High harmonic fast waves heating revisited*

In this work we revisit the available modeling on high harmonic fast wave (HHFW) heating regime, which was originally proposed in 1995 by M. Ono [Ono, Phys. Plasmas 2, 4075 (1995)]. NSTX-Upgrade (NSTX-U) is presently scheduled to operate with toroidal magnetic fields (B_T) up to 1 T, which is nearly twice the B_T value used in the experiments on NSTX, and with NBI power up to 10 MW. The doubling of both magnetic field and the NBI power in NSTX-U retaining the 30 MHz rf source frequency can strongly affect the power absorption partitioning. For this reason, it is crucial to have an accurate model to  evaluate the power absorbed by electron, fast and thermal ions for experimental analysis. Detailed benchmarking comparisons between the full wave codes TORIC v.5 [Brambilla, Plasma Phys. Control. Fus. 44, 2423 (2002)], TORIC v.7 [Brambilla and Bilato, Nucl. Fus. 55, 023016 (2015)], AORSA [Jaeger et al, Phys. Plasmas 8, 1573 (2001)], and the Petra-M FEM framework [Shiraiwa et al, Nucl. Fus. 63, 026024 (2023)] assuming a local hot dielectric tensor, will be presented. Potential limitations, advantages, and improvements of each code/model will be also discussed.