J. Boedo, UCSD UCSD Program at NCSX J. Boedo for The UCSD and NCSX Teams

J. Boedo, UCSD Scanning Fast Probe General Information: –Rotatable shaft (adjust to pitch angle) –10 tips (1xIsat, 2xDP, 2xImach, 4xVf (Er, E  ) –Measures: Te, Ne (~3 ms), Isat, 2xE r, 2x E   Mach #, V par,  r, V r, etc) –Yet to be implemented (Fast Te) –Bandwidth ~ 4 MHz –DAQ Sampling 1MS/s –In/out time ~ 80 ms –Pedestal (-6 cm) penetration in lowish power plasmas (2 MW) There is spare probe it PPPL! –Head and shaft from exiting probe –Needs new control system –Use existing electronics box –Can move some kepcos, ideally new ones

J. Boedo, UCSD SFP: Fundamental Potential Contributions DIII-D measurements during I-Coil experiments show: –Potential increases (electron loss?) –Shift in Isat (due to boundary being pushed or pulled) –Increase in Ne and Vr fluctuations (core density drops) –Te fluctuations drop! High spatial resolution and dense measurements important when geometry counts! NSTX Physics we can test:  NCSX has low flow-damping >> Mach probe  Can manipulate flows for flow-shear stabilization. Can vary ripple to study:  Effects of flow damping >> Mach Probe  Zonal flows should be similar or larger than equiv. tokamak >> Measure Reynolds Stress  Designed to eliminate resonant field perturbations >> Ne, Te Vp structures  Designed for good flux surfaces at vacuum, intermediate and high  >> dito  High density operation  Lower plasma edge temperature >> Measure  Greenwald limit impervious? >> Look at intermittency  Design PFCs >> Determine SOL/edge profiles

J. Boedo, UCSD Field Effects Require Fine Resolution I-Coil experiments at DIII Perturbation at edge is narrow Fluctuations change

J. Boedo, UCSD Swinging Arm Probe Used in ASDEX and ALCATOR Proposed for DIII-D Very Compact, tucked in tiles Measurement capabilities (# tips, # cables, complexity) depend on space Can be placed in divertor or wall structures Smick et al, JNM 2005

J. Boedo, UCSD Limiter Probes/Calorimeters Modular system (instrumented tile) w probes and calorimeters Rooftop probes. Brazed contacts Staggered design for high spatial resolution Crucial for PFC design and Heat/particle load evaluation

J. Boedo, UCSD Fast Bolometer/SXR array 30 channels on DIII-D Fast total radiated power estimate during disruption Modular system, in vacuum Sensitive to radiated power over wide energy range (1 eV - 10 keV) UV to SXR. Filter wheel..remote! Fast time response (up to 2 MHz). Can be filtered to look at different energy ranges Multicolor system easy Relatively inexpensive ~$25k! Divertor ELM brightness Shell inversion of emission during disruption (center post) Uses for NCSX: Plasma position Rough Te (breemstrahlung) Rough impurity monitor Plasma control?

J. Boedo, UCSD Fast Multi-Color Cameras Re-entrant optics w/ periscope for tangential view OR Radial view Tangential or radial view imaging whole plasma –Two or more cameras w beam splitters and filter wheels –One camera with a rotating filter wheel (air or belt) Use He-I lines 668, 728, 706 nm for: –Imaging plasma boundary –Measuring ne, Te in the edge > Band at the edge (puff some He) –Other impurities (CI, CII, CIII) localize radial region > impurity monitoring –Plasma positioning –Plasma wall contact Filter wheel Periscope Movable Mirror Beam splitter Camera 1 Camera 2 Lens

J. Boedo, UCSD Fast Multi-Color Cameras CMOS chip with 12 bit pixel depth. 1 pixel corresponds to ~0.4cm in vessel. 800x600 max spatial resolution. Typically run at 256x256 res., with max possible frame rate of 26,000 sec -1. Camera RAM = 2.8 GB (21,680 frames at 256x256). 50mm collimating lens Filter Wheel Boronated polyethelyne shielding box Phantom 7.1 Camera 12mm objective lens 50mm camera lens Fiber Bundle (2.73m) Or periscope Vacuum window at 90R0 Object CIII filter, f = 5000 sec -1, exposure = 180  s Inter-ELM imageELM filaments

J. Boedo, UCSD Movable Divertor Plates Pivoting point and only change angle Two movable points Similar to movable limiters in ALT-II collaboration Wormscrew actuated from outside (magnetically connected feedthru) Vessel Pivot point Actuator Divertor plate

J. Boedo, UCSD Additional Slides

J. Boedo, UCSD

divertor vacuum vessel