IC wall conditioning antenna for W7-X with potential for heating and fast particle generation

The current planning of IC systems in W7-X foresees in a first phase the construction of a single strap IC wall conditioning (ICWC) antenna, fed by one generator providing max 1MW at frequencies between 4 and 26 MHz. While this system is expected to be well suited for ICWC applications, we show that it could also be used for ICRF plasma heating and current drive (H&CD) upon making modest modifications to the original design and adding a second generator. A two strap antenna design is proposed (i) with at least the same performance for wall conditioning as the original design; (ii) allowing flexible relative strap phasings for ICRF heating, fast particle generation and/or current drive; (iii) using the full ICRH power from the two generators available; (iv) with a compact design, such that it can be embedded in the wall panels, causing minimal perturbations for various magnetic configurations. The use of such an antenna would allow exploring experimentally various H&CD scenarios, and generate the necessary data sets for validating numerical tools. Experimental tests of various H&CD scenarios now, would thus offer important advantages for the design of a dedicated H&CD antenna later.