SIST EN 61788-9:2005

Superconductivity -- Part 9: Measurements for bulk high temperature superconductors - Trapped flux density of large grain oxide superconductors

Specifies a test method for the determination of the trapped field (trapped flux density) of bulk high temperature superconductors. This International Standard is applicable to large grain bulk oxide superconductors that have well defined shapes such as round discs, rectangular, and hexagonal pellets. The trapped flux density can be assessed at temperatures from 4,2 K to 90 K. For the purpose of standardization, the trapped flux density will be reported for liquid nitrogen temperature.

Supraleitfähigkeit -- Teil 9: Messungen an massiven Hochtemperatursupraleitern - Eingefrorene magnetische Flussdichte bei grobkörnigen oxidischen Supraleitern

Supraconductivité -- Partie 9: Mesures pour supraconducteurs haute température massifs - Densité de flux résiduel des oxydes supraconducteurs à gros grains

Spécifie une méthode d'essai pour la détermination du champ résiduel (densité de flux résiduel) des supraconducteurs haute température massifs. La présente Norme internationale s'applique aux oxydes supraconducteurs à gros grains ayant des formes bien définies telles que les disques et les pastilles rectangulaires et hexagonales. La densité de flux résiduel peut être déterminée pour des températures comprises entre 4,2 K et 90 K. Pour les besoins de la normalisation, la densité de flux résiduel sera consignée pour la température de l'azote liquide.

Superprevodnost - 9. del: Meritve volumskih lastnosti visokotemperaturnih superprevodnikov - Ujet magnetni pretok v oksidnih superprevodnikih z velikimi zrni (IEC 61788-9:2005)

General Information

• Status: Published
• Publication Date: 30-Nov-2005
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 29.050 - Superconductivity and conducting materials
• Technical Committee: I09 - Imaginarni 09
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2005
• Due Date: 01-Dec-2005
• Completion Date: 01-Dec-2005
• Ref Project: EN 61788-9:2005 - Superconductivity - Part 9: Measurements for bulk high temperature superconductors - Trapped flux density of large grain oxide superconductors

Standards Content (Sample)

SLOVENSKI SIST EN 61788-9:2005

STANDARD
december 2005
Superprevodnost – 9. del: Meritve volumskih lastnosti visokotemperaturnih
superprevodnikov - Ujet magnetni pretok v oksidnih superprevodnikih z
velikimi zrni (IEC 61788-9:2005)
Superconductivity – Part 9: Measurements for bulk high temperature
superconductors – Trapped flux density of large grain oxide superconductors (IEC
61788-9:2005)
ICS 17.220.20; 29.050 Referenčna številka
SIST EN 61788-9:2005(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD EN 61788-9
NORME EUROPÉENNE
EUROPÄISCHE NORM August 2005

ICS 17.220; 29.050


English version


Superconductivity
Part 9: Measurements for bulk high temperature superconductors -
Trapped flux density of large grain oxide superconductors
(IEC 61788-9:2005)


Supraconductivité Supraleitfähigkeit
Partie 9: Mesures pour supraconducteurs Teil 9: Messungen an massiven
haute température massifs – Hochtemperatursupraleitern -
Densité de flux résiduel des oxydes Eingefrorene magnetische Flussdichte
supraconducteurs à gros grains bei grobkörnigen oxidischen Supraleitern
(CEI 61788-9:2005) (IEC 61788-9:2005)






This European Standard was approved by CENELEC on 2005-06-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 61788-9:2005 E

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EN 61788-9:2005 - 2 -
Foreword
The text of document 90/167/FDIS, future edition 1 of IEC 61788-9, prepared by IEC TC 90,
Superconductivity, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC
as EN 61788-9 on 2005-06-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2006-03-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-06-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61788-9:2005 was approved by CENELEC as a European
Standard without any modification.
__________

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- 3 - EN 61788-9:2005
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
NOTE Where an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60050-815 2000 International Electrotechnical Vocabulary - -
(IEV)
Chapter 815: Superconductivity

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NORME CEI
INTERNATIONALE IEC
61788-9
INTERNATIONAL
Première édition
STANDARD
First edition
2005-04
Supraconductivité –
Partie 9:
Mesures pour supraconducteurs
haute température massifs –
Densité de flux résiduel des oxydes
supraconducteurs à gros grains
Superconductivity –
Part 9:
Measurements for bulk high temperature
superconductors –
Trapped flux density of large grain
oxide superconductors
© IEC 2005 Droits de reproduction réservés ⎯ Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
CODE PRIX
PRICE CODE R
Commission Electrotechnique Internationale
International Electrotechnical Commission
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Pour prix, voir catalogue en vigueur
For price, see current catalogue

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61788-9 ¤ IEC:2005 – 3 –
CONTENTS
FOREWORD.5
INTRODUCTION.9
1 Scope.11
2 Normative references .11
3 Terms and definitions .11
4 Principle .11
5 Requirements .15
6 Apparatus.17
7 Measurement procedure.19
8 Precision and accuracy of the test method.19
9 Test report.21
Annex A (informative) Additional information related to Clauses 3 to 6.23
Annex B (informative) Measurements for levitation force of bulk high temperature
superconductors .29
Annex C (informative) Test report (example).35
Bibliography.39
Figure 1 – Principle of trapped flux density in bulk superconductor .13
Figure 2 – Schematic view of the experimental set-up.15
Figure A.1 – Thickness dependence of the trapped flux density (B ).23
z
Figure A.2 – Gap dependence of the field strength .27
Figure C.1 – Distribution map of trapped flux density .37

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61788-9 ¤ IEC:2005 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
__________
SUPERCONDUCTIVITY –
Part 9: Measurements for bulk high temperature superconductors –
Trapped flux density of large grain oxide superconductors
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 in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). 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. 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 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 IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61788-9 has been prepared by IEC technical committee 90:
Superconductivity.
The text of this standard is based on the following documents:
FDIS Report on voting
90/167/FDIS 90/175/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 2.

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61788-9 ¤ IEC:2005 – 7 –
IEC 61788 consists of the following parts, under the general title Superconductivity:
Part 1: Critical current measurement – DC critical current of Cu/Nb-Ti composite super-
conductors
Part 2: Critical current measurement – DC critical current of Nb Sn composite super-
3
conductors
Part 3: Critical current measurement – DC critical current of Ag-sheathed Bi-2212 and
Bi-2223 oxide superconductors
Part 4: Residual resistance ratio measurement – Residual resistance ratio of Nb-Ti
composite superconductors
Part 5: Matrix to superconductor volume ratio measurement – Copper to superconductor
volume ratio of Cu/Nb-Ti composite superconductors
Part 6: Mechanical properties measurement – Room temperature tensile test of Cu/Nb-Ti
composite superconductors
Part 7: Electronic characteristic measurements – Surface resistance of superconductors at
microwave frequencies
Part 8: AC loss measurements – Total AC loss measurement of Cu/Nb-Ti composite
superconducting wires exposed to a transverse alternating magnetic field by a
pickup coil method
Part 9: Measurements for bulk high temperature superconductors – Trapped flux density of
large grain oxide superconductors
Part 10: Critical temperature measurement – Critical temperature of Nb-Ti, Nb Sn, and
3
Bi-system oxide composite superconductors by a resistance method
Part 11: Residual resistance ratio measurement – Residual resistance ratio of Nb Sn
3
composite superconductors
Part 12: Matrix to superconductor volume ratio measurement – Copper to non-copper
volume ratio of Nb Sn composite superconducting wires
3
Part 13: AC loss measurements – Magnetometer methods for hysteresis loss in Cu/Nb-Ti
multifilamentary composites
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.

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61788-9 ¤ IEC:2005 – 9 –
INTRODUCTION
Large grain bulk high temperature superconductors (BHTSC) have significant potential for a
variety of engineering applications, such as magnetic bearings, flywheel energy storage
systems, load transports, levitation, and trapped flux density magnets. Large grain
superconductors have already been brought to market worldwide.
For industrial applications of bulk superconductors, there are two important material
properties. One is the magnetic levitation force, which determines the tolerable weight
supported by a bulk superconductor. The other is the trapped flux density, which determines
the maximum field that a bulk superconductor can generate. The users of bulk
superconductors must know these values for the design of their devices. However, these
values are strongly dependent on the testing method, and therefore it is critically important to
set up an international standard for the determination of these values both for manufacturers
and industrial users.
The test method covered in this standard is based on the VAMAS (Versailles Project on
Advanced Materials and Standards) pre-standardization work on the properties of bulk high
temperature superconductors.

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61788-9 ¤ IEC:2005 – 11 –
SUPERCONDUCTIVITY –
Part 9: Measurements for bulk high temperature superconductors –
Trapped flux density of large grain oxide superconductors
1 Scope
This part of IEC 61788 specifies a test method for the determination of the trapped field
(trapped flux density) of bulk high temperature superconductors.
This International Standard is applicable to large grain bulk oxide superconductors that have
well defined shapes such as round discs, rectangular, and hexagonal pellets. The trapped flux
density can be assessed at temperatures from 4,2 K to 90 K. For the purpose of
standardization, the trapped flux density will be reported for liquid nitrogen temperature.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050(815):2000, International Electrotechnical Vocabulary – Part 815: Superconductivity
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050(815) and the
following apply.
3.1
trapped flux density
strength of the magnetic flux density (T) trapped by a bulk high temperature superconductor
(BHTSC) at a defined gap and at a defined temperature
3.2
maximum trapped flux density
peak value of the trapped flux density
NOTE For most measurements, only the z component of the flux density is measured, which is strongly affected
by the sample geometry or the demagnetizing effect (see Clause A.2). Thus the total flux density, which is the
integration of all the field components, may also be regarded as the materials property to stand for the trapped flux
density (see Clause A.1).
4 Principle
Superconductors that exhibit flux pinning are capable of trapping magnetic fields, as shown in
Figure 1. Here the internal magnetic flux density rotation (’uB ) in the BHTSC is proportional
to the critical current density (J ), as expressed by the following equation:
c
’ uB P J
0 c

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61788-9 ¤ IEC:2005 – 13 –
In one dimension, the equation is reduced to
y
dB dx = µ J
z 0 c
in rectangular coordinates or to
θ
dB dr = µ J
z 0 c
in cylindrical coordinates.
The maximum value of the trapped flux density in the z component (B , ) in an infinite
z max
cylinder (2 R in diameter) is given by the following equation:
θ
B = µ J R
z,max 0 c
In practical samples, this value is reduced by the demagnetizing effect or the geometrical
effect as follows:
θ
B =D(R /t) µ J R
z,max 0 c
where D(R/t) is a geometrical constant that depends on the shape (the ratio of
radius/thickness) of the BHTSC.
B
z
y
dB /dx = J
z c
x
IEC  557/05
Figure 1 – Principle of trapped flux density in bulk superconductor

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61788-9 ¤ IEC:2005 – 15 –
Figure 2 shows a schematic diagram of the experimental set-up for trapped flux density
1)
measurements [1] . There are several ways to measure the trapped flux density of BHTSC.
A typical measurement procedure is as follows. Firstly, the field is applied on the
superconductor. Secondly, the sample is fixed on the cold head of a cryostat, which is cooled
to the target temperature by using a cooling device. After reaching the target temperature, the
external field is removed. The distribution of the field trapped by the BHTSC is then measured
by scanning a Hall sensor over the specimen surface at a defined gap. This is the so-called
field-cooled (FC) method of magnetization.
z
Hall sensor
x
Superconductor
Cryostat
y
x
Superconducting magnet
IEC  558/05
Figure 2 – Schematic view of the experimental set-up
5 Requirements
Upon removal of the external field, the trapped flux density will decay with time from its initial
value. This is due initially to flux flow and later to flux creep (collectively termed flux
relaxation). The initial peak value shall not be used for the design of machines.
The trapped flux density values are those measured after a sufficiently long time has passed
since the appropriate measurement conditions were reached. The trapped flux density values
shall be measured at least 15 min after the external field is removed from the specimen under
test.
The target precision of this method is that the coefficient of variation in any inter-comparison
test shall be 5 % or less for measurements performed within 1 month of each other [2].
It is the responsibility of the user of this standard to consult and establish appropriate safety
and health practices and to determine the applicability of regulatory limitations prior to use.
Specific precautionary statements are given below.
———————
1)
Figures in square brackets refer to the bibliography.

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61788-9 ¤ IEC:2005 – 17 –
Hazards exist in this type of measurement. Very large direct currents with very low voltages
do not necessarily provide a direct personal hazard, but strong magnetic fields trapped by the
BHTSC may cause the problem. It is imperative to shield magnetic fields. Also the energy
stored in the superconducting magnets commonly used for generating the magnetic field can
cause large current and/or voltage pulses, or deposit a large amount of thermal energy in the
cryogenic systems causing rapid boil-off or even explosive conditions. Direct contact of skin
with cold liquid transfer lines, storage dewars or apparatus components can cause immediate
freezing, as can direct contact with a spilled cryogen. It is imperative that safety precautions
for handling cryogenic liquids be observed.
6 Apparatus
6.1 Cryostat
The
...