[Physics] What stops us from creating a nuclear fusion reactor as we already have the hydrogen bomb working on the same principle of fusion

Question

I have been out of physics for some time now since my childhood, so please bear with me if the question below feels too novice.

I grew up with the understanding that the nuclear fusion reaction is still a dream of many people as it's a source of clean energy without the side effects of nuclear waste as we observe in nuclear fission.

Now recently I was just checking the principle on which the hydrogen bomb works, and I was shocked that it uses nuclear fusion to generate all that energy. This contradicted my understanding that nuclear fusion is not a dream but it actually is a reality.

So if we already achieved nuclear fusion why can't we create a nuclear fusion reactor out of it to generate all the power we need? Also why can't we have the small scale fusion reaction on Jupiter (as mentioned in my other question) that can help us take over the outer planets of solar system.

Also I just wanted to know if we can continue this fusion reaction to generate precious heavy metals – is it possible?

Answer 1

The example of a Molotov bomb, a favorite of anarchists, and a car engine are a good analogy. The technology needed to contain the energies in a fusion reaction is much harder than the one needed for a car engine because of the MeV energies needed to initiate fusion. Once initiated it is explosive, so it must be engineered into small explosions from which energy can be extracted continuously.

Various ways of controlling fusion in a hot plasma of fusible materials, isotopes of hydrogen mainly, have been proposed and are being worked on. The tokamak is the basis of the international collaboration aiming to build an industrial prototype, ITER..

It is mainly an engineering problem coupled with the sociological problem of so many engineers and scientists working together in a project controlled by many research institutes. ( "too many cooks spoil the broth")

Also just wanted to know if we can continue this fusion reaction to generate precious heavy metals, is it possible?

Heavy metals are on the wrong curve for fusion, which can happen with elements up to iron or so. Each specific reaction will have to be considered, and it will be a completely different problem.