UG – Diagnostics

Diagnostics Systems

DIII-D is presently equipped with the most comprehensive diagnostic set of any magnetic fusion facility in the world, providing extensive coverage of essential parameters with sufficient resolution for detailed fusion research. The measurement of these physics parameters is key to understanding events during fusion reactions and producing breakthroughs in fusion development and control. The diagnostic set assembled on DIII-D is the result of many fruitful collaborations among national and international partners. Developing and fielding a diagnostic on DIII-D remains a key involvement for many research groups, especially those from universities; offers the capability to participate directly in experiments and scientific discoveries; and opens a particularly engaging and formative path for students.

In addition, the operation, development, and maintenance of these diagnostics broadly extend across institutional boundaries, with well over 100 diagnosticians working in integrated teams. Presently, the DIII-D tokamak contains more than 180 access ports, with the majority dedicated to diagnostic use.

Successful fusion research at DIII-D requires the pursuit of three important aspects related to diagnostics:

· QUALITY of measurements, including accuracy and precise calibration

· RELIABILITY of measurements to support experiments

· COMPLETENESS of the set (in coverage, resolution, and/or parameters)

DIII-D Diagnostics Systems

To access the full list of DIII-D diagnostics and Responsible Officers, please visit DIII-D Diagnostics List 🔒.

DiagnosticSystemParametersLead Institution
Electron Temperature and DensityThomson scattering: Core9 lasers, 54 pointsGA
Electron Temperature and DensityECE Michelson interferometerHorizontal midplaneU Texas
Electron Temperature and DensityECE radiometerHorizontal midplane, 48 channelsU Texas
Electron Temperature and DensityCO2 interferometer3 vertical chords, 1 radial chordGA
Electron Temperature and DensityDensity profile reflectometerFull radial profile into SOLUCLA
Electron Temperature and DensityECE Imaging (ECEI)2D ECE emission, 2 areas, 320 channelsUC Davis
Electron Temperature and DensityMicrowave Imaging Reflectometer (MIR)2D imaging reflectometer, 48 channels (pedestal)UC Davis
Electron Temperature and DensityHe Beam Diagnostic (He Beam)18 spatial point profilesU Wisconsin
Electron Temperature and DensityFast wave interferometer/reflectometerGA
Ion Temperature, Velocity, and DensityCharge exchange recombination spectroscopy (CER)32 vertical, 44 tangential chordsGA
Ion Temperature, Velocity, and DensityMain Ion CER (MiCER)32 tangential chordsPPPL
Ion Temperature, Velocity, and DensityPassive MiCERNewPPPL
Ion Temperature, Velocity, and DensityFast ion density profile (FIDA)15 tangential chordsUCI
Ion Temperature, Velocity, and DensityImaging fast ion density profile (IFIDA)Camera viewGA
Ion Temperature, Velocity, and DensityImaging Neutral Particle Analyzers (INPA)Imaged scintillator phase‑space viewGA
Core Impurity ConcentrationVUV survey spectrometer (Core SPRED)Radial midplane viewLLNL
Core Impurity ConcentrationVisible Bremsstrahlung arrayRadial profile at midplane, 16 channelsORNL
Radiated PowerBolometer arrays2 poloidal arrays, 48 chordsGA
Radiated PowerUpper view Bolometer (UVB)1 poloidal position, 12 chordsGA
Radiated PowerFast bolometers (DISRAD II)3 poloidal arrays, 106 channelsUCSD
Radiated PowerFiber Optic Bolometer (FOB)NewORNL
Boundary DiagnosticsThomson Scattering: Divertor Subsystem1 laser, 14 channels in lower divertor[shelf], 12 channels in upper divertorGA
Boundary DiagnosticsDivertor TS 2D system (DTS‑2D)83 scanned points, lower divertor[floor]
Boundary DiagnosticsVisible spectrometer (MDS)12 channels, upper and lower divertorORNL
Boundary DiagnosticsDivertor EUV/VUV Survey Spectrometer (DivSPRED)Vertical view upper/lower divertorsLLNL
Boundary DiagnosticsWide Spectral Emission (WiSE) SpectroscopyVertical view through SAS and lower divertorLLNL
Boundary DiagnosticsLyman‑alpha X‑pt imagingTangential view, 1 cameraORNL
Boundary DiagnosticsCoherence Imaging Spectroscopy (CIS)2 cameras: tangential and lower divertorLLNL
Boundary DiagnosticsIRTV Infrared imaging3 camera views, a lower divertor, a wide‑angle tangential view, and a close‑up view of DIMES in the lower divertor.LLNL
Boundary DiagnosticsFast Neutral Pressure Gauges (ASDEX Gauges)3 pumping plenums, 1 upper divertor, 2 SAS divertor, 1 main chamberORNL
Boundary DiagnosticsWisconsin In‑Situ Penning (WISP) gaugesUpper, Upper SAS, lower divertor baffleU Wisconsin
Boundary DiagnosticsBaratron GaugesUnder divertor baffle (upper and lower)U Wisconsin
Boundary DiagnosticsLyman‑alpha Measurement Apparatus (LLAMA and ALPACA)Below Midplane, 20 channels on HFS and LFSMIT/PPPL
Boundary DiagnosticsFixed Langmuir probes32 lower divertor, 40 upper divertorSNL
Boundary DiagnosticsMoveable scanning probes (RCP)Vertically scanning, lower divertorUCSD
Boundary DiagnosticsMidplane Reciprocating ProbeRadially scanning, outer midplaneUCSD
Boundary DiagnosticsTile current monitors (TCA)10 in lower divertorGA
Boundary DiagnosticsFast Thermocouple array20 in lower divertorGA/SNL
Boundary DiagnosticsSurface Eroding Thermocouples (SETC)18 in SAS divertorUTK
Boundary DiagnosticsDiMES, MiMESLower divertor, outer midplaneUCSD, GA
Boundary DiagnosticsDiMES TV1 cameraGA
Boundary DiagnosticsHigh Resolution UV spectrometry1 vertical view of DiMES. SAS viewAuburn U
Boundary DiagnosticsPlasma Tangential TV (TangTV)4 cameras, 2 upper and 2 lower divertorLLNL
Boundary DiagnosticsFast framing camera (FASTCAM)2 tangential viewsUCSD
Boundary DiagnosticsVisible filterscopes24 locations, 96 channelsORNL
Boundary DiagnosticsDoppler‑free saturation spectroscopy (DFSS)1 toroidal locationORNL
Magnetic PropertiesPlasma current Rogowski loops3 toroidal locationsGA
Magnetic PropertiesFlux/voltage loops44 poloidal locationsGA
Magnetic PropertiesBq probes135 probesGA
Magnetic PropertiesDiamagnetic loops2 toroidal locationsGA
Magnetic PropertiesExternal Br loops4 arrays, 36 loopsGA
Magnetic PropertiesInternal Br loops64 loopsGA
Magnetic PropertiesInternal BT loops4 toroidal locationsGA
Magnetic PropertiesCoil current Rogowski loops52 loops on 40 coil circuitsGA
Fluctuations/Wave ActivitiesBeam Emission Spectroscopy (BES)2D, 64 channelsUW Madison
Fluctuations/Wave ActivitiesPhase Contrast Imaging (PCI)Vertical view, 32 channels
vertical view interferometer
Fluctuations/Wave ActivitiesCorrelation ECE system (CECE)8 radial channelsUCLA
Fluctuations/Wave ActivitiesUltrafast Charge Exchange Recombination Spectroscopy (UF-CHERS)1 radial channelUW Madison
Fluctuations/Wave ActivitiesCross-polarization Scattering (CPS)8 radial channelsUCLA
Fluctuations/Wave ActivitiesDoppler Backscattering (DBS)8 radial channelsUCLA
Fluctuations/Wave ActivitiesMirnov coilsToroidal, poloidal, radial arrays
60 probes
Fluctuations/Wave ActivitiesHigh Frequency Mirnov Coil Array1 toroidal location, 5 probesGA
Fluctuations/Wave ActivitiesToroidal Radial Interferometer Polarimeter (TRIP)3 radial chords, 1 Toroidal chordUCLA
Fluctuations/Wave ActivitiesX-ray Imaging System (SXR)5 arrays, 100 channelsUCSD
Fluctuations/Wave ActivitiesIon Cyclotron Emission (ICE)7 plasma facing probes (5 outer wall, 2 centerpost)
FW straps at 275˚ and 285˚
Fluctuations/Wave ActivitiesSoft X-ray Imaging (SXRI)tangential lower divertor viewORNL
Fluctuations/Wave ActivitiesMillimeter-wave Imaging (ECEI/MIR)270 degree ECEI 160 channels (20 poloidal x 8 radial) MIR 48 channels (12 poloidal x 4 radial)UC Davis
Fluctuations/Wave ActivitiesCharge eXchange Imaging (CXI)NewUW-Madison
Particle DiagnosticsNeutronsUC Irvine
Particle DiagnosticsFast Neutron Scintillation Counters4 channelsUC Irvine
Particle Diagnostics2.45 Mev Neutron Counting System4 channelsUC Irvine
Particle Diagnostics14 Mev Neutron Detection System2 channelsUC Irvine
Particle DiagnosticsFast Ion Loss Detector (FILD)2 poloidal locationsUC Irvine
Plasma Current ProfilesMotional Stark Effect Polarimeter (MSE)3 views, 40 channels, full radial profileLLNL
X-Ray and Gamma RayGamma Ray Imager (GRI)Midplane tangential view, 55 channelsGA
X-Ray and Gamma RayHard X-ray Monitors4 toroidal locationsUC Irvine
X-Ray and Gamma RayHard X-ray Scintillator Array (Bismuth Germanate Array BGO)16 locationsGA
Pellet, Impurity, and Gas IntroductionORNL Pellet Injectors:
Pellet, Impurity, and Gas IntroductionRepetitive Pellet InjectorORNL
Pellet, Impurity, and Gas IntroductionMassive Gas InjectorsORNL
Pellet, Impurity, and Gas IntroductionArgon Pellet InjectorORNL
Pellet, Impurity, and Gas IntroductionShotgun pellet InjectorORNL
Pellet, Impurity, and Gas IntroductionImpurity Powder Dropper (IPD)Gravitational injection of powders and granules (B, BN, Li, C etc.), by 4 independent feedersPPPL
Pellet, Impurity, and Gas IntroductionImpurity Granule Injector (IGI)Repetitive, midplane injection of granules (Li, C, Si etc.)PPPL
Pellet, Impurity, and Gas IntroductionLaser Blow Off (LBO)MIT and GA
Pellet, Impurity, and Gas IntroductionDIII-D gas injection systemUW Madison and GA

*Items in Blue indicate systems that were added or were significantly upgraded in the past five years.


For diagnostics systems installed in previous years, please visit DIII-D Capabilities and Tools for Plasma Science Research.

Share your thoughts on replacement of DIII-D's graphite wall with this form and on June 12-13 at a virtual community workshop!