1Session II-A:Lithium in Magnetic Confinement Topical Experiments

Six papers have been presented on measurements taken in the edge region to understand the plasma behaviour in presence of lithium.

The main results are: • Divertor surface pumping reduce ion density (inventory) by up to 50 %• Decreased fueling efficiency and increased target plasma temperature consistent with an actively absorbing surface (LLD)• Sheath heat transmission coefficient is measured to be 2.49 +/- 0.04. One third of the classical value, so what accounts for this discrepancy?• LLD surface shows significant signs of clamping in peak and radially averaged temperature compared to graphite where no clamping occurs•The rise in temperature of the Li is less than one would find with a simple 1-D analysis. Evaporation of Li is of interest. The work function depends on surface chemistry and impurities.• White-appearance of PFCs after evaporation suggested passivation of first layers of lithium coatings and motivated further investigation•Evidence of C on LLD due to sputtering from graphite PFCs