Post on 18-Jul-2019
C-Mod Quarterly ReviewFY2009 Q3
21 July 2009
Developing the steady state, high-Z wall,
high-field tokamak for ITER and beyond
FY09 Q3 Status and Plans
• Alternator Recertified (April, 2009)– Now in service and operating normally
• Disassembly, inspection, TF refurbishment complete– Also improved LN2 systems, vessel heaters, etc.
• Lower Hybrid Launcher– Delayed by combination of redeployment of
engineering resources to deal with alternator and unexpected technical issues
– Installation after end of FY09 campaign• Advanced ICRF antenna
– Aimed at strong reduction of RF sheath induced impurity generation
– Design progressing well, schedule can be accelerated with ARRA incremental funding
FY09 Q3 Status and Plans
• Successful Ideas Forum (April, 2009)– >130 presentations, including strong student,
collaborator and international participation– Follow-up planning and prioritization
• FY09 research campaign underway– Completed 1.2 research weeks (as of July 17) out of
planned 9 weeks total– Decreased emphasis on Advanced Scenarios; will
increase in FY10• ARRA increments will enable significant facility and
diagnostic enhancements, plus 6 additional research run weeks in FY10
MIT/PSFC Generator:Summary of re-certification process
DoE quarterly review2009/07/21
C-Mod’s generator rotor
C-Mod’s generator rotor
Extensive inspections and materials tests were done by outside firms and by MIT PSFC
• WesDyne performed an independent NDE re-examination (ultrasound, bore inspection, eddy current)
• ReGENco and Structural Integrity Associates independently analyzed both GE and WesDyne inspection data sets
• Continental Field Services obtained internal ring samples from the bore transition region at each end of the rotor for materials tests
• The locations of all machining were smoothed and honed after samples were removed
• Extensive materials properties tests for both forging rings werecarried out according to ASTM specifications
• Chemistry (from bore chips)• Ultrasound imaging• Tensile tests• Fracture toughness tests• Cyclic fatigue crack growth tests• Microstructural and fractographic analysis
Bore Ring from the Collector End Transition Region
RotorCollector end ring sample
UIltrasound Images of the Bore Rings
Collector EndFlywheel End
Metals Testing Company, South Windsor, Connecticut
Locations of Samples from the Collector End Ring
Compact Tension (Fracture Toughness) and Crack Growth
sample locationsTensile sample locations
Samples, before and after testing
Tensile
Fracture Toughness
Crack Growth
1 inch
Testing carried out by Peter Stahle (Research Engineer, NSE) under supervision of Ron Ballinger
Microstructural and Fractographic AnalysisReveals No Evidence of In-Service Changes
200 μm• SEM and X-ray analyses carried out by Michael Short and Ron Ballinger
• Main conclusions:─ Microstructure observations
imply no change in rotor since forging
─ Chemistry control implemented correctly (sulphur bound with Mn)
─ Presence of oxides, decarburized layers and MnS precipitates implies voids formed during forging
─ Absence of cracks growing from existing voids suggests stresses well below limits
Typical microstructure and voids in a sample from the collector end bore ring
Crack Growth Rates more than a Factor of 10 Slowerthan “Conservative” Assumed Rates
Table 1. Results of 2009 bore sample materials testing Forging: Collector End Sample Test Results 0.2% Yield Ultimate Elong. Red. Area Temp.
(oC)CE-TS-A-1 Tensile 90.6 ksi 111.8 ksi 13.0 % 30.3% 60 CE-TS-A-2 Tensile 88.6 ksi 111.8 ksi 10.8% 39.4% 60 CE-TS-B-4 Tensile 79.9 ksi 99.6 ksi 4.8% 4.3% 64 CE-TS-B-5 Tensile 84.7 ksi 103.1 ksi 7.4% 10.1% 64
K_Jq [ksi*sqrt(inch)] CE-CT-1* Fract. Tough. 69.5 64 CE-CT-2 Fract. Tough. 79.6 64 CE-CT-3 Fract. Tough. 80.6 64
Paris Fit (inch/cycle) Max K CE-CG-A-1, 2 Crack Growth da/dn=5.7e-10* K^2.80 50.4 22 Forging: Flywheel End Sample Test Results 0.2% Yield Ultimate Elong. Red. Area Temp.
(oC)FE-TS-A-3 Tensile 72.2 ksi 96.9 ksi 64 FE-TS-A-5 Tensile 100.0 ksi 132.4 ksi 15.6% 36.4% 64 FE-TS-A-6 Tensile 73.7 ksi 98.6 ksi 64
K_Jq [ksi*sqrt(inch)] FE-CT-1 Fract. Tough. 118.2 64 FE-CT-3 Fract. Tough. 135.1 64
Paris Fit (inch/cycle) Max K FE-CG-A-1, 2 Crack Growth da/dn=3.7e-11* K^3.65 50.0 22
* Dimensions of CE-CT -1 did not conform to the ASTM specifications, and the sample had a curved back; K value has been increased by 8%, based on 3-d ALGOR simulations
Structural Integrity Associates recommendations:Rotor is fit for service with significant safety factors
ReGENco Recommendations:Rotor can continue to run in service as-is.
Summary
• All materials tests have shown that the rotor steel has good properties, well beyond those used in the conservative assumptions of industry specialists
• Two independent outside expert analyses have certified that the rotor is fit for continued safe service
Considering the rotor alone, operation for at least 12 calendar years before the next boresonic inspection is recommended
– Other components (bearings, for example) can require more frequent inspection; we will continue to observe industry standards and expert recommendations for inspection intervals
• A detailed report was prepared and presented to MIT Prof. C. Canizares (VP for Research & Associate provost) in a meeting on 2009/04/17. At the conclusion of that meeting, Prof. Canizares officially approved returning the generator to service.
Generator is back in operation
• Westinghouse reassembled the generator and performed high-voltage electrical tests and full-speed vibration tests (April – May). The generator passed all tests.
• The generator is now in regular operation at full performance for the 2009 C-Mod run campaign.
1
DoE Quarterly Review07/21/09
Status of Machine and Alternator
2
FY2009 Campaign History
• Initial Pumpdown on 6/10/2009• Bake and ECDC cleanup of vessel• First full cooldown and initial power testing on
6/18/2009• First plasma 6/24/2009• Completed 1.2 weeks of our 9 week 2009 campaign
(220 discharges) as of 7/17/2009• H/(H+D) is at the 10 to 20% level
– Efficient minority heating– Transmitters coming back online– Preparing for first boronization
3
Machine Status
• From 5/23/2008 to 6/10/2009 C-Mod was completely disassembled, inspected, and reassembled– All TF feltmetal was replaced– All connections, coaxes, cooling lines, and instrumentation were
inspected and refurbished– A great deal of in-vessel work done in support of new diagnostics
• Upgrades to Machine– Improvements to TF cooling
• Vertical leg cooling from one to two manifolds with separate control valves
• Improvements to instrumentation cabling• Improvements to inspection process of liquid nitrogen fittings• Shot cycle time clearly reduced
– Several more discharges/day– Less liquid nitrogen used
– Improvements to vessel heater system -- Thermocouple located in center of each heater for improved feedback control
– OH stack preload increased -- Changes to Belleville washer stack and OH support blocks reduces tension in stack
4
Alternator Status
• Alternator has been successfully returned to service and has provided primary power for C-Mod as needed
• No re-balancing of the rotor was required• Vibration levels are all well below industry standard
recommendations• We continue to improve instrumentation
– All vibration levels trended on PLC and stored in MDSPlus tree.
– Levels also recorded by data acquisition system during shot
– All critical temperatures and pressures now trended by PLC and also stored in tree
5
Diagnostic Status
• Diagnostics– Greatly improved edge diagnostics now operational in
support of FY2010 USDoE Joint Facilities Milestone
Conduct experiments on major fusion facilities to improve understanding of the heat transport in the tokamak scrape-off layer (SOL) plasma, strengthening the basis for projecting divertor conditions in ITER
• Scanning and embedded probes• Thermocouples in divertor and limiter tiles• Surface thermocouples• IR and visible cameras• Divertor bolometry• Emissive probes• Improved Spectroscopy
Spectroscopic Views of GH Limiter
Boron Coated Tilesand New Instrumentation
6
Status
• Diagnostics – MSE (PPPL/MIT)
• Worked to reduce shot-to-shot variation in MSE baseline data
• Design changes made to reduce temperature gradients across the collection optics lenses that result in stress induced birefringence
– Polarimetry• Full mock-up of a C-Mod polarimeter chord
being developed in the polarimeter lab• 3-Chord system to be installed before end of
current campaign• Upgrade number of chords with ARRA
funds for 2010 campaign
MSE Heat Shield
3-Chord Polarimeter
7
Plans
• Operation– 2009 campaign concludes end of September– Short up-to-air to install new lower hybrid launcher– First part of 2010 campaign through late spring
• Primary focus – operation of new launcher– Up-to-air to install new 4-strap ICRF antenna– Complete 2010 campaign
Lower Hybrid Launcher Status as of 07/21/2009
C-Mod Engineering Group
Status
• We had planned to install the launcher during the last up-to-air, however– Large amount of engineering effort went into
recertification of the alternator– Issues with cracking/vacuum leaks of stainless steel
waveguide components during e-beam welding as a result of the EDM process have added several more weeks of delay
– We now plan to install launcher in early October following 2009 run campaign
Status
Cracks in the steel near the weld at transformer
Vacuum leaks in the front waveguides in steel
Plasma facing guides and vacuum windows
• Leaks in front waveguides have been successfully repaired
• Testing underway for repair of waveguide at transformer
Status• Front waveguide assemblies have been welded onto nine
of sixteen 4-way splitters, and they have been successfully leakchecked
• Four 4-way splitters have front waveguide assemblies aligned and tacked in place and are ready for welding
• Three 4-way splitters are waiting to be brazed and butt- welded– 9 forward waveguide assemblies ready for brazing– 3 forward waveguide assemblies ready for welding
• Copper WR187 waveguides have been prepared for installation
• Brazing of WR-187 waveguides to the transformers will be done in-house using our induction heater
Status
Welding of the Aluminum Frame complete this week
Welding of the Bellows Box Assembly begins this week
New Rails with the Rail Carriage Blocks are ready for installation
All Waveguides
in-housePort extensionComplete and Installed in vessel
Manufacture of Rear Attachment plate has begun in-house
16 Rear Waveguides ready for installation
Gaskets annealed and cleaned.
Support Structure manufactured and in-house.
Support Box Tubes manufactured
Support plates for dummy wave-guide at welderAll other support plates in-house
Support bearings complete
Probes & probe supportPlates complete & in-house
(Not shown)
Plans
• Complete launcher assembly– Leakcheck all vacuum components– Power test all high power components before assembly
• Bake and leakcheck assembled launcher in test chamber• Prepare waveguide runs to launcher
– Launcher fed by 10 klystrons– 4 central 4-way splitters run at full available klystron power
(allows power handling limits of launcher to be tested)– 12 remaining 4-way splitters fed by remaining 6 klystrons
(following 3db splitter) • Launcher ready for installation 9/09
EOT
Present design
4-way splitterSS/copper plated
transformer
Copper C101Diffusion brazeSS-to-Cu
SS wave-guide
EBW butt joint
Present transformer
Modified transformer
Status of C-Mod 4-Strap ICRF Antenna
July 21, 2009 MIT PSFC, Cambridge MA 02139
S.J. Wukitch, W.K. Beck, M. Garret, P. Koert, Y. Lin, N.P. Mucic
General Requirements for New Antenna
Design is to be based upon the modified J antenna while targeting performance 25% higher in voltage than D and E antennas.• Reduce boronization erosion and impurity production.Reduce boronization erosion and impurity production.• Improve voltage and power handling.
Antenna general specifications:g p• Operate at 2 MW (down from 3 MW) and 50 kV,• Have pulse length up to 5 seconds at repetition time of 1800 s,• Have thermal loads at plasma limiter of 12 MW/m2 with a 3 mm scrape-
off length,• Withstand a disruption load of 1 T/msec at 9 T, • Utilize single horizontal port, and
H 50 80 MH• Have 50-80 MHz range.
Reliability is a critical issue.Antenna assembly in-vessel needs to be efficient.Diagnostics should be built into the design from the outset.
Proposed ICRF Antenna
Proposed ICRF 4-Strap Antenna
All dimensions in cm Proposed
F ll li i 91 0Full limiter 91.0
Antenna limiter 91.3
F d d 91 7Faraday rod 91.7
Clearance between rod and strap
0.7
Feedthrus are 5” diameter (present are 4.5”).Power density at 2 MW (3MW) is 9 8 MW/m2 (14 8 MW/m2)
Strap Face radius 93.45
Power density at 2 MW (3MW) is 9.8 MW/m2 (14.8 MW/m2)Strip line impedance is 30 Ω (J is 50 Ω and D/E is 30 Ω)Screen is aligned to B-field and is 50% transparent (same as J)Peak nφ = 14 (0,π,0,π); 11 (0,π,π,0); and 8 (0,π/2,π,3π/2) in vacuum
spectrum (bit higher than J antenna).
Summary of Design Progress
Conceptual Design review held at MIT December 19, 2008.• Dave Rasmussen, Phil Ryan, and Rick Goulding (ORNL); Bob Pinsker
(GA); and Randy Wilson (PPPL).( ); y ( )Order has been placed for 5” feedthrus.Folded strap geometry has been decided.
• Similar in shape as J antenna but a bit shorterSimilar in shape as J antenna but a bit shorter.Impact of rotation on E|| fields has been investigated.
• Used lossy dielectric to model plasma load.• Have begun cold plasma modeling with artificial plasma loading toHave begun cold plasma modeling with artificial plasma loading to
investigate validity of lossy dielectric model.Detailed RF modeling to reduce areas of high electric field.
• Completed modeling of coax to strip line transition.p g p• Antenna strap connection and bridge section are yet to be completed.
Manufacturing of material testing device is underway.• Test high strength, high melting temperature materials against copper to g g , g g p g pp
investigate if significant voltage handling can be realized.
Antenna ⊥ Total B-field Reduces Integrated E||
Reduce coupled E|| by making antenna symmetric along a field line.
• Modeled antenna with lossy• Modeled antenna with lossydielectric.
• For 10° rotation, reduction at the strap ends is ~10 and at the midplane ~30midplane ~30.
For comparison, impurity production from [0,π] is significantly improved compared to [0,0].p p [ ]
Integrated E|| is reduced by factor of 2-3.
P t l h llPresents several challenges.• Geometry is more complex.• Geometry decreases the area available to couple by ~25%.• Forced us to confront helical geometry and associated complexities. g y p• Assembly is greatly complicated.
RF Analysis Summary
Peak nφ = 14 (0,π,0,π); 11 (0,π,π,0); and 8 (0,π/2,π,3π/2) in vacuum spectrum.
Using lossy dielectric to approximate plasma loadUsing lossy dielectric to approximate plasma load.• Vacuum modeling has limited value.
» Current is low and difficult to assess importance of geometrical features.• Observe critical change in antenna currents and patterns with load, likely
to influence sheath formation.» Set load to be equivalent to observed J antenna Q.
• Investigated simple loop, folded and end fed center grounded strap configurationconfiguration.
» End-fed has clear advantage but limited access prevents utilization unless the number of straps is decreased to 2.
» Folded is more sensitive to load variations than end-fed but superior to simple loop.» Simple loop has largest reflection for all loads investigated.p p g g
• Plan to utilize COMSOL to investigate more realistic load conditions.Present antennas have highlighted regions where RF voltages are critical.
• Coax to strip line transition and bridge section of folded strap.p g pVacuum striplines are covered and connect at back of strap.
Replacing Cu with Material X to Improve Voltage Handling
DC breakdown studies show significantly higher breakdown field with refractory metals. 700
800900
A. Descoeudres et al., Proc. EPAC08.
Breakdown models suggest a four step process with differing trigger mechanisms.
• Mechanical breakup model – (J. Norem).» Fatigue can play significant role 300
400500600700]
m/V
M[E b» Fatigue can play significant role.
» External B field can
• Material melting model - (P. Wilson).» Gas trapped at grain boundaries play important
role. 0100200300
C W Vpc rZ u C oM
iTlA aT b rC Su
Identified vendor, Plasma Processes, that can VPS Mo and plate W onto Inconel 625.
C W VcdG
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Local test of materials and surface preparations will begin in August/September.• Utilize ridge wave guide transmission cavity to provide high electric field (100
MV/m).• Evaluate solid and film materials• Evaluate solid and film materials.
Summary
Design will be based upon the modified J antenna with the antenna rotated 10º such that the entire antenna structure is perpendicular to total magnetic field.
A iAntenna is to:• Operate at 2 MW (down from 3 MW) and 50 kV,• Have pulse length up to 5 seconds at repetition time of 1800 s,• Have thermal loads at plasma limiter of 12 MW/m2 with a 3 mm scrape-off length,
i h d di i l d f /• Withstand a disruption load of 1 T/msec at 9 T, • Utilize single horizontal port, and • Have 50-80 MHz range.
Impurity production is addressed by rotating antenna and enforcing symmetry along a 10º field line.
• Reduce E|| by factors of 10-30.• Results in 25% increase in power density for given power.Results in 25% increase in power density for given power.• Raises the peak in the toroidal vacuum spectrum
Utilize larger feedthrus, shortest vacuum transmission lines, and Mo or W instead of copper to achieve higher voltage and power handlingof copper to achieve higher voltage and power handling.
• Material tests are planned to begin in August/September.
Many Challenges for Antenna Performance
Many experiments request fault free, maximum power and minimum impurity production. 2
4 PRF (MW)
BT=5.4 T, IP=1 MA 10504260226
impurity production.Reduce boronization erosion and
impurity production.Load tolerance and robust coupling
0.1
0.2
0.3WMHD (MJ)
4 T 0 (keV)Load tolerance and robust coupling.• Utilize FFTs
Voltage and power handling.• Where E||B <10 kV/cm
2
3
4
Te0 (keV)
ne (x1020 m-3)
• Where E||B, <10 kV/cm.• Maximized size of feedthrus.• Utilize high strength, high melting
temperature material instead of
2
1
2 Rneut (x1014 s-1)
pcopper.
Antenna conditioning requirements. • Shorter vacuum transmission lines. 0.6 0.8 1 1.2 1.4
1
2
3PRad (MW)
Time (s)
Reducing ICRF Impurity Production
Underlying cause of impurity generation is thought to be generation of E||.
Insulating limiters did not eliminate RF
H-mode
L-mode
H-mode with
150
V]
Insulating limiters did not eliminate RF sheaths.
Simulations suggest E|| is generated by• Radial strip line generating unwanted
BN tiles100
ma
Po
ten
tial
[V
120015
• Radial strip line generating unwanted fields and
• Misalignment of current strap with total magnetic field.
50
Pla
sm
000516014-20, 22, 1031
1
∼P1/2
Proposed solution:• Rotate straps and antenna structure to
be perpendicular to total magnetic field.
1.51.00.50RF Power [MW]
1
• Ensure symmetry along total field line within near field of antenna.
Alcator C-Mod 2009 Ideas Forum
Jerry Hughes
OFES C-Mod Quarterly ReviewJuly 21, 2009
Hughes, “Alcator C-Mod 2009 Ideas Forum” OFES C-Mod Quarterly Review Slide 2 of ?
2009 Alcator C-Mod Ideas Forum
• What it is: An open, relatively informal, forum for presenting new experimental proposals (ideas), held every 1—2 years.
• Ideas Forum for FY09/10 was held April 6—8, 2009– Contributions from collaborators actively sought– Meeting was broadcast for remote participation
• Speakers were allowed 5 minutes per presentation (+2 for questions) – Motivation and Goals of proposal– General plan of execution (MP-level details not required)
Hughes, “Alcator C-Mod 2009 Ideas Forum” OFES C-Mod Quarterly Review Slide 3 of ?
Many valuable proposals were generated by this meeting • Final tally = 137
– Comparable to previous IF– Proportion of ideas submitted
under each topic also similar• Contributions from
collaborators: 27%– up from FY07 – Domestic, international
contributions– ITER Organization
• 28% of submissions were from students
• Proposals were organized into sessions (mostly) according to theme, and tagged with their author-identified topics
DD, Ops, Basic Sci.,
12
MHD, 9
Adv. Scenarios,
10
ICRF, 10
LH, 12Transport,
38
Divertor + Edge, 28
H-mode Scenarios,
18
Hughes, “Alcator C-Mod 2009 Ideas Forum” OFES C-Mod Quarterly Review Slide 4 of ?
Proposals were submitted under a long-standing topical categorization
Task Force Area (Primary Area, Alternate) Coordinator
Diagnostic Development (11, 4)
Basic Science (1, 0)
Operations (0, 2)Jim Irby
Transport (38, 15) Martin Greenwald
MHD (9, 0) Bob Granetz
Divertor/Edge (28, 5) Brian LaBombard
ICRF (10, 5) Yijun Lin
Lower Hybrid (12, 2) Randy Wilson (PPPL)
H-mode Baseline Integrated Scenarios (18, 7) Steve Wolfe
Advanced Integrated Scenarios (10, 3) Amanda Hubbard
Hughes, “Alcator C-Mod 2009 Ideas Forum” OFES C-Mod Quarterly Review Slide 5 of ?
Follow-up process has refined plans for run campaign
• April/May: Task Forces evaluated proposals to define priorities
– New Ideas presented– Ideas presented at previous Fora– Existing mini-proposals
• Combination and compromise to optimize machine usage, based on run-time guidance:– 9 weeks in FY09 – 13 weeks in FY10
• Initially focused on FY09• Task force leaders called open
meetings for discussions• Optional sub-topical meetings
useful for larger groups
Optional “sub-topical” groups:(e.g. rotation, ITBs)
Topical and thrust groups
(e.g. Transport)
Initial run-time allocations
Prioritization + consolidation of similar proposals
Ideas Forum
to the EPC
Hughes, “Alcator C-Mod 2009 Ideas Forum” OFES C-Mod Quarterly Review Slide 6 of ?
Follow-up process has refined plans for run campaign
• Cross-cutting program themes of strong interest received added attention, coordination:
• H-mode pedestal physics• Improved L-mode operation• Divertor heat flux diagnosis
Initial run-time allocations
Prioritization + consolidation of similar proposals
Ideas Forum
to the EPC
Hughes, “Alcator C-Mod 2009 Ideas Forum” OFES C-Mod Quarterly Review Slide 7 of ?
Follow-up process has refined plans for run campaign
• Outcome of follow-up planning includes a research plan for FY09 experimental campaign (more in Martin’s talk)
• High priority proposals are being expanded into mini-proposals
• Current and new MPs will drive schedule during the current and following run campaigns
• Experimental Program Committee meets frequently to review and approve new proposals
Initial run-time allocations
Prioritization + consolidation of similar proposals
Ideas Forum
to the EPC
Hughes, “Alcator C-Mod 2009 Ideas Forum” OFES C-Mod Quarterly Review Slide 8 of ?
Ideas Forum information, presentations will remain online indefinitely
2009 and previous IFs all found under “Research Program Information” link
http://www.psfc.mit.edu/research/alcator/program/ideas2009/
C-Mod Research Plan – Quarterly Review 7/21/2009
Alcator C-Mod Near-Term Research Plans
C-Mod Quarterly Review
7/21/2009
Presented by M. Greenwald
C-Mod Research Plan – Quarterly Review 7/21/2009
Initial Run Allocations for 2009
Topical Area Run Days
H-mode Scenarios 5
Advanced Scenarios 2
Operations and Diagnostic Development
3
Divertor/Edge 8
ICRF 4
MHD 3
Transport 11
Total 36
C-Mod Research Plan – Quarterly Review 7/21/2009
• Operations
– Characterize and correct error fields after reassembly
– Low Bt start-up
• Diagnostic commissioning
– Polarimeter
– New MSE w/ thermal shielding
Verifying magnetic reconstructions w/ constrained EFIT
– New heat-flux and divertor diagnostics
– New impurity injector
– etc.
Operations and Diagnostic Development
C-Mod Research Plan – Quarterly Review 7/21/2009
• Driven by ITER urgent needs
• “Pre-Nuclear” Scenarios
– L-H threshold, confinement, ELMs in H, He
• H-mode access – power requirement for good confinement
• ITER Scenario Demonstrations
– Ramp-up, ramp-down, dimensionless scaling
Themes – H-mode Scenarios
C-Mod Research Plan – Quarterly Review 7/21/2009
• Current profile and transport modification via LHCD
– Hybrid regimes – flat shear
– Advanced regimes – reversed shear
– Longer pulse development
• Two-frequency ICRF ITB work
• Low Bt start-up
• Mostly deferred to FY2010 due to LHCD & calendar constraints
Themes – Advanced Scenarios
C-Mod Research Plan – Quarterly Review 7/21/2009
• Heat-flux footprint (joint 2010 milestone)
– Interplay of parallel and perpendicular transport, atomic physics
– Supported by major diagnostic upgrades
– Initial data coming in
• SOL turbulence
– New 2D array for GPI supplements probes, fast cameras, etc.
• Hydrogen retention (joint 2009 milestone)
– (C-Mod experiments mostly complete)
• Physics of RF sheaths and impurity sources (w ICRF group)
Themes – Edge/Divertor
C-Mod Research Plan – Quarterly Review 7/21/2009
• RF sheaths and impurity sources
– New instrumentation (Katsumata, emissive probes)
– New boron coated tiles to mitigate impurity effects
• ICRF flow drive (via mode converted waves)
– Optimize driven rotation
– Understand mechanisms
• RF scenarios and fast-ion physics
– Broaden operating range and validate models
Themes – ICRF
C-Mod Research Plan – Quarterly Review 7/21/2009
• Commissioning of new launcher
• LHCD density limit
– Characterize scaling and mechanisms
– Comparison of L and H-modes
• Fast electron transport
• LHCD into enhanced L-modes
• Deferred to FY2010
Themes – Lower Hybrid
C-Mod Research Plan – Quarterly Review 7/21/2009
• Rotation and momentum transport
– ICRF flow drive – optimization and effects on transport
– Mechanisms for self-driven rotation and momentum transport
• Particle transport
– Quantitative comparisons w/simulation
– Impurity injection – new hardware
• Pedestals and L-H transition
– Turbulence and shear flows near transition
– Pedestal widths, gradient and underlying physics, scaling
• Enhanced L-mode – physics and optimization
Themes – Transport
C-Mod Research Plan – Quarterly Review 7/21/2009
• Disruption related
– Runaway electron physics and disruptions
(Most require LHCD – deferred)
– Runaways in non-disruptive discharges
– 3D radiation distribution during gas-jet mitigated disruptions
• Fast particle modes
– RSAE tunneling
• Non-resonant rotation breaking – β dependence
Themes – MHD
ARRA Supplemental Proposal – FY09-10
C-Mod Quarterly ReviewFY2009 Q3
21 July 2009
Developing the steady state, high-Z wall,
high-field tokamak for ITER and beyond
ARRA “Stimulus” Funding Proposal
• Enhance Facility Operations– Increase by 6 research weeks in FY10– Currently only about 1/3 of priority research
accommodated within guidance run-time• Facility Enhancements and Upgrades
– Speed implementation of advanced ICRF antenna, testing sheath reduction
– Complete Fast-Ferrite ICRF tuners for real-time matching (add 3 systems to existing 1)
– Upgrade to 4 MW total microwave source power for LHCD
• Addition of 7 new klystrons• Completion of 4’th control cart
– Upgrades to DNB power systems• Reduced power requirements• Improved reliability/availability
ARRA “Stimulus” Funding Proposal
• Diagnostic upgrades– Polarimeter upgrades to increase spatial resolution
• Along with MSE, provides current density profile measurements
• Also has application to magnetic field fluctuations
– New divertor spectrometer diagnostic to monitor Mo and W sources• Particularly important for ICRF induced sheath
studies
ARRA Proposal Budgets
• Research Runtime: $935k• ICRF antennas: $1130k• FFT real-time matching: $940k• Klystron microwave sources (LH): $1450k• 4th cart and control upgrades for LH: $810k• Polarimeter upgrade: $150k• Divertor spectrometer: $50k
• Total $5895k