SIST EN 61788-15:2012

SLOVENSKI STANDARD
SIST EN 61788-15:2012
01-marec-2012
Superprevodnost - 15. del: Meritve elektronskih karakteristik - Lastna površinska
impedanca superprevodnih plasti pri mikrovalovnih frekvencah
Superconductivity - Part 15: Electronic characteristic measurements - Intrinsic surface
impedance of superconductor films at microwave frequencies
Supraleitfähigkeit - Teil 15: Messungen der elektronischen Charakteristik -
Oberflächenimpedanz von Supraleiterschichten bei Mikrowellenfrequenzen
Supraconductivité - Partie 15: Mesures de caractéristiques électroniques - Impédance de
surface intrinsèque de films supraconducteurs aux fréquences micro-ondes
Ta slovenski standard je istoveten z: EN 61788-15:2011
ICS:
17.220.20 0HUMHQMHHOHNWULþQLKLQ Measurement of electrical
PDJQHWQLKYHOLþLQ and magnetic quantities
29.050 Superprevodnost in prevodni Superconductivity and
materiali conducting materials
SIST EN 61788-15:2012 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 61788-15:2012

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SIST EN 61788-15:2012

EUROPEAN STANDARD
EN 61788-15

NORME EUROPÉENNE
December 2011
EUROPÄISCHE NORM

ICS 29.050


English version


Superconductivity -
Part 15: Electronic characteristic measurements -
Intrinsic surface impedance of superconductor films at microwave
frequencies
(IEC 61788-15:2011)


Supraconductivité -  Supraleitfähigkeit -
Partie 15: Mesures de caractéristiques Teil 15: Messungen der elektronischen
électroniques - Charakteristik -
Impédance de surface intrinsèque de films Oberflächenimpedanz von
supraconducteurs aux fréquences micro- Supraleiterschichten bei
ondes Mikrowellenfrequenzen
(CEI 61788-15:2011) (IEC 61788-15:2011)





This European Standard was approved by CENELEC on 2011-11-28. 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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
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Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

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

Management Centre: Avenue Marnix 17, B - 1000 Brussels


© 2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61788-15:2011 E

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SIST EN 61788-15:2012
EN 61788-15:2011 - 2 -
Foreword
The text of document 90/280/FDIS, future edition 1 of IEC 61788-15, prepared by IEC/TC 90
"Superconductivity" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
EN 61788-15:2011.

The following dates are fixed:
(dop) 2012-08-28
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2014-11-28
• latest date by which the national
standards conflicting with the
document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent
rights.

Endorsement notice
The text of the International Standard IEC 61788-15:2011 was approved by CENELEC as a European
Standard without any modification.

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SIST EN 61788-15:2012
- 3 - EN 61788-15:2011
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  When 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) -
Part 815: Superconductivity


IEC 61788-7 2006 Superconductivity - EN 61788-7 2006
Part 7: Electronic characteristic
measurements - Surface resistance of
superconductors at microwave frequencies

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SIST EN 61788-15:2012

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SIST EN 61788-15:2012

IEC 61788-15
®

Edition 1.0 2011-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside


Superconductivity –
Part 15: Electronic characteristic measurements – Intrinsic surface impedance
of superconductor films at microwave frequencies

Supraconductivité –
Partie 15: Mesures de caractéristiques électroniques – Impédance de surface
intrinsèque de films supraconducteurs aux fréquences micro-ondes

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX X
ICS 29.050 ISBN 978-2-88912-710-8

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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SIST EN 61788-15:2012
– 2 – 61788-15  IEC:2011
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Requirements . 8
5 Apparatus . 9
5.1 Measurement equipment . 9
5.2 Measurement apparatus . 9
5.3 Dielectric rods . 13
5.4 Superconductor films and copper cavity . 14
6 Measurement procedure . 14
6.1 Set-up . 14
6.2 Measurement of the reference level. 14
6.3 Measurement of the R of oxygen-free high purity copper . 14
S
6.4 Determination of the effective R of superconductor films and tanδ of
S
standard dielectric rods . 17
6.5 Determination of the penetration depth . 18
6.6 Determination of the intrinsic surface impedance . 20
7 Uncertainty of the test method . 21
7.1 Measurement of unloaded quality factor . 21
7.2 Measurement of loss tangent. 21
7.3 Temperature . 22
7.4 Specimen and holder support structure . 22
8 Test Report . 22
8.1 Identification of test specimen . 22
8.2 Report of the intrinsic Z values . 22
S
8.3 Report of the test conditions . 22
Annex A (informative)  Additional information relating to clauses 1 to 8 . 24
Annex B (informative) Uncertainty considerations . 41
Bibliography . 45

Figure 1 – Schematic diagram for the measurement equipment for the intrinsic Z of
S
HTS films at cryogenic temperatures . 10
Figure 2 – Schematic diagram of a dielectric resonator with a switch for thermal
connection . 10
Figure 3 – Typical dielectric resonator with a movable top plate . 11
Figure 4 – Switch block for thermal connection . 12
Figure 5 – Dielectric resonator assembled with a switch block for thermal connection . 13
Figure 6 – A typical resonance peak. Insertion attenuation IA, resonant frequency f
0
and half power bandwidth ∆f are defined . 16
3dB
Figure 7 – Reflection scattering parameters S and S . 18
11 22
Figure 8 – Definitions for terms in Table 5 . 22
Figure A.1 – Schematic diagram for the measurement system . 24
Figure A.2 – A motion stage using step motors . 25

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SIST EN 61788-15:2012
61788-15  IEC:2011 – 3 –
Figure A.3 – Cross-sectional view of a dielectric resonator . 26
Figure A.4 – A diagram for simplied cross-sectional view of a dielectric resonator . 30
Figure A.5 – Mode chart for a sapphire resonator . 33
Figure A.6 – Frequency response of the sapphire resonator . 34
Figure A.7 – Q versus temperature for the TE and the TE modes of the sapphire
U 021 012
resonator with 360 nm-thick YBCO films . 35
Figure A.8 – The resonant frequency f versus temperature for the TE and TE
0 021 012
modes of the sapphire resonator with 360 nm-thick YBCO films . 35

Figure A.9 – The temperature dependence of the R of YBCO films with the
Se
thicknesses of 70 nm to 360 nm measured at ~40 GHz . 36
Figure A.10 – The temperature dependence of ∆λ for the YBCO films with the
e
thicknesses of 70 nm and 360 nm measured at ~40 GHz . 36
Figure A.11 – The penetration depths λ of the 360 nm-thick YBCO film measured at
10 kHz by using the mutual inductance method and at ~40 GHz by using sapphire
resonator . 37
Figure A.12 – The temperature dependence of the intrinsic surface resistance R of
S
YBCO films with the thicknesses of 70 nm to 360 nm measured at ~40 GHz . 37
Figure A.13 – Comparison of the temperature-dependent value of each term in
Equation (A.35) for the TE mode of the standard sapphire resonator . 38
021
Figure A.14 – Comparison of the temperature-dependent value of each term in
Equation (A.35) for the TE mode of the standard sapphire resonator . 38
012
Figure A.15 – Temperature dependence of uncertainty in the measured intrinsic R of
S
YBCO films . 39

Table 1 – Typical dimensions of a sapphire rod . 14
Table 2 – Typical dimensions of OFHC cavities and HTS films . 14
Table 3 – Geometrical factors and filling factors calculated for the standard sapphire
resonator . 17
Table 4 – Specifications of vector network analyzer . 21
Table 5 – Type B uncertainty for the specifications on the sapphire rod . 21
Table A.1 – Geometrical factors and filling factors calculated for the standard sapphire
resonator . 31
Table B.1 – Output signals from two nominally identical extensometers . 42
Table B.2 – Mean values of two output signals . 42
Table B.3 – Experimental standard deviations of two output signals. 42
Table B.4 – Standard uncertainties of two output signals . 42
Table B.5 – Coefficient of variations of two output signals. 43

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SIST EN 61788-15:2012
– 4 – 61788-15  IEC:2011
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_____________

SUPERCONDUCTIVITY –

Part 15: Electronic characteristic measurements –
Intrinsic surface impedance of superconductor
films at microwave frequencies


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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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 61788-15 has been prepared by IEC technical committee 90:
Superconductivity.
The text of this standard is based on the following documents:
FDIS Report on voting
90/280/FDIS 90/283/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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SIST EN 61788-15:2012
61788-15  IEC:2011 – 5 –
A list of all parts of the IEC 61788 series, published under the general title Superconductivity,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability 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.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.

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SIST EN 61788-15:2012
– 6 – 61788-15  IEC:2011
INTRODUCTION
Since the discovery of high T superconductors (HTS), extensive research has been
C
performed worldwide on electronic applications and large-scale applications with HTS filter
1
subsystems based on YBa Cu O (YBCO) having already been commercialized [1] .
2 3 7-δ
The merits of using HTS films for microwave devices such as resonators, filters, antennas,
delay lines, etc., include i) possibility of microwave losses from HTS films being extremely low
and ii) no signal dispersion on transmission lines made of HTS films due to extremely low
microwave surface resistance (R ) [2] and frequency-independent penetration depth (λ) of
S
HTS films, respectively.
In this regard, when it comes to designing HTS-based microwave devices, it is important to
measure the surface impedance (Z ) of HTS films with Z = R + jX and X = ωμ λ (here ω
S S S S S 0
and μ denote the angular frequency and the permeability of vacuum, respectively, X , the
0 S
surface reactance, and X = ωμ λ is valid at temperatures not too close to the critical
S 0
temperature T of HTS films).
C
Various reports have been made on measuring the R of HTS films at microwave frequencies
S
with the typical R of HTS films as low as 1/100 - 1/50 of that of oxygen-free high-purity
S
copper (OFHC) at 77 K and 10 GHz. The R of conventional superconductors such as
S
niobium (Nb) could be easily measured by using Nb cavities by converting the resonator
quality factor (Q) to the R of Nb. However, such conventional measurement method could no
S
longer be applied to HTS films grown on dielectric substrates, with which it is basically
impossible to make all-HTS cavities. Instead, for measuring the R of HTS films, several
S
other methods have been useful, which include the microstrip resonator method [3], the
coplanar microstrip resonator method [4], the parallel plate resonator method [5] and the
dielectric resonator method [7-10]. Among the stated methods, the dielectric resonator
method has been very useful due to that the method enables to measure the R in a non-
S
invasive way and with accuracy. In 2002, the International Electrotechnical Commission (IEC)
published the dielectric resonator method as a measurement standard [11].
The test method given in this standard enables measurement not only of the intrinsic surface
resistance but also the intrinsic surface reactance of HTS films, regardless of the film’s
thickness, by using a single sapphire resonator that differs from the existing IEC standard
(IEC 61788-7:2006), which is limited to measuring the surface resistance of superconductor
films having a thicknesses of more than 3λ at the measured temperature by using two
sapphire resonators. In fact, the measured surface resistances of HTS films with different
thicknesses of less than 3λ mean effective values instead of intrinsic values, which cannot be
used for directly comparing the microwave properties of HTS films among one another [12,
13]. Use of a single sapphire resonator as suggested in this standard also makes it possible
to reduce uncertainty in the measured surface resistance that might result from using two
sapphire resonators with sapphire rods of even slightly different quality.
The test method given in this standard can also be applied to HTS coated conductors, HTS
bulks and other superconductors having established models for the penetration depth.
This standard is intended to provide an appropriate and agreeable technical base for the time
being to engineers working in the fields of electronics and superconductivity technology.
The test method covered in this standard has been discussed at the VAMAS (Versailles
Project on Advanced Materials and Standards) TWA-16 meeting.

___________
1
 Numerals in square brackets refer to the Bibliography.

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SIST EN 61788-15:2012
61788-15  IEC:2011 – 7 –
SUPERCONDUCTIVITY –

Part 15: Electronic characteristic measurements –
Intrinsic surface impedance of superconductor
films at microwave frequencies



1 Scope
This part of IEC 61788 describes measurements of the intrinsic surface impedance (Z ) of
S
HTS films at microwave frequencies by a modified two-resonance mode dielectric resonator
2
method [13, 14] . The object of measurement is to obtain the temperature dependence of the
intrinsic Z at the resonant frequency f .
S 0
The frequency and thickness range and the measurement resolution for the intrinsic Z of
S
HTS films are as follows:
− frequency: up to 40 GHz;
− film thickness: greater than 50 nm;
− measurement resolution: 0,01 mΩ at 10 GHz.
2
The intrinsic Z data at the measured frequency, and that scaled to 10 GHz, assuming the f
S
rule for the intrinsic surface resistance R (f < 40 GHz) and the f rule for the intrinsic surface
S
reactance X for comparison, shall be reported.
S
2 Normative references
The following referenced documents are indispensible 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
IEC 61788-7:2006, Superconductivity – Part 7: Electronic characteristic measurements –
Surface resistance of superconductors at microwave frequencies
3 Terms, definitions and general concepts
3.1 Terms and definitions
For the purposes of this document, the definitions given in IEC 60050-815, one of which is
repeated here for convenience, apply.
3.1.1
surface impedance
impedance of a material for high frequency electromagnetic wave which is constrained to the
surface of the material in case of metals and superconductors
NOTE The surface impedance governs the thermal losses of superconducting RF cavities.
___________
2
Numerals in square brackets refer to the Bibliography.

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SIST EN 61788-15:2012
– 8 – 61788-15  IEC:2011
(IEC 60050-815:2000, 815-04-62)
3.2 General concepts
3.2.1 Intrinsic surface impedance
In general, the surface impedance Z of conductors, including superconductors, is defined as
S
the ratio of the tangential component of the electric field (E ) and that of the magnetic field (H )
t t
at a conductor surface:
E
t
Z = = R + jX . (1)
S S S
H
t
Here R denotes the surface resistance and X , the surface reactance. If the thickness of the
S S
conductor (or the superconductor) under test is sufficiently greater than the penetration depth
of electromagnetic fields, Z is expressed by
S
1 1
2 2
µ  jµω
0
Z = = (2)
   
S
ε σ
 
 
with ε and µ denoting the permittivity and the permeability of the conductor (or the
µ , the permeability of vacuum, σ, the conductivity
superconductor) under test, respectively,
0
of the conductor (or the superconductor), and ω, the measured angular frequency, and is
called the intrinsic surface impedance. σ is real for the conductor and complex for the
superconductor.
3.2.2 Effective surface impedance
If the thickness of the conductor (or the superconductor) under test is not sufficiently greater
than the penetration depth of electromagnetic fields, Z as defined by Equation (1) in 3.2.1
S
becomes significantly different from that defined by Equation (2) in 3.2.1. In this case, Z as
S
defined by Equation (1) is called the effective surface impedance Z with
Se
E
t
Z = = R + jX (3)
Se Se Se
H
t
Here R denotes the effective surface resistance and X , the effective surface reactance.
Se Se
4 Requirements
The Z of HTS films shall be measured by applying a microwave signal to a dielectric
S
resonator with the superconductor specimen and then measuring the attenuation of the
resonator at each frequency. The frequency shall be swept around the resonant frequency as
the centre, and the attenuation-frequency characteristics shall be recorded to obtain the
Q-value, which corresponds to the loss.
The target relative uncertainty of this method is less than 10 % at temperatures of 30 K to
80 K.
It is the responsibility of the user of this standard to consult and establish safety and health
practices and to determine the applicability of regulatory limitations prior to use.
Hazards exist in this type of measurement. The use of a cryogenic system is essential to cool
the superconductors to allow transition into the superconducting state. Direct contact of skin
with cold apparatus components can cause immediate freezing, as can direct contact with a
spilled cryogen. The use of an r.f.-generator is also essential to measure high-frequency

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SIST EN 61788-15:2012
61788-15  IEC:2011 – 9 –
properties of materials. If its power is too high, direct exposure to human bodies can cause an
immediate burn.
5 Apparatus
5.1 Measurement equipment
Figure 1 shows a schematic diagram of the equipment required for the microwave
measurement. The equipment consists of a network analyzer system for transmission
measurements, a measurement apparatus, and thermometers for monitoring the temperature
of HTS films under test.
An incident power generated from a suitable microwave source such as a synthesized
sweeper is applied to the dielectric resonator fixed in the measurement apparatus. The
transmission characteristics are shown on the display of the network analyzer.
The measurement apparatus i
...