Facilities Presented by Jim Irby for the C-Mod Group
Outline Machine History and Status 2008 run campaign Machine inspection Alternator and Flywheel Inspections Availability Chart Contributions to ITER Technology Update RF Systems ICRF LH PFCs Boron tiles Damage Mitigation New outer divertor Data System Software and Infrastructure Short Term Plans PAC 2009
Machine History and Status 2008 run campaign completed May 23 rd, 2008 15.7 research weeks of operation (JOULE target of 15 weeks) 1888 research grade discharges Routine operation of upper divertor cryopump Inspection of the C-Mod machine began immediately following end of operations (after ~14,200 machine cycles) Inspection of Alternator and flywheel began August 2008 PAC 2009
Machine History and Status Machine Inspection All joints/connections/components checked New feltmetal on all TF sliding joints and OH coax connections 1920 TF sliding joints Three OH coaxes All mating surfaces silver plated Re-assembly now well underway Improvements made to heater and cryo systems 5 more years of operation Reassembly as of 1/30/09
Machine History and Status Alternator/Flywheel inspections Flywheel and alternator stator in excellent condition Rotor was not given a Return-to-Service recommendation Details on rotor status following this presentation
PAC 2009 Availability
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 extremely well Will be extended to all antennas Wall conditioning/coating technology Boron coated tiles were installed for the FY2007 campaign and for FY2009 the inventory of tiles will be 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
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 FY2009 campaign ITER-like geometry and fields
ICRF Systems New 4-strap antenna rotated to reduce impurity generation Completed PDR Feedthrus determined and on order Vacuum tube based IPA (intermediate power amplifier) stages being replaced with 10 kw solid-state components 10 kw vs 5 kw Broadband operation with very clean spectrum Good impedance match Upgrade to control system Improved phase control of 4-strap antenna CPLD and μp components replace many discrete components and handwired boards Improved rf isolation between stages Straps ~ aligned with field lines
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)
Lower Hybrid Systems Prototype 4-way splitter performed extremely well under test (no arcs) 250 kw input power and 0.5 s pulses Temperature extremes acceptable (17 o C/s) Matched and unmatched loads Input 4-Way Splitter Prototype Load and directional coupler
Plasma Facing Components Boron layer added to suspect impurity source locations Limiters Outer divertor plates Antenna protection tiles Aid in identification of impurity sources Reduce need for boronization??
New initiative to understand and mitigate damage to main-chamber limiter components melt damage Melt damage is observed near midplane on all main limiters melt damage G-H Limiter melt damage A-B Limiter K Limiter Plan: - Reshape G-H limiter - Instrument: TCs, visible camera & fibers
New initiative to understand and mitigate damage to main-chamber limiter components G-H Limiter Tile Surface Modification R 31.6 Profile 1992-2008 C D G 13.3 Reshape of G-H limiter: Increase midplane major radius by 5 mm better match to standard discharge better match to Lower-Hybrid launcher shape New Limiter Profile -- provides a better match to C-Mod s standard dischcarges, including ITER shape dicharges C D Old profile New profile R29.6 New Profile 2009 12.8 -- Reshaping increases midplane major radius of limiter surface by 5 mm 1080201031 EFIT: 1.000 1080201031 EFIT: 1.000 B. LaBombard 8/8/08
New initiative to understand and mitigate damage to main-chamber limiter components Limiter instrumentation: Thermocouples Visible-Light Monitoring Micro-camera plus individual fiber views (spectrometer) of G-H limiter - Assessment of local impurity sources 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...
Plasma Facing Components Work continues on new outer divertor Thermal models being developed (with PPPL) to determine acceptable heat loads Long pulse operation at high input power loads Actively heated divertor surfaces Vertical surfaces w/o large gaps and ski-jump design Temperature effects to support hardware being considered Tungsten in important locations New Outer Divertor
Data System and Infrastructure Servers and storage systems New data acquisition/data analysis server localizes I/O and computation to improve inter-shot performance New external RAID array (32TB with 24TB usable) New Switched GB networks in the Cell New GB campus and ESnet network connection Data archives MIT TSM central backup system Archive of original pulse files moved from local LTO to MIT (~10TB) Entire shot archive backed up to MIT service (~11TB) 2 nd copy on local RAID array (immediate restore of online versions) PAC 2009
Data System and Infrastructure Software New data acquisition device support MDSplus Objects (MDSobjects) development Python (near completion) C++ (near completion) Java (near completion) Matlab (under development) Fortran9x (proposed) Python MDSobjects data acquisition device support API (completed) Prototype device support (in test)
Data System and Infrastructure
Short Term Plans Machine re-assembly complete --- April/May 2009 Installation of new lower hybrid launcher New diagnostics and diagnostic upgrades as will be discussed on Thursday Alternator returned to service --- May 2009 2009 operation --- 10 research weeks DoE facility milestone