Why is it so hard to make a nuclear fusion reactor efficient?

Question

In other words, why is it so hard to get the Q value above 1 (ration between energy output and input)

In: 179

Answer 1

Really Really simply put, to initiate a fusion reaction takes a huge amount of energy to smash the fusing atoms together enough to fuse them.

Enough energy, in fact, that we have a hard time creating that much energy outside of a fission detonation (a nuclear explosion).

The issue Really isn’t so much the difficulty of initiating the fusion, because we do it every time we detonate a thermonuclear bomb. It’s been done literally thousands of times.

The issue is controlling the reaction after you’ve initiated it by pumping in a nuclear bombs worth of energy, and having a container strong enough to contain it.

The Youtube channel Thunderf00t does a really good job of explaining it. YouTube search Thunderf00t fusion and watch.