Speaker
Alexei R. Polevoi
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.1050.pdf
Integrated modelling of ITER scenarios with D-T Mix control
A.R. Polevoi1, A. Loarte1, S.Yu. Medvedev2, E. Fable3, A.Yu. Dnestrovskiy4, E.A. Belli5,
M. Hosokawa1, A.A. Ivanov2, F. Köchl 6, A. Kuyanov4
1
ITER Organization, Route de Vinon-sur-Verdon, 13067 St Paul Lez Durance, France
2
Keldysh Institute of Applied Mathematics, Miusskaya 4, 125047 Moscow, Russia
3
Max-Planck Inst. für Plasmaphysik, Boltzmanstraße 2, D-85748 Garching, Germany
4
NRC "Kurchatov Institute", Kurchatov sq. 1, 123098 Moscow, Russia
5
General Atomics, PO Box 85608, San Diego,CA 92186-5608,USA
6
Atominstitut, Technische Universität Wien, Stadionallee 2, 1020 Vienna, Austria
An analysis of D and T fuelling requirements for DT mix control for ITER H-mode plasmas
is presented in this paper. This includes the use of pellet injection for core plasma fuelling
and ELM pacing, and gas fuelling for edge density and divertor power load control,
consistent with the ITER fuelling and pumping systems capabilities. The simulations are
carried out by 1.5D core transport modelling with separate treatment of D and T ions with the
ASTRA suite of codes with boundary conditions and particle sources from gas puffing
derived from scalings based on SOLPS simulations. The width and height of the pedestal
evaluated by the EPED1+SOLPS scaling prediction which are compared with direct
simulations of the pedestal stability limits by the KINX code. In this way the effect of the
impact of core pressure from self-consistent core simulations with TGLF on the pedestal
height is included. The ITER simulations have been carried out with GLF and TGLF
transport models for the range of currents and densities foreseen to be required to develop the
ITER baseline q95 = 3 scenario from low field 5 MA/1.8T, 7.5 MA/2.65T to high field
operation 15 MA/5.3 T Q = 10 for DT plasmas with varying T levels in a wide range of
plasma densities. In most plasma conditions, penetration of recycled neutrals is found to be
very limited so that pellet fuelling is an efficient tool to control the DT mix with a timescale
determined by the relaxation of the D and T profiles. TGLF modelling predicts highly stiff
temperature profiles for ITER plasmas with T′~ const, rather than LT~ const and more robust
access to high Q conditions than previously evaluated with GLF23. A factor that also
contributes to this H-mode access robustness is the rapid decrease of the fast particle energy
associated with fast D ions from NBI and alpha particles in the low density phase which slow
down as the density increases thus providing additional heating to the plasma to keep it in H-
mode as the density increases in the core. This increase is predicted to occur on a faster
timescale by TGLF than by GLF23.
