Divertor configuration studies on JET

In the 1994/1995 JET experimental campaign, with the MkI divertor, a systematic study of the influence of X-point height, flux expansion and target orientation on the plasma performance was executed. Various plasma configurations were tested under a number of different conditions, including Ohmic density limits, L-mode with 3 MW of NBI, H-mode at 10 MW of NBI and divertor seeding with nitrogen at 10 MW of NBI. The behaviour of the main plasma for the various configurations was quite similar, although there were small differences, for example in impurity control and fuelling efficiency. The paper describes the details of the experiment and presents the results, comparing the findings to the results of simulations using the EDGE2 D plasma boundary code.