Results of confinement studies on an L mode database covering 10 years of operation of ASDEX are presented. During this time, the ASDEX divertor was modified several times. Scaling expressions for closed and open divertor configurations are compared. Strong evidence is found that the confinement time of plasmas in closed divertor configurations scales more weakly with the plasma current and shows weaker degradation with heating power. Furthermore, full profile information is used to evaluate scaling expressions for the thermal energy confinement time. They confirm the scaling differences between the divertors and show a stronger density dependence than the total confinement time
First island divertor experiments on the W7-AS stellarator