Singularities of the cold plasma theory: Modeling challenges for ICRF operation in low-density edge plasma
Abstract
Sustained ICRF operation in a fusion power plant may require low edge densities to mitigate plasma-wall interactions, a regime which was recently achieved in WEST with very little impurity sputtering. Cold plasma theory, however, predicts singular radiofrequency electric fields in this regime, both at the lower hybrid resonance and along the resonance cones, raising the question of whether standard collisional cold plasma models suffice to describe low-density edge ICRF at all. Collisions in principle remove these singularities, replacing them with finite but sharply peaked fields. We derive these peak length scales analytically and confirm them with a 2D finite-element simulation using exponential mesh refinement, achieving micrometer resolution where needed. We conclude that edge collisions in cold plasma do not remove the need to resolve length scales ordinarily associated with hot-plasma and Bernstein-wave physics.
Related
- Operational Challenges in Efficient and Sustainable Operation of the Event Processing Nodes GPU Farm at the ALICE Experiment
- High Energy Density Plasma Nanorod by Collisionless Absorption of Ultrafast Laser Pulse Inside Dielectrics
- In-situ measurements of space plasma: recent progress and future challenges
- Beamstop-free small-angle X-ray scattering for multiscale structure measurement of high-energy-density plasma
- Counter-rotating density and current structures in a partially magnetized E×B plasma
BibTeX
@misc{tierens2026singularities,
title = {{Singularities of the cold plasma theory: Modeling challenges for ICRF operation in low-density edge plasma}},
author = {Wouter Tierens and Chris Klepper and Raymond Diab and Guillaume Urbanczyk},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.30155},
eprint = {2609.30155},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.30155},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Singularities of the cold plasma theory: Modeling challenges for ICRF operation in low-density edge plasma
AU - Wouter Tierens
AU - Chris Klepper
AU - Raymond Diab
AU - Guillaume Urbanczyk
PY - 2026
DA - 2026/09/24
PB - arXiv
DO - 10.48550/arxiv.2609.30155
UR - https://arxiv.org/abs/2609.30155
AB - Sustained ICRF operation in a fusion power plant may require low edge densities to mitigate plasma-wall interactions, a regime which was recently achieved in WEST with very little impurity sputtering. Cold plasma theory, however, predicts singular radiofrequency electric fields in this regime, both at the lower hybrid resonance and along the resonance cones, raising the question of whether standard collisional cold plasma models suffice to describe low-density edge ICRF at all. Collisions in principle remove these singularities, replacing them with finite but sharply peaked fields. We derive these peak length scales analytically and confirm them with a 2D finite-element simulation using exponential mesh refinement, achieving micrometer resolution where needed. We conclude that edge collisions in cold plasma do not remove the need to resolve length scales ordinarily associated with hot-plasma and Bernstein-wave physics.
ER -