Facilities and Upgrades PAC Presented by Jim Irby for the C-Mod Group

Transcription

1 Facilities and Upgrades PAC 2010 Presented by Jim Irby for the C-Mod Group

2 Outline Machine History and Status Alternator/Machine 2009 run campaign 2010 run campaign Availability Chart Contributions to ITER Technology Update RF Systems ICRF LH New outer divertor Data System Infrastructure Alternator Cooling Upgrade Short Term Plans FY2011 Plans FY2012 Plans Diagnostics

3 Machine History and Status Alternator return-to-service authorized by VP of Research and Expert Panel April 14 th, 2009 Alternator assembly complete May 27 th, 2009 C-Mod pumpdown June 10 th, 2009 Restart plasma operations June 24 th, run campaign completed Sept 25 th, research weeks of operation (JOULE target of 9 weeks) 1165 research grade discharges 2010 run campaign began on Oct 6 th, 2009 Planning for 18 weeks of operation (Target TBD) 7.5 research weeks thus far (including 5 incremental weeks under ARRA funding: complete)

4 Facility Upgrades: Availability

5 Contributions to ITER Technology Update Tungsten Lamella Tiles Tungsten belt installed and in operation Tungsten planned for new outer divertor Fast Ferrite Tuners for Real-time ICRF matching Prototype installed and operating well Will be extended to all antennas (ARRA funded) Wall conditioning/coating technology Boron coated tiles were installed for the FY2007 campaign and for FY2009 the inventory of tiles was greatly expanded Diagnostics developed to quantify coating Diagnostics planned to do in-situ film measurements Gas Jet Disruption Mitigation Gas jet is operational and has already greatly extended our understanding of the physics of this process

6 Contributions to ITER Technology Update Remote Participation Tools Audio, video and MDS-Plus tools to communicate with off-site personnel continue to be upgraded We continue to work directly with the US and international ITER teams to define remote conferencing technologies for ITER Polarimetry Installation for FY2010 campaign ITER-like geometry, fields, and laser wavelength

7 ICRF Systems New 4-strap antenna rotated to reduce sheaths/impurity generation Design of rotated system much more difficult than a similar straight antenna Engineering time limited by LH and alternator demands Antenna delayed from June to October 2010 installation More details in rf talk by Steve Wukitch Vacuum tube based IPA (intermediate power amplifier) stages replaced with 10 kw solidstate components 10 kw vs 5 kw Broadband operation with very clean spectrum Good impedance match High power more reliably produced Straps ~ aligned with field lines ARRA funding will allow accelerated fabrication of FFT systems

8 Lower Hybrid Systems New lower hybrid launcher Improved efficiency Novel 4-way splitter design Much simplified feed system with no multi-waveguide rf gaskets Rf probes monitor coupling and provide added protection N 2 or SF 6 purge to vacuum window Vacuum window location Rf probes SOL Reflectometer (ORNL)

9 All components for the new lower hybrid launcher have been fabricated and assembled Fit-ups have been completed in the cell However, rf tests indicated reflection and loss at many of the vacuum windows were unacceptable Lower Hybrid Systems

10 Lower Hybrid Systems At the last PAC meeting we expected installation of the launcher by May of 2009, however: Return-to-service of the alternator consumed a large fraction of our engineering effort into May of 2009 Development of ss-cu-ss compression brazes, vacuum window braze, e-beam welding techniques, and extensive testing of components extended well beyond what we had anticipated (an additional 4 to 5 months) Improperly specified braze material for our WR-187 in-vacuum waveguides delayed start of assembly an additional 1 to 2 months An error by our vendor of a critical e-beam setting coated many of the vacuum windows during one of the last welding operations This occurred in spite of our having qualified the process with extensive prototyping and successful welding of the first column and prototype We are proceeding with ultrasonic cleaning of the windows Low power rf measurements indicate very good results from this technique on test pieces (welded by vendor using same settings) We are investigating clean-up techniques that do not require disassembly, to be followed by extensive rf testing

11 Lower Hybrid Systems The launcher fabrication is complete Not shown are support plates, the bellows, and the vacuum flange

12 Lower Hybrid Systems New lower hybrid klystron cart will bring source power up to 4 MW from 3 MW (ARRA funded) Design complete Procurement and assembly begun Cart supports 4 additional klystrons Procurement underway for 7 additional klystrons (ARRA funded) First new tube could be tested as early as 4/10 We are working with vendor to ensure proper operation of these new tubes with our high voltage power supply (208 A, 50 kv) Tube rating of 300 kw CW, but require more water cooling than currently available for our 250 kw tubes to reach this level (no plans to increase flow rates, will continue to operate at 250 kw) Fabrication Phase of an Existing Cart

13 Lower Hybrid Systems Control and Data Acquisition System Minor changes since 1 st launcher operation Phase and amplitude control at 9 khz update rate Coupler Protection System (CPS) New system will come on-line with 2 nd launcher Integrates 5 MHz sampling rate digitizers with on board FPGA for fast fault detection and handling 5 s of data storage Remote parameter changes (trip levels) Transmitter Protection System (TPS) Remote parameter setting Better noise immunity and isolation Developed under Phase II SBIR

14 New Outer Divertor Divertor upgrade allows long pulse (~5 s), high power (~10 MW) operation and enables new fuel retention experiments Toroidally continuous outer divertor eliminates leading edges and reduces electromagnetic loading from disruptions. Heating to ~600 C allows critical new fuel retention studies. 4 rows of tungsten lamallae tiles at strikepoint. Tungsten

15 New Outer Divertor Ten 36 divertor plate sections provide full toroidal coverage. Adjacent plates bolted together behind the divertor structure using toroidally oriented bolts. Toroidal bolting force Cutouts in divertor plate accomodate diagnostic views where necessary.

16 New Outer Divertor Solid Molybdenum tiles cover the top 6 rows (2 not shown on cover plate.) Lamellae Tungsten tiles cover bottom four rows of divertor leg.

17 New Outer Divertor Thermal expansion (11mm diameter) of the new divertor ring must be accommodated by support designs and be robust to disruption loading Evaluation underway of three primary support designs Flexure/leaf spring Pin and clevis Sliding plate and cable

18 New Outer Divertor Engineering and design is underway to overcome challenging technical requirements of heating the outer divertor tiles to 600 C. Thermal FEA shows significant distribution of temperature during heatup when heaters are only on lower portion of divertor plate. The temp. distribution of the Inconel divertor plate determines the temp. distribution of the tiles. Due to low thermal conductivity of Inconel, heaters or conductive strips must be distributed evenly across the entire back of divertor plate. Adequate and uniform heating power must be achieved with UHV compatible heater solution. A commercial supplier has been identified. Lighter => Higher T Darker => Lower T

19 New Outer Divertor Evaluation of the impact of a continuous divertor structure operating at high temperature is underway Thermal shielding of in- The heat flux around the vessel strongly vessel components and depends on emissivity of the divertor tiles diagnostics will be necessary. The addition of a dome in the private flux region reduces radiative heat flux to the inner wall from the hot divertor Plasma Shapes [W/m2] Dome

20 New Outer Divertor Calculations of disruption forces indicate that the frequency response of the divertor hoop is important in determing the impact of E&M loads, i.e. the disruption loads may be faster than the response time of the divertor structure.

21 Data System The amount of data taken during a C-Mod shot continues to increase with an ~2 year doubling time We are acquiring about 6 GB/shot during the current run campaign We are increasing online data archive by 50 TB to 75 TB We are improving networking capability

22 Alternator Cooling Upgrade The primary cooling system for the alternator relies on cooling water from the Charles river ( MW level sink required) Restrictions on both the absolute temperature and the temperature change of the water at the river outfall could/will result in restrictions to C-Mod operations during the late Summer months MIT has agreed to fund an upgrade to the alternator cooling system that will supplement the river water cooling with water from the MIT chilled water system (~$850 k cost) Multiple heat exchangers isolate alternator systems from the river water The MIT chilled water system supplies cooling as required Installation in Spring 2010

23 Short Term Plans Operation until April operation research weeks Up-to-Air April 2010 (LH, diagnostics) Operation until August 2010

24 FY2011 Plans Installation and operation of the new advanced ICRF antenna is a major goal in FY2011 The installation of the FFTs is also major activity 4 th Klystron Cart should be available Spring/Summer Preliminary schedule assuming 12 weeks of research operation is shown

25 FY2012 Plans Currently assuming 12 weeks of research operation Major activities will be Installation of 3 rd launcher Installation of 2 nd 4-strap antenna Installation of new outer divertor Relocation of diagnostics Long up-to-air period required

26 Diagnostics

27 Diagnostic Upgrades: Availability

28 The Multi Pulse Laser Blow-off System A new laser blow-off system was installed on C-Mod during the 2009 run campaign. The key features of this system include: -A 680 mj pulsed ND:YAG laser operating at 10 Hz -Fast piezo-electric beam steering allowing for up to 10 injections per plasma shot. -Laser ablation of a wide range of target Z. The system demonstrated all of its design goals which include nonperturbative impurity introduction. -These trace impurities are ideal for studying impurity transport. (Above) The laser blow-off system installed on C-Mod. (Below) The determination of impurity confinement times from laser blow-off produced impurity injections New impurity transport studies are possible by coupling the laser blow-off system with the extensive diagnostic suite present on C- Mod (X-ray crystal, VUV, Soft X-rays, etc.). Experiments were performed in 2009 and further analysis and impurity transport studies in L, I, and H-Mode are planned for the 2010 campaign (PhD thesis work)

29 SOL Reflectometer (MIT/ORNL) GHz X-mode frequency swept SOL reflectometer to measure density profiles and fluctuations at ITER relevant SOL densities and magnetic fields Differential phase and full phase capability to get best possible profile measurements Allow direct evaluation of average profiles measured from differential phase and full phase profiles. Three pairs (send and receive) of launcher antennas (top, middle, bottom) in both LH launcher and ICRF antenna Critical part of the diagnostic set for evaluating LH wave coupling Assess the importance of potential density up-down asymmetry due to RF power. G. Hanson, J. Wilgen (ORNL) C. Lau, Y. Lin, S. Wukitch (MIT)

30 Wide-View CXRS Upgrades Core CXRS Upgrades for Wide-View CXRS consists of poloidal (in red) and toroidal (in blue) views Upgrades: 1. Higher throughput optics are designed for poloidal array 2. An improved optical array for the toroidal periscope is manufactured and ready to install (increased number of channels 10 20) 3. A new high transmission toroidal vacuum feedthrough is manufactured and ready to install. 4. Install next manned entry

31 New CXRS Methods for Density Measurements 1 CXRS/BES layout 2 - sample He spectra 1. Integrated CXRS/BES optical system: higher accuracy impurity density measurements A multi-channel optical splitter is assembled and tested 2. Spectrometer modifications : He measurements for ash transport 3. More spectrometer modifications: Fast ion measurements 3 - sample fast-ion spectra

32 High Resolution T e FRCECE Diagnostic 32 channels Spatial resolution = 0.6 cm; Temporal resolution < 0.02 ms Full T e profile at 5.4 T (has been typical C-Mod TF) Upgrades completed Replaced high frequency receiver (worked with PSFC) Improved shielding, acquired spare LO = higher reliability Plans Increase temporal resolution < ms (fluctuations) Add new receiver in 2011 Result: Full profile measurements at lower TF (4.5T) For H-mode, ITB, LH,...

33 X-Ray Extended Ultraviolet Spectrometer (XEUS)

34 X-Ray Extended Ultraviolet Spectrometer (XEUS)

35 Polarimeter (MIT/UCLA) Upper optical table and beamlines installed in cell Single chord mock-up being tested in lab Working with collaborators to identify sources of phase (rotation) error Expect to reduce noise levels below 0.1 o Lower table with lasers, detectors, and other optical components in cell soon New reliable, sensitive detectors being developed under ARRA funding (increased reliability and sensitivity) Upper optical table Lower optical table

36 Polarimeter Upper optical table Feedback controlled mirror mounts Enclosure allows purging of beam-paths with dry air or nitrogen Purge continued into lower optical table enclosure Test with alignment beams during plasma operation show very stable mounting system Upper Optical Table Installed in Cell Beamlines to lower optical table

37 Divertor Diagnostics Upgrade Major upgrades have been made to our divertor diagnostics in support of the FY2011 Joint Facilities Milestone Surface thermocouples Tile thermocouples Probes IR imaging Calorimeters New cpci data acquisition system Limiters also diagnosed Upgrade process will continue during next manned up-to-air (will be discussed by Bruce Lipschultz)

38 Embedded Heat-Flux Sensors on Inner/Outer Divertor Inner Divertor TCs Ramped Outer Divertor Tiles Tile TCs Surface TCs Tile TCs Calorimeters Inner Divertor Outer Divertor - Two columns of ~2 o ramped tiles on ODIV - Unique surface thermocouples and calorimeters - New cpci data acquisition system for all sensors including all Langmuir probes Present Operational Status: IDIV: 14 of 16 Langmuir probes 15 Tile TCs ODIV: 10 Langmuir probes 11 of 14 Calorimeters only 3 of 10 Surface TCs (repair next manned access)

39 Embedded Heat-Flux Sensors on Inner/Outer Divertor now provide immediate feedback to assess divertor heat deposition Example: Tile temperature rises show effect of impurity seeding* Increasing impurity concentration ===> *ITER urgent need, MP564: Power requirements for high confinement H-modes and the role of radiated power spatial distribution, Loarte et al.

40 Limiters also instrumented for heat deposition Limiter Heat Deposition: Thermocouples G-H Limiter A-B Split Limiter K-port Limiter For 2009 Campaign: Limiter les instrumented with 22 embedded TC sensors - 5 mm from surface - signals before, during & a er shot - between-shot thermal analysis - opera ons warning... Operational Status: - 16 of 20 sensors working - Delta-T displayed for operators between shots - Software for thermal analysis in progress

41 New CNPA on Alcator C-Mod A new CNPA was installed on the J- Top port looking down vertically at the heating region in front of the J-Port ICRF antenna (2 MeV range, 40 kev resolution). The CNPA views neutralized fast ions that escape the plasma and impinge on the detector. This CNPA has 8 spatial channels spanning from R= 78 cm to R= 69 cm (in C-Mod the magnetic axis is at R=67 cm and the horizontal minor radius is ~22 cm) The J-Top CNPA complements the previously installed 3 channel CNPA viewing the DNB (Diagnostic Neutral Beam) at major radii between R=67 cm and R=71 cm (1.2 Mev, 20 kev). The J-Top CNPA expands detection abilities both in space and in energy Collimators Teflon Socket Detectors 15 mm Detectors are silicon diodes with a thin Al foil covering (150 nm) to block soft x-rays Vacuum feedthroughs F-Top view (old) J-Top view (new)

42 Reflectometer Upgrade Microwave and IF components have been upgraded at PPPL in order to improve the dynamic range and overall system performance Antennas have been redesigned: Moved out of the vacuum vessel to eliminate surface contamination during plasma operation Designed to have a constant 23 dbi gain over the 110GHz-140GHz frequency range The vacuum windows have been enlarged and changed from sapphire to fused quartz to improve transmission. Correlation data has been obtained and is under analysis New quasi-coherent mode observed during I-Mode center frequency approx 200 khz approx line width 100 khz 1 Vacuum New Reflectometer Antenna Design

43 Outboard Limiter Instrumented with TV and Spectroscopic Views TV view of GH Lim. back-illumimated spect. views limiter during radiation event

44 44

45 nozzle New 2D Arrays of Views, New Fast Cameras, and New Rad-resistant Fibers for GPI are Operational new arrays of fibers coupled to diodes PPPL collab. provided arrays of new quartz fibers coupled to fast-cameras D nozzle views coupled to APDs; 1 MHz time res. 0.8<k pol <8 cm -1 spatial res. views coupled to fast cameras; 195 khz time res. 1<k pol <20 cm -1 spatial res.

46 Example: APD Array System Measures Radial Profile of k pol,f-resolved QC-mode Conditional spectrum, S(k pol,f)/s(f), 12 mm inside sepx during EDA H-mode

47 4.6 GHz reflectometer Expansion of the existing O-mode reflectomter Measurement of both waves upshifted and down-shifted by 4.6GHz Added to 50 GHz and 68 GHz channels. Up/down-shifted signals have a broad spectrum (~ MHz) IF stage ( ) development is underway Dynamic range > 65 db Frequency sweep ±150 MHz in 30 ms PAC 2010

48 Fluctuation Spectrometer He-like Argon at 3.1 kev will be viewed at very high count rates v, T i, T e Fluctuations Count rates from 200 to 500 MHz High reflectivity crystal (Ge[1,1,1]) Working with vendors to develop fast camera 20 to 50 KHz (1% statistics) Scoping experiments done during FY2009 campaign with low count rate camera Fluctuation Spectrometer 48

49 EOT 49