2D Position Sensitive Detector for Plasma diagnosis Cheon Jong-Kyu.

2D Position Sensitive 2D Position Sensitive Detector for Plasma Detector for Plasma

diagnosisdiagnosis

Cheon Jong-KyuCheon Jong-Kyu

ContentsContents Fusion reactorFusion reactor Plasma DiagnosticsPlasma Diagnostics Charge exchange recombination spectroscopyCharge exchange recombination spectroscopy Charge exchange neutral analyzerCharge exchange neutral analyzer Visible spectrometerVisible spectrometer X-ray Crystal spectrometerX-ray Crystal spectrometer 3D view of the x-ray imaging crystal imaging spectrometer3D view of the x-ray imaging crystal imaging spectrometer Position Sensitive Detector for Position Sensitive Detector for

X-ray Crystal spectrometerX-ray Crystal spectrometer Performance test at Alcator C-Mod tokamak(MIT)Performance test at Alcator C-Mod tokamak(MIT)

Fusion reactorFusion reactor Inertial confinementInertial confinement

Tokamak fusion test reactor at PPPL(Princeton Plasma PhysicsLaboratory )

Trident laser facility at LANL (Los Alamos National Laboratory)using inertial confinement fusion

•Tokamak

Plasma Diagnostics for tokamakPlasma Diagnostics for tokamak

Layout of the horizontal ports for KSTAR diagnostics and for the main systems.

Charge exchange recombination Charge exchange recombination spectroscopy spectroscopy [Objectives][Objectives]

Measurement of ion temperature, toroidal & poloidal rotMeasurement of ion temperature, toroidal & poloidal rotation velocities and impurity density. ation velocities and impurity density.

[Principle][Principle]Neutral atom (HNeutral atom (H00) and impurity ion (A) and impurity ion (Aq+q+) undergo a charg) undergo a charge transfer that leaves the product ion in an excited state transfer that leaves the product ion in an excited state.e.HH00 + A + Aq+q+ --> H --> H++ + [A + [A(q-1)+(q-1)+]]**

In usual JT-60U discharges, the source of neutral atom In usual JT-60U discharges, the source of neutral atom is a neutral beam for the plasma heating, and the reactiis a neutral beam for the plasma heating, and the reaction with Con with C6+6+ is used for this measurement. This is becau is used for this measurement. This is because carbon is one of intrinsic impurities and they are fullse carbon is one of intrinsic impurities and they are fully stripped throughout the plasma volume. Emissions ary stripped throughout the plasma volume. Emissions are excited at wavelengths long enough for making accure excited at wavelengths long enough for making accurate Doppler broadening and shift measurements. ate Doppler broadening and shift measurements.

[Diagnostic Method][Diagnostic Method]One of heating beams NB #14 is used for this measureOne of heating beams NB #14 is used for this measurement (see figures). Due to the above reaction, carbon ioment (see figures). Due to the above reaction, carbon ions near the neutral beam emit green light (529.2 nm at ns near the neutral beam emit green light (529.2 nm at n=8-7 transition). The light is collected by a quartz lens n=8-7 transition). The light is collected by a quartz lens onto fiber optics and is transmitted to spectrometers in onto fiber optics and is transmitted to spectrometers in the diagnostic room; then the spectrum is detected by the diagnostic room; then the spectrum is detected by an intensified CCD cameras for the subsequent analysian intensified CCD cameras for the subsequent analysis of Doppler broadening (--> temperature), Doppler shift s of Doppler broadening (--> temperature), Doppler shift (--> rotation velocity) and its area (--> impurity density). (--> rotation velocity) and its area (--> impurity density). According to the ionization balance, there are C5+ ions According to the ionization balance, there are C5+ ions in the edge region, which can emit at the same transitioin the edge region, which can emit at the same transition due to direct excitation by electrons (not by neutral ben due to direct excitation by electrons (not by neutral beams). Therefore it is important to separate the spectruams). Therefore it is important to separate the spectrum by beam excitation from that by electron excitation. Im by beam excitation from that by electron excitation. In order for this, CXRS system in JT-60U has an exclusivn order for this, CXRS system in JT-60U has an exclusive optics for the background spectrum. e optics for the background spectrum.

Charge exchange neutral Charge exchange neutral analyzeranalyzer [Objectives][Objectives]

Measure energy spectrum of charge-exchange neutral parMeasure energy spectrum of charge-exchange neutral particles of energetic alpha particle and hydrogen isotopes ticles of energetic alpha particle and hydrogen isotopes (H, D, T) emitted from the plasma.(H, D, T) emitted from the plasma.

[Detectors, Diagnostic Method][Detectors, Diagnostic Method]Energetic neutral particles entering the analyzer are ionizEnergetic neutral particles entering the analyzer are ionized by stripping in a thin carbon foil. The energy and mass ed by stripping in a thin carbon foil. The energy and mass of secondary ions are resolved by a combination of magnof secondary ions are resolved by a combination of magnetic and electrostatic fields (E//B type). Secondary ions aetic and electrostatic fields (E//B type). Secondary ions are measured with detectors consisting of CsI(Tl) scintillatre measured with detectors consisting of CsI(Tl) scintillators each connected to a photomultiplier tube (PMT).ors each connected to a photomultiplier tube (PMT).

http://www-jt60.naka.jaeri.go.jp/diag/html/diag_35.html

Tangential analyzerVertical analyzer

Visible spectrometerVisible spectrometer [Objectives][Objectives]

To observe spectral lines, bandTo observe spectral lines, bands and their spatial profile for sts and their spatial profile for study of atomic and molecular prudy of atomic and molecular processes in the divertor plasmaocesses in the divertor plasmas.s.

[Diagnostic method][Diagnostic method]Emission collimated with lenseEmission collimated with lenses is transmitted through 16 opts is transmitted through 16 optical fibers from the torus hall to ical fibers from the torus hall to a diagnostic room. The light froa diagnostic room. The light from the optical fibers is dispersem the optical fibers is dispersed with the spectrometer and thd with the spectrometer and the image-intensified CCD camere image-intensified CCD camera observes the image of the fiba observes the image of the fibers.ers.

http://www-jt60.naka.jaeri.go.jp/diag/html/diag_30.html

X-ray Crystal spectrometerX-ray Crystal spectrometer

X-ray emitted from the shaded area of the plasma pass through beryllium window into a helium-filled tube and are Bragg reflected by the crystal onto the position-sensitive detector. Photons of different energies are focused to different detector points

3D view of the x-ray imaging 3D view of the x-ray imaging crystal imaging spectrometercrystal imaging spectrometer

Horizontal XCS : the ion and electron temperature profiles

Vertical XCS : spatial resolution in horizontal mid-plane of the KSTAR tokamak, the toroidal plasma rotation velocity

Position Sensitive Detector for Position Sensitive Detector for X-ray Crystal spectrometerX-ray Crystal spectrometer

Spatial resolution : 0.5 mmOperating Voltage : 3350 VWindow : Be 0.1 mm

Performance test at Alcator C-Mod tPerformance test at Alcator C-Mod tokamak(MIT)okamak(MIT)

The measured photon count rate vs time.*ICRH(ion cyclotron resonance heating)

A spatially resolved image ofHelium-like argon lines

2 segmented detector2 segmented detector

Electronics

Electronics

800 k count/s

Plan for futurePlan for future

ElectronicsElectronics 는 는 Trigger Trigger 신호에 의해 신호에 의해 동작되므로 두 개 이상 독립된 시스템 동작되므로 두 개 이상 독립된 시스템 가능하다 따라서가능하다 따라서 , , 하나의 검출기에 하나의 검출기에 독립된 두개 이상의 검출 영역을 두어 한계 독립된 두개 이상의 검출 영역을 두어 한계 계수율의 제한을 높이려 한다계수율의 제한을 높이려 한다 ..

최적의 검출기 센서 영역의 패턴을 찾아 최적의 검출기 센서 영역의 패턴을 찾아 0.0.3 mm 3 mm 이하의 분해능이 되도록 한다이하의 분해능이 되도록 한다 ..