Exhaust power and particle handling by plasma-facing components (PFCs) such as divertor is a key issue, affecting the successful operation of a steady-state magnetic fusion power reactor.
Most of the presently operating confinement devices such as JET and also the International Thermonuclear Experimental Reactor (ITER) employ the divertor design in which a plasma-facing surface plate made of tungsten is brazed onto an actively cooled heat sink made of a copper alloy such as GridCop. The maximum heat flux that can be handled by this design is believed to be of the order of 20MW/m2, which may be sufficient for ITER for which the total heating power is of the order of 100MW. However, in the case of fusion power reactors, the heating power may be reaching 500MW, in which case the heat flux to the divertor plate will easily exceed the maximum heat flux. Furthermore, for induced radiation safety, the use of reduced activation ferritic steel such as F82H will be required for the divertor heat sink in a fusion power reactor, which would worsen the heat removal situation. In addition to this heat handling issue, either powder metallurgy (PM) or chemical vapor deposition (CVD), commercially available tungsten will suffer from thermomechanical cracking due to its exceptionally high ductile–brittle transition temperature (DBTT) of around 400°C .
To resolve these technical issues, the use of a selected liquid metal for the plasma-facing surface of the divertor has been discussed over the past two decades. Possible liquid metals include: molten lithium, gallium, tin and their alloys. Up to present, the use of liquid lithium has most widely been examined in the presently operating confinement devices as well as in laboratory-scale experiments.
All of these issues have been addressed at the ISLA series of symposia, the only international forum dedicated for the discussion of liquid metals applications for fusion energy development. The scope of ISLA-7 covers a wide range of subjects, including:
 Liquid (metal)-plasma interaction experiments and modelling;
 Liquid (metal) fluid dynamics experiments and modelling;
 Liquid (metal) handling and safety experiments and modelling;
 Liquid (metal) chemical compatibilities experiments and modelling;
 Liquid (metal) applications for PFCs in a fusion power reactor (design);
 Liquid (metal) applications for neutron production as the breeder or others such as IFMIF; and
 All other areas related to the use of liquids (metals) for non-fusion energy production.