ISSUE 1 Year 2001 - Information Bulletin issued quarterly

European Fusion Development Agreement

EFDA NEWSLETTER
by the EFDA Close Support Unit in Garching – http://www.efda.org
The Report on Safety and Environmental
Impact of Fusion approved by the CCE-FU• The ITER TF Model Coil (TFMC)
In the internal Pages:
Test Preparations

p. 2• “The ITER Central Solenoid Model
Coil is a major Milestone”

p. 2• Another Step towards Steady-StateTokamaks
p. 3• The Rise and Rise of high-power
Gyrotrons

p. 3• A Fusion Springboard to commercialSuccess
p. 4

The CCE-FU (EURATOM Consultative Committee forFusion) has approved the report on Safety andEnvironmental Impact of Fusion (SEIF) presented by
EFDA at the April meeting in Bruxelles.
This is an integrated report which updated and improved
the analysis carried out for the report on the Safety andEnvironmental Assessment of Fusion Power (SEAFP-1) in
1995. The new results take into account the improvements
in data and in the methods of analysis and the changes inmaterials specifications. The results in the SEIF reportconfirm once again the attractive safety andenvironmental characteristics of fusion energy.

EFET, the European Industrial Support to ITER
In 1993 the EuropeanCommission issued a call for
tender for the European
industrial support to the ITER
Engineering Design Activities(EDA) being performed by theEuropean ITER Home Team,now represented by the EFDA
Close Support Unit inGar ch i n g . F o l l o w i n g acompetitive tendering exercise
involving European wideindustry groupings with aninterest in fusion technology,
a Framework Contract
covering these industrial
support activities wasawarded to EFET (EuropeanFusion
Engineering&Technology) in April 1994.
EFET is a European Economic
Interest Grouping (EWIV)
with its administration offices
atFramatome Advanced
Nuclear Power GmbH in
Erlangen, Germany. It brings
together major systems
engineering companies fromseven European countries:
Ansaldo Ricerche (Italy),
Belgatom (Belgium), Fortum(Finland), Framatome ANP
S.A.S. (France), Framatome
ANP GmbH (Germany),
IBERTEF (Spain) and NNC(United Kingdom).
The Member Companies of
EFET jointly cover all the major
technology areas required forthe design, construction andprocurement of the systems andcomponents of the next step
fusion device. The range of
EFET's expertise covers areas asdiverse as superconductingmagnets, large mechanicalstructures, such as the vacuum
vessel, and complex remotehandling systems required forcomponent inspection andreplacement.
Since 1994, throughout the ITER
EDA and its extension related toITER-FEAT, EFDA in Garchinghas frequently relied on EFET's
expertise for the design,assessment and costing ofsystems and components for theITER
device,including
fabricability investigations.
These activities have also
included safety, design and costassessments of ITER aspresented by ITER Joint Central
Team (JCT) in their design
reports at various stages of theITER project.
EFET is also able to include thespecific expertise of third-party
industries from Europe when

explicitly requested by EFDA,in particular in plasma physics
areas.
Within the overall objectives oftheEuropeanFusion
Programme,EFET
hasperformed significant safetyand design studies for future
fusion power plant concepts(SEAFP, PPCS).
In addition to contributing tothe final design report for
ITER-FEAT, EFET is currently
participating in the activities
for the assessment of thepossible European ITER site
proposal at Cadarache (F)including related licensing
activities.
The application of industrial
know-how to the ITER design
is very important to the successof the project. By pooling withthe expertise and competenceof its Members in the field ofcontrolled thermonuclear
fusion, EFET is able to provide
such know-how and to support
theEuropeanFusion
Programme in making the next
step device an engineering
reality.
EFET Contact on page 4

European Fusion Development Agreement Newsletter – Issue 1 / 2001 –Page 1

The ITER Toroidal Field Model Coil (TFMC) Test Preparations
In 2000 the fabrication of theTFMC was completed by theEuropean Consortium AGAN.
The Intercoil Structure (ICS)
was delivered in June 2000 tothe Toroidal Coil Facility(TOSKA) test site at theAssociation
EURATOMForschungszentrum Karlsruhe
and the TFMC followed January
11, 2001. The TFMC wasassembled with the ICS and set
in a vertical position. Thisarrangement was lifted onto thegravitational support frameand assembled with theauxiliary structure. In the firsttest campaign this will replace
the EU Large Coil Task (LCT)
coil and the TFMC will betested as single coil starting inJune 2001 to provide key results
until the end of the ITER EDA.
Afterwards, in the second
campaign until 2002, the TFMC
will be tested in the backgroundfield of the LCT coil forachievingcomparable
mechanical stresses of the ITER
full size coils.
Before the TFMC arrangement

was lifted in the TOSKA
vacuum vessel the coil
instrumentation (voltage taps,temperature, pressure and flow
sensors,displacementtransducers, strain gauges) wascarefully checked.

The TFMC during lifting procedurein the TOSKA vacuum vessel

After the lifting of thearrangement in the TOSKA
vacuum vessel a vacuum leaktest is performed to assure thatthe whole arrangement has an
overall leak tightness of 5 .10 -7
mbarl/s.
When this specification isfulfilled, the arrangement will
be connected to the cryogenic
and the electrical high current
supply systems as well as tothe data acquisition system.
Specific equipment (2 kW
refrigerator, 80 t crane, 80 kA
power supply with discharge
circuit, a modern measuring
and control system for thecryogenic supply) was
installed and commissioned
for previous superconducting
coil tests (LCT at forced flow
He II operation at 1.8 K, test of
the W 7-X prototype coil) in
the years before. Two 80 kA
current leads were developed
and constructed for this test.

The electrical insulation wastested by DC, AC and pulse
voltage up to 10 kV.

“The ITER Central Solenoid Model Coil is a Major Milestone”
The large coils which will
generate the major magnetic
field components in ITER will
all be superconducting. The
high currents and long pulse
duration would generate toomuch heating in conventionalcoils. However, the constructionof superconducting coils withthe required performance is amajor technological challenge,
so working prototypes need tobe built to prove it can be done.
Dr Robert Aymar, the ITER
Director, recently announced
the successful testing of a modelof the central solenoid coil – theone which sits at the centre of
the doughnut and acts as theprimary winding of thetransformer to drive the plasma
current.
But this is no small model.
The test coil is 2 m high, 3.6 m
in diameter, carries a current of

Test facility at Naka (Japan) for themodel of the ITER central solenoid
coil (courtesy of JAERI, Japan)

46000 amperes and produces afield of 13 tesla.
To put that in perspective, themagnets in the biggest hi-fi
loudspeakers produce no morethan about one tesla, over a
volume more than a million
times smaller!

The development and testingof this coil is an example of aremarkable international collaboration, involving industry as
well as fusion labs. The
superconducting strand wasproduced by companies in theEU, Japan and the USA (withsupport from the RussianFederation), the conductors
were then manufactured byindustry in the EU, the magnet
was assembled from modules
made in Japan and the USA,and the whole assembly wastested on a purpose built
facility in Japan.
Dr Aymar says that thesuccessful testing of the coil is“a major milestone of the ITER
R&D programme and conveys
a strong message about thequalityoftheITER
collaboration and the strengthof industrial involvement”.

European Fusion Development Agreement Newsletter – Issue 1 / 2001 –Page 2

Another Step towards Steady-State Tokamaks
The Tore Supra Tokamak at theAssociation EURATOM-CEA(Cadarache, France) has
pio n e e r e dtheuseofsupercond u c t i n g c o i l s t ogenerate its strong toroidal
magnetic field. This is an
important technology for futuremachines, since it opens theway to very long plasma
pulses, and perhaps evensteady state operation. This
unique feature of Tore Suprameans that it is the rightmachine for making long pulse
experiments. In fact Tore Supraholds the world record of 2
minutes for a hot Tokamak
plasma.
The limitation on the plasma
performance in these very longpulses is due to heating of theinner surfaces of the machine
which define the plasma edge
(the “limiter”), and which must
absorb most of the injected
power. In order to achieve
higher performance in longpulses, the physicists andengineers at Cadarache are now

This is a prototype of one of the576 “fingers” which will line thebase of the upgraded Tore Supramachine and form the pumplimiter. One of the big challenges of
the CIEL upgrade is ensuring thereliability of the bonding of every
one of the tiles to the copper basematerial.

working on a major upgrade of
the machine called CIEL(“Composants Internes etLimiteur”).
The most important newcomponent of CIEL is a “pumplimiter” made up of 576
individual fingers. Each finger
consists of plasma facing tiles
made of a composite ofgraphite and carbon fibre
bonded to a copper substrate
which contains a cooling water
channel.
This high tech structure has
ideal properties for a fusion

machine : a refractory, low
atomic weight material incontact with the plasma, and ahigh thermal conductivity
substrate which can be watercooled. The bonding of the twouses state of the art techniquesdeveloped in collaboration withindustry. Prototypes havesustained heat fluxes up to 15
MW/m2.
The whole set of fingers isdesigned to be able to support a15 MW load in steady state.
Apertures located under thefingers allow exhaust gas fromthe plasma to be pumped away.
Other elements of the upgrade
include improved protection for
the remainder of the innersurface of the machine, infrared
cameras to monitor the surface
temperature of the limiter, andenhanced control systems toallow the long pulses to beoperated safely. Full scale
plasma operation of theupgraded machine will start in2002.

The Rise and Rise of High-Power Gyrotrons
Fusion plasmas require many
megawatts of heating to reachthe temperatures at which
fus i o nreactions
occur.
Gyrotrons are one of thepossible solutions. They aresources of high power, highfrequency microwaves which
can be absorbed in a very
localised region of the plasma.
The technique is attractive forvarious plasma physics reasons,and it also has some significant
practical advantages linked tothe high frequency of theradiation (which corresponds toa few millimetres wavelength):
the radiation can be transported
efficiently over large distancesand very high power can betransmitted through the small
apertures which are permitted
in the wall of the plasma vessel.
Gyrotrons use the interaction
between a high energy electronbeam and radiation in amagnetic field to generate themicrowaves. High power ispossible because the interaction
cavity is large, unlike low
power devices which use afundamental mode cavity. The
cavity is carefully designed tosupport a single high-orderwaveguide mode which must
be converted to a low ordermode for transmission to theplasma through waveguides.

A number of years of codevelopment with industry has led
to a solution using an ideal
material: diamond. It has very low
absorption, high strength and goodthermal conductivity. The example
here is 80 mm diameter and 1.5 mmthick.

The big problem has always
been the severe technologicaldifficulty of making sources
which reliably combine highpower output, long pulse
length and high frequency. Fora machine like ITER, the targets
are at least 1 MW per gyrotron
for many tens of seconds at up
to 170 GHz. A practical device
also needs an overall efficiencyof several tens of percent.
Fusion research has beenpushing gyrotron development
for over two decades. In thistime the progress has been
astounding. For example, in1980 a low frequency (28 GHz)
output of 200 kW was anachievement. Today, gyrotrons
with 0.5 MW for about 10 s at
100 GHz, and an efficiency
greaterthan30%arecommercially available. Tubes
which will meet the ITER
requirements are currently indevelopment.

European Fusion Development Agreement Newsletter – Issue 1 / 2001 –Page 3

A Fusion Springboard to Commercial Success
What happens when an SME(Small and Medium sizedEnterprise) realises that it has
produced a high-tech productof potential value to fusion
R&D? This case study shows
howthedevelopment,encouraged by the fusion
community, can be just thebeginning.
In the early 1970s, scientists at
Queen Mary College (London)
were developing a new type of
millimetre-wave(shortwavel e n g t hmicrowave)
detector for use in astronomy.
At about the same time, fusion
physicists were developing a
newplasmadiagnostic
technique based on themeasurement of the millimetrewave radiation emitted byfusion plasmas. The newdetector had exactly thecharacteris t i c s
theyweresearching for: high sensitivity,
large bandwidth and good
optical access when built into
the liquid helium cryostat usedto cool it.
Following successful tests of thedetector at UKAEA-Culham,
the College started to market
the new detector through asmall spin-off company, QMC
Instruments Ltd.
The company rapidly evolved
into the supplier of complete
mi l l i me t r e -w a v e d e t e c t o r
packages to the world’s fusion
laboratories.

During the 1980s, the newdiagnostic was adopted byalmost all the world’s fusion

The sensitive element in QMC
Instruments’ detector is a small
slice of ultra-pure Indium
Antimonide which is cut in a zigzag pattern and mounted in aliquid helium cryostat at –269 C.
Low thermal conductivity wires
carry the tiny electrical signals toexternalroomt e mperatureelectronics.

experiments, and further
evolutionoftheinstrumentation (multi-channel
spectrometers with up to 20
detectors) created a lot ofbusiness.
At the same time, otherrequirements of the fusion
environment, such as reduced
liquid helium consumption to
prolong the interval between
refills,
pushedQMC
Instruments into new areas
such as the development ofsophisticated filters to block
unwanted thermal radiation
without sacrificing signal.

Systems now operate for manyweeks
withoutanymaintenance.
By the early 1990s, most of theleading fusion laboratories hadenough detectors for theirneeds and the volume of fusion
related business began to fall.
However, QMC Instruments
was able to use the expertise it
had acquired to adapt thedetectors for non-fusion
applications. Today, fusion
laboratories account for only asmall part of the more than 1 M
Euro turnover of QMC
Instruments.
Itsellssophisticated detectors forspace applications, laboratory
spectroscopy and remotesensing.
Recently,
newapplications have started
opening up in biological andmedical research. In the wordsof Sales and Marketing
Director, Ken Wood, “Byinvesting in development tosatisfy the demands of thefusion community in the earlyyears, we produced muchbetter products which have
now found applications inmany other areas. We areproud of the contribution we
have made to scientificendeavor, but it would never
have got off the ground without
the impetus provided by thefusion community”.

EFET Contact
Mr. Edgar Bogusch EFET EWIV
c/o Framatome Advanced Nuclear Power GmbH
Freyeslebenstr. 1D-91058 Erlangen, Germany
Phone: +49-9131-189 5314 Fax:+49-9131-189 5098
Email: Edgar.Bogusch@framatome-anp.deEFDA Close Support Unit – Garching
C/o Max Planck Institut für Plasmaphysik(Association Euratom IPP), Boltzmannstr,2D-85748 Garching bei München
Tel: +49 89 3299 – 4237
Fax: +49 89 3299 – 4197
e-mail: casci@efda.org
For more information:www.efda.org , www.jet.efda.org,www.iter.org© EFDA 2001. K.Lackner, EFDA Leader
This internal newsletter or parts of it may not be reproduced withoutpermission. Text, pictures and layout, except where noted, courtesy of theEFDA Associates.
EFDA parties are the European Commission and the Associates of theEuropean Fusion Programme which is co-ordinated and managed by theCommission.
Neither EFDA, the Commission, the Associates nor anyone acting on theirbehalf is responsible for any damage resulting from the use of information
contained in this publication.

European Fusion Development Agreement Newsletter – Issue 1 / 2001 –Page 4