Radiation Distribution and Neutral-Particle Loss in the JET Mk I and Mk HA Divertors

摘要

1. Bolometer tomography gives reliable emission profiles during highly radiative discharges. Estimates of the neutral particle contribution to the signals are in reasonable agreement with EDGE2D/NIMBUS simulations. The total loss power due to neutrals is >1 MW in the MkllA case, but only 0.2 MW in Mkl, to be compared with 9-10 MW of electromagnetic radiated power (of which about 70% from the X point and the divertor). 2. Going from open to more closed divertors, the power loss by neutral particles increases whereas the electromagnetic power fraction decreases. 3. These observations have consequences for the bolometer system planned for ITER, which has a very closed divertor. To be able to accurately distinguish between electromagnetic and particle loss a large number of lines-of-sight is required from both outside and inside the divertor.