SI-2[ECシステムの設計開発の進展]
Design Progress on ITER Electron Cyclotron Heating & Current Drive System

大森俊道, T. Omori , F. Albajar , S. Alberti , K. Avramidis , U. Baruah , T. Bigelow , T. Bonicelli , A. Bruschi ,
123

45627

R. Chavan3, F. Cismondi2, C. Darbos1, G. Denisov8, A. Dumur9, D. Farina7, F. Gandini1, G. Gantenbein10,T. Gassmann1, T.P. Goodman3, G. Hanson6, M.A. Henderson1, J.P. Hogge3, J. Jelonnek10, K. Kajiwara11,W. Kasparek12, N. Kobayashi11, M. Kushwah1, G.P. Latsas13, A. Moro7, C. Nazare14, Y. Oda11, A. Oustinov8,I. Pagonakis10, B. Piosczyk10, L. Popov8, D. Purohit1, S.L. Rao5, D. Rasmussen6, D.M.S. Ronden15, G. Saibene2,
K. Sakamoto11, T. Scherer10, M.A. Shapiro16, N. P. Singh5, C. Sozzi7, P. Spaeh10, D. Straus10, O. Sauter3,
K. Takahashi11, R.J. Temkin16, H. Zohm17
1

イーター機構, ITER Organization, Route de Vinon sur Verdon, St. Paul-lez-Durance, 13115 France

2 Fusion for Energy, C/ Josep Pla 2, Torres Diagonal Litoral-B3,E-08019 Barcelona – Spain

3 CRPP, Association EURATOM-Confédération Suisse, EPFL Ecublens, CH-1015 Lausanne, Suisse
4 SECE, National Technical University of Athens, Greece
5 Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar, 382428, India
6 US ITER Project Office, ORNL, 055 Commerce Park, PO Box 2008, Oak Ridge, TN 37831, USA
7 Istituto di Fisica del Plasma, Association EURATOM-ENEA-CNR, Milano, Italy
8 Institute of Applied Physics Russian Academy of Sciences, 46 Ulyanov Street, Nizhny Novgorod, 603950 Russia
9 C-con, ZAC Rourabeau, St. Paul-lez-Durance, 13115 France
10 KIT, Association EURATOM-KIT, IMF, Postfach3640 D-76021 Karlsruhe, Germany
11 Japan Atomic Energy Agency (JAEA) 801-1 Mukoyama, Naka-shi, Ibaraki 311-0193 Japan
12 Institut fur Plasmaforschung, Universitat Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart, Germany
13 National and Kapodistrian University of Athens, Greece
14 Assystem Facilities, 23 Place de Wicklow CS 30713, 78067 Saint Quentin en Yvelines Cedex
15 Association EURATOM-FOM, 3430 BE Nieuwegein, The Netherlands
16 MIT Plasma Science and Fusion Center, Cambridge, MA 02139, USA
17 IPP-Garching, Association EURATOM-IPP,D-85748 Garching, Germany

Overview
An Electron Cyclotron (EC) system is one offour auxiliary plasma heating systems to bedeployed in ITER [1]. The EC system consists of 170
GHz gyrotrons (RFPS; RF power source) withassociated high voltage power supplies (HVPS), aset of evacuated transmission lines (TL) andlaunchers, is designed to inject ≥ 20MW of
microwave power into the plasma for plasma
start-up, central H&CD and control of MHD
activity on the ITER Tokamak.
The ITER EC system is expected to realize thechallenges as an advanced microwave device forthe future plasma heating and current drive
applications. CW operation with 20MW injected
power represents a large step forward in the use of
the EC system as compared to the present state of
the art. It is anticipated difficulties in thedevelopment and installation with complicatedprocurement strategy under the international
cooperation project. It is noted that ITER became
the first fusion device qualified as basic nuclear
installations as of 9 November 2012. The EC
system especially for launchers shall comply withspecific requirements associated with nuclear
safety.

RFPSs and part of the TLs. The TLs pass throughthe Building 13 to Building 11. The TLs offer a low
loss transmission of the microwave power from
RFPS to the launchers (~160m in length). Twotypes of launchers are installed in Building 11, thefirst type located in an equatorial port (EL;Equatorial Launcher) and the second type located infour upper ports (UL; Upper Launcher). There areseveral Physics applications required of the EC
system, which partitions these applications between
the EL and the ULs. For the first plasma on ITER,
one third of the EC power is required while fullpower of 20 MW will be available by the secondphase.
B15

B13

B11EC system description

Fig. 1 Layout of the EC system with the power supplies and 24 gyrotrons in B15 (the RFBuilding, upper left) and the transmission lines passing through B13 (the assembly hall) to B11(the tokamak building) leading to the four upper and one equatorial launchers.

The EC system is installed in three buildings (seefigure 1). Building 15 houses the 12 HVPSs, 24

These subsystems are integrated together byintroducing a modular structure[2] to provide amaximum operating flexibility and minimum
impact arising from component failure, e.g., asingle HVPS is feeding for two 1MW gyrotrons
such that the delivered power can be isolated in 2
MW increments when subsystem fails.
The HVPS system consists of 12 main, 24 bodyand 8 anode (for triode gyrotrons) power supplies.
They will be procured by Europe and India
domestic agencies (DAs). The HVPSs are designed
to use the pulse step modulation technology whichenables fine voltage control with high frequency
modulation for gyrotron operation.
The RFPS is comprised of 24 gyrotrons which
will be supplied by four DAs of Europe, India,
Japan and Russian Federation. The output beam ofwhich TEM00 mode at the gyrotron’s diamondwindow is to be converted to HE11 mode by theMatching Optics Unit for highly-efficient couplingwith TL subsystem.
The TL subsystem is comprised of 24 lines ofcorrugated waveguides with associated brunchedsections and components to guide RF power toeither the EL or the ULs. The TL also controls thepolarization for optimum plasma coupling,monitors the RF power during operation andswitches the power to load for gyrotron
conditioning. To avoid the unnecessary losses, theTL routing is designed to minimise the number ofthe mitre bends which are between 7 to 9. The TL
subsystem is going to be provided by the US DA.
Two launchers are planned to achieve therequired functionality of central H&CD and theoff-axis CD for stabilizing MHD activity. These
functions will be fulfilled by the rightcombinational use of the EL and the ULs. Thelaunchers are procured with the ex-vessel
millimetre wave subsystem which is comprised ofthe diamond windows, the isolation valves androughly 15 m length of the ex-vessel waveguides.
These components together with the closure flangesof the launchers form the first confinement barrier.
In addition, waveguide compensates for the torus
displacements (≤±25mm) due to temperature
variations, plasma disruptions, thermal quenches
and loss of coolant without any damage on the first
confinement function.
The single EL is to be deployed at the equatorial
port #14 and will be procured by Japan DA. A total
number of 4 ULs are going to be deployed in theupper ports #12, 13, 15 and 16 with ex-vessel
millimetre wave subsystem for both EL and ULs
will be by Europe DA.

Future advancement
The EC system design is progressing towards thefinal stage according to the 2020 first plasma datewith aiming at further enhancement of the EC
system capabilities. The ITER EC section isproactive in promoting collaborations and joint
efforts among the international EC community,
through contracts and task orders, with the aim toaddress the challenges and new technology
development needed to successfully achieve theambitious ITER requirements.
R&D is on-going to confirm reliable
performances: the gyrotron prototypes by both
Japan and Russian DAs have operated for 1MW
and ≥800sec; the launcher final designs areadvancing using a series of on-going task
agreements by Europe DA and Japan DA; thewhole EC system is controlled by the EC control
system, which is a new procurement arrangement tobe established with Europe DA and Japan DA; andthe functional capabilities of the EC system arebeing validated by EC beam physics analysis which
verifies the heating and current drive potential foreach plasma operation scenario and to study power
management from break down to end of
ramp-down.
Future modifications under consideration
include: increase HVPS specifications toaccommodate possible future EC power upgrade up
to 1.4 MW per gyrotron; removal of Be from thefirst wall for the EL and the ULs and introduce a 10cm recession from the neighbouring wall mounted
blankets; and modification in the EL beam scan
direction from toroidal to poloidal plane in order todouble the driven current capability especially at
mid radius (see figure 2).
These challenges can offer a simplified technicaldesign and increase the functional capabilities ofthe EC system for plasma heating and current driveapplications.

Fig. 2 The Project Change Request No. 505 has accepted into the baseline for implementation,is proposing EL to have poloidal beam scan, enables doubling EC CD capability in region of0.45 <ρ<0.6.

The views and opinions expressed herein do not necessarily reflect
those of the ITER Organization.
[1] T. Omori, et al., Fusion Eng. Des. (2011), doi:10.1016/j.fusengdes.
2011.02.040[2] M. Henderson and G. Saibene, Nucl. Fusion 48 (2008) 054017