Jump to content

Antimatter production


Recommended Posts

From what I've seen and read, the process of creating antimatter is so costly and energy-intensive, that it makes antimatter not worth using as an energy source. Not for a long time, at least

Anitmater has some practical uses, it makes good rocket fuel for once.

Its not an energy source at all only a very good carrier.

Link to post
Share on other sites

We are not yet sure what the majority of Antimatter in the universe is made up of yet; It could be that there is more floating around between the stars than we would even know what to do with!

A strange radio 'signal' was picked up recently from the direction of one of the biggest things in the sky; something in the M82 Galaxy has started giving out radio waves; scientists really don't know what it is, but theories include either a 'microquasar' or possibly some sort of antimatter...

Link to post
Share on other sites
A strange radio 'signal' was picked up recently from the direction of one of the biggest things in the sky; something in the M82 Galaxy has started giving out radio waves; scientists really don't know what it is, but theories include either a 'microquasar' or possibly some sort of antimatter...

Perhaps some civilization got careless while trying to produce large amounts of antimatter.

Link to post
Share on other sites
We are not yet sure what the majority of Antimatter in the universe is made up of yet; It could be that there is more floating around between the stars than we would even know what to do with!

A strange radio 'signal' was picked up recently from the direction of one of the biggest things in the sky; something in the M82 Galaxy has started giving out radio waves; scientists really don't know what it is, but theories include either a 'microquasar' or possibly some sort of antimatter...

Was it not theorized that it could be emissions from sterile neutrons?

Link to post
Share on other sites
Anitmater has some practical uses, it makes good rocket fuel for once.

Its not an energy source at all only a very good carrier.

This... The energy density is what makes it interesting for certain applications.

...

A more interesting question is where they're formed naturally and can we scoop them up?

Link to post
Share on other sites

Due to the strong magnetic field, Jupiter would also be a good place to look for places to harvest antimatter.

If you want to make antimatter instead of just harvesting it, one of the better ways I've heard of to go about it is to put gigantic solar panel farms in a low orbit around the sun, inside Mercury's orbit. I'm talking multiple hundreds of square kilometers of solar panel area, per station. All of that energy is used to drive a massive particle accelerator optimized for producing antiprotons and positrons, slowing them down enough so that they form antihydrogen, and storing them in gigantic Penning traps.

Link to post
Share on other sites
Is it possible to create huge amount of antimatter, say several gram of antihydrogen, in reasonable time, say 1 year or so?

Positrons are relatively easy to produce; they are a natural product of beta decay from radioactive elements. They can also be produced by pair production with lasers or very strong magnetic fields. My very simplistic understanding is that if a particle's kinetic energy exceeds the energy equivalent of its inertial mass than it can produce an antiparticle when it collides with a target. In this way particle accelerators accelerate protons until their energy is on the order of 1 GeV (the energy equivalent of their rest mass E=mc^2), and collide them with a very dense target, made of tungsten or gold to produce anti-protons. The process is very energy intensive and capturing the particles thus produced is horribly inefficient (like .001% efficient). AFAIK the best we've done is capture a few hundred atoms at a time. And they don't store for very long, even when cooled to very low temperatures in a high vacuum.

I have faith that we could someday produce large volumes of antimatter economically, but our current technology and engineering isn't optimized with industrial scale anti-proton production in mind. And efficient production technologies like gamma-ray lasers are probably still a very very long way off. Also even if the process was 100% efficient, we would still need tremendous amounts of power to produce large volumes of anti-matter; thousands and thousands of terawatts to produce maybe a few hundred kilograms of antihydrogen a year. We would need huge Dyson arrays, or similar megastructures closely orbiting the sun, to produce this much power.

Still, assuming warp drive doesn't pan out then antimatter rockets, despite their many practical problems, are about the only half-way feasible way in which humans could travel to nearby stars in reasonable time spans. When antihydrogen is reacted with hydrogen it produces , among other things, charged pi-mesons that could be funneled out of a magnetic nozzle with exhaust velocities of up to .9 c. Put that in your Tsiolkovsky's rocket equation and smoke it! You could crank up to .5 c and make the crossing to Alpha Centauri in less than 15 years in a single stage rocket with a mass ratio of 3! FTW!!

Edited by architeuthis
Link to post
Share on other sites
Sciman, Saturn would actually be a better place to look. Apparently particles in its magnetosphere impacting the Rings produce "large" quantities of antimatter.

Saturn is also far less dense than Jupiter, getting in-and-out of the gravity field would be easier. Also, you could mine the rings for propellant (ice or methane) in a NERVA engine.

Link to post
Share on other sites

I'm not sure if it's possible to do it that way. I've never heard of that kind of method, but that doesn't mean it's impossible.

I know for a fact that particle accelerators can be made to create both positrons (electrons with positive instead of negative charge) and antiprotons (protons with negative instead of positive charge). You can slow down those positrons and antiprotons and then mix them, which results in anti-hydrogen (one anti-proton with one positron orbiting it). Storing that should be somewhat easier, since all you have to do is keep it from touching regular matter, and you can do that with a Penning trap (aka magnetic bottle).

The main problem as I see it is one of scale. We don't have big enough particle accelerators on Earth right now to make Antimatter much more than a research item, at the moment. That's why I suggested forgetting about harvesting the stuff, and putting purpose-built solar powered antimatter production particle accelerators in orbit around the sun closer than Mercury. That's the best way to get enough energy cheaply enough, quickly enough. The materials for the solar panels would probably come from either Mercury itself or from asteroids that cross the orbit of the a-matter factory stations.

Link to post
Share on other sites
This... The energy density is what makes it interesting for certain applications.

...

A more interesting question is where they're formed naturally and can we scoop them up?

Scooping up does not make sense as we probably would need antimatter to reach natural deposits of it.

This would only be likely if we develop warp drives soon.

Link to post
Share on other sites
what reactions yield antimatter particles?

Heavy nuclei collisions. You want a whole mess of quarks to interact at pretty much the same time if you want a good chance at anything more exciting than a meson. Naturally, you'll need at least two GeV of energy as well. In practice, way more, since you are going to lose a bunch of energy to a shower of stuff you don't want. Again, mostly mesons. There are a handful of accelerators in the world capable of managing that. RHIC and LHC spring to mind, but there are at least a couple more, maybe a few.

Beam-beam collisions are good for increasing CoM energy, but if you want to increase amount of antimatter produced, density is going to be important, so it's probably better to use a stationary target. Something like gold foil, probably. Beam would consist of some massive nuclei as well. Again, gold would work, but there could be better combinations. To be honest, I don't know how much it depends on structure of the nuclei involved. Some might be better than others, and energy you can put into the beam is also a factor, but this isn't my field. At any rate, you still need at least one heavy ion accelerator if you want a decent rate of production.

Link to post
Share on other sites
Scooping up does not make sense as we probably would need antimatter to reach natural deposits of it.

This would only be likely if we develop warp drives soon.

Saturn, Jupiter, Earth's own magnetic field, hell, there's probably a significant ammount of it in the Sun's magnetosphere too.

Link to post
Share on other sites

Only positrons are present in significant numbers. Trying to scoop up anti-protons from magnetosphere is not going to go any faster than manufacturing them at an accelerator.

Link to post
Share on other sites

An absolutely absurd (but usefull) idea I have is making (or gathering) anti-hydrogen and fusing it into anti-ferrum so as to make storage easier.

But seeing how we are still unable to do even regular fusion this sounds like a technological power fantasy.:P

Link to post
Share on other sites
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...