Plasma Diagnostics

Thomas J. Dolan

ASIPP, Hefei, China 2011

American Nuclear Society Speakers Bureau

dolan asipp 2011 1 Topics Goals Electric Probes Magnetic Probes Passive Particle Methods Deposition Diagnostics Active Particle Methods Passive Wave Methods visible, ultraviolet, x-ray Active Wave Methods ITER diagnostics

dolan asipp 2011 2 Goals of Diagnostics

space-time mapping n

f(vi) or Ti f(ve) or Te J, B, E Impurity concentrations Rotation velocity Plasma waves MHD instabilities Turbulence & microinstabilities Redundancy: 2-3 techniques Accuracy: a few percent.

dolan asipp 2011 3 Goals of Diagnostics

Resolution Tokamaks: 1 cm 0 . 1 ms Inertial: 1 m 10 ps

Fourier analysis of waves (, k) Improved signal-to-noise ratios Optical filters Modulation of incident beam Statistical methods of error analysis Computer graphics displays

dolan asipp 2011 4 Electrical Probes

dolan asipp 2011 5 Flexible Bellows for Probe Insertion

from Hutchinson, 1987 dolan asipp 2011 6 Langmuir Probe Tip

from Hutchinson, 1987

dolan asipp 2011 7 Langmuir Probe

dolan asipp 2011 8 Langmuir Probe Data

In exponential region ln(I2/I1) = e(2 –1)/kTe  Te

Ion saturation current Ii 1/2 1/2 -3 ni = 171.7 Ii mi /[Ape(kTe) ]m] m

dolan asipp 2011 9 Electric Probes

Multiple probes  voltages at different points  E field an d res is tiv ity.

Probe disturbs the local ppplasma parameters.

Double probe reduces the error.

dolan asipp 2011 10 Floating Double Probe

dolan asipp 2011 11 Electric Probes

• Resonance probe has rf voltage applied to couple w ith p lasma waves

• Fluctuations of n and f  information on turbulence (k, , …)

• Probe may melt if plasma temperature high

• Reciprocating probes enter and leave in ms.

dolan asipp 2011 12 Magnetic Probes

dolan asipp 2011 13 Toroidal and Poloidal Magnetic Field Components

dolan asipp 2011 14 Toroidal and Poloidal Angles

dolan asipp 2011 15 Poloidal Mode Numbers

m = 0 m = 1 m = 2

dolan asipp 2011 16 Toroidal Mode Numbers

dolan asipp 2011 17 Coil to Measure the Magnetic Field Maxwell equation

N-turn coil

 = NAc ( B / t)

from Hutchinson, 1987

dolan asipp 2011 18 Magnetic Field Measuring Coils

C1  dBt/dt

Roggpowski loop:

C2  dBp/dt

C3  dBv/dt

C4  dBp/dt at various   mode numbers (m/n)

C5  dB/dt inside plasma (perturb plasma; may melt, impurities) dolan asipp 2011 19 Poloidal Field Measurements

from Hutchinson, 1987 dolan asipp 2011 20 Measuringgp Fourier Components of Waves

from Hutchinson, 1987 dolan asipp 2011 21 Evolution of Plasma Boundary Shape

from Hutchinson, 1987 dolan asipp 2011 22 Internal Magnetic Field Probes

from Hutchinson, 1987 dolan asipp 2011 23 Poloidal Magnetic Field Profile vs. Time

from Hutchinson, 1987 dolan asipp 2011 24 Magnetic Flux Surfaces from Internal Magnetic Field Probe Measurements

from Hutchinson, 1987 dolan asipp 2011 25 Toroidal Current Density from measurements of magnetic field

J = ∇xB/o

dolan asipp 2011 from Hutchinson, 1987 26 Pressure Profile from Magnetic Field Data

from Hutchinson, 1987 dolan asipp 2011 27 Passive Particle Diagnostics

dolan asipp 2011 28 Gridded Energy Analyzer

from Hutchinson, 1987 dolan asipp 2011 29 Gridded Energy Analyzer Data

b

dolan asipp 2011 30 Sensitive Ion Detector Ions  secondary electrons  photons  photoelectrons  more secondary electrons.

dolan asipp 2011 31 Neutral Atom Energy Analyzer

Ionization Deflection by magnet Deflection by electrodes

Analysis  f(vn) Calibrate using known neutral beam energies.

dolan asipp 2011 32 Fast Neutral Atom Spectrum

from Hutchinson, 1987 dolan asipp 2011 33 Fast Neutral Spectrum with Neutral Beam

from Hutchinson, 1987 dolan asipp 2011 34 Fast neutral atoms in ITER

Hot, dense tokamak plasma Energy analyzer Neutral atoms

Most atoms are ionized before escaping. Atoms near edge can reach the analyzer.

dolan asipp 2011 35 Neutron Production

• Thermonuclear (high-Ti plasma) – JET, TFTR

• Beam-plasma interactions -- TFTR

• Plasma instabilities – Zeta toroidal pinch (1950s)

• Ions bombarding surfaces

• Runaway electrons

• Gamma ray impact

• CiCosmic rays

dolan asipp 2011 36 Fusion Reaction Rate vs.Temperature

from Hutchinson, 1987 dolan asipp 2011 37 Proportional Counters

Gas-filled proportional counters

dolan asipp 2011 38 Fast Neutron Energy Spectrum

Gas-filled proportional counters with CH4

Fast neutrons  recoil protons  ionization proportional to proton energy.

The neutron energy spectrum can be estimated from the ppgpulse height spectrum of the detector.

dolan asipp 2011 39 Scintillation Detector

Pulse height analysis  estimate of neutron energy spectrum

Shielding from x-rays

dolan asipp 2011 40 Foil Activation

109Ag + n  110Ag*  110Cd +  , half-life 24 s.

Number of betas detected  neutron emission rate.

No neutron energy spectrum information

Insensitive to x-rays

Useful to calibrate other detectors

Neutron detector calibration also by 252Cf.

dolan asipp 2011 41 Neutron Time-of-Flight Spectrometry  Eno Ep1 scintillator

En1

Ep2 Measure Ep1, Ep2, t

Calculate En1, Eno

Walk er, RSI 57 , 1740

dolan asipp 2011 42 Neutron Time-of-Flight Spectrometry

Peak at 14. 06 + 039MeV0.39 MeV

dolan asipp 2011Walker, RSI 57, 1740 43 Neutron Imaging in JET qa ~ 8.5 3.3

14 MeV neutrons from Triton beam injection

Simulation tracking fast ion orbits

dolan asipp 2011 JET Bulletin 060314 44 Particle Deppgosition Diagnostics

dolan asipp 2011 45 Deposition Diagnostics

Knowledge needed for materials selection mirror and window lifetime safety -- tritium and beryllium hazards

Proposed limits for ITER 10–20 k g of b erylli um dus t on ho t sur faces 100 kg for carbon dust 100–400 kg for tungsten dust

Skinner, RSI 75, 4213 (2004)

dolan asipp 2011 46 Deposition Diagnostics Eroded C, Si, O, Fe, Ni, Be, …

Characterization: particle size distribution composition quantity toxicity

Skinner, RSI 75, 4213 (2004) dolan asipp 2011 47 Deposition Diagnostics Current tokamaks ITER

Thermal energy 10 M 300 MJ

Disruptions < 1 MJ/m2 ~ 10 MJ/m2

Hours per year ~ 10 > 200

Carbon erosion < 0.3 mm/year > 10 mm/year

Car bon depositi on~ 60 m/h 50 m/day

Tritium per pulse 0.2 g 120 g

Skinner, RSI 75, 4213 (2004) dolan asipp 2011 48 Deposition Diagnostics

6 MHz quartz crystal microbalance in NSTX

Deposited hydrocarbon film  ~ 161.6 g /cm3

Skinner, RSI 75, 4213 (2004)

dolan asipp 2011 49 Deposition Diagnostics

NSTX 0.15 s discharge

Skinner, RSI 75, 4213 (2004)

dolan asipp 2011 50 Deposition Diagnostics

Grid to detect dust particles

Skinner, RSI 75 , 4213 (2004)

dolan asipp 2011 51 Deposition Diagnostics

Dust detectors in NSTX

Skinner, RSI 75, 4213 (2004) dolan asipp 2011 52 Deposition Diagnostics

Grid spacing 125 m x 381 m o 762 m

Skinner, RSI 75, 4213 (2004)

dolan asipp 2011 53 AiActive P arti ilDicle Diagnosti cs

dolan asipp 2011 54 Electron Beam Probe

Electron gun

detector

Measure  alonggpgy field lines in open magnetic systems

Beam energy loss related to plasma heating by beam

dolan asipp 2011 55 Heavy Ion Beam (HIB) Probe

Detector measures energy ++ of Tl ions  1

dolan asipp 2011 56 Potential Profile from HIB Probe

from Hutchinson, 1987 dolan asipp 2011 57 HIBP in Tuman-3M Tokamak

1 80 keV 275 3 65 4 60 555 645 7 40

1’, 2’, 3’, 4’ denote poloidal variations of injection angle

dolan asipp 2011 58 HIBP in TJ-II Stellarator, Spain

Multiple Cell Array Detector

dolan asipp 2011 59 Neutral Atom Beam Probes

Attenua tion: UftiUse of two ion speci es  ne andTd Te.

Scattering: Beam atoms (mass mb) scattered by cold gas, maximum angle = Arcsin(mi/mb) In hot plasma, larger scattering angles  estimate of Ti.

Charge exchange: beam enhances cx losses of hot plasma ions.

Spectroscopy: Analyze light caused by neutral beam as it passes through plasma  local ne and B.

dolan asipp 2011 60 Charge Exchange Recombination Spectroscopy (CXRS)

Heidbrink PPCF 46, 1855 (2004) dolan asipp 2011 61 CXRS Doppler-shifted photon

area under curve --> relative ion density

Courtesy of D. J. Den Hartog dolan asipp 2011 62

Quartz fibers heated to prevent browning during DT operation

Hillis, RSI 75, 3449 (2004)

dolan asipp 2011 63 Charge Exchange Recombination Spectroscopy

Viewing optics see ions moving both down (red shift) and up (blue shift). 80 keV deuterons in DIII-D. Heidbrink PPCF 46, 1855 (2004) dolan asipp 2011 64 Charge Exchange Recombination Spectroscopy

Re-neutralized 80 keV D+ beam ions in DIII-D

D light

o = 656.1 nm Doppler shift ~ 4 nm Stark splitting < 1 nm

Heidbrink PPCF 46, 1855 (2004) dolan asipp 2011 65 CXRS in DIII-D CVI

B2TB = 2 T

n ~ 2x1019 m-3

8.8 MW NBI

tangential

vertical

Burre ll, RSI 75 , 3455 (2004)

dolan asipp 2011 66 CXRS in DIII-D Edge Localized MdMode (ELM) at t = 3152 ms

Burre ll, RSI 75 , 3455 (2004)

dolan asipp 2011 67 Helium Ash Measurement in JET

5% He injected

Hillis, RSI 75 , 3449 (2004)

dolan asipp 2011 68 McKee HTPD 2006 dolanDRAFT: asipp not 2011 for transmission 69 McKee HTPD 2006 dolanDRAFT: asipp not2011 for transmission 70 McKee HTPD 2006 dolanDRAFT: asipp not2011 for transmission 71 McKee HTPD 2006 dolanDRAFT: asipp not2011 for transmission 72 McKee HTPD 2006 dolanDRAFT: asipp not2011 for transmission 73 McKee HTPD 2006 dolanDRAFT: asipp not2011 for transmission 74 McKee HTPD 2006 dolanDRAFT: asipp not2011 for transmission 75 McKee HTPD 2006 dolanDRAFT: asipp not2011 for transmission 76 McKee HTPD 2006 dolanDRAFT: asipp not 2011 for transmission 77 McKee HTPD 2006 dolanDRAFT: asipp not2011 for transmission 78 Lithium Beam Probe Zeeman Effect

from Hutchinson, 1987 dolan asipp 2011 79 Motional Stark Effect (MSE) diagnostic  |B|

•H atom beam is excited and radiates H0  e-  H0  H0  h

plasma

0 h • H electron energy levels are split by motional E = vbeam x B

n = 3

n = 2

Measure f ull Stark spectru m – Assume statistical population of excited levels – Derive local |B| to 2% precision

dolan asipp 2011 81

• For most fusion research devices, E = vbeam  B is large (~ 10 MV/m) –  and  components can be isolated – polarimetry of the direction of the component emission gives the magnetic field pitch angle

TFTR F. M. Levinton, Rev. Sci. Instrum. 70, 810 (1999)

dolan asipp 2011 82

Malaquias, RSI 75, 3393 (2004) dolan asipp 2011 83 Calculated Spectra from DNB

Malaquias, RSI 75, 3393 (2004) dolan asipp 2011 84 Rutherford scattering  D+ temperature

He beam atoms scattered by plasma ions

He D Energy spectrum of scattered Ti = 153 ± 17 eV He atoms  Ti and vi rb) signal (a

energy/(beam energy)

dolan asipp 2011 85

dolan asipp 2011 86 Photography of Plasma Light

Electrostatic-Inertial Plasma Confinement

dolan asipp 2011University of Illinois, 1967 87 Imaging in MAST

Photograph of ELM.

Preceding frame subtrac ted to eliminate backggground light.

Carolan, RSI 75 , 4069 (2004)

dolan asipp 2011 88 Infrared photography in JET

dolan asipp 2011 89 Bolometer Arrays in JET

dolan asipp 2011 90 JET Bolometer Images

From S. Hacquim, FZK Summer School 2008

dolan asipp 2011 91 Streak Camera

dolan asipp 2011 92 Image Converter Camera

High voltage pulse switches camera on for 0.1 s. Fluorescent screen continues to glow.

dolan asipp 2011 93 Spectroscopic Analysis of Hydrogen • Measure absolute intensity of H (656.28 nm) or H (486.13 nm) with monochromator or filter & detector • Calibrate with tungsten lamp of known intensity • Spatial resolution: collimator with fiber optics or rotating mirror. • Scan several chords, then invert to estimate radial profile. • Bright light from plasma edge makes interior measurements inaccurate.

dolan asipp 2011 94 Spectrum for Zeff Measurement

from Hutchinson, 1987 dolan asipp 2011 95 Impurity Radiation

 < 185 nm ultraviolet radiaton absorbed by air “vacuum ultraviolet (()pVUV) spectrosco py”

Scan wavelengths by rotatihing the grat ing

Tilt device at entrance bellows to study other positions in plasma.

dolan asipp 2011 96 Impurity Concentrations AbltAbsolute i itntensiti es of i mpurit y li nes (O++ , F e+++ , et c.)

Branching ratio method of calibration: Measure visible line and vuv line from the same upper energy level, such as transitions from n=6 to n=2 and n=1 levels (410. 2 and 93. 7 nm in hydrogen).

The intensity ratio of the two lines should equal the ratio of their transition probabilities, 0.606 for example case.

Uncertainty of branching ratio method ~ + 50%.

dolan asipp 2011 97 Oxygen Charg e State vs. Temperature

from Hutchinson, 1987 dolan asipp 2011 98 Oxygen Ionization States vs. Radius

Measure along chords, Unfold radial profiles.

Tokamak data for oxygen.

OIII means O++

dolan asipp 2011 99 Spectral Line Broadening • Instrumental broadening – entrance and exit slits

• DlbdiDoppler broadening – motion o f at om:  = o(1 + vx/)/c)

• Stark broadening – charged particle interactions  E fields  splitting of energy levels

• Zeeman effect – Magnetic field  sppglitting of atomic ener gy levels.

dolan asipp 2011 100 Spectral Line Shapes

Unbroadened Doppler Stark Stark Holtzmark profiles

dolan asipp 2011 101 Ion Temperature Profile from Doppler Broadening

from Hutchinson, 1987 dolan asipp 2011 102 Spectral Line Intensities

Absolute intensities  particle densities.

Ratios of spectral line intensities from one

kind of atom Te.

Bolometer (foil heated by plasma radiation) tttemperature  ttltotal radi ditiation power

dolan asipp 2011 103 X-ray Specta

dolan asipp 2011 104 X-ray Spectra vs. Temperature

Bremsstrahlung  continuum

Peak at h ~ 2 Te

Electron impact ejection of inner shell electron  discrete spectral lines.

dolan asipp 2011 105 Foil Attenuation of X-ray Intensity Pb Foil 1 collimator DtDetec tor 1

Detector 2

Foil 2 plasma

Different thickness foils with 2 co llima te d de tec tors.

Intensity ratios  Te (x,t)

dolan asipp 2011 106 X-ray Spectrum with High-Energy Tail Caused by RF Current Drive

from Hutchinson, 1987 dolan asipp 2011 107 X-ray Emission Spectrum

from Hutchinson, 1987 dolan asipp 2011 108 Hard X-ray Measurements

Electron cyyggclotron resonance heating and rf heating  very hot electrons  hard x-rays (> 0.1 MeV)

Runaway electrons  hard x-rays

NaI scintillation detectors  information about runaway eltlectrons or wave htiheating con ditions.

dolan asipp 2011 109 Electron Cyclotron Emission (ECE)

dolan asipp 2011 110 Electron Cyclotron Emission Imaging

 = eB/2me Measure f()  f(B)  f(R)

Park, RSI 75, 3787 (2004) dolan asipp 2011 111 Electron Cyclotron Emission

Electron cyclotron emission

ce = 28 B N (GHz), where N = 1,2,3, …

In tokamaks B t(R) = BoRo/R

ce varies with R Each frequency corresponds to a particular R.

dolan asipp 2011 112 Electron Cyclotron Emission

Second harmonic intensity I(,R) = 2(R)T(R)/83c2  T(R) = 83c2I(,R)/2(R)

Microwave measurements or Far-infrared (FIR) spectroscopy (for exampl e usi ng quart z wi nd ows, I nSb de tec tors )

dolan asipp 2011 113 Electron Temperature Profile vs. Time from Electron Cyclotron Emission

dolan asipp 2011 from Hutchinson, 1987 114 Two Intersecting Lines of Sight

Correlation of ECE waves 

fluctuations of Te in intersection volume V.

Watts, RSI 75, 3177 (2004)

dolan asipp 2011 115 One Line of Sight

Correlation of signals at two frequencies  Te fluctuations

Both methods compared in W7 -AS stellarator.

Watts,,,() RSI 75, 3177 (2004)

dolan asipp 2011 116 W7-AS ECE Radiometer Antennas

Watts, RSI 75, 3177 (2004)

dolan asipp 2011 117 Comparison of Two Methods

Watts, RSI 75, 3177 (2004) dolan asipp 2011 118 SftXSoft X-RTRay Tomograph y

dolan asipp 2011 119 Viewing Angles for Soft X-ray Tomography

dolan asipp 2011 120 Diode Housing and Preamplifier

dolan asipp 2011 121 Silicon Diode Array for Soft X-ray Tomography

12 PIN diodes

dolanUniversity asipp 2011 of Missouri-Rolla 122 Soft X-ray Tomography Data

Missouri Magnetic Mirror plasma, 1 kW microwave power

dolan asipp 2011 123 Soft X-ray Tomography

from Hutchinson, 1987 dolan asipp 2011 124 Active Wave Diagnostics

dolan asipp 2011 125 Active Wave Proceses

refraction

dolan asipp 2011 126 Active Wave Techniques

• Wave transmission & attenuation • Wave reflection • Resonant cavity • Refractive index • PlPolar iza tion • Wave scattering • Fluorescence

dolan asipp 2011 127 Reflection of Electromagnetic Waves 2 2 Wave cutoff when  < pe CtffdCutoff densit y 

If plasma column is moving, reflected microwaves will be Doppler shifted  plasma position and motion. Useful for feedback control.

dolan asipp 2011 128 Microwave Imaging and Reflectometry (MIR)

TEXTOR

Combination of ECEI and MIR  ne, Te andfld fluc tuati ons Park, RSI 75, 3787 (2004) dolan asipp 2011 129 Microwave Imaging and Reflectometry

Teo

Te(R,Z) images at different times during crash.

White lines indicate q=1 surface.

Park, RSI 75 , 3787 (2004)

dolan asipp 2011 130 LHD Radar Reflectometer for measuring density profile and fluctuation in the edge region

4ch(33,39,60,65GHz) heterodyne system ＃34676 (35s discharge)

Green : Launched Pulses Pulse width : 2 ns (typical) Repetition rate : 200 kHz (typical) Yellow : 39GHz TOF resolution : 50 ps (=7 .5mm) Blue : 33GHz Red : 60GHz dolan asipp 2011 Reflected Pulse131 Courtesy of Prof. K. Kawahata, NIFS Refractive Index Measurements Cutoff density

1/2 Refractive index Ñ = kc/=(1= (1 – n/nc) ℓ Phase of wave (x) = ∫ dx k(x) 0 ℓ 1/2  = (plasma) – (vacuum) = (/c) ∫ dx[1 – (1-n/nc) ] 0 ℓ if n/nc << 1, ≈ (/2cnc) ∫ dx n 0

dolan asipp 2011 132 Microwave Interferometer

I/Imax    n

dolan asipp 2011 133 Abel Inversion

Convert chord data F(h) to radial profiles F(r).

Assuming symmetry in the  direction

= 

dolan asipp 2011 134 Mach-Zehnder Laser Interferometer

per fringe

I/Io = 1 + k cos(1v +  – 2)

Problem of interppgreting cosine function to measure . dolan asipp 2011 135 Quadrature Interferometer

Wollaston prism

Two detectors

Quarter-wave plate Quarter-wave plate converts linearly-polarized wave into circularly polarized. Wollaston prism splits combined beam into I1 and I2, which are 90º out of phase .

dolan asipp 2011 136 Quadrature Interferometers

Two beams 90º out of phase.

where n = integer.

 can be interpreted unambiguously.

dolan asipp 2011 137 Far Infrared (FIR) Interferometers

FIR  = 10 to 1000 m, more sensitive to low ne.

Feedback stabilization: laser mirror electromechanically moved to compensate for its vibrations (Or use two wavelengths) .

Reference beam modulation: Oscillating mirror produces fringe pattern in detector, which is shifted by plasma. facilitates phase-shift sensitivity ~ 0.05 fringe.

dolan asipp 2011 138 Frequency Shifting Interferometer

BtfBeat frequency ~ 10-1000 kHz

TFR tokamak system

Phase shift  determined from measurement of t.

dolan asipp 2011 139 Large Helical Device (LHD)

dolan asipp 2011 140 Courtesy of Prof. K. Kawahata, NIFS Long Pulse Experiment Sustained by NBI

Two-color CO2 Laser Interferometer

ne(R) #17311 2.0

)

m 1 . 5

 1.0

(

n 0 . 5

0.0 NBI (m) t (s R t(t (secec) )

dolan asipp 2011 141 Courtesy of Prof. K. Kawahata, NIFS FIR Laser Interferometer 13 channels, 50mm beam width, 1sec time resolution, 1/100 fr inge ph ase resol uti on.

FIR Laser Interferometer mounted on an anti-vibration frame.

dolan asipp 2011 142 Courtesy of Prof. K. Kawahata, NIFS LHD FIR Interferometer Data

Time evolution of

the ne profile in case ofif ice pell lltet injection.

K. K. Kawahata, K. Tanaka, A. Ejiri, Y. Ito , T. Tokuzawa

dolan asipp 2011 143 Laser Fluorescence Measurement

Tunable dye laser excites an upper energy level, such as

H ( = 656.3 nm).

from Hutchinson, 1987

dolan asipp 2011 144 Faraday Rotation Measurement of B

10 kHz

Amplifier output signal:

Computer analysis  Bp(r).

dolan asipp 2011 145 Textor Faraday Rotation Data

From rotation angle Computer analysis

Bp(r) and J(r).

from Hutchinson, 1987 dolan asipp 2011 146 Heterodyne Faraday Rotation System

Two laser beams, different frequencies. Both pass through plasma.

Measures ne and p Simultaneously.

from Hutchinson, 1987 dolan asipp 2011 147 LHD Polarimetry for Density Measurements

Faraday effect Helical system：Accurate B// can be calculated numerically. e32 L   n B dz  2 2 3 e // 8 0me c 0 ne measurement

CO2 laser （wavelength 10.6 m） was selected. A tangential 3- 1 # 26088 ch1 channel CO2 laser 0.8 Time constant of ch2 0.6 lock-in amplifier of 10 ms ch3 polarimeter has 0.4 been developed, day Rotation ngle (deg.) 020.2 aa AA and as a result , 0 Far Measured with FIR interferometer Faraday rotation )

-3 4 angle is measured m d Density 19 ee 2 with high reliability & resolution. (×10

Averag 0 dolan asipp 2011 148 0 10 20 30 T.Akiyama, S. Iio Time (s) Courtesy of Prof. K. Kawahata, NIFS Thomson Scattering of Laser Light

dolan asipp 2011 149 Thomson Scattering of laser beam

Ruby laser 10 J 20 ns 500 MW

Minimize stray light noise.

dolan asipp 2011 from Hutchinson, 1987 150 Scattered Light Spectra

Ps/Po  ne o = 694.3 nm

Spectrum  Te

dolan asipp 2011 151 Multipoint Thomson Scattering

76 spatial channels 20 wavelength channels

dolan asipp 2011 152 Thomson Scattering Profiles of Electron DitdTDensity and Tempera ture

Te ne

From TFR tokamak.

dolan asipp 2011 153 dolan asipp 2011 154 Hatae, LAPD-2005C dolan asipp 2011 Hatae, LAPD-2005155 dolan asipp 2011 Hatae, LAPD-2005 156 dolan asipp 2011 157 Hatae, LAPD-2005 dolan asipp 2011 Hatae, LAPD-2005158 dolan asipp 2011 Hatae, LAPD-2005159 Edggge Pedestal Diagnostics

Profiles Thomson, CER, reflectometry, ECE Neutral Profile D with modeling

Er CER, Doppler reflectometry Turbulence Microwave scattering, beam emission spectroscopy (BES) MHD equilibrium Magnetic probes J(r) Li beam polarimetry ELMs Maggp,,netic probes, BES, reflectometr y soft x-rays

Leonard , RSI 75 , 3780 (2004)

dolan asipp 2011 160 Edge Pedestal Measurements

CX-Recombination JT60-U Spectroscopy

Leonard, RSI 75, 3780 (2004)

dolan asipp 2011 161 Edge Pedestal Measurements

DIII-D

Leonard, RSI 75, 3780 (2004) dolan asipp 2011 162 Imaging in MAST

Thomson scattering data showing a bump outside the separatrix sometimes observed during an ELM.

Carolan,,,() RSI 75, 4069 (2004)

dolan asipp 2011 163 Small-Angle Photon Scattering

Gives inf orm ati on about wave number spectrum S(k).

Can also be related to Ti, but impurities make interpretation difficult.

from Hutchinson, 1987 dolan asipp 2011 164 Turbulence Measurements

DIII-D diagnostics phase conjugate imaging beam emission spectroscopy

Inst abiliti es

Rhodes IAEA-2004

dolan asipp 2011 165 Turbulence Measurements in DIII-D

Rhodes IAEA-2004 dolan asipp 2011 166 Turbulence Measurements

Far Infrared (FIR) f = 288 GHz Forward scattering angles + 1º probes long- turbulence k = 0-2 cm-1. Forward scattering 8-15º probes medium- turbulence k=8k = 8-15 cm -1

Microwaves 94 GHz wave backscatter (180º) probes short- turbulence k = 30-40 cm-1 k resolution ~+ 1cm1 cm-1

Rhodes IAEA-2004 dolan asipp 2011 167 Turbulence Measurements

k kr k 

Rhodes IAEA -2004

dolan asipp 2011 168 dolan asipp 2011 Rhodes, APS169 2005 Summary of Techniques Available to Measure Each Plasma Parameter

dolan asipp 2011 170 Measurements of E and B B Field E and  • magnetic flux • electrical probes • microwave harmonics • plasma conductivity • Zeeman effect (V-I measurements) • heavy-ion beam probe • heavy-ion beam probe • neutral beam probe • electron beam probe • Faraday rotation (weak magnetic field) • Motional Stark Effect (MSE) • Stark effect •plidlasma impedance (applied oscillating E)

dolan asipp 2011 171 Electron or Ion Density Measurement

Langmuir probe rf conductivity probes microwave, FIR, & optical interferometers reflectometry microwave cavity resonance heavy-ion beam probe neutral atom beam probe Stark broadening holographic interferometry Thomson scattering Alfven wave & sound wave propagation photography

dolan asipp 2011 172 Velocity Distribution or Temperature

Electrons Ions Gridded analyzers neutral atom energy analyzer Thomson scattering Doppler broadening heavy-ion beam probe neutron emission visible & uv spectroscopy coherent Thomson scattering x-ray intensity distribution Gridded analyzers electron cyclotron emission diamagnetism spectral line intensity ratios calorimetry Langmuir probes CXRS

dolan asipp 2011 173 Flow Velocity of Plasma

Time-of-flight from probes or photography Doppler frequency shift of waves emitted Doppler shift of reflected microwaves Magnetic flux measurements Ruuanaw ayeectosay electrons fr om h adard x-ray m easur em en ts

dolan asipp 2011 174 Neutral Atoms & Impurities

Optical, UV, VUV spectroscopy, and CXRS Charge-exchange neutral analyzer Mass spectrometer Resonance absorption & scattering (light, infrared) Ion cyclotron resonance absorption Vacuum pressure gage Refractivity measurements (high density) Neutral beam probing Laser induced fluorescence

dolan asipp 2011 175 Instabilities and Turbulence magnetic flux measurements electrical probes x-ray fluctuations microwave reflection electromagggnetic wave scattering (microwaves and FIR) heavy-ion beam probe electron cyclotron emission photography of plasma shape plasma resistivity (external V—I measurements) neutron energy spectrum and isotropy CXRS

dolan asipp 2011 176 International Thermonuclear Experimental Reactor (ITER) Diagnostics

dolan asipp 2011 177 ITER Oppgerating Phases

H Phase – study plasma stability & transport , heat flux, divertor, runaway electrons, electromagnetic loads, diagnostics. ~ 3 years

D Phase – deuterium operations, nuclear reactions, small amounts of tritium, shielding performance. ~ 1 year

DT Phase – full fusion power operation, non-inductive steady-state current drive, long-term burn, blanket module testing, high-heat-flux and neutron fluence testing. many years

dolan asipp 2011 178 ITER H Phase Diagnostics Magnetic Diagnostics Vessel Wall Sensors, Divertor Magnetics, Continuous Rogowski Coils, Diamagnetic Loop

Neutron Diagnostics Radial Neutron Camera, Vertical Neutron Camera Micro-fission Chambers (In-Vessel) (N/C) Neutron Flux Monitors Gamma-Ray Spectrometer Activation System (In-Vessel), Lost Alpha Detectors Knock-on Tail Neutron Spectrometer (N/C)

Bolometric Systems Arrays for Main Plasma, Arrays for Divertor dolan asipp 2011 179 ITER H Phase Diagnostics

Spectroscopic and Neutral Particle Analyzer Systems

H Alpha Spectroscopy, Visible Continuum Array Main Plasma and Divertor Imppyurity Monitors XRay Crystal Spectrometers Charge eXchange Recombination Spectroscopy (CXRS) based on diagnostic neutral beam Motional Stark Effect (MSE) based on heating beam Soft X-Ray Array NtlPtilAlNeutral Particle Analyzers (NPA) Laser Induced Fluorescence

dolan asipp 2011 180 ITER H Phase Diagnostics

Optical/IR(Infra-Red) Systems Thomson Scattering Core Edge X-Point Divertor Toroidal Interferometer/ Polarimeter Polarimeter(Poloidal Field Measurement) Collective Scattering System (N/C) Penetrations

Diagnostic Neutral Beam

dolan asipp 2011 181 ITER H Phase Diagnostics

Microwave Diagnostics Electron Cyclotron Emission (ECE) EC a bsorp tion (ECA), Plasma Reflectometers low field side X-mode and O-mode Plasma Position Reflectometer Divertor Reflectometer Main Plasma Microwave Scattering Fast Wave Reflectometry

Plasma-Facing Components & Operational Diagnostics IR/Vis ible Cameras, Thermocoup les, Pressure Gauges Residual Gas Analyzers, IR Thermography (Divertor), Langmuir Probes

dolan asipp 2011 182 ITER Upper Diagnostics

dolan asipp 2011 183 ITER Midplane Diagnostics

dolan asipp 2011 184 ITER Divertor Diagnostics

dolan asipp 2011 185 ITER Vacuum Ultraviolet (VUV) Port

dolan asipp 2011 186 ITER Divertor Diagnostics

dolan asipp 2011 187 ITER Magnetic Loops

dolan asipp 2011 188 ITER Neutron Cameras

Each array is at a different toroidal location.

dolan asipp 2011 189 Thomson Scattering, Upper Port Plasma facing mirror: radiation damage and dust problems. Rh on V substrate

dolan asipp 2011 190 Polarimeter, Top View  =106and93= 10.6 and 9.3 m

dolan asipp 2011 191 ITER Toroidal Polarimeter

 = 10.6 m and 9.27 m Opto-acoustic modulators  Intermediate freqqyuency =10 MHz

Measure ne and Faraday rotation simultaneously

10 W commercial sealed CO2 lasers

ZSZnSe wi idndows  rottitation of pol ari zati on Diamond windows  much less rotation  better accuracy, but veryyp expensive

Kondoh, RSI 75, 3420 (2004) dolan asipp 2011 192 ITER Toroidal Polarimeter

rot ~ 20º

Kondoh, RSI 75, 3420 (2004) dolan asipp 2011 193 Spectroscopy and Neutral Particle Analysis

dolan asipp 2011 194 Diagnostic Neutral Beams

Measure nHe(r), nc(r), nBe(r) dolan asipp 2011 195 ECE Path Prevents Neutron Streaming

dolan asipp 2011 196 ITER Diagnostics Issues

Lifetime of in-vessel magnetic and electrostatic probes Radiation-induced and thermoelectric voltages Changes of properties (resistivity, transparency, …) Overheating Thermal stresses Neutron streaming Rapid replacement of damaged items Damaggpe to plasma-facing mirrors: bombardment & dust Diagnostic neutral beam

dolan asipp 2011 197 Summary Several techniques for each parameter

Good spatial and time resolution

ITER : great diagnostics, limited by available ports space around outside budget

Better understanding of stability and transport ______

dolan asipp 2011 198 EXTRA SLIDES

dolan asipp 2011 199 References - Diagnostics

dolan asipp 2011 200 Heat Wave Damping by ITB ICRF deposited at R = 3.0 and 3.6 m

Internal Transport Barrier (ITB) atRt R ~ 3 335.35 m

Heat wave amplitude (red squares) Phase lag (blue circles)

JET Bulletin 060314 dolan asipp 2011 201 dolan asipp 2011 202 Hatae, LAPD-2005 dolan asipp 2011 Hatae, LAPD-2005203 Hollow profiles during off-axis ECRH

• During application of off-axis ECRH + NBI + ohmic ECRH (140 GHz, 800 kW) in ECRH + ohmic TEXTOR plasmas (2.34 T, Ohmic 19 -3 2.5×10 m ), hollow Te profiles are es ta blis he d a fter some time

• What i s th e und er ly ing mechanism?

ECRH deposition zone indicated in red

dolan asipp 2011 204 10 kHz intra-cavityyy system

5 Pumping power, MW rear mirror 4 3 2 Pkl’llPockels’ cell 1 0 polarizer 30 Inversion, J 20 ruby 10 0 20 Probing energy, J telescope 15 10 18 m 5 0 0123456 t, ms Simulation: TEXTOR plasma balance between inversion rise time and pulse energy is essential for flat probing pulse energy distribution spherical mirror dolan asipp 2011 205 Fast detection system

rear mirror Littrow polychromator Full chord TS: -450 mm < z < +450 mm Pkl’llPockels’ cell spatia l reso lu tion 7. 5 mm

polarizer 50 eV < Te< 5 keV Edge TS: +340 mm < z < +500 mm ruby spatial resolution 1. 7 mm

5 eV < Te < 500 eV telescope 18 m mm 00

90 TEXTOR plasma

spherical mirror dolan asipp 2011 206

Fast detector Motivation

Dynamics of plasma phenomena: • MHD modes • Internal transport barriers • Edge and DED induced phenomena

Measurement of former TEXTOR TS system, showing m= 2 islands. Spatial resolution 7.5 mm 10kHz high spatial resolution Thomson scattering system

• Fast repetitive high power laser R r • Fast detection system

• Core and edge viewing system

dolan asipp 2011 207 Detector Gen III image intensifier Effective QE ~ 27% for 580-850 nm, P46 Phosphor. Photon gain setting: 235 generation III 3 proximity intensifier focused ultra-fast CMOS Stack of 3 proximity focused intensifiers intensifiers camera 512384 Present photon gain: 200 px (in summer 2005 enhanced to 660)

Two Phantom V7.0 CMOS cameras Frame: 512×384 pixels (22 m2) @10.9 kfps effective dynamic range 10.2 bit

beam splitter fiber optics F=50 mm/0.75 Sensitivity per photo electron (Gen III) isolation F=110 mm/2.0 Q = 110 cnts/pe per spatial channel

photons pe Ne N_photons photons e N_photons

photo cathode MCP Phosphor photo cathode Phosphor An image intensifier Proximity focused intensifier dolan asipp 2011 208 system MPTS SYSTEM

dolan asipp 2011 209 CMOS Camera

(complementary metal oxide semiconductor)

1. Frame: 512×384 pixels (22 m2) @10.9 kfps

2. Inversed sensitivityyp: 50 photons/cnt

3. Pixel to pixel cross talk (blooming) 10-5

4. Image-to-image cross talk is smaller than 2 %, only when bias illumination of chip is applied.

Effective dynamic range goes from 10 .2 to 9 .5 bit

dolan asipp 2011 210 Typical ima ge/s pectrum

Z = 450 mm

Z = 0 mm

Z = - 450 mm

694, 3 nm 587, 56 nm

dolan asipp 2011 211 Summary of performance

Laser system Core system • ppgyulse energy 10-15 J • -450 mm < z < 450 mm • pulse width at FWHM 1 s • spatial resolution 7.5 mm • rep. rate 5 kHz ( 10 kHz) • 50 eV < Te < 5 keV • Number of pulses > 20 • accuracy < 8% in Te, <4% in ne @ 19 -3 • burst length > 3 ms ne~2.510 m • divergence  0.7 mrad • number of bursts 1 ( 3) Edge system • 340 mm < z < 500 mm Detector • spatial resolution 1.7 mm • Overall transmission till first • 5 eV < Te < 500 eV photocathode 0.15 • accuracy < 8% in Te, <4% in ne @ 19 -3 • Effective quantum efficiency 0.27 ne~10 m • 2 × 10.9 kframes/s • On-board memory > 3 kframes dolan asipp 2011 212 Hollow profiles

• Detailed temperature evolution after ECRH switch-on is measured by MPTS on a shot- to-shot basis

• Hollow profiles are established ~15-20 ms after switch-on

• Can the hollowness be attributed to a net heat sink in the core (e-i exchange being larger than the local ohmic Times of MPTS are indicated power density)? along x-axis

dolan asipp 2011 213 Internal transport barrier

• In T-10 and more recent 1.1.66 #32913 T also in TEXTOR it is e-in 1.4 20ms T observed that after e-out r=3cm eV)

kk 121.2

switching off off-axis (

ECE T ECRH, the central Te 1.0 r=11cm

stays constant for some ECRH time before it starts to 080.8 520 560 600 640 680 decrease Time (ms)

• Can this effect be attributed to a transient internal transport barrier?

See K. Razumova, A.J.H. Donné, et al., Nucl. Fusion 44 (2004) 1067 dolan asipp 2011 214 Countour plot

Analysis of data is on-going, but Switch-off is difficult because TS doesn’t see the very plasma core. Data can be either explained by:

- Low e in whole plasma core - Local transport barrier near the position offf former heating (~ q=1 surface)

dolan asipp 2011 215