Effect of wall boundary on the scrape-off layer losses of high harmonic fast wave in NSTX and NSTX-U
We perform numerical simulations of high harmonic fast waves (HHFWs) in the scrape-off-layer (SOL) of National Spherical Torus Experiment (NSTX)/NSTX-U using a recently developed 2D full wave code. We particularly show that a realistic NSTX SOL boundary can significantly affect HHFW propagation and power losses in the SOL. In NSTX SOL boundaries, HHFW is easily localized near the antenna and propagates less to the SOL, and thus, less power is lost to the SOL. Here, we also show that the lower SOL power losses occur when the SOL volume is smaller and the distance between the last closed flux surfacemore »