ICRF Heating Scenarios for SPARC

In this talk we will present an overview of the most recent analysis of the ion cyclotron radio frequency (ICRF) heating performance in SPARC H and L-mode scenarios. This includes discussion of the absorbed power fractions that are predicted during both high and low field operation and the status of analysis of RF sheath formation and the potential ICRF coupling during plasma formation.

SPARC is designed to have a 25 MW coupled ICRF system as its sole proposed auxiliary heating method. Even with the expected single pass absorption of approximately 90%, power on the order of 1MW can reach the high field side. We will present analysis of sheath formation and power loss in the far scrape-off layer and plasma facing components. ICRF sources have to efficiently heat the plasma during current ramp up and flat top at two nominal magnetic field strengths. Each of these require different species mixtures for activate and non-activated phases. Using TORIC and AORSA simulations with Fokker-Planck analysis from FPPRF and CQL3D we will characterize the single pass absorption and optimal minority fractions for efficient core heating in each of these regimes.