Patent Number: 052895092
Section: abstract

A comb-line antenna structure (80) includes a multiplicity of parallel current straps (86) through which an appropriate rf electrical current passes in order to launch a desired magnetosonic wave (42) into an adjacent plasma mass (39). The current straps are mounted within a conductive, shallow, open box (88, 90) that faces the plasma mass. The current straps are inductively coupled, thereby requiring only a single rf input port (82) at one end of the comb-line structure. The rf input port provides a substantially constant impedance to an rf power source. A single rf output port (84) at the other end of the comb-line structure allows for the recirculation of the rf power. A multiplicity of U-shaped wickets (92) loop over and enclose each current strap. Such wickets function as a Faraday shield to shield the plasma and adjacent current straps from electrostatic fields. The comb-line antenna structure finds primarily applicability in providing plasma heating and/or current drive in a tokamak, or equivalent plasma-forming structures.