@article{5810,
  author = {J. Rapp and M. Z. Tokar and L. Konen and H. R. Koslowski and G. Bertschinger and M. Brix and H. Claassen and R. Jaspers and A. KramerFlecken and K. Ohya and V. Philipps and A. Pospieszczyk and U. Samm and T. Tanabe and G. Telesca and B. Unterberg and G. Van Oost},
  title = {Transport studies of high-Z elements in neon edge radiation cooled discharges in TEXTOR-94},
  abstract = {High-Z materials as tungsten are intended to be used in future fusion reactors due to their low sputtering rates and high melting points. In this context the important question is whether the use of high-Z materials is compatible with the concept of a cold radiative boundary. To investigate the local release and transport behaviour of the high-Z Impurities, Mo and W test limiters were used in auxiliary heated discharges under different radiation scenarios with neon seeding. In addition, laser blow-off of tungsten as well as xenon gas puffing were performed. In some particular discharge conditions impurity accumulation was observed in the plasma core, which in the case of ohmic discharges led to minor disruptions. The connection between the accumulation and the evolution of the current density profiles is discussed. A transport analysis is made, in order to compare the observations with the neoclassical theory. it is shown that with neon the impurity-impurity driven fluxes enhance the high-Z concentration in the plasma core. However, if the source of the high-Z elements is significantly reduced, by increasing the plasma density, a development of an accumulation instability can be avoided.},
  year = {1997},
  journal = {Plasma Physics and Controlled Fusion},
  volume = {39},
  number = {10},
  pages = {1615-1634},
  month = {Oct},
  isbn = {0741-3335},
  doi = {10.1088/0741-3335/39/10/009},
  language = {eng},
}