Reactive processes at the surfaces of a fusion reactor


Aart W. Kleyn

FOM Institute for Plasma Physics Rijnhuizen, Euratom FOM Association

P.O. Box 1207 3430 BE Nieuwegein, NL

and Leiden Institute of Chemistry, Leiden University

P.O. Box 9502, 2300 RA  Leiden, NL


By turning 2D + 3T into 4He + 1n, an inexhaustible source of energy can be created. The first demonstration that this can be done in a controlled fashion, was given more than a decade ago, when neutron powers exceeding 10 MW were demonstrated in pulsed experiments.

The next step along the way is the ITER reactor, shown in the figure, that should deliver 500 MW of neutron power. In terms of size ITER is not such a big step forward.

In terms of the potential damage of the various plasma facing components it is several orders of magnitude more demanding than the earlier devices. Wall contact cannot be avoided, because the reaction product  4He is removed via neutralization at a surface.

To control the stability of the walls further study of the plasma-surface interaction is needed. Besides studies of wall materials of large plasma devices dedicated experiments are needed to elucidate the underlying surface physics and chemistry. Erosion, redeposition, tritium retention, polymerization and dust formation are major issues to be studied.

In this talk I will introduce the state of the art in fusion research, and subsequently zoom in on the relevant plasma-surface interaction. I will conclude by sketching experiments currently being proposed by the FOM Institute.