The bundle divertor – part II: plasma properties

This paper presents simple estimates of some aspects of the behaviour of plasma in a tokamak with a bundle divertor. The effect of the divertor on charged-particle orbits and the consequent changes in cross-field diffusion are calculated using simple models. The factors determining plasma flow into the divertor are discussed, and a model of the divertor scrape-off layer is used to calculate the exhaust and screening efficiencies. Finally the problems of trapping and pumping the diverted plasma are considered.