SOL Reflectometer for Alcator C-Mod

Conference · Tue Jan 01 00:00:00 EST 2008

OSTI ID:958879

Hanson, Gregory R ^[1]; Wilgen, John B ^[1]; Wukitch, Dr. Steve ^[2]; Lin, Dr. Yijun ^[2]; Lau, Cornwall H ^[2]; Wallace, Gregory M ^[2]

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1. ORNL
2. Massachusetts Institute of Technology (MIT)

A two-frequency x-mode reflectometer operating from 100 146 GHz is being deployed on Alcator C-Mod to measure the density profile and fluctuations in the scrape-off layer (SOL) immediately in-front of the new J-port ICRF antenna and the new B-port Lower Hybrid launcher. The reflectometer will cover densities from 1016 to 1020 m-3 at 5 5.4 T. To provide the greatest flexibility and capability to deal with density fluctuations approaching 100% peak to peak in the SOL, both full-phase and differential-phase measurement capabilities with sweep speeds of ~10 s to >1 ms are being implemented. The differential-phase measurement will use a difference-frequency of 500 MHz, corresponding to cutoff layer separations ranging from about 0.1 mm to 1 mm. The reflectometer will have 6 sets of launchers: 3 on the J-port ICRF antenna and 3 on the B-port LHRF launcher. The ICRF and LHRF antennas will incorporate reflectometer antennas at their top, bottom and mid-plane locations.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 958879
• Resource Relation: Conference: 17th Topical Conference on High-Temperature Plasma Diagnostics, Albuquerque, NM, USA, 20080512, 20080516
• Country of Publication: United States
• Language: English