1. D. A. Rasmussen, NCSX Research Forum 2006 Page 1 ECH and Fast Wave Electron Heating Systems for NCSX Tim Bigelow, Dave Rasmussen, Phil Ryan, Mike Cole ORNL Joel Hosea, Elmer Fredd PPPL

2. D. A. Rasmussen, NCSX Research Forum 2006 Page 2 Utilize existing standalone gyrotron @28 GHz – 40 kW for 500 ms. – Socket can be upgraded to 200 kW with HV supply Replace 25 kA ohmic First Plasma scenario with currentless ECH Eliminates iota profile control complications from ohmic currents ECH could be used to selectively heat passing or trapped populations for confinement studies. Low power CW ECH at low B field may be a useful for vessel conditioning 28 GHz ECH has multiple applications on NCSX

3. D. A. Rasmussen, NCSX Research Forum 2006 Page 3 Standalone - Gyrotron, HV power supply socket, magnet, water manifold Footprint is 4’x6’ Controls, magnet, waveguide all compatible with 200 kW cw power upgrade at 28 GHz using existing PPPL supplies

4. D. A. Rasmussen, NCSX Research Forum 2006 Page 4 Inside vacuum Waveguide and launcher configuration Block Diagram - Proposed NCSX 28 GHz ECH System

5. D. A. Rasmussen, NCSX Research Forum 2006 Page 5 ATF ECH launcher A modified version of the ATF ECH launcher could be used on NCSX

6. D. A. Rasmussen, NCSX Research Forum 2006 Page 6 ICRF fast wave heating on NCSX with a 57 MHz FWG antenna 2-4 MW of tunable ICRF transmitters located adjacent to NCSX test cell (can be retuned in ~ 1 month) Utilize direct electron heating mode at 57 MHz, 0.5 -1.2 T IBW mode may also be feasible Tilt antenna to match edge field line pitch 40 kW 28 GHz startup could provide adequate target plasma Loading modeling for startup and other target plasmas can be done by M. Carter

7. D. A. Rasmussen, NCSX Research Forum 2006 Page 7 57 MHZ FOLDED WAVEGUIDE Monopole or dipole face plates provide options on wave launch spectrum Rear coaxial feed and coupling loop Vacuum tank to enclose antenna allows arbitrary antenna rotation angle Monopole Dipole

8. D. A. Rasmussen, NCSX Research Forum 2006 Page 8 FWG can be mounted on a NB port 57 MHz folded WG will fit on NCSX NB port Coils and cryostat do not appear to interfere Folded WG can be rotated in port for field line optimization and IBW experiments

9. D. A. Rasmussen, NCSX Research Forum 2006 Page 9 Approximately to Scale drawing of FWG on NCSX NB port FWG body Existing FWG Vacuum tank Coaxial RF feed line Vacuum Interface Flange and in-vessel Support structure

10. D. A. Rasmussen, NCSX Research Forum 2006 Page 10

11. D. A. Rasmussen, NCSX Research Forum 2006 Page 11 PPPL ICRF transmitters can be utilized to drive the FWG Two FMIT units 40-80 MHz ~ 2 MW each; can be combined Can be tuned to 57 MHz in < 1 month Transmission line to NCSX exists to wall Tuner, RF instrumentation installed and operational