Work

Linear simulations of a wide pedestal quiescent H-mode plasma with the extended-MHD code NIMROD

Year: 2026

Type: article

Abstract: We present linear simulations of a Wide Pedestal QH (WPQH)-mode DIII-D plasma with the NIMROD code to address the role of ion multispecies collisionality on WPQH-modes. We use a full extended-MHD model that captures Alfvénic and magnetoacoustic waves, including two-fluid, ion gyroviscosity and cross heat flux. We show that two-fluid and ion gyroviscous effects destabilize electron-directed peeling–ballooning modes in the pedestal. The linear growth rates of the modes decrease when carbon (C) is added to a deuterium plasma because the multispecies collisional effects increase the plasma resistivity. When replacing C with tungsten (W), the multispecies collisional effects increase the resistivity further, as well as the stabilizing effect on the instabilities. The resistivity impact on mode stability is reversed when both two-fluid and ion gyroviscous effects are ignored, which is consistent with previous works, proving that multispecies collisional effects, together with two-fluid and ion gyroviscosity, should be considered to address the stability of plasmas with significant impurity content.

Source: Nuclear Fusion

DOI: 10.1088/1741-4326/ae3844

Authors: J.J. Dominguez-Palacios Duran, J.R. King, V.A. Izzo, X. Chen, F. Ebrahimi, A. Pankin

Institutions: Fiat Lux, General Atomics (United States), Princeton Plasma Physics Laboratory

Language: English

Topic: Magnetic confinement fusion research

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,595