IEC 61788-17:2021

IEC 61788-17 ®
Edition 2.0 2021-04
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Superconductivity –
Part 17: Electronic characteristic measurements – Local critical current density
and its distribution in large-area superconducting films

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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IEC 61788-17 ®
Edition 2.0 2021-04
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Superconductivity –
Part 17: Electronic characteristic measurements – Local critical current density

and its distribution in large-area superconducting films

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.220.20; 29.050 ISBN 978-2-8322-9765-0

– 2 – IEC 61788-17:2021 RLV © IEC 2021
CONTENTS
FOREWORD . 5
INTRODUCTION . 2
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 9
4 Requirements . 10
5 Apparatus . 11
5.1 Measurement equipment . 11
5.2 Components for inductive measurements . 12
6 Measurement procedure . 13
6.1 General . 13
6.2 Determination of the experimental coil coefficient . 13
6.3 Measurement of J in sample films. 18
c
6.4 Measurement of J with only one frequency . 18
c
6.5 Examples of the theoretical and experimental coil coefficients . 19
7 Uncertainty in the test method . 20
7.1 Major sources of systematic effects that affect the U measurement . 20
7.2 Effect of deviation from the prescribed value in the coil-to-film distance . 21
7.3 Uncertainty in the experimental coil coefficient and the obtained J . 22
c
7.4 Effects of the film edge . 23
7.5 Specimen protection . 23
8 Test report . 23
8.1 Identification of test specimen . 23
8.2 Report of J values . 23
c
8.3 Report of test conditions . 23
Annex A (informative) Additional information relating to Clauses 1 to 8 . 24
A.1 Comments on other methods for measuring the local J of large-area HTS
c
films . 24
A.2 Requirements . 24
A.3 Theory of the third-harmonic voltage generation . 25
A.4 Calculation of the induced electric fields . 26
A.5 Theoretical coil coefficient k and experimental coil coefficient k′ . 27
A.6 Scaling of the U –I curves and the constant-inductance criterion to
3 0
determine I . 27
th
A.7 Effects of reversible flux motion . 29
Annex B (informative) Optional measurement systems . 30
B.1 Overview. 30
B.2 Harmonic noises arising from the power source and their reduction . 31
Annex C (informative) Uncertainty considerations .
Annex C (informative) Evaluation of the uncertainty . 40
C.1 Evaluation of the uncertainty in the experimental coil coefficient . 40
C.2 Uncertainty in the calculation of induced electric fields. 41
C.3 Experimental results on the effect of the deviation of the coil-to-film distance . 42

C.4 Examples of the Type-A uncertainties of J and n-values, originating from
c
the experimental uncertainty in the U measurement . 42
C.5 Evaluation of the uncertainty in the obtained J . 43
c
C.6 Experimental results that reveal the effect of the film edge . 44
Bibliography . 46

Figure 1 – Diagram for an electric circuit used for inductive J measurement
c
of HTS films . 11
Figure 2 – Illustration showing techniques to press the sample coil to HTS films . 12
Figure 3 – Example of a calibration wafer used to determine the coil coefficient . 13
Figure 4 – Illustration of the sample coil and the magnetic field during measurement . 15
Figure 5 – Illustration of the sample coil and its magnetic field generation . 15
Figure 6 –Example of the normalized third-harmonic voltages (U /fI ) measured with
3 0
various frequencies .
Figure 6 – E-J characteristics measured by a transport method and the U inductive
method . 17
Figure 7 – Illustration of coils 1 and 3 in Table 2 . 20
Figure 8 – The coil-factor function F(r) = 2H /I calculated for the three coils. 20
0 0
Figure 9 – The coil-to-film distance Z dependence of the theoretical coil coefficient k . 22
Figure A.1 – Illustration of the sample coil and the magnetic field during measurement . 26
Figure A.2 – U and U /I plotted against I in a YBCO thin film measured in applied
3 3 0 0
DC magnetic fields, and the scaling observed when normalized by I (insets) . 28
th
Figure A.3 – Example of the normalized third-harmonic voltages (U /fI ) measured
3 0
with various frequencies . 28
Figure B.1 – Schematic diagram for the variable-RL-cancel circuit . 31
Figure B.2 – Diagram for an electrical circuit used for the two-coil method . 31
Figure B.3 – Harmonic noises arising from the power source . 32
Figure B.4 – Noise reduction using a cancel coil with a superconducting film . 32
Figure B.5 – Normalized harmonic noises (U /fI ) arising from the power source . 33
3 0
Figure B.6 – Normalized noise voltages after the reduction using a cancel coil with a
superconducting film . 33
Figure B.7 – Normalized noise voltages after the reduction using a cancel coil without
a superconducting film . 34
Figure B.8 – Normalized noise voltages with the two-coil system shown in Figure B.2 . 34
Figure C.1 – Effect of the coil position against a superconducting thin film on the
measured J values . 45
c
Table 1 – Specifications and theoretical coil coefficients k of sample coils . 16
Table 2 – Specifications and coil coefficients of typical sample coils . 19
Table C.1 – Output signals from two nominally identical extensometers .
Table C.2 – Mean values of two output signals .
Table C.3 – Experimental standard deviations of two output signals .
Table C.4 – Standard uncertainties of two output signals .
Table C.5 – Coefficient of variations of two output signals .

– 4 – IEC 61788-17:2021 RLV © IEC 2021
Table C.1 – Uncertainty budget table for the experimental coil coefficient k′ . 41
Table C.2 – Examples of repeated measurements of J and n-values . 43
c
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SUPERCONDUCTIVITY –
Part 17: Electronic characteristic measurements –
Local critical current density and its distribution
in large-area superconducting films

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
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Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possibl
...

IEC 61788-17 ®
Edition 2.0 2021-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Superconductivity –
Part 17: Electronic characteristic measurements – Local critical current density
and its distribution in large-area superconducting films

Supraconductivité –
Partie 17: Mesurages de caractéristiques électroniques – Densité de courant
critique local et sa distribution dans les films supraconducteurs de grande
surface
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC online collection - oc.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always
committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 000 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 18 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
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Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

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IEC 61788-17 ®
Edition 2.0 2021-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Superconductivity –
Part 17: Electronic characteristic measurements – Local critical current density

and its distribution in large-area superconducting films

Supraconductivité –
Partie 17: Mesurages de caractéristiques électroniques – Densité de courant

critique local et sa distribution dans les films supraconducteurs de grande

surface
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20; 29.050 ISBN 978-2-8322-1022-0

– 2 – IEC 61788-17:2021 © IEC 2021
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Requirements . 9
5 Apparatus . 10
5.1 Measurement equipment . 10
5.2 Components for inductive measurements . 11
6 Measurement procedure . 12
6.1 General . 12
6.2 Determination of the experimental coil coefficient . 12
6.3 Measurement of J in sample films. 16
c
6.4 Measurement of J with only one frequency . 16
c
6.5 Examples of the theoretical and experimental coil coefficients . 17
7 Uncertainty in the test method . 18
7.1 Major sources of systematic effects that affect the U measurement . 18
7.2 Effect of deviation from the prescribed value in the coil-to-film distance . 19
7.3 Uncertainty in the experimental coil coefficient and the obtained J . 20
c
7.4 Effects of the film edge . 20
7.5 Specimen protection . 20
8 Test report . 21
8.1 Identification of test specimen . 21
8.2 Report of J values . 21
c
8.3 Report of test conditions . 21
Annex A (informative) Additional information relating to Clauses 1 to 8 . 22
A.1 Comments on other methods for measuring the local J of large-area HTS
c
films . 22
A.2 Requirements . 22
A.3 Theory of the third-harmonic voltage generation . 23
A.4 Calculation of the induced electric fields . 24
A.5 Theoretical coil coefficient k and experimental coil coefficient k′ . 25
A.6 Scaling of the U –I curves and the constant-inductance criterion to
3 0
determine I . 25
th
A.7 Effects of reversible flux motion . 27
Annex B (informative) Optional measurement systems . 28
B.1 Overview. 28
B.2 Harmonic noises arising from the power source and their reduction . 29
Annex C (informative) Evaluation of the uncertainty . 33
C.1 Evaluation of the uncertainty in the experimental coil coefficient . 33
C.2 Uncertainty in the calculation of induced electric fields. 34
C.3 Experimental results on the effect of the deviation of the coil-to-film distance . 35

C.4 Examples of the Type-A uncertainties of J and n-values, originating from
c
the experimental uncertainty in the U measurement . 35
C.5 Evaluation of the uncertainty in the obtained J . 36
c
C.6 Experimental results that reveal the effect of the film edge . 37
Bibliography . 39

Figure 1 – Diagram for an electric circuit used for inductive J measurement
c
of HTS films . 10
Figure 2 – Illustration showing techniques to press the sample coil to HTS films . 11
Figure 3 – Example of a calibration wafer used to determine the coil coefficient . 12
Figure 4 – Illustration of the sample coil and the magnetic field during measurement . 13
Figure 5 – Illustration of the sample coil and its magnetic field generation . 14
Figure 6 – E-J characteristics measured by a transport method and the U inductive
method . 16
Figure 7 – Illustration of coils 1 and 3 in Table 2 . 17
Figure 8 – The coil-factor function F(r) = 2H /I calculated for the three coils. 18
0 0
Figure 9 – The coil-to-film distance Z dependence of the theoretical coil coefficient k . 19
Figure A.1 – Illustration of the sample coil and the magnetic field during measurement . 24
Figure A.2 – U and U /I plotted against I in a YBCO thin film measured in applied
3 3 0 0
DC magnetic fields, and the scaling observed when normalized by I (insets) . 26
th
Figure A.3 – Example of the normalized third-harmonic voltages (U /fI ) measured
3 0
with various frequencies . 26
Figure B.1 – Schematic diagram for the variable-RL-cancel circuit . 29
Figure B.2 – Diagram for an electrical circuit used for the two-coil method . 29
Figure B.3 – Harmonic noises arising from the power source . 30
Figure B.4 – Noise reduction using a cancel coil with a superconducting film . 30
Figure B.5 – Normalized harmonic noises (U /fI ) arising from the power source . 31
3 0
Figure B.6 – Normalized noise voltages after the reduction using a cancel coil with a
superconducting film . 31
Figure B.7 – Normalized noise voltages after the reduction using a cancel coil without
a superconducting film . 32
Figure B.8 – Normalized noise voltages with the two-coil system shown in Figure B.2 . 32
Figure C.1 – Effect of the coil position against a superconducting thin film on the

measured J values . 38
c
Table 1 – Specifications and theor
...