples

m-r

e (n

orm

.)

T [K]

NbN/AlN/Nb/Cu

NbN

NbAC susc. sample holder

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3rd harmonic voltage detection

Plans for IFAST

set-up in preparation (for a long time…)

Determining the Hen as onset of 3rd harmonic voltage induced above the thin film

• Small AC coil (ø~mm) close to big flat sample (~cm’s)

• one-side H exposure, H || surface, edge effects negligible

– 1st version of electric & support hw. ready (minicoils, holder …)

– prolonged issues with electronics (false signals)

inner d = 1.25 mm

outer d = 3.45 mm

height h = 2.2 mm

turns N = 235

Sample holder minicoils

M. Aurino et al., J. Appl. Phys. 98, 123901, 2005

G. Lamura et al., J. Appl. Phys. 106, 053903, 2009

See e.g.:

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Note:

ARIES – characterisation of ~ 320 samples performed

● nothing close to this number will be possible in IFAST

considerable reduction of available man-power compared to ARIES

(of both the formal FTE and the actual persons involved)

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Thank you

for your attention