ICRF heating schemes for the ITER non-active phase

Abstract

Abstract. ITER plasma operation requires a non-active phase for tokamak initial commissioning, covering First Plasma and Pre-Fusion Power Operation phases, PFPO-1 and PFPO-2. Non-active operation consists of hydrogen and helium plasmas to minimize the neutron production rate. The present document describes some Ion Cyclotron Radio Frequency (ICRF) heating schemes in terms of their predicted performance for the main foreseen scenarios of the ITER non-active phase in hydrogen and helium. Emphasis is given on remaining issues and physics uncertainties to be addressed for successful ICRF heating in ITER.

A fast tool for ICRH + NBI modelling within the EU-IM framework

“…While beam deposition profiles are commonly very wide (the beam ionisation starts taking place as soon as the neutral beam penetrates a plasma of sufficient density), ICRH can deposit power in a much more localised way. For that reason, ICRH has become of the tool of reference to chase high Z impurities from the core and to 'land' JET discharges (Goniche et al 2014;Lerche et al 2017;Litaudon et al 2017). Understanding the interplay between NBI and ICRH is crucial for optimising high performance JET shots.…”

“…Available codes are compiled as ‘actors’ and can be linked together in a flexible way via a ‘Kepler’ graphical user interface (The Kepler Project 2008) or, more directly, via a Python wrapper (Schneider et al. 2017). More importantly, the common input and output structure allows us to interchange codes which look into a specific aspect of the physics with other similar ones.…”

“…(2019) for an application of the ICRH+NBI heating modules in ETS focused on JET and Schneider et al. (2017, 2019, 2020) for ITER applications. To account for the birth of fusion-born populations and to compute accurate estimates of the neutron production in deuteron–tritium (D–T) plasmas, data banks of nuclear cross-sections are interfaced with ETS (Coster et al.…”

“…A dedicated team ensures the backbone is maintained, and contributors, external to the basic team, make their codes conform to the backbone to allow their codes to run in a bigger 'workflow'. Available codes are compiled as 'actors' and can be linked together in a flexible way via a 'Kepler' graphical user interface (The Kepler Project 2008) or, more directly, via a Python wrapper (Schneider et al 2017). More importantly, the common input and output structure allows us to interchange codes which look into a specific aspect of the physics with other similar ones.…”

Solving the all-FLR ICRH integro-differential wave equation as a high-order differential equation for studying combined ICRH-NBI heating

“…Prior to D − T operation, the ITER team will test the proper working of the machine by gradually stepping up field and current, making use of heating methods available at that time. Suitable RF heating schemes have been identified at 1/3 and 1/2 of the nominal magnetic field strength [61,62]. The physics reason is the beneficial scaling of the heating efficiency with the magnetic field strength: Harmonic heating at the Nth cyclotron layer relying on the fast magnetosonic wave for which the FLR2 expansion is adequate for not too energetic populations dominantly scales as B −2(N−1) o [63] and hence operating at 1/3 the field enhances the heating efficiency by an order of magnitude compared to operation at the nominal field when relying on second harmonic heating (N = 2).…”