Theoretically Cannot Any Mass Intiate Nuclear Fusion?

[Spacescifi]

For reference I considered this first:

https://en.m.wikipedia.org/wiki/Pure_fusion_weapon

At sufficient tech scales Clarke is right I think.

I know it would require manipulation at subatomic scales never done by us, but in theory, if an advanced scifi race had a bunch of regular earth dirt, and had a high enough tech level, could they not somehow fuse the nuclei found in the dirt together to create a bomb?

Basically, what I am saying is that should it not be possible to fuse ANYHING that has a nucleus with another nucleus?

Sounds like all you would need is super precise manipulation of the strong and weak forces to pull off. Since IRL it is hard precisely because nuclei do not want to fuse and we force them to with nukes.

Implications?

No reliance on uranium necessary, only on whatever fantastic machine that can fuse anything and whatever mass you can grab...which is everywhere.

Would be perfect for the spaceship always hungry for propellant concept. Now she (the ship) does not have to be a picky eater. Anything will do so long she is doing it Orion style.

 

What do you think?

 

Edited April 14, 2021 by Spacescifi

[cubinator]

Well, clearly there's some way to fuse pretty much all the elements.

[Nuke]

yes, the evidence is most of the periodic table. its just for some elements the energy requirements to fuse are pretty high and cant put out more energy than what is put in. thermonuclear weapons are pretty much energy amplifiers, they amplify the output of a fission warhead. but if your fusion fuel gets up to iron or heavier, then it becomes an energy sponge. 

[Spacescifi]

28 minutes ago, Nuke said:

yes, the evidence is most of the periodic table. its just for some elements the energy requirements to fuse are pretty high and cant put out more energy than what is put in. thermonuclear weapons are pretty much energy amplifiers, they amplify the output of a fission warhead. but if your fusion fuel gets up to iron or heavier, then it becomes an energy sponge. 

 

I see, so the lightesr element on the list...hydrogen, is the most likely one to be used.

 

Least energy required in comparison with the rest...and coincidentally also the one stars use.

So water and ice are  like gold in space. Not too much has changed I see LOL.

[magnemoe]

We can not make fusion happen and get more energy out than in without setting off an nuke anyway.

Some more advanced technology who make it easier to work with higher energy density like room temperature superconductors and more efficient lasers would it easier to make an pure fusion bomb. It will still be bomb sized  however and much more complex than an standard nuclear bomb as have to cram an fusion engine into an bomb case.
Yes it has the benefit that you don't get the fallout from the plutonium but its still an weapon with limited use. 

Now if we can make small fusion reactors, small as in able to power submarines we can start thinking about pure fusion bombs 

 

[Nuke]

16 minutes ago, Spacescifi said:

 

I see, so the lightesr element on the list...hydrogen, is the most likely one to be used.

 

Least energy required in comparison with the rest...and coincidentally also the one stars use.

So water and ice are  like gold in space. Not too much has changed I see LOL.

its more complicated than that. for example deuterium has a lower cross section and its heavy a neutron. that, along with its abundance is why they want to use it for fusion power. in contrast with normal hydrogen where stars need to be huge to fuse.

you can in theory use advanced fusion technologies to create island of stability elements, such elements might allow for tiny nuclear devices. the energy costs to make those would be extreme, more than the output of the devices. but the tactical advantage of having a nuclear warhead that can fit into a rifle cartridge would be huge. could be a very scary mcguffin for one of your stories. or perhaps a micro-orion drive. 

Edited April 14, 2021 by Nuke

[Spacescifi]

24 minutes ago, Nuke said:

its more complicated than that. for example deuterium has a lower cross section and its heavy a neutron. that, along with its abundance is why they want to use it for fusion power. in contrast with normal hydrogen where stars need to be huge to fuse.

you can in theory use advanced fusion technologies to create island of stability elements, such elements might allow for tiny nuclear devices. the energy costs to make those would be extreme, more than the output of the devices. but the tactical advantage of having a nuclear warhead that can fit into a rifle cartridge would be huge. could be a very scary mcguffin for one of your stories. or perhaps a micro-orion drive. 

 

Well as I have said for sometime...if you have FTL/warp/space translation/jump drives, you would think fusion they also have. As it SHOULD be easier of a feat.

 

That said, common sense means average joes won't be toting rifles with fusion bullets.

 

But SSTO belly lander orions with bomb pellet propellant utilizing pure fusion?

Yeah..why not? I have no argument against them. Just means the launch station is in the desert. And landing is done with conventional rockets.

 

It is possible to make a tall belly lander vessel SSTO with dual axis rockets for initial launch and landing, and an oblong pusher plate that is below sitting crossways while landed.

During ascent rocket engines would cut off, the pusher plate would rotate to fit straight across the ship's belly (thereby protecting belly/rocket engines from blast) and release the bomb pellets and continue to ascend vertically VTOL style.

No flipping required. 

 

The only flip required is once it reaches space, then it flips to face orbit so as to circularize  and stabilize an orbit while impelling itself  forward via pusher plate blast.

Edited April 14, 2021 by Spacescifi

[Nuke]

29 minutes ago, Spacescifi said:

That said, common sense means average joes won't be toting rifles with fusion bullets.

i was thinking spec ops. to think a commando on a small moon could nuke a city on its host planet simply by firing in the right direction. such ammunition would be prohibitively expensive for anything other than a planetary government.

Edited April 14, 2021 by Nuke

[kerbiloid]

No greater energy per mass than D+T.
No sense in using something heavier than LiD.

[Nuke]

1 hour ago, kerbiloid said:

No greater energy per mass than D+T.
No sense in using something heavier than LiD.

i think proton-boron is probably the best bet for true clean energy. but thats maybe a fourth or fifth gen fuel. first gen reactors will be d+t.

[kerbiloid]

51 minutes ago, Nuke said:

i think proton-boron is probably the best bet for true clean energy. but thats maybe a fourth or fifth gen fuel. first gen reactors will be d+t.

The OP was about the bomb.

Aneutronic is possible with B, N, C, yes.

[Scotius]

Sure you can have a handheld fusion device. You just need to throw it very, very fast

Behold! Relativistic baseball!

https://what-if.xkcd.com/1/

[magnemoe]

2 hours ago, Nuke said:

i was thinking spec ops. to think a commando on a small moon could nuke a city on its host planet simply by firing in the right direction. such ammunition would be prohibitively expensive for anything other than a planetary government.

Then I would used an tiny rocket instead of an gun. 

Scale this down to something like the fatman in fallout but obviously with an real rocket behind it. 

https://www.schlockmercenary.com/ has antimatter in an Fullerene matrix as an very strong explosive, no I don't think it would work but an fun idea. 

[cubinator]

7 hours ago, Scotius said:

Sure you can have a handheld fusion device. You just need to throw it very, very fast

Behold! Relativistic baseball!

https://what-if.xkcd.com/1/

Maybe you could use a binary black hole to accelerate a particle beam. 

[kerbiloid]

Spoiler

  

2 minutes ago, cubinator said:

Maybe you could use a binary black hole to accelerate a particle beam. 

It took for me a minute to understand how can binary data form a black hole...

 

[KerikBalm]

On 4/14/2021 at 2:10 AM, Spacescifi said:

I know it would require manipulation at subatomic scales never done by us,

Its no different than ignition of a fusion fuel pellet by laser fusion/inertial confinement fusion... just on a larger scale. You'd need a much larger ICF facility to make an explosion of a decent size, or a much much much more efficient system. Also, such a system is bound to be pretty expensive, more expensive than a fission primary, and would destroy itself in the exposion.

On 4/14/2021 at 2:10 AM, Spacescifi said:

but in theory, if an advanced scifi race had a bunch of regular earth dirt, and had a high enough tech level, could they not somehow fuse the nuclei found in the dirt together to create a bomb?

You could fuse elements in dirt to get energy, yes. Dirt contains hydrogen, carbon, nitogen, oxygen. All of which are involved in fusion reactions in stars.

https://en.wikipedia.org/wiki/CNO_cycle

On 4/14/2021 at 2:10 AM, Spacescifi said:

Basically, what I am saying is that should it not be possible to fuse ANYHING that has a nucleus with another nucleus?

Yes, that's how we get heavy elements, they are formed in super nova.

On 4/14/2021 at 2:10 AM, Spacescifi said:

Sounds like all you would need is super precise manipulation of the strong and weak forces to pull off.

No, you just need very high energy density, like in a super nova

On 4/14/2021 at 2:10 AM, Spacescifi said:

No reliance on uranium necessary, only on whatever fantastic machine that can fuse anything and whatever mass you can grab...which is everywhere.

Would be perfect for the spaceship always hungry for propellant concept. Now she (the ship) does not have to be a picky eater. Anything will do so long she is doing it Orion style.

Fusing anything into an element larger than Iron will just suck up energy, not release it. That's why you get energy from splitting heavy elements, wheras you get energy from fusing lighter elements.

If you find an chunk of iron and nickel on some asteroid, that material cannot be used to generate energy via fusion.

If you have a bunch or energy available, and you need a heavier element to build something, you could start fusing that together to make heavier elements, but that's going to take a bunch of energy, not release it.

Also, I think you are confusing propellent and fuel. If you have a bunch of iron, and a little He3, you can fuse the He3 to throw iron out the back for more thrust.

Any mass can be used for propellent, without needing to be fused.

On 4/14/2021 at 2:10 AM, Spacescifi said:

What do you think?

I think you need a very powerful fusion reactor, but it would operate on the same principles as current ones. I also know that you will not be able to use any mass

[RCgothic]

Iron is the most energetically stable element. To fuse anything to a heavier weight than Iron takes energy rather than releases it.

All the elements heavier than Iron were created in Supernovae where fusion of comparatively vast quantities of light elements powered fusion of comparatively tiny traces of heavy elements as byproducts.

Dirt is mostly oxygen, silicon and aluminium though. These are all lighter than Iron, so you could perhaps expect to get some power out of fusing dirt. But you wouldn't get any power from, e.g. gold.

As alchemy though, transmuting one element into another, sure, go nuts. A civ capable of atomic manipulation and at-will fission/fusion could change anything into anything else. Justkeep in mind transformations towards Iron release power and away from Iron consume power. Vast vast quantities of power.

[kerbiloid]

Or redirect a lot of iron asteroids together, let them collapse into a black hole by their self-gravity, then use it as a blackhole reactor.

[JcoolTheShipbuilder]

What about fusing uranium atoms? That will surely go well lol

[kerbiloid]

Yeah.... uranium... Who needs that fusion.

Redirect many uranium asteroids, so they form firstly blackhole, then fission critical mass of the uranium blackhole...

[RCgothic]

17 hours ago, JcoolTheShipbuilder said:

What about fusing uranium atoms? That will surely go well lol

Will consume power and the fused product would be so large and unstable you'd likely get all the power back instantaneously in some other form along with a shower of decay products.

[JoeSchmuckatelli]

7 hours ago, RCgothic said:

Will consume power and the fused product would be so large and unstable you'd likely get all the power back instantaneously in some other form along with a shower of decay products.

Whatever would we use such a device for, anyway?

[magnemoe]

13 Jupiter worth of mass will initiate fusion. however this is not the answer you was looking for

[kerbiloid]

Fusion happens when two nuclei collide enough fast to break through the barrier and merge in one.
The more often they collide, the more energy per volume and time they produce.
Once this happens enough often to produce more energy than loose at the surface, the things run faster.

To make them move fast, you have to heat the fuel to make its atoms chaotically move.
Some of the atoms are randomly having greater speed than others' average thermal speed.
And some of these fast ones collide, and see what happens above.

But moving fast means they tend to fly away instead of be reflected from the reaction zone surface.
You should either apply external pressure to keep them inside, or hold them in a magnetic field, as they are ionized.

They former case is what they have in trivial devices since 1950s.
The latter case is what they want to achieve.

So, you should just produce enough intensive magnetic field to heat and hold the reaction mass.
But to produce it you have to either produce a lot of energy to feed the magnets, or operate with nano-amounts of the fuel .

In the former case you need a trivial fusion reactor.
In the latter case you need an army of nanites equipped with laser guns.

Or you should cause a very dense shockwave, but then you still need to first produce enugh energy.

Edited April 16, 2021 by kerbiloid