Speaker
Description
Stability analysis is of fundamental importance for the operation of plasma fusion devices, as it helps prevent poor confinement with consequent loss of plasma performance and potential damage to plasma-facing components. For these reasons, a detailed analysis of plasma stability properties is being carried out for the Divertor Tokamak Test (DTT) [1], a new machine under construction in Frascati, Italy, aimed at designing and testing a divertor capable of handling high thermal loads and power exhaust.
In this work, the full power scenario is investigated for both positive and negative triangularity configurations. High-resolution plasma equilibria are computed using the CHEASE code [2] and analyzed with the linear stability code MARS [3]. The considered scenario is characterized by the presence of a q < 1 region, which can give rise to ideal and resistive internal kink modes [4]. Moreover, high-performance scenarios relevant to next-generation reactors may also drive a class of MHD instabilities known as infernal modes, which occur near rational surfaces with low magnetic shear and sufficiently steep pressure gradients.
In addition, a preliminary analysis of global Alfvénic modes has been performed as a first step toward future investigations including energetic particles produced by neutral beam injection (NNBI). The energetic particle distribution function, obtained from ASCOT simulations [5], is modeled using an anisotropic slowing-down distribution within the hybrid MHD–gyrokinetic code HYMAGYC [6]. Finally, indicative results illustrating the impact of energetic particles are presented using a single-null equilibrium and a Maxwellian distribution function.
References
[1] R. Martone, R. Albanese, F. Crisanti, A. Pizzuto, P. Martin. “DTT Divertor Tokamak Test facility Interim Design Report, ENEA (ISBN 978-88-8286-378-4), April 2019 ("Green Book")” https://www.dtt-dms.enea.it/share/s/avvglhVQT2aSkSgV9vuEtw.
[2] H. Lütjens, et al., 97, Issue 3, 1996, Pages 219-260.
[3] A. Bondeson, G. Vlad, and H. Lütjens. Physics of Fluids, B4:1889–1900, 1992.
[4] V. Fusco et al, 2022 47th EPS Conference on Plasma Physics P2a.125,
http://ocs.ciemat.es/EPS2022PAP/pdf/P2a.125.pdf
[5] J. A. Heikkinen et al. , Computer Physics Communications 181 1968–1983, 2010.
[6] G. Fogaccia, et al., Nuclear Fusion, 56:112004, 2016.
