IEC 61788-3:2000

Superconductivity - Part 3: Critical current measurement - DC critical current of Ag-sheathed Bi-2212 and Bi-2223 oxide superconductors

Covers a test method for the determination of the d.c. critical current of short and straight Ag- or Ag alloy-sheathed Bi-2212 and Bi-2223 oxide superconductors that have a monolithic structure and a shape of round wire or flat or square tape containing mono- or multicores of oxides.

General Information

• Status: Published
• Publication Date: 13-Dec-2000
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 29.050 - Superconductivity and conducting materials
• Technical Committee: TC 90 - Superconductivity
• Drafting Committee: WG 3 - TC 90/WG 3
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 27-Apr-2006

Relations

• Revised: IEC 61788-3:2006 - Superconductivity - Part 3: Critical current measurement - DC critical current of Ag- and/or Ag alloy-sheathed Bi-2212 and Bi-2223 oxide superconductors
• Effective Date: 05-Sep-2023

Standards Content (Sample)

INTERNATIONAL IEC
STANDARD
61788-3
First edition
2000-12
Superconductivity –
Part 3:
Critical current measurement –
DC critical current of Ag-sheathed Bi-2212
and Bi-2223 oxide superconductors
Supraconductivité –
Partie 3:
Mesure du courant critique –
Courant critique continu des oxydes supraconducteurs
Bi-2212 et Bi-2223 avec gaine en argent

Reference number
Publication numbering
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60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.

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INTERNATIONAL IEC
STANDARD
61788-3
First edition
2000-12
Superconductivity –
Part 3:
Critical current measurement –
DC critical current of Ag-sheathed Bi-2212
and Bi-2223 oxide superconductors
Supraconductivité –
Partie 3:
Mesure du courant critique –
Courant critique continu des oxydes supraconducteurs
Bi-2212 et Bi-2223 avec gaine en argent

 IEC 2000  Copyright - all rights reserved
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International Electrotechnical Commission
For price, see current catalogue

– 2 – 61788-3 © IEC:2000(E)
CONTENTS
Page
FOREWORD . 3

INTRODUCTION .4

Clause
1 Scope. 5

2 Normative references . 5
3 Terminology. 6
4 Requirements .6
5 Apparatus. 7
6 Specimen preparation. 7
7 Measurement procedure. 8
8 Precision and accuracy of the test method. 9
9 Calculation of results . 10
10 Test report. 11
Annex A (informative) Additional information relating to clauses 1 to 9 . 13
Annex B (informative) Magnetic hysteresis of the critical current of high-temperature
oxide superconductors . 19
Bibliography . 21
Figure 1 – Intrinsic U-I characteristic . 12
Figure 2 – U-I characteristic with a current transfer component . 12
Figure A.1 – Illustration of a measurement configuration for a short specimen
of a few hundred A class conductors. 18
Figure A.2 – Illustration of superconductor simulator circuit. 18

Table A.1 – Thermal expansion data of Bi-oxide superconductor and selected materials . 17

61788-3 © IEC:2000(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION

__________
SUPERCONDUCTIVITY –
Part 3: Critical current measurement –

DC critical current of Ag-sheathed Bi-2212

and Bi-2223 oxide superconductors

FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International
Organization for Standardization (ISO) in accordance with conditions determined by agreement between the
two organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61788-3 has been prepared by IEC technical committee 90:
Superconductivity.
The text of this standard is based on the following documents:
FDIS Report on voting
90/80/FDIS 90/86/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
Annexes A and B are for information only.
The committee has decided that the contents of this publication will remain unchanged until
2005. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this standard may be issued at a later date.

– 4 – 61788-3 © IEC:2000(E)
INTRODUCTION
In 1986 J.G. Bednorz and K.A. Mueller discovered that some Perovskite type Cu-containing

oxides show superconductivity at temperatures far above those which metallic

superconductors have shown. Since then, extensive R & D work on high-temperature oxide

superconductors has been and is being made worldwide, and its application to high-field

magnet machines, low-loss power transmission, electronics and many other technologies is in

progress [1].
Fabrication technology is essential to the application of high-temperature oxide

superconductors. Among high-temperature oxide superconductors developed so far,

BiSrCaCu oxide (Bi-2212 and Bi-2223) superconductors have been the most successful at
being fabricated into wires and tapes of practical length and superconducting properties.
These conductors can be wound into a magnet to generate a magnetic field of several tesla
[2]. It has also been shown that Bi-2212 and Bi-2223 conductors can substantially raise the
limit of magnetic field generation by a superconducting magnet [3].
In summer 1993, VAMAS-TWA16 started working on the test methods of critical currents in
Bi-oxide superconductors. In September 1997, the TWA16 worked out a guideline (VAMAS
guideline) on the critical current measurement method for Ag-sheathed Bi-2212 and Bi-2223
oxide superconductors. This pre-standardization work of VAMAS was taken as the base for
the IEC standard, described in the present document, on the d.c. critical current test method
of Ag-sheathed Bi-2212 and Bi-2223 oxide superconductors.
The test method covered in this International Standard is intended to give an appropriate and
agreeable technical base to those engineers working in the field of superconductivity
technology.
The critical current of composite superconductors like Ag-sheathed Bi-oxide superconductors
depends on many variables. These variables need to be considered in both the testing and
the application of these materials. Test conditions such as magnetic field, temperature and
relative orientation of the specimen and magnetic field are determined by the particular
application. The test configuration may be determined by the particular conductor through
certain tolerances. The specific critical current criterion may be determined by the particular
application. It may be appropriate to measure a number of test specimens if there are
irregularities in testing.
––––––––––––––
The numbers in brackets refer to the bibliography.

61788-3 © IEC:2000(E) – 5 –
SUPERCONDUCTIVITY –
Part 3: Critical current measurement –

DC critical current of Ag-sheathed Bi-2212

and Bi-2223 oxide superconductors

1 Scope
This part of IEC 61788 covers a test method for the determination of the d.c. critical current of

short and straight Ag- or Ag alloy-sheathed Bi-2212 and Bi-2223 oxide superconductors that
have a monolithic structure and a shape of round wire or flat or square tape containing mono-
or multicores of oxides.
This method is intended for use with superconductors that have critical currents less than
500 A and n-values larger than 5. The test is carried out with and without applying external
magnetic fields. In the test of the tape specimen in magnetic fields, the magnetic fields are
parallel or perpendicular to the tape surface. The test specimen is immersed either in a liquid
helium bath or a liquid nitrogen bath during testing. Deviations from this test method that are
allowed for routine tests and other specific restrictions are given in this standard.
Substantial parts of the test method covered in this standard are in common with, or similar
to, those for Nb Sn composite superconductors (IEC 61788-2). Special features newly found
for oxide superconductors may be classified into two groups. The first group is specific to
oxide composite superconductors, including mechanical fragility originating from the presence
of weak links, cryogen gas bubble formation, aging degradation, magnetic flux flow and creep,
large anisotropy, hysteresis in critical current with magnetic field sweep, etc. The second
group is due to the short length of the specimen used in the standard. A critical current
measurement on such a specimen may easily pick up different voltage signals due to thermal
electromotive force, inductive voltage, thermal noise, current redistribution, specimen motion
relative to the holder, etc. Current transfer voltages may be present due to the short distance
from a current contact to a voltage tap. Short specimen length may reduce mechanical
tolerance against the Lorentz force, for example, by promoting the formation of cryogen gas
bubbles within the composite.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 61788. For dated references, subsequent
amendments to, or revisions of, any of these publications do not apply. However, parties to

agreements based on this part of IEC 61788 are encouraged to investigate the possibility of
applying the most recent edition of the normative document indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of IEC
and ISO maintain registers of currently valid International Standards.
IEC 60050-815:2000, International Electrotechnical Vocabulary (IEV) – Part 815: Super-
conductivity
IEC 61788-2:1999, Superconductivity – Part 2: Critic
...