Comment by willis936

27 comments and not one hit of the word “inertial”! The line about not being thermonuclear and the description of the device in question (a sphere with lasers) points towards an inertial confinement fusion (ICF) device. Most of the fusion research eggs are in the thermonuclear basket, specifically magnetic confinement fusion. It is good to research a diverse set of approaches, but there are more engineering challenges to ICF reactors than there are to MCF reactors. Pulses on the order of 1-2 Hz requires a mechanical system that can cycle out the exhaust and replace the pellet in that time. Going to reactor scales also requires high load thermal cycles. MCF ain’t easy, and brings it’s own engineering challenges. The ones I always hear are things like wall materials and fuel recycling, but these are largely solved or in the process of being solved. The engineering challenge I see as the most difficult for MCF are related to steady state operation. Tokamaks have no way of being steady state. Stellarators do, but now the next problem is wall conditioning. Wall materials outgas in hot plasma. A lot. Like more than the fuel puffed in. The way this is handled in science machines is with glow discharges of various species: plasma just below the temperature to cause wall sputtering, coating the wall with carbon and boron for their absorptive properties, etc. No one’s run a steady state hot plasma before, so no one knows if these will be a non issue in reactors. Keeping the plasma clean may be a challenge to keep the plasma from terminating. Aside from that MCF is ready for prime time. It needs a big reactor for scaling laws to make it energy profitable (and potentially money profitable). We just need some very expensive test reactors to smooth out these issues.