ERO is a three–dimensional Monte–Carlo code to simulate plasma-wall interaction and impurity transport in nuclear fusion devices. The code was originally developed in the beginning of the 1990s . In the meanwhile, continuous development and application to a large number of experiments has been done. The simulations are typically focused on localized wall components with sizes in the range of cm to m like divertor target plates, limiter tiles, or samples exposed to linear plasmas. Currently, the source code is subject of a major rewriting (ERO2.0). With an increased computational performance and a generalized definition of surfaces by polygon meshes, ERO2.0 should become capable of simulating significantly larger simulation volumes than before while maintaining acceptable computation times.
The task of this master thesis is to implement and test the guiding center (GC) approximation  for the impurity transport in ERO2.0. Up to now, impurity particle trajectories were calculated resolving the full orbit (FO) of the gyromotion. While FO is necessary to get accurate results for particles in the sheath (i.e. within a few cm from the wall), it unnecessarily slows down computational performance for particle further away from the wall (long-range transport). Therefore, a mixed model for the transport, using transitions from GC to FO and back under appropriate conditions, should be implemented. The performance gain from this should be demonstrated by application to a current problem from the field of fusion research (e.g. Beryllium (Be) limiter erosion and Be transport at the JET tokamak).
 D. Naujoks, R. Behrisch, J.P. Coad and L. de Kock, Nucl. Fusion 33 (1993) 582
 T.G. Northrop, The guiding center approximation to charged particle motion, Annals of Physics 15, p.79-101, 1961