FIREFLY: heat load and particle exhaust approximations for rapid evaluation of divertor designs

TL;DR

FIREFLY is a rapid evaluation tool for divertor designs in fusion reactors, combining simplified heat load modeling with particle tracking to optimize exhaust efficiency.

Contribution

It introduces a new package that extends FLARE for fast divertor design assessment using simplified heat and particle transport models.

Findings

Efficient particle exhaust can be optimized using FIREFLY.

Sensitivity analysis shows model parameters significantly affect results.

FIREFLY successfully applied to the W7-X divertor geometry.

Abstract

The divertor in a magnetic confinement fusion reactor is an essential component for power dissipation and particle removal. The FIREFLY package for rapid evaluation of divertor designs is presented as an extension of the FLARE code for field line reconstruction from a flux tube mesh. First, divertor loads are approximated with a simplified heat transport model. Neutralized particles are then sampled from the resulting load distribution, and the EIRENE code is used to track molecules and atoms in a plasma background while accounting for dissociation, charge exchange and ionization. Particles are removed on pumping surfaces in order to estimate the exhaust efficiency for a given divertor geometry. Optimization of the divertor geometry for more efficient particle exhaust is explored by using W7-X as an example, and the sensitivity to model parameters for the plasma background in the proxy calculations is evaluated.