Numerical simulation on MARFE development in a diverted tokamak with a coupled plasma, neutral, and impurity transport code

Abstract

Summary form only given, as follows. Summary form only given. The formation of a Multifaceted Asymmetric Radiation From the Edge (MARFE) near the X-point in a diverted tokamak is simulated with KTRAN, a two-dimensional transport code which selfconsistently couples the transport phenomena for plasma, recycling neutral, and intrinsic carbon impurity particles in the scrape-off layer (SOL) and the divertor region. In KTRAN, the transports of the neutrals and the physically sputtered carbons are computed by the Monte Carlo method while the plasma transport is obtained by solving the conventional single-fluid equations. The calculation results from this new fluid-particle hybrid code are compared with those from some previous work using the coupled fluid plasma and Monte Carlo neutral transport code, B2-EIRENE. In addition, since the prediction of the MARFE formation is important regarding the tokamak density limit disruption and the radiative divertor solution, the density thresholds for the MARFE formation are calculated in terms of operating parameters of tokamak devices and compared with the results from an analytic model obtained in the previous work.