Question regarding fusion reaction containment and procedure

[Hayes]

Good evening,
I am new to this forum and do not have a strong physics background. So if my questions seem woefully inept please respond with a simple laymans answer.

I understand that there are 2 basic ideas for fusion containment, and that the main 2 components of any successful fusion reaction is a ton of heat, and a ton of pressure. The Sun I know is an example of this, and happens to get away with less heat than man made fusion reactions due to its massive size which means that the particles that do happen to react are much more likely to hit each other than in our small man made reactions.

It is my understanding then, that pressure is paramount with a fusion reaction.

My basic question then involves a physics article I was reading. People were able to create the fastest spinning disk ever made by having a tiny calcium crystal suspended in a vacuum spin at speeds of 600million rpm. Why couldn't hydrogen gas or a similar fuel be spun at these speeds in a disk in order to create compression? From my very basic understanding, this would create enough compression that much less heat would be required for the fusion of the heated plasma. Of course the disk would have to be in a vacuum and would require a levitating force such as a magnetic field. Kind of like a tiny tire made of graphene filled with hydrogen. What role would friction between the spinning disk and the hydrogen play?

 

[etudiant]

A diamond anvil press will do 100 million psi, apparently just enough to make hydrogen a metallic solid, but no fusion sadly enough, because as you say,.
it takes more than pressure, it also takes very energetic atomic motion, aka high temperature, to get the atoms energetic enough to fuse.
Spinning something makes it tend to fly apart, unless it is held together by some force. Unfortunately, no known material can hold together under such strain.

 

[raining Pete]

Hello and welcome to the forum! Your question about using a spinning disk to create compression for fusion reactions is an interesting one. While it may seem like a viable solution, there are a few factors that make it difficult to achieve in reality.

Firstly, creating a disk that can spin at 600 million rpm is a tremendous engineering challenge. The forces involved at such high speeds are enormous and would require extremely precise and durable materials. Additionally, the disk would need to be suspended in a vacuum and kept at a stable temperature in order to prevent any interference or disruptions to the spinning.

Secondly, as you mentioned, friction between the disk and the hydrogen would be a major issue. The heat generated from this friction would actually contribute to the overall heat required for fusion, making it counterproductive to the goal of reducing the need for heat.

Lastly, even if these challenges were overcome, it is still unclear if the compression achieved from the spinning disk would be enough to initiate a fusion reaction. The pressure required for fusion is incredibly high and it is uncertain if a spinning disk would be able to generate enough force to reach this level.

In summary, while your idea may seem feasible in theory, it would be extremely difficult to implement in practice and may not even produce the desired results. Fusion research is a complex and ongoing field, and scientists are constantly exploring new methods and technologies to achieve successful fusion reactions. I hope this helps answer your question!

 

[LoneWolf2007822]

Could we just use a tungsten box cooled with liquid nitrogen with a lead sheet inside the box to make the decay of the tungsten box slower? and also the liquid nitrogen would cool the tungsten box so it doesn't undergo heat decay. i would think that this setup would be the best option but impractical to use since the walls of the box would be pretty thick. the lead sheet inside the box would also have to be thick in order to keep the tungsten from being radioactive. and also it has to be in a vacuum chamber to resemble a fusion reaction in space because the reactions in space result in suns which does not do enclosed in a confined space.

 

[PeterDonis]

the main 2 components of any successful fusion reaction is a ton of heat, and a ton of pressure

You missed one: it's a lot of heat, a lot of pressure (more precisely enough density to achieve a non-negligible reaction rate, but in practice it's pressure that gets you to that point), and enough time for the heat and pressure to produce the desired reaction before everything flies apart. That's why "containment", as you call it, is necessary: the natural thing for a hot, dense plasma to do is to fly apart, but that prevents the fusion from ever occurring, so you need to stop that from happening.

The Sun does it not just by having a lot of pressure, but by having the pressure be part of a static system, kept that way by the Sun's gravity. Our human devices don't have that option, so we have to cobble together alternatives like magnetic fields, light pressure from huge lasers, etc. They don't work very well because there are always "holes", so to speak, in the confinement that allow the plasma to escape.

And note that if the plasma reaches the actual physical walls of the reaction chamber, you've already lost. The whole point is to keep the plasma from doing that. So your proposal, which relies on a physical wall to contain a rapidly spinning plasma, would have even worse problems than the ones that are being tried.