Abstract. Although the requirement of shape flexibility in TCV precludes the use of fixed baffle or optimised divertor target structures, it does allow for the investigation of diverted equilibria not possible in more conventional tokamaks. One such single null configuration is simultaneously characterised by a very short inboard poloidal depth from X-point to strike point on a vertical target and an extremely long poloidal depth to a horizontal target on the outboard side. Density ramp discharges leave the inboard target plasma attached even at the highest densities, whilst clear partial detachment is observed at the outboard target. Modeling of this configuration using the B2-Eirene code package shows that the outboard divertor achieves high recycling at very low densities, with the rollover to detachment occurring near the outer strike point very soon after the density ramp begins. An important result of the modeling effort is that, due to the low apparent densities in the TCV outboard divertor, the code cannot quantitatively reproduce the absolute level of observed detachment without artificially increasing fivefold the charged particle sink due to three-body and radiative recombination.
IAEA 2001