# Isotope effect on filament dynamics in fusion edge plasmas

## TL;DR

This study uses a gyrofluid model to analyze how ion mass affects filament dynamics in fusion plasmas, revealing that heavier ions slow filament propagation and potentially improve confinement.

## Contribution

It provides the first detailed computational analysis of isotope mass effects on filament dynamics in fusion edge plasmas, highlighting the role of various physical mechanisms.

## Key findings

- Heavier hydrogen isotopes slow filament outward propagation.
- Helium filaments move more slowly than deuterium.
- Mass effects influence filament inertia through multiple physical processes.

## Abstract

The influence of the ion mass on filament propagation in the scrape-off layer of toroidal magnetised plasmas is analysed for various fusion relevant majority species, like hydrogen isotopes and helium, on the basis of a computational isothermal gyrofluid model for the plasma edge. Heavy hydrogen isotope plasmas show slower outward filament propagation and thus improved confinement properties compared to light isotope plasmas, regardless of collisionality regimes. Similarly, filaments in fully ionised helium move more slowly than in deutrium. Different mass effects on the filament inertia through polarisation, finite Larmor radius, and parallel dynamics are identified.