Space and time resolved measurements of the impurity particle fluxes in the scrape off layer (SOL) have been made on Frascati Tokamak Upgrade (FTU) by means of deposition probes. In this work experimental results are presented for ohmic plasma discharges with a molybdenum toroidal limiter, and with BT= 6 T, IP= 0.7 MA, n̄e= (0.8-1.3)×1020m-3. In the stationary phase the total collected molybdenum flux shows a large asymmetry between the electron and the ion side of the probes and the radial profiles are generally quite flat at low density. Simulations of the FTU SOL with the 2D multifluid numerical code EPIT reproduce the profile flatness only if a high perpendicular diffusion coefficient is assumed for the impurities. The code shows that the e-/i+asymmetry can be accounted for by the shorter magnetic connection length on the e-side (2.2 against 7 m).
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Materials Science(all)
- Nuclear Energy and Engineering
Apicella, M. L., Maddaluno, G., Pericoli Ridolfini, V., Zagórski, R., Alessandrini, C., Apruzzese, G., ... Verdini, L. (1999). Molybdenum flux measurements in the FTU scrape off layer by deposition probes. Journal of Nuclear Materials, 266, 429 - 433. https://doi.org/10.1016/S0022-3115(98)00536-4