LOW-ENERGY NEUTRAL PARTICLE FLUXES IN THE JET DIVERTOR

First measurements are presented of the total power loss through neutr al particles and their average energy in the JET divertor. The method used distinguishes between the heat flux and the electromagnetic radia tion on bolometers. This is done by comparing measurements from inside the divertor either with opposite lines of sight or with a tomographi c reconstruction of the radiation. The typical value of the total powe r loss in the divertor through neutrals is about 1 MW. The average ene rgy of the neutral particles at the inner divertor leg is 1.5-3 eV whe n detachment is in progress, which agrees with EDGE2D/NIMBUS modelling .