We develop a hybrid model to describe the parallel transport in a tokamak scrape-off layer following an edge-localized mode (ELM) event. The parallel dynamics is treated with a kinetic Vlasov–Poisson model, while the evolution of the perpendicular temperature is governed by a fluid equation. The coupling is ensured by isotropising collisions. The model generalises an earlier approach where was constant in space and time (Manfredi et al 2011 Plasma Phys. Control. Fusion53 015012). Numerical results show that the main effect comes from electron–electron collisions, which limit the decrease of the parallel electron temperature and increase the potential drop in the Debye sheath in front of the surface. Ion–ion collisions have an almost negligible impact. The net effect is an increased peak power load on the target plates.
Overview of the isotope effects in the ASDEX Upgrade tokamak