Transport of energetic ion and electron energy through the vapor shield during a tokamak plasma disruption

Energetic (>10 keV) particles incident on divertor plate surfaces may penetrate the vapor shield (VS) formed under extremely high heat flux conditions (>10¹⁰ W/m²). In this case the total energy transmission factor f, through the VS can increase drastically which leads to more surface damage. `MAGFIRE´ a 1D time dependent coupled MHD-radiation transport code, originally used in modeling the vapor shield development under a blackbody radiation source, has been modified to include a charged particle source. The sources used to model a disruption are mono-energetic beams of electrons and/or deuterons with any given incident heat flux and energy/particle. An electron source will eventually (<100 μs) be completely absorbed by the vapor and will give the same f as an equivalent ion heat flux source. Results show that in fact all three sources converge (~100 μs) to the same steady-state value of f for any given heat flux