So far the main problem with fusion power generation is that it doesn’t actually produce more thermal energy than the electrical energy required to keep the reaction going. In its current form, fusion power is useless. Hopefully, though, a new discovery made by Princeton Plasma Physics Lab (PPPL) — the home of Project Matterhorn in the ’50s and ’60s — could result in magnetic confinement fusion that breaks even, or even produces electricity.

Basically, to keep fusion going you need to sustain a temperature of around 11 million degrees Celsius, which requires a huge amount of electricity. Fusion chambers are usually lined with heat-resistant carbon tiles in an attempt to reduce wastage, but the problem is that protons and neutrons escaping from the fusion reaction hit the wall, cool down, and then bounce back into the reaction, reducing the temperature. Electricity must then be used to increase the temperature back to 11 million Celsius.

The PPPL, led by Bruce Koel, have found that a thin layer of lithium metal (the third element in the Periodic Table) absorbs these protons and neutrons, preventing them from bouncing back into the pot, and thus reducing the power requirement of keeping the fusion reaction going. The research is still in its early stages — Koel and co are now analyzing whether lithium is viable over the long term — but so far, PPPL seems fairly confident that lithium will enable the construction of smaller, more efficient fusion reactors.