IEC 61788-17:2013 describes the measurements of the local critical current density (Jc) and its distribution in large-area high-temperature superconducting (HTS) films by an inductive method using third-harmonic voltages. The most important consideration for precise measurements is to determine Jc at liquid nitrogen temperatures by an electric-field criterion and obtain current-voltage characteristics from its frequency dependence. Although it is possible to measure Jc in applied DC magnetic fields, the scope of this standard is limited to the measurement without DC magnetic fields. This technique intrinsically measures the critical sheet current that is the product of Jc and the film thickness d. The range and measurement resolution for Jcd of HTS films are from 200 A/m to 32 kA/m, with a measurement resolution of 100 A/m.

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6	English CONTENTS
8	INTRODUCTION
10	1 Scope 2 Normative reference 3 Terms and definitions
11	4 Requirements 5 Apparatus 5.1 Measurement equipment
12	5.2 Components for inductive measurements 5.2.1 Coils Figure 1 – Diagram for an electric circuit used for inductive Jc measurement of HTS films
13	5.2.2 Spacer film 5.2.3 Mechanism for the set-up of the coil 5.2.4 Calibration wafer Figures Figure 2 – Illustration showing techniques to press the sample coil to HTS films Tables
14	6 Measurement procedure 6.1 General 6.2 Determination of the experimental coil coefficient 6.2.1 Calculation of the theoretical coil coefficient k Figure 3 – Example of a calibration wafer used to determine the coil coefficient
15	6.2.2 Transport measurements of bridges in the calibration wafer 6.2.3 U3 measurements of the calibration wafer 6.2.4 Calculation of the E-J characteristics from frequency-dependent Ith data Figure 4 – Illustration for the sample coil and the magnetic field during measurement
16	6.2.5 Determination of the k’ from Jct and Jc0 values for an appropriate E Figure 5 – E-J characteristics measured by a transport method and the U3 inductive method
17	6.3 Measurement of Jc in sample films 6.4 Measurement of Jc with only one frequency Figure 6 –Example of the normalized third-harmonic voltages (U3/fI0) measured with various frequencies
18	6.5 Examples of the theoretical and experimental coil coefficients Figure 7 – Illustration for coils 1 and 3 in Table 1 Table 1 – Specifications and coil coefficients of typical sample coils
19	7 Uncertainty in the test method 7.1 Major sources of systematic effects that affect the U3 measurement Figure 8 – The coil-factor function F(r) = 2H0/I0 calculated for the three coils
20	7.2 Effect of deviation from the prescribed value in the coil-to-film distance 7.3 Uncertainty of the experimental coil coefficient and the obtained Jc Figure 9 – The coil-to-film distance Z1 dependence of the theoretical coil coefficient k
21	7.4 Effects of the film edge 7.5 Specimen protection 8 Test report 8.1 Identification of test specimen 8.2 Report of Jc values 8.3 Report of test conditions
22	Annex A (informative) Additional information relating to Clauses 1 to 8
24	Figure A.1 – Illustration for the sample coil andthe magnetic field during measurement
25	Figure A.2 – (a) U3 and (b) U3/I0 plotted against I0 in a YBCO thin film measured in applied DC magnetic fields, and the scaling observed when normalized by Ith (insets)
28	Annex B (informative) Optional measurement systems
29	Figure B.1 – Schematic diagram for the variable-RL-cancel circuit Figure B.2 – Diagram for an electrical circuit used for the 2-coil method
30	Figure B.3 – Harmonic noises arising from the power source Figure B.4 – Noise reduction using a cancel coil with a superconducting film
31	Figure B.5 – Normalized harmonic noises (U3/fI0) arising from the power source Figure B.6 – Normalized noise voltages after the reduction using a cancel coil with a superconducting film
32	Figure B.7 – Normalized noise voltages after the reduction using a cancel coil without a superconducting film Figure B.8 – Normalized noise voltages with the 2-coil system shown in Figure B.2
34	Annex C (informative) Uncertainty considerations
35	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
36	Table C.4 – Standard uncertainties of two output signals Table C.5 – Coefficient of variations of two output signals
39	Annex D (informative) Evaluation of the uncertainty Table D.1 – Uncertainty budget table for the experimental coil coefficient k’
42	Table D.2 – Examples of repeated measurements of Jc and n-values
43	Figure D.1 – Effect of the coil position against a superconductingthin film on the measured Jc values
45	Bibliography

Status	Withdrawn
Title	Superconductivity – Electronic characteristic measurements. Local critical current density and its distribution in large-area superconducting films
Publisher	BSI
Committee	W/-
Pages	48
Publication Date	2013-04-30
Withdrawn Date	2021-12-21
Replaced By	BS EN IEC 61788-17:2021
ISBN	978 0 580 69204 8
Standard Number	BS EN 61788-17:2013
Identical National Standard Of	IEC 61788-17:2013, EN 61788-17:2013
Descriptors	Data transmission methods, Transport layer (OSI), Open systems interconnection, Interfaces (data processing), Data transfer, Electricity supply meters, Electrical equipment, Test equipment, Copper, Reports, Current measurement, Superconductors, Electric current, Electrical conductivity, Electrical resistivity, Direct current, Reliability, Electrical properties of materials, Titanium, Electric fields, Testing conditions, Error correction, Composite materials, Specimen preparation, Superconductivity, Niobium, Magnetic field effects, Mathematical calculations
ICS Codes	91.140.50 - Electricity supply systems


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BS EN 61788-17:2013

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