eli5: once we are able to sustain a fusion reaction, it is supposed to be a self sustaining process (so I have read). How would we be able to “switch off ” this process, and wouldn’t a self sustaining process be an example of a perpetual process?
In: 4
Fusion needs to generate enough heat to keep itself going without us needing to add outside heat to it, that’s true yes. Otherwise the energy production can not be net positive.
It’s quite similar to a fire in a fireplace being self-sustaining; it keeps burning without human intervention, but the process would be radically altered if you deconstructed the fireplace, or opened or closed the air vents, or if the fuel ran out, etc.
Though, while a fire in a fireplace needs oxygen that typically comes from the outside, the fusion reaction inside a fusion reactor doesn’t necessarily need anything else from the outside but some sort of means of maintaining high pressure. That pressure is typically reached with magnetic fields. And it of course needs fuel like a fireplace would.
Latest Answers