How Can Science and Physics Contain Fusion Ignition?

[Bab5space]

Fusion ignition is a self sustaining fusion reaction because the heat is so high that any cooling that does happen due to radiation or loss of mass will not stop the fusion reaction. This is really the key to the dream of endless energy, since fusion will give you electrical power forever... until the fusion stops, which will happen if the heat lowers somehow or if magnetic holding fields loosen.

Right now we are not even close to that, the closest we get is by detonating nukes (if the explosion could be contained rather than expanding into the air without destroying everything).
So the actual question is... how do you scientifically contain a nuclear blast in atmosphere?

We cannot do it, but if we could what scientific means could we use?

Magnetic fields with some super high strength, more than anything we have done to date. You would need a magnetic field at least as strong as the energy released in a nuclear blast if not greater. I do not know how many Tesla that is, but I know it's a lot!
So I wager to bet that if we ever figure out a way to actually contain a self sustaining fusion reaction, we will also have a way to shield against nuclear blast waves in atmosphere.

In vacuum it would be even easier to do, since any blast waves would be much smaller.

Hello scifi shields! Won't shield against the radiation though, so a lot of mass will be required to soak up thermal energy without melting the entire spaceship.

In other words... only truly massive spaceships shoud have a selfsustaining fusion reaction onboard. Small spacecraft would overheat too fast.

What do you think? How can mankind use science and physics to contain a self sustaining nuclear fusion reaction (AKA nuclear blast, closest we have reached)?
EDIT: Fun fact, if containment of self sustaining fusion fails the result will be bad. Why?

It's a contained nuclear blast wave... what do you think will happen when it is released from captivity?

 

[PeterDonis]

how do you scientifically contain a nuclear blast in atmosphere?

You don't. A controlled fusion reaction is not a contained nuclear blast. It releases energy at a much, much slower rate, and therefore has a much, much smaller amount of fuel in it at any given time.

Also, you posted this in the sci-fi forum. Are you asking because you want to write something that involves a controlled fusion reaction? If so, what?

 

[berkeman]

So the actual question is... how do you scientifically contain a nuclear blast in atmosphere?

Can you compare and contrast such a blast in an atmosphere versus in the vacuum of space? What are the fundamental differences, and why is that important for you question?

 

[anorlunda]

There was a series of stories in Analog SF about "enbobulating" Inside, the bubble time was frozen. So if you embobulate your city, nuclear explosions on the outside would dissipate before the bubble ended. Then other people turned it around to embobulate a nuclear bomb whose blast would be released when the bubble ended.

 

[member 656954]

So I wager to bet that if we ever figure out a way to actually contain a self sustaining fusion reaction, we will also have a way to shield against nuclear blast waves in atmosphere.

I'll take your bet, though I doubt I'll ever see the win. Research fusion - bombs and energy - and you'll note they are not equivalent. It's like saying because we can control gasoline explosions in an internal combustion engine, we can therefore control a Molotov cocktail thrown through the lounge room window.

 

[mfb]

Peaceful nuclear explosions were considered for a while. To use them as energy source one could detonate them underground to heat up a lot of stuff (water, maybe) and then use that to drive a turbine, similar to a nuclear reactor. It is too impractical and too expensive, but not too far out to be used in science fiction. The explosion is contained by all the mass underground that gets heated.

So I wager to bet that if we ever figure out a way to actually contain a self sustaining fusion reaction, we will also have a way to shield against nuclear blast waves in atmosphere.

ITER is expected to get a basically self-sustaining fusion reaction (its fusion power will be 10 times the heating power), but we are nowhere close to shield against blast waves from relevant nuclear explosions. The energy scale is just too different. Even a small nuclear weapon, what was used against Hiroshima for example, releases as much energy in fractions of a second as ITER will in 1.5 days.

 

[Bab5space]

Peaceful nuclear explosions were considered for a while. To use them as energy source one could detonate them underground to heat up a lot of stuff (water, maybe) and then use that to drive a turbine, similar to a nuclear reactor. It is too impractical and too expensive, but not too far out to be used in science fiction. The explosion is contained by all the mass underground that gets heated.ITER is expected to get a basically self-sustaining fusion reaction (its fusion power will be 10 times the heating power), but we are nowhere close to shield against blast waves from relevant nuclear explosions. The energy scale is just too different. Even a small nuclear weapon, what was used against Hiroshima for example, releases as much energy in fractions of a second as ITER will in 1.5 days.

True.

I do think strong enough magnetic fields could contain the blast wave though.

Since magnetic fields can hold plasma, albeit like a waterbucket with holes, since plasma involved with fusion research tends to leak out the fields.

I do not know if the answer to the leaks is better tweaking of the fields through some kind of scheme, or if it simply requires the brute force of a magnet we currently cannot build (elecromagnets break apart when the field strength is super high).

Makes me wonder if new tech research on liquid magnets may help.
Ideally a superconducting liquid magnet would be ideal since it could not mechanically break. Although it could lose it's magnetism if boiled... which is what a nuke can do in spades.

Oh well... I tried folks. Leave it to the future to figure it out.

Even if we had some super magnet that did not break, the radiant energy from the blast alone would heat the magnet up enough to destroy it anyway.

For what it's worth, fusion is not like in Star Trek that's for sure.

 

[mfb]

Magnetic fields are not magic. At best they transfer the momentum to the coils. Then your coils disintegrate from the momentum transfer via the magnetic field instead of a momentum transfer via the shock wave.

An explosion in a vacuum will reduce the momentum but not the energy release that needs to be transferred away, and you get the additional effort to re-create the vacuum every time.