Upgrades to the 4-strap ICRF Antenna in Alcator C-Mod

Schilling, G. ; Hosea, J.C. ; Wilson, J.R. ; Beck, W. ; Boivin, R.L. ; Bonoli, P.T. ; Gwinn, D. ; Lee, W.E. ; Nelson-Melby, E. ; Porkolab, M. ; Vieira, R. ; Wukitch, S.J. ; Goetz, and J.A.

Princeton University. Plasma Physics Laboratory.

关键词: Modifications;    Alcator Device;    70 Plasma Physics And Fusion Technology;    First Wall;    H-Mode Plasma Confinement;   

DOI  :  10.2172/786538
RP-ID  :  PPPL-3575
RP-ID  :  AC02-76CH03073
RP-ID  :  786538

美国|英语

来源: UNT Digital Library

【 摘 要 】

A 4-strap ICRF antenna suitable for plasma heating and current drive has been designed and fabricated for the Alcator C-Mod tokamak. Initial operation in plasma was limited by high metallic impurity injection resulting from front surface arcing between protection tiles and from current straps to Faraday shields. Antenna modifications were made in February 2000, resulting in impurity reduction, but low-heating efficiency was observed when the antenna was operated in its 4-strap rather than a 2-strap configuration. Further modifications were made in July 2000, with the installation of BN plasma-facing tiles and radio- frequency bypassing of the antenna backplane edges and ends to reduce potential leakage coupling to plasma surface modes. Good heating efficiency was now observed in both heating configurations, but coupled power was limited to 2.5 MW in H-mode, 3 MW in L-mode, by plasma-wall interactions. Additional modifications were started in February 2001 and will be completed by this meeting. All the above upgrades and their effect on antenna performance will be presented.