Max-Planck-Institute for Plasma Physics Status of the Diagnostics Development for the Stellarator Wendelstein 7-X R. König1, W. Biel2, C. Biedermann1, R. Burhenn1, G. Cseh4, M. Endler1, T. Estrada5, O. Grulke1, D. Hathiramani1, M.Hirsch1, M. Jakubowski1, G. Kocsis4, P. Kornejew1, A. Krämer-Flecken2, M. Krychowiak1, M. Laux1, A. Lorenz1, O. Neubauer2, M. Otte, 1E. Pasch1, B. Plaum6, T. Sunn Pedersen1, O. Schmitz2, B. Schweer2, T. Szepesi4, H. Thomsen1, T. Windisch1, S. Wolf7, D. Zhang1, S. Zoletnik4 1Max-Planck-Institute for Plasma Physics, D-17491 Greifswald, Germany, 2Institute of Energy- and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany, 3Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA, 4Wigner RCP RMI, H-1121 Budapest, Konkoly Thege 29-33, Hungary, 5Laboratorio Nacional de Fusi´on, CIEMAT para Fusi´on, Madrid, Spain, 6IGVP Univ. Stuttgart ,Pfaffenwaldring 31, 70569 Stuttgart, Germany Thomson Scattering Diagnostic Flux Surface Measurements Lasers 5 (2) (Q-switch, Nd-YAG, 2 J) Spatial p channels: up p to 60 ((10)) 20 eV < Te < 10 keV, 5·10 5 1018 m-3 < ne< 5 5·10 1020 m-3 Δreff ≈ 2.5 cm, laser freq.: 20 Hz. Obs. optic: N.A. 0.37, f/1.3, 7 lenses, Ø160 mm, f=172 mm, ~23 kg (lenses), 20-200°C, lens system housing: Titanium Complete measurement i HM51/10 in Partial measurement i HM21/30 in 2D-positioning of fluorescence rods, each equipped q pp with an e-gun (repeatability of ~1mm) Q Quartz fibres: rectangular g on p plasma side 1.1 x 3.2 mm2 consisting g of separate p bundles of differing length (delay line), optic side Ø 3 mm Polychromators W7-AS 3D field line tracing Fluorescent rodd Two interleaving push rods (outer & inner tube) for axial movement (outer) and rotation (inner) in combination with slide bearings to fully scan the plane in the triangular plasma vessel cross section 4 reference points provided in heat shield tiles via metal coated optical fibres Δt = 10-30s e-beam Electron beam in background gas (~450m approx. 12 revolutions) 2D Poincaré plot −Outer tube: axial movement 1550mm, v ≈ 10mm/s, repeatability: ±0.5mm −Inner tube: axial movement120mm Æ Δα=160°, v ≈ 1mm/s, repeatability : ±0.05mm Polychromator filter curves silicon avalanche diode detectors utilizing moveable fluorescent rod, 4 reference points Water cooled shutter Dispersion Interferometer Reflectometry Systems Steering Doppler Reflectometer Corner Cube Reflector (CCR) Irrradiation angle / ° 32 elements phased array beam steering by changing the freq. Î no movable parts, fast scan of Bragg angle electronically Doppler Reflectometry K-spectrometer: measures changes in turbulence amplitude and propagation velocity for selected K and r Phase shift due to the plasma: e2 λ2 ⋅ ⋅ ne L 2 ⋅ 4π 2 c 2 ε 0 me 2 2 ( ) e 2 π λ 2 2ω: ⋅ ⋅ ⋅n L λ 2 2 ⋅ 4π 2 c 2 ε 0 m e e ω: 2π λ ⋅ ω Δϕ p = 2Δϕ p − Δϕ p 2ω 3 e2 = λ⋅ ⋅ ne L 2 4πc2ε 0me Frequency / GHz fixed angle 18o Î ~1cm structures 50 GH GHz - 110 GH GHz, x/o-mode / d optimized spot diameter: 2*w0=50mm @80 GHz (λ=3.75mm) ~sqrt( λ ) W7-X single chan. interferometer Poloidal Correlation Reflectometry P. Rohmann, et al., IEEE International Symposium on Phased Array Systems & Technology, p. 559 (2013) CCR - Stack of thin Al and Cu sheets - Stack covered by galvanic Cu - Al sheets etched away −turbulence characteristics (correlation length) around the separatrix −poloidal propagation velocity Î ExB velocity Î separatrix position from Er=0 Î “quasi coherent”-mode? Î magnetic g ppitch ((aimingg at jBS) Interferometer and Thomson scattering laser beams are using the same pair of ports hopping reflectometer system, Ka-band 1 launch, 4 receiving antennas -> 5 waveguides 10mm x 10mm -> max. length ~10m -> rack in torus hall 10 Simplified IR/vis. Divertor Observation Systems for OP1 2 Long Pulse Compatible IR/vis. Endoscopes for OP1.2 (10 for OP2) Toroidally directed AEQ Port 3 observation windows protected by uncooled rotating shutter: Camera transport system Actual view with EDICAM from AEQ21 J-port Diamagnetic Loops (all 3 loops installed) Compensation loops only in triangular plane measure the toroidal magnetic flux measure the toroidal magnetic flux due to the magnetic field coils cancelled plasma 1.5 µm < λ < 13 µm Î solutions still need to be developed: Water cooled cold aperture IR camera 3-5 µm outer vessel flange 115 x 60 wide angle endoscope Design and manufacturing by ©Thales SESO Optical design frozen: IR spatial resolution with 40% MTF 6 mm most of the target area 10 mm near edges Investigation of Transparent Single-Walled Carbon Nanotube Coatings SW-CNTs produced by IWS Fraunhofer (Dresden, L. Hu et al, Appl. Phys. Germany) y) and by y Nanolab were tested: L tt 94, 94 081103 2009 Lett. el. conductivity of IWS SW-CNTs ~10-80x higher (varies with surface density) IWS SW-CNTs: 1.5% ECRH transmission would require: 3g/m2 (factor 100 higher than in publication)) resulting p g in 3-5 Ω Î IR transmission @ 2.5 µm: 3.5% & 3-5 µm: 1.5% Î IR Transmission much lower than expected! λ = 3 – 5 µm “Quality“ of SW-CNTs obviously important λ = 2 mm Detectors attached to endoscopes are not affected by ECRH Next steps: K. Kamaras at KFKI stray radiation due to ECRH absorber (Al2O3/TiO2) coated B d Budapest t (use ( doped d d materials?) t i l ?) , cold ld apertures, divergence di behind b hi d last l mirror i (-120x), ( ) losses l in windows & lenses (~20%) Î 0.02µW/pxl. ~ 0.01K/s Unidym Inc. Multi-purpose Manipulator, Therm. He-beam, Divertor Langmuir Probes and Visible Spectroscopy Target integrated Langmuir probes D Downstream ne & Te T optical unit Visible spectroscopy & tomography L-port tiltable solid angle of observation He-beam HM51 Ionization, dissociation, impurity concentration, ne & Te optical unit J-port Limiter Langmuir g probes (only in OP1.1) divertor gas nozzles Rogowski Coils (all 5 coil systems installed) Mirnov Coils (all 124 for OP1 manufactured, ~50% installed) measure the total toroidal electric current and moments ECRH stray rad. protection Observation of MHD modes and magnetic fluctuations: Frequency range: 1 kHz - 1 MHz 124 installed for OP1.1 44 to be installed for OP2 Location → outside and inside the plasma vessel Fast reciprocating Langmuir probe HM11 Upstream Γio, v||, ne, Te, DC & turbulent time scale In-board limiter in OP1.1 Visible Spectroscopy & Tomography Ionization, dissociation, impurity concentration, ne & Te Segmented Rogowski coils → measure the poloidal distribution of the toroidal electric current promising i i publication: bli ti L Hu L. H et al, l Appl. Phys. Lett. 94, 081103 2009 L. Hu et al, Appl. Phys. Lett. 94, 081103 2009 UV/Vis./IR endoscope (250 nm – 5 µm) 2 UV and 3 vis. CCD & 1 IR camera covering 70x70 mm area with 0.5 0 5 mm resolution + fibre optics to high & low resolution spectrometers per endoscope with front sweeping mirror Module 51 system looks at He-beam gas injection system (UV/)vis. spectral range Î ITO (successfully tested at IPP R. König et al., Rev. Sci. Instr. Xxx) visible camera 0.4-0.8 µm Viewing and scanning geometry 2 endoscope pairs covering - upper divertor module 51 - lower divertor module 30 L-port ECRH Stray Radiation Protection of Windows Transparent conductive coatings Minimisation of mirror contamination by observation through small pinhole (entrance pupil Ø=6mm) hydrogen gas flow through pinhole uncooled shutter closed between discharges first mirror heatable to 350 C for overnight/weekend cleaning shutter integrated ceramic heater for relative calibration of IR and visible channels The cameras with wide angle optics are mounted directly behind the windows: 1 IR micro-bolometer camera 2 visible light cameras with interference filters for Hα, Hγ, C II, C III Cameras were tested in 2.5T magnetic field Endoscopes for Tomographic Observation of Line Emission from the Divertor Main loops: Compensation loops: pinhole port protection 10 observation systems are monitoring each of the 10 discrete divertors Pinhole optics + relay optics + PCO PixelFly CCD or image guide spectroscopy, illumination etc. quartz air vacuum vacuum vacuum shutter Video camera view Pinhole optics + EDICAM (CMOS) water cooled front head Water cooled front plate sap pphire 10 Toroidally Viewing Video Camera Systems P1 P6 P5 P7 B// He-beam HM30 P2 P3 P4 BN+ZrO2 Bθ Downstream Multiple array Langmuir probes (LP)(5 tips) Magnetic coils (MC) (2 x 6 connectors) ne & Te Mach probe (MP) (2 tips) LP: P1Æ vf1 (floating potential) P2 Æ Isat (negative biased) P3 Æ v3 (positive biased) P4 Æ vf4 (floating potential) therm. He-beam box with gas bo t 5 piezo valves MP: P6 Æ Isat (negative biased) P7 Æ Isat (negative biased) MC: Two sets of coils at different radial position; Bt; Bθ; Br fluctuations Arrangement of the multi-purpose manipulator at port AEK40 Folded loop made of continuous ribbon ibb cable bl fits through large ports for installation In-vessel assembly test without ECRH stray radiation shield High Efficiency Extreme Ultraviolet Overview Spectrometer (HEXOS) - impurity release and transport Spectral survey instrument: Channel 1: 2 2.5 5 – 10.5 10 5 nm Channel 2: 9 – 24 nm Channel 3: 20 – 66 nm Channel 4: 50 – 160 nm Outer vessel Cryostat High Efficiency Extreme Ultraviolet Overview Spectrometer (HEXOS) Bolometer Wavelength and absolute calibration with: coating screen Kock-source Spark-source - system successfully operated on TEXTOR for several years - now installed on W7-X Tube support Exchange chamber Linear drives plasma Fraunhofer-Institute Aachen Gate valves Inner vessel Calibration: A. Greiche et al, RSI 79, 093504 (2008) HEXOS No. 1 detectors Horizontal camera Vertical camera HEXOS No. 2 Vertical camera: front end HEXOS No. N 4 Design criteria Front plate active cooling required for steady-state operation: p thermal loads up p to 100 kW/m2 Factor 300 microwave stray radiation reduction by damping & screening water cooled aperture clamp ring HEXOS No. N 3 detector holder microwave shield Port AEK40 Vacuum systems