Commissioning of high power LH operation J. R. Wilson, S. Bernabei, J Commissioning of high power LH operation J.R. Wilson, S. Bernabei, J.C. Hosea Goal: Establish operating power limits, Position of coupler, outer gap as function of plasma density Empirical laws derived from past experiments show that the coupler (4 arrays) should be capable of 2 MW power launched in the plasma. above ~1.7 MW source might need some conditioning. B = width of the waveguide

Coupling at high power Check coupling at high power: ponderomotive effects could affect the plasma in front of the coupler. Scan of plasma-coupler gap is most important. Move coupler respect to Molybdenum limiters. Scan of density and scan of plasma position.

Scans at high power We will not know the precise conditions of the plasma in front of the waveguides. Therefore, since all the modeling scans assume either a value for the density, or for the gradient of density, or for the gap, it will be essential during operation to expand modeling to try to arrive at some sort of matching. An important clue for the existence of ponderomotive forces will be the comparison of coupling in the four arrays.