Liquid metals · Future bench (tested)
Liquid metal PFCs (Li, Sn, capillary porous systems)
Li/Snvalues describe: liquid Li CPS
Fusion, private
What it enables
Self-healing plasma-facing surfaces: erosion stops being a lifetime limit, and vapor shielding self-regulates transients.
Status and pusher
CPS tin divertor concept designs published for EU-DEMO; tokamak tests (FTU lineage, NSTX-U lithium program) accumulating. Pushed by EU-DEMO design teams, PPPL, and DIFFER.
Watch out
Tin: three roles in this table (EUV source, EUV contaminant, fusion wall).
Properties
The values below are candidate: compiled from the sources named, not yet individually validated. Provisional provenance: EUROfusion and international fusion materials programmes.
Wet cleaning
| Recipe | not applicable: the surface renews itself, which is the entire idea |
|---|---|
| Forbidden | water, violently, for lithium |
| Limit | vapour pressure into the plasma, and tritium retention in lithium |
Vacuum and outgassing
| Vapour pressure | THE governing number: Li reaches 1e-4 Torr near 500 °C, Sn far lower, which is why tin is gaining |
|---|
Temperature
| Metallurgical limit | Li melts 181 °C, Sn 232 °C |
|---|
Thermal
| Melting / softening | 181 / 232 °C |
|---|
Mechanical
| Strength | liquid |
|---|---|
| Density | 0.53 Li, 7.3 Sn g/cm3 |
Electrical and magnetic
| Relative permeability | 1.0 |
|---|
Engineering
| Joining | capillary porous substrate |
|---|---|
| Process notes | a self-healing wall |
| Availability and cost | research |