Self-consistent impurity modeling in the Frascati Tokamak Upgrade

SCOUT ‐ a simple but self-consistent impurity model [1‐4] ‐ is used to describe impurity production and transport in the Frascati Tokamak Upgrade (FTU) operated with a molybdenum alloy (TZM) poloidal or segmented toroidal limiter. The values of main plasma impurity concentration parameter Zeff , radiated power fraction FP ” Prad/Pin, and edge plasma density and temperature are computed and compared with measurements. Good agreement between model and experiment is found for medium to high plasma densities while at the lowest density Zeff and FP are typically underestimated and overestimated respectively. ” 1999 Elsevier Science B.V. All rights reserved.