Effect of limiter recycling on measured poloidal impurity emission profiles in Tore Supra
Poloidal impurity emission profiles measured with the Tore Supra grazing incidence duochromator that exhibit a complex spatial structure during ergodic divertor operation with an outboard poloidal guard limiter. As previous measurements with inboard-wall limited plasmas have shown that these profiles give important information about the ergodic field structure, so the contribution of local neon recycling from the limiter-induced plume has been modelled. This permits a discrimination of edge and core transport effects. The BBQ 3D scrape-off layer code calculates the asymmetric contribution to the emission and MIST 1D simulation gives the symmetric part. A systematic increase is observed in the decay rate of neon emission after injection as the ergodic divertor strength is increased. The calculations permit identification of the limiter plume contribution to the profile structure, and, with this identification, the effect of the divertor to enhance impurity efflux can be seen from the decay data.
Bibliographic Reference: An article published in: Journal of Nuclear Materials, Vol.290-293 (2001), pp.628-632
Record Number: 200113852 / Last updated on: 2001-10-05
Original language: en
Available languages: en