Real-time estimates of the ICRF single-pass absorption for ITER

¹ Laboratory for Plasma Physics, ERM/KMS, B-1000 Brussels, Belgium
² ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul-lez-Durance Cedex, France

^* Corresponding author: Ernesto.Lerche@mil.be

Published online: 7 January 2026

Abstract

Estimating the single-pass absorption (SPA) of a given Ion Cyclotron Resonance Heating (ICRH) scenario as function of the plasma and the radio-frequency (RF) wave properties requires a multispecies hot plasma wave solver. Even in 1D and using truncated finite Larmor radius expansion for the plasma dielectric response, the simulations cannot be done much faster than in a couple of seconds. In ITER, it is envisaged to estimate the single-pass absorption of the ICRF waves in real-time to take preventive actions in case of poor absorption for avoiding increased plasma-wall interaction and enhanced heat loads on the plasma facing components. This work proposes a potential solution based on pre-calculated look-up tables of the ICRF single-pass absorption that can be interpolated in real-time by the Advanced Protection System (APS) and by the Plasma Control System (PCS) in ITER [1,2,3] during the discharge evolution. The tables can also be used as input for the Pulse Design Simulator (PDS) [4] and other modelling tools that require the ICRF absorption information for control and/or protection. The SPA tables are produced as function of the dominant parameters governing the RF wave propagation and absorption using the 1D TOMCAT code [5] for some ITER-relevant ICRH scenarios.