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Recent Progress inITER Diagnostics Development in Japan

10th Meeting of the ITPA Topical Groupon Diagnostics

Kurchatov Institute, Moscow, Russia, 10 – 14 April, 2006

Y. Kusama forH. Ogawa, S. Kasai, T. Sugie1), T. Hatae, K. Sato,

Y. Neyatani, Y. Kawamata, K. Kurihara,K. Ebisawa2)

Japan Atomic Energy Agency (JAEA)1)ITER-IT, 2)AITEL Corp.

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Outline

Recent Progress in Designs and R&Ds of ITER Diagnostics (Partially related to ITA Task ITA 55-10)•Impurity Flux Monitor (Divertor)•Thomson Scattering (Edge) •Neutronics Analysis for the Port Plug Design

•Integrator for Magnetic Measurement

Planed Designs and R&Ds in 2006 (considered to be carried out under new ITA Task)

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Impurity Influx Monitor (Divertor) Mechanical Design - H. Ogawa, S. Kasai, T. Sugie (ITER-IT)

Collection Optics

Front End Optics in Upper Port

Front End Optics in Equatorial Por

Front End Optics in Divertor Cassette

Front End Optics on Divertor Diagnostics Support Structure

Correction lens

Secondary Mirror

Primary Mirror

Micro-lens Array

Field lens

Alignment Optics

Cassegrain Telescope

to Plasma

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Design and R&D Plan in 2005 - 2006 JAEA

(1) Design of Header Optics - Conceptual design of front end optics with the mirror folder for the integration into

the ports. - Conceptual design of the cooling channel for the optical components. - Estimation of the temperature rise of the cooled optical components by a simple

model calculation. - Studies of productivity and integration of optical components.

(2) R&D of the optical components - Prototype micro retro-reflector array (10 mm x 10 mm) made of nickel is produced

for feasibility study and optical properties (reflectivity, scattering property of reflective light, etc.) will be studied.

- Prototype micro-lens array (100 channels) made of fused silica is produced for feasibility study and optical properties ( the imaging property and the transmissivity, etc. ) will be studied.

Impurity Influx Monitor (Divertor)

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Mechanical Design of Front End Optics of Upper Port- As a result of the integration in the upper port,

optical components were installed inside the pipe (ID: 300 mm) for the remote-handling of the port plug.

- Three mirrors can be installed on the mirror mounting module with 300 mm diameter. It is also used for a neutron shielding and cooling the mirror.

- The tilt angel of each mirror can be adjusted and be fixed before the installation on the port.

Front End Optics

Pipe

Port Plug

Cross-sectional View of Mirror Holder

First Mirror Third Mirror

Second MirrorShutter

Holder for Third Mirror

Holder for First Mirror

to PlasmaShutter

Mirror Mounting Module

To Collection Optics

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Mechanical Design of Shutter

Bottom View of Shutter

-Rotary disk shutter driven by the wire is designed. It is also used for the sensitivity calibration.

-Bearings made of non-magnetized stainless steel (housing) and Silicon Nitride (ball) is a candidate for a fixed and flexible pivot in this area.

-Further R&D such as double-sealed bellow type linear motion feedthrough and/or wire-winding mechanism is necessary for a realization.

Schematic Drawing of Front End Optics and Shutter

First Mirror

Third Mirror

Second Mirror Shutter

to Collection optics

Pulleys

Shutter Plate(micro retro-reflector array is mounted)

to Plasma

to Collection Optics

Driving Wire

Micro Retro-Reflector Array(for Calibration)

Holder for Shutter

to Plasma

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Development of the edge Thomson scattering diagnostic system for ITER

(progress report)

T. Hatae for JA diagnostics group (Japan Atomic Energy Agency)

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• Development SLM laser oscillator based on the design carried out in 2004.

• Design of high-average-power laser system (Flash-lamp-pumped high power amplifier) toward final performance (5J, 100Hz)

• Optimization of collection optics, and engineering design of port plug

Thomson Scattering (Edge)

Design and R&D Plan in 2005 - 2006 JAEA

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Nd:YAG laser system for the edge Thomson system for ITER

• A high output-energy (5J) and high repetition-rate (100 Hz) YAG-laser is required to the edge Thomson scattering system in ITER.

• To develop the high power laser, stimulated-Brillouin-scattering-based phase conjugate mirrors are to be used to compensate the wavefront distortion induced in the high-power amplifying laser rods.

• In the laser system, stable single-longitudinal-mode (SLM) is necessary to draw out its performance of the phase conjugate mirror.

0.1

1

10

100

1 10 100 1000

Commercial laser(Low average-power)Repetition rate (Hz)ITER5J, 100Hz(Goal)

TU-Berlin3.15J, 100Hz(25kHz Burst)

LLNL30J, 5HzHIT0.3J, 300HzJAERI-Naka&ILE7.4J, 50HzSpecial laser(High average-power)JAERI-Kansai7J, 10HzRussia8J, 25HzLDFlash lamp pumping

Average power = 1W

10W

100W

1000W

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A flash-lamp-pumped high power laser amplifier is under development

•Pumping energy: 100 J

•Repetition rate: 100 Hz

•Average input power: 10 kW

•Pumping: 6 flash lamps

• Amplification test will be carried out soon using new SLM laser oscillator.

• Cr,Nd:YAG ceramics (not Nd:YAG synthetic crystal) is used as the laser medium.

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Collection optics• Collection optics designed by US team during ITER-EDA has the

vacuum boundary at the center of the port plug.• JA team is investigating the possibility to move the vacuum

boundary to the end of the port plug for – easy maintenance, and– reducing radiation damage of the lens and fiber optics.

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Optimization of collection optics design is carrying out

Slenderly cut lens

3 4

5 6 7 8 9

10

11 12

13

14 15

16

17

18 19

20

21 22 23

24 25 26 27

28 29 30 31

32 33 34 35

36

37

1000.00 MM

Vacuum window (~100mm in diameter)

Intermediate image（ possible to set a slit for shield）

Primary mirror (flat mirror)

Third mirror(cylindrical concave mirror)

30.79°

Secondary mirror (toroidaly concave mirror)

Secondary mirror (toroidaly concave mirror)

To fiber coupling optics

To fiber coupling optics

• Optical configuration is almost the same as the US design.• Vacuum boundary is arranged at the end of the port plug.• Considering the influence by the radiation, the lens is arranged more backw

ard.

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Neutronics Analysis of Upper PortY. Kusama, K. Ebisawa

Objectives

Evaluation of the following engineering quantities;• Neutron Streaming through a Large Optical Labyrinth, Gaps

between the Port Plug and the Vacuum Vessel Port,• Nuclear Heating of Diagnostic Components and the Port Plug,• Neutron and Gamma-ray fluxes and fluence on the Diagnostic

Components,• Radioactivity of the Port Plug and External Dose Rate, • Relocation of front balk shield to the rear end.

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Progress in Neutronics Analysis

1. Nuclear Heating for cooling channel design• Total ~550 kW on BSM, about half of the specification

(maximum input)• Maximum heat load on the side plates: 30 mW/cm3

• First Mirror: 16 mW/cm3, • At the end of Labyrinth: below 0.1 mW/cm3

• Flange Portion: negligible

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31度

1st Mirror

16 mW/cm3

6.6E+12 n/cm2/sec

2nd Lens 180x50

0.1mW/cm3

Fluence: 1.4E+17n/cm2, 1MGy

1.50ｍ

0.85ｍ0.43ｍ

0.89ｍ

Optical Labyrinth of Edge Thomson Scattering: Original configuration designed by US HT in the EDA

1.07ｍ

2.32ｍFiber window 90x50

Fluence: 7E+14 n/cm2,

10 kGyVacuum window 100x100

Fluence:

8E+13 n/cm2, 1kGyLarger Aperture

than original　500x120

1.9E+14 n/cm2/sec 2nd Mirror

0.7 mW/cm3

Fluence: 5E+17 n/cm2, 6 MGy

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2. Neutron fluence* and Gamma-ray absorbed dose on the candidate optical materials

• Originally proposed lens location:1.4E+17 n/cm2, 1 MGy, marginal to use silica glass

• Originally proposed fiber location: 7E+14n/cm2, 10 kGy, some transmission loss in fiber

*Plant life time accumulation is considered (= 0.3 MWa/m2 on the 1st wall)

KUVI-S, HO<10E-4%

X: 1E+17 n/cm2

J.Nucl.Mater.212215(1994),1059

SI Fiber

Irrad.

JMTR

Task T246

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Gap streamings

Flange

Cooling Pipes

Mirrors

Labyrinth streamings

Aperture

BSM Nuclear heating: 550 kW

Neutron Streaming and bulk shielding

Cut out of the Lower Blanket

External Dose Rate:

6 Sv/h

Relocate front bulk shield (1m) to the rear

Lens

BSM support

Nucleat heating in TFC: M

ax. 2E-2mW/cm3

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3. External Dose Rate around the flange for maintenance scheme

• Vacuum window: 6 Sv/hr 11.5 days after shutdown, satisfy the requirement <100 Sv/hr

• 1 m apart from the flange: 4 Sv/hr, allow hands-on access

4. Influence on Magnet by relocation of the shield• Maximum Nuclear Heating in the TF Coil:100 times high flux t

han before, but still order of 1E-2 mW/cm3, satisfy the requirement <1 mW/cm3

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Integrator for Magnetic Measurement - Design, fabrication and test of new integrator - Y. Kawamata, K. Kurihara, I. Yonekawa

Scope of Design Works and Results under ITA 55-10(1) Investigate a method to avoid the saturation of the integrator circuit

FET for circuit protection is damaged by excessive voltage inputs due to successive disruptions. The input circuit should be robust to them.

(2) Design and fabricate a new integrator(3) Test newly fabricated integrator, statically and by using the thunder sur

ge simulator (that simulates extremely high voltage input at disruption) to confirm performanceThree types of input circuit (Attenuator type, Zener diode type, Power Mos-FET) have been fabricated and tested. The Zener diode type has been found to be acceptable and tested in JT-60U.

(4) Discuss and propose methods to allow the integrator reject common-mode currents due to RIEFMThe effect of RIEMF would be neglected.

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Integration gap occurs after excessive voltage inputs due to successive disruptions

(Low-gain range)

Çw10

1MÉ∂

1.6kÉ∂ FET

2.0kÉ∂+15V

-15V

-+

Çw0.01

1MÉ∂1.6kÉ∂ -

+Çw1.0

+-1MÉ∂

Voltagegenerator

OP.amp

OP.amp

to VFC

to VFC

to VFC

(High-gain range)

Input protection circuitagainst excessive high voltage

Same as above

(Normal range)

+12V

-12VTP1

Signal input equivalent circuits for durability test of “stepped change”

Zenerdiode OP.amp

Disruptions

Excessive voltage inputs

Current flows over the limit of FET

The oxide film of FET-Zener diode is damaged

200s0s

30mVs

0s 200s

85mVs

Normalrange

gapDisruption

Selectedresults

(High - lowgain range)

Disruption

gap

shot No.E042997

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0.0008 % FS (10 V range) < 0.001 % FS (Op. amplifier spec.)

Signal input circuit using attenuators

· Acceptable for the accurate magnetic measurement.

Circuit Type 1 : An attenuator with feedback compensator to keep the attenuation ratio, and high-voltage resistant operational amplifier (250 V).< Linearity Test >

< Conclusion >

Feedback compensator to keep the attenuation ratio seems to provide stability of measurements.

x0.1x10

x0.01

OP.amp

OP.amp

OP.amp

to VFC

to VFC

to VFC

Inputsignal

(High-gain range)

(Normal range)

(Low-gain range)

-12.0

-8.0

-4.0

0.0

4.0

8.0

12.0

Output voltage Linearity error(%/FS)

10 V range

Input voltage (V)

(V)

-0.000826 [%/FS]

-0.000778 [%/FS]

-10.0 -5.0 0.0 5.0 10.0

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Test of “Attenuator Type” in JT-60U discharges

Integration Results

The “Attenuator Type” was applied to one of the magnetic probes of JT-60U and tested in disruptive discharges.

“Gap Phenomenon” has been perfectly resolved so far and integration error caused by over range had been successfully corrected.

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Design and R&D Plan in 2005 - 2006 JAEA

Microfission Chamber• Design of installation, cabling, ---.• Optimization of installation position, especially position of MCF for lo

w fusion power operation.