present status of the nd:yag thomson scattering system development for time evolution measurement of...
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Present Status of the Nd:YAG Thomson Scattering System Development for Time
Evolution Measurement of plasma profile on Heliotron J
Present Status of the Nd:YAG Thomson Scattering System Development for Time
Evolution Measurement of plasma profile on Heliotron J
Takashi Minami, Shohei Arai, Naoki Kenmochi, Hiroaki Yashiro, Chihiro Takahashi, Shinji Kobayashi, Tohru Mizuuchi, Shinsuke Ohshima, Satoshi Yamamoto, Hiroyuki Okada, Kazunobu Nagasaki, Yuji Nakamura,
Kiyoshi Hanatani, Shigeru Konoshima , Fumimichi Sano Institute of Advanced Energy, Kyoto University, Gokasho, Uji 611-0011,
Japan
Takashi Minami, Shohei Arai, Naoki Kenmochi, Hiroaki Yashiro, Chihiro Takahashi, Shinji Kobayashi, Tohru Mizuuchi, Shinsuke Ohshima, Satoshi Yamamoto, Hiroyuki Okada, Kazunobu Nagasaki, Yuji Nakamura,
Kiyoshi Hanatani, Shigeru Konoshima , Fumimichi Sano Institute of Advanced Energy, Kyoto University, Gokasho, Uji 611-0011,
Japan
2011.11.3 APFA20112011.11.3 APFA20112011.11.3 APFA20112011.11.3 APFA2011
Outline
•Introduction of Heliotron J
•Recent results
•SMBI Experiments
•Plasma startup without ECH
•Nd:YAG Thomson scattering
•Introduction
•Design overview for collective optics
•polychromator
•present status of development
•Summary
ITER
FFHR HSR SPPS
Compact Reactor
A steady-state, compact,
high-β helical reactor
- No disruptions
(currentless operation)
- No close conducting wall or active feedback control of instabilities
(no serious MHD instabilities)
- High Qeng (= net Pele. / Poper. )
(at minimum recirculating powers)
- High power density
(3~4 MW/m2 under the development of advanced wall materials)
Heliotron J Project Aims To Develop Attractive Compact Fusion Reactor
Heliotron J Device•Major Radius: R=1.2 m•Plasma Minor Radius: a=0.1-0.2 m•Magnetic Field: B 1.5 T≦•Vacuum iota: 0.3-0.8 with low magnetic shearHeating System:•ECH 0.4MW•NBI 0.8MW•ICRF 0.4MW•Magnetic coil system :
•one l/m=1/4 continuous helical coil•two sets of toroidal coils•three pairs of vertical field coils
Typical plasma parameters;
ne=0.2-4 x 1019 m-3
Te=0.3-1 keV
Ti=150-200 eV
Inner Vertical Coil
Toroidal Coil A
Outer Vertical Coil
Toroidal Coil BHelical Coil
Plasma
Vacuum Chamber
SMBI Has Extended Operational RegimeSMBI Has Extended Operational Regime• The stored energy reached Wp~4.5 kJ for ECH(~0.35 MW)+NBI(~0.6 MW), about 50% higher than that of conventional
gas-puff fueling. • The optimization study of SMBI-relevant operation scenario is in
progress.
• The stored energy reached Wp~4.5 kJ for ECH(~0.35 MW)+NBI(~0.6 MW), about 50% higher than that of conventional
gas-puff fueling. • The optimization study of SMBI-relevant operation scenario is in
progress.
Mizuuchi, Contribution to Plasma Physics 50 (2010) 639
NBI Plasmas Have Been Successfully Started Up By Assist of 2.45GHz 5kW Microwaves
NBI Plasmas Have Been Successfully Started Up By Assist of 2.45GHz 5kW Microwaves
•Plasmas of ne=1x1019 m-3 have been successfully produced 20msec after NBI turn-on with assistance of 2.45GHz 5kW microwaves
•No high-power ECH is applied
•Plasma startup without ECH widely will extend the operation region
•High β experiment
•B dependence of confinement
•B dependence of high-energy particles
•Extension of configuration
•Off-axis 70GHz ECH
Kobayashi, Nucl. Fusion 51 (2011) 062002
Production of Low-Density Plasma and High-Energy Electrons by 2.45GHz Microwaves is Important
No density build-up
• There is no EC resonance for 2.45GHz microwaves
• Plasma is successfully started up when ECE intensity exceeds a critical value
Objective for Construction new Nd:YAGThomsonObjective for Construction new Nd:YAGThomson
•Previous experiments show the improved confinements phenomena accompany with the transient phenomena. The plasma profile is rapidly changed by the transition.
•Therefore, the time evolution of the plasma profile should be measured to understand the physics of the improved confinement.
•For this purpose, we are developing new Nd:YAG Thomson scattering system for Heliotron J device.
Design of Heliotron J Nd:YAG Thomson systemDesign of Heliotron J Nd:YAG Thomson system
• Goal: Performance
• Spatial resolution ~1cm
• Spatial channels : 25
• Time intervals of measurement ~10ms (Period of discharge ~200ms,confinement time~1-10ms)
• Range of Te 10eV-10keV
• Range of ne >0.5x1019m-3
• Nd:YAG Laser spec
• 100Hz (50Hz two lasers), 550mJ 10ns pulse by Continuum.inc.
• We have a future plan to improve time interval to ~5ms (2 lasers->4 lasers)
• Goal: Performance
• Spatial resolution ~1cm
• Spatial channels : 25
• Time intervals of measurement ~10ms (Period of discharge ~200ms,confinement time~1-10ms)
• Range of Te 10eV-10keV
• Range of ne >0.5x1019m-3
• Nd:YAG Laser spec
• 100Hz (50Hz two lasers), 550mJ 10ns pulse by Continuum.inc.
• We have a future plan to improve time interval to ~5ms (2 lasers->4 lasers)
Schematic of YAG Thomson Scattering system
Design of Scattered Light Collective System Design of Scattered Light Collective System
Dimeter: 800mm F/2.25
20 度
(mm)
(mm
) Scatter volume imageconcave mirror
Scattered angle:20deg.
25 spatial points->resolution ~10mm Image length:14cm
Scattered angle: 20degree
Laser Length inside plasma: 25-30cm
Magnification: 0.3-0.5
Large concave mirror is used for large solid angleHigher F number for low aberration
Solid angle and aberrationSolid angle and aberration
✓Large solid angle: 0.08-0.1str.
=>Considerable scattered light can be
collected
✓Back scattered light is small due to small
backward region.
=>Good S/N ratio
✓Aberration (<3mm) is small due to larger
F number (Fiber width ~3mm)
✓It is easy to choose optical fiber,
because required fiber NA(numerical
aperture) is >0.25.
✓Uniform optical characteristic for all
spatial points
✓Large solid angle: 0.08-0.1str.
=>Considerable scattered light can be
collected
✓Back scattered light is small due to small
backward region.
=>Good S/N ratio
✓Aberration (<3mm) is small due to larger
F number (Fiber width ~3mm)
✓It is easy to choose optical fiber,
because required fiber NA(numerical
aperture) is >0.25.
✓Uniform optical characteristic for all
spatial points
>80mstr
<3mm
~0.25
6 channel Interference PolychromatorPolychromatorPolychromator
•Wavelength channel 5ch.•Rayleigh channel 1ch.
•Interference filter
•Relay lens
•Detector
•Avalanche photo diode -Hamamatsu photonics: S8890-30,[area: 3Φ]
•Bias: High voltage regulator with temperature control
•Preamplifier is made by JFET input OP amplifier.
APD
HV regulator
Amplifier performanceSignal response by SPICE Circuit Simulator
ADA4817
Output signalof preamplifier
Gate width 60ns-80ns
APD signal
Time
manufacturer Cin(F)G.B.
(MHz)S.R.
(V/μs)Iout
(mA)en
(nV/√Hz)
ADA4817 Analog Devices 1.5p 410 870 70 4n
OPA627 Texas Instruments 8p 16 55 45 4.5n
LF356 National Semiconductor 3p 5 12 5 12n
Design for Filter Combination of Polychromator
Filter Combination•Ch1(FIlter1) : 700-845nm•Ch2(FIlter2) : 845-960nm•Ch3(FIlter3) : 960-1025nm•Ch4(FIlter4) : 1025-1050nm•Ch5(FIlter5) : 1050-1060nm
Filter Combination•Ch1(FIlter1) : 700-845nm•Ch2(FIlter2) : 845-960nm•Ch3(FIlter3) : 960-1025nm•Ch4(FIlter4) : 1025-1050nm•Ch5(FIlter5) : 1050-1060nm
•Te : 10-10keV ne: 3x1019m-3
•Error from bremsstrahlung is below 2% for Te and 3% for ne
•Filter set optimization using modeling code.
•Te : 10-10keV ne: 3x1019m-3
•Error from bremsstrahlung is below 2% for Te and 3% for ne
•Filter set optimization using modeling code.
>80%
Development of Data Acquisition System for Fast SIgnal
PolychromatoPolychromatorsrs
25x6ch.25x6ch.=150ch.=150ch.
PolychromatoPolychromatorsrs
25x6ch.25x6ch.=150ch.=150ch.
V792 QDCV792 QDC32ch.x532ch.x5
V792 QDCV792 QDC32ch.x532ch.x5
CINOSCINOSControllerControllerMemoryMemory
VMEVMECAMACCAMAC
CINOSCINOSControllerControllerMemoryMemory
VMEVMECAMACCAMAC
Heliotron JHeliotron JFedoraFedoraLinuxLinux
Data baseData base
Heliotron JHeliotron JFedoraFedoraLinuxLinux
Data baseData base
CAEN V79232 Channel Multi-event QDC ( Charge-to-Digital Conversion)VME bus system based on CHS CINOS system
V792
CINOS
Movie:Manufacturing new port on Heliotron J
Outer Port
Inner Port
New Heliotron J port for Nd:YAG Thomson
Window for scattered light(30cm)
Laser injection port
Heliotron J
New Nd:YAG Thomson Scattering Stage
SummarySummary
• To investigate the relation between the plasma profile and the
improved confinement on Heliotron J. We develop the new
Nd:YAG Thomson scattering system.
• Spatial resolution ~1cm
• Spatial channels : 25
• Time interval of measurement ~10ms
• Range of Te 10eV-10keV
• Range of ne >0.5x1019m-3
• Laser optics, Collection optics for scattered light (Concave
mirror, optical fiber bundles), Polychromator (filter combination,
relay lens, preamplifier), Data acquisition system are developed.
• To investigate the relation between the plasma profile and the
improved confinement on Heliotron J. We develop the new
Nd:YAG Thomson scattering system.
• Spatial resolution ~1cm
• Spatial channels : 25
• Time interval of measurement ~10ms
• Range of Te 10eV-10keV
• Range of ne >0.5x1019m-3
• Laser optics, Collection optics for scattered light (Concave
mirror, optical fiber bundles), Polychromator (filter combination,
relay lens, preamplifier), Data acquisition system are developed.