Pumping of particles during events in tokamaks. Application of ergodic divertors of the Tore Supra Tokamak
In the first part pf this work, we present the Tore Supra database, which contains 56 well-documented discharges summarizing the main physical features of particle control in the ergodic divertor configuration. Then, we discuss the physical processes that govern particle collection: ion pumping (ballistic collection, essentially a geometrical effect) and neutral pumping (ions recycling on the neutralizer plates are re-emitted towards the plasma under molecular form; dissociation and charge-exchange reactions back-scatter a part of the neutral flux towards the neutralizer plates, where it can be pumped). These two processes are modelling accounting for a realistic description of the divertor geometry. A comparison between simulations and experiments is presented for measurements characterizing the three main actors of plasma-wall interaction: the edge plasma (input of the calculation), the D-alpha light emission which characterizesw the ionization source, and the neutral pressure in the divertor plenum which characterizes the extracted flux.
Bibliographic Reference: Report: EUR-CEA-FC-1695 EN (2000) 203 pp.
Availability: Available from Association Euratom-CEA, Saint Paul Lez Durance (FR)
Record Number: 200012110 / Last updated on: 2000-09-20
Original language: fr
Available languages: fr