Modelling of the transport of methane and higher hydrocarbons in fusion devices

New Monte Carlo modelling with the ERO-TEXTOR code has been done for methane transport in the scrape off layer of TEXTOR using recently published rate coefficients of the methane family from Brooks/Janev. Compared to former used rate coefficients from Ehrhardt–Langer the new data result in significantly larger D/XB-values at plasma temperatures above ∼20 eV. The computed amount of re-deposition is at high plasma temperatures up to a factor of 100 smaller with the new rate coefficients. Parameter studies of the transport of locally injected methane and C2D4 in the divertor MkIIa of JET with ERO-JET (adapted version of ERO-TEXTOR) show a strong influence of the location of injection on D/XB. Calculated D/XB-values can increase up to a factor of 1000 if hydrocarbons are puffed at a location inside the SOL instead at the strike point.