The Many Applications Of Antimatter

[Spacescifi]

 

Just wondering... for scifi.

I know antimatter is by no means an 'I can do anything I want' card,  I just want to know as many applications for it as possible.

The scenario: We figure out how to process antimatter (anti-iron) in bulk and store it with magnetic fields. A processing facility takes 2 months on average to produce 1 ton of antimatter.

On average it takes $30,000 to produce one ton of antimatter every two months.

 

So what are the uses of this anti-iron?

 

My guesses: I may be wrong but you will let me know.

 

1. Super long lived batteries thanks to anti-iron? I dunno. I do know that a magnetic field to hold the anti-iron must be made so as not to disrupt any electronic device utilizing it for power.

2. Supercharged ion craft. I still doubt if ion planes xan exist since plasma thrust is weak, and you would need colossal wing intakes to generate much thrust through mass of air alone. Planes and rockets work so well because they are combusting heavy fluids out the back so hard that the thrust exceeds any weight they have.

 

That's all I got... what about you?

Edited April 9, 2020 by Spacescifi

[Wjolcz]

Just blow it up. Just do it. Make sure it pushes real hard on that pusher plate. That's the only way.

[StrandedonEarth]

Make a gamma-ray laser?

 

[kerbiloid]

6 hours ago, Spacescifi said:

as many applications for it as possible.

Just one. It's a capacitor with high capacity.
You spend a lot of energy by a power plant to store a small part of it as antimatter.

Not many applications for an overpowered capacitor. Definitely none in usual life. Just blow up an asteroid or enforce a nuclear reactor.

6 hours ago, Spacescifi said:

We figure out how to process antimatter (anti-iron) 

That's in fact easy. Take anti-silicon and anti-carbon and do the fusion. Anti-stars do this, so why we couldn't?

Of course, we should first process iron to have a tutorial.

6 hours ago, Spacescifi said:

On average it takes $30,000 to produce one ton of antimatter every two months.

So, that's why that's the actual reason of the hype around gas prices. Cheap antimatter for every house.
Btw, somebody above should start worrying about antimatter alternative for coal.

6 hours ago, Spacescifi said:

Super long lived batteries thanks to anti-iron?

Yes! Tesla Antipower.
What can be better than blue flashes in the night where the road incidents happen.

6 hours ago, Spacescifi said:

Supercharged ion craft.

Spending 99.9999% of their energy to keep the propellant rather than to propel.

[sevenperforce]

Antimatter is just matter that is impossible to contain and explodes catastrophically via e = mc² whenever you sneeze in its general direction. It is not magic.

[Guest]

It's not impossible to contain. Merely hard. We can do it right now. It's an energy hog, but a combined reactor/storage unit would have no trouble with that. It would power either just itself or itself+whatever is hooked up to it. The beauty of this arrangement is that it works as long as it has antimatter, and once it doesn't, there's nothing to worry about.

Antimatter is great for energy storage, but not much more. To use it, you need to have both a means of producing that much energy, and an application that can not just hook up to the aforementioned powerplant directly, or use a less expensive means of storage. That means bombs and rocket engines. 

[sevenperforce]

6 hours ago, Dragon01 said:

It's an energy hog, but a combined reactor/storage unit would have no trouble with that. It would power either just itself or itself+whatever is hooked up to it. The beauty of this arrangement is that it works as long as it has antimatter, and once it doesn't, there's nothing to worry about.

A fair point.

6 hours ago, Dragon01 said:

To use it, you need to have both a means of producing that much energy, and an application that can not just hook up to the aforementioned powerplant directly, or use a less expensive means of storage. That means bombs and rocket engines. 

I have yet to see a really solid analysis of what kind of performance you would get out of an engine with full antimatter containment.

22 hours ago, Spacescifi said:

So what are the uses of this anti-iron?

You could synthesize some anti-carbon, mix it, and make anti-steel. You could then take your anti-carbon and react it using energy with anti-hydrogen to make anti-methane, and then if you could make some anti-oxygen you could react the anti-methane with the anti-oxygen in an anti-steel engine to make an anti-rocket stage.

[wafflemoder]

Antimatter is absolutely terrible for energy storage. Currently antimatter requires ~1,000,000,000,000,000 times more energy to make than is stored in it. While matter-antimatter annihilation is 100% efficient, you'll only be able to get about 70% of the energy from it at most, as much of it is released in gamma rays which creates significant amounts of waste heat. This is to say that of the energy you put in, you only get 0.00000000000007% of it back. Compare this to a common battery, from which you get 80% of what you put in back out.

Even with perfectly efficient antimatter production, so only the 70% energy retrieval is considered, batteries still beat out antimatter. To make things worse, any device capable of liberating energy from antimatter in a controlled manner would need to be fairly big, and certainly not compact enough for any real applications. A lack of miniaturization is what doomed the "atomic future" of the 50s, and antimatter will likely suffer a similar fate. In terms of energy density  (usable energy per volume) and specific energy (usable energy per mass), fission probably beats out antimatter, when storage vessels are factored in.

Something to point out, there is very little point to creating antimatter atoms larger than helium or lithium. With any conceived methods of producing or harvesting antimatter, you're only going to be getting single antiprotons and antineutrons out of it. While you could in theory get energy from "anti-fusing" it up to iron, this is a barely plausible idea for regular matter, and even more lucrative for antimatter. The density of the antimatter itself does very little to impact the density of it when stored electromagnetically, and electromagnetic antimatter storage does not require ferromagnetic antimatter (that might even hinder storage attempts). If the density of antimatter is a factor, you could probably settle with anti-lithium, which should be a solid metal like in standard conditions like its matter counterpart. Most systems that would use antimatter also function better with lighter antimatter particles, especially in rocketry.

 

[Guest]

1 hour ago, wafflemoder said:

Antimatter is absolutely terrible for energy storage. Currently antimatter requires ~1,000,000,000,000,000 times more energy to make than is stored in it. While matter-antimatter annihilation is 100% efficient, you'll only be able to get about 70% of the energy from it at most, as much of it is released in gamma rays which creates significant amounts of waste heat. This is to say that of the energy you put in, you only get 0.00000000000007% of it back. Compare this to a common battery, from which you get 80% of what you put in back out.

First of all, this is comparing to current tech. We're not really trying to make antimatter storage, so "current technology" in this area does not exist. There are a couple of designs that, if built, would be better at storing antimatter than anything we have. 

Second, you're barking up the wrong tree. You focused on storage efficiency, but that doesn't matter at all. Why don't we have battery-powered rockets, then? Electron is not the case, it's a chemical rocket with electric engine pumps. What matter is energy per unit of mass. There, antimatter leaves everything in the dust due to simple physics. As long as your storage method is sensible (say, a frozen ball of antihydrogen suspended with superconducting magnets), you can't beat that even with fusion power. Not only that, gamma rays are actually perfect for energy conversion, exactly because they generate heat (and guess what's the easiest way of getting useful energy out of something. That's right, a heat engine). It's the other particles that are problematic, and only neutrinos are a total loss, in a well designed reactor or rocket engine.

[wafflemoder]

30 minutes ago, Dragon01 said:

First of all, this is comparing to current tech. We're not really trying to make antimatter storage, so "current technology" in this area does not exist. There are a couple of designs that, if built, would be better at storing antimatter than anything we have. 

Second, you're barking up the wrong tree. You focused on storage efficiency, but that doesn't matter at all. Why don't we have battery-powered rockets, then? Electron is not the case, it's a chemical rocket with electric engine pumps. What matter is energy per unit of mass. There, antimatter leaves everything in the dust due to simple physics. As long as your storage method is sensible (say, a frozen ball of antihydrogen suspended with superconducting magnets), you can't beat that even with fusion power. Not only that, gamma rays are actually perfect for energy conversion, exactly because they generate heat (and guess what's the easiest way of getting useful energy out of something. That's right, a heat engine). It's the other particles that are problematic, and only neutrinos are a total loss, in a well designed reactor or rocket engine.

I had pointed out in my previous post that both antimatter's specific energy and energy density are only comparable to fission when factoring in storage and energy liberation. It's quite probably that this may improve with time, but so may fission and fusion technologies. Furthermore, fusion can very handily beat antimatter in terms of energy density (per volume, not mass), as Ultra Dense Deuterium can have a density of 130 kg/cm^3, which is more than enough to make up for the lower specific energy of fusion compared to antimatter. Both specific energy and energy density are important to have, with certain applications valuing one over the other.

While heat engines are certainly the efficient and one of the simplest ways of harnessing energy, they are not very mass efficient, so if trying to minimize the mass of your antimatter fuel cell, alternative methods of energy extraction are preferred. Magnetohydrodynamic generators, while slightly less efficient, are far lighter and more compact than a heat engine (which is why they are often proposed for fission, fusion, and antimatter bimodal power generation on spacecraft instead of more traditional brayton cycle heat engines.

Considering this discussion is about general uses for antimatter, not specifically in rocketry, discussing the storage efficiency of the antimatter batteries previously brought up in the original post seems like a fairly reasonable tree to bark up. Additionally, we don't have battery powered rockets for the same reason we don't have fission powered phones, it doesn't have the desired properties for the application with our current level of technology.

Gamma rays are pretty useful in heat engines and antimatter thermal rockets, but not in MHD generators. This is because MHD generators work with charged particles (which photons are not). Similarly in more advanced antimatter beam-core/pion-core rockets, only charged pions can be magnetically directed as exhaust. These charged pions eventually decay into neutrinos and muons (which decay into more neutrinos), which can lead to some losses via scattering. Neutral pions and gamma ray photons, not having an electric charge, cannot not be redirected as exhaust and heat up the rocket, facilitating the use of an ungodly amount of radiators.

[Guest]

14 minutes ago, wafflemoder said:

(per volume, not mass)

Last time I checked, only mass factored into rocket equation, not volume. Volume efficiency is nice, but it's not what you're after if you're using antimatter for propulsion. For weapons, maybe, but in that case, antimatter is more useful for lighting a fusion bomb than as the main charge, especially in space. For propulsion, however, volume is cheap.

"Super long-lived batteries" is more along the lines of a self-contained antimatter storage/reactor unit. It's certainly a nice idea from a logistical standpoint, due to how much energy it takes to store AM in first place. However, this would be a lot more like a canned nuclear reactor than a battery. 

14 minutes ago, wafflemoder said:

Gamma rays are pretty useful in heat engines and antimatter thermal rockets, but not in MHD generators. This is because MHD generators work with charged particles (which photons are not). Similarly in more advanced antimatter beam-core/pion-core rockets, only charged pions can be magnetically directed as exhaust. These charged pions eventually decay into neutrinos and muons (which decay into more neutrinos), which can lead to some losses via scattering. Neutral pions and gamma ray photons, not having an electric charge, cannot not be redirected as exhaust and heat up the rocket, facilitating the use of an ungodly amount of radiators.

Or a thermal rocket. Antimatter thermal is a perfectly viable means of propulsion, and much less complex than beam core. Also, MHD can work with any kind of hot gas (such as coal powerplant exhaust, which is what they're used for right now), so if you can use these gammas and pions to make hot gas, you can use them for MHD, as well. In fact, with antimatter thermal, you can get anywhere in the solar system with a mass ratio of about 2 and a tiny amount of antimatter. This is due to a quirk in how rocket equation works. 

Alternatively, just make the walls thin. The rocket will spew highly energetic radiation, but not heat up nearly as much. This will not eliminate waste heat, but will limit it considerably. Most beam core concepts I've seen weren't thick enough to worry about absorbing very much.

[wafflemoder]

2 hours ago, Dragon01 said:

Also, MHD can work with any kind of hot gas (such as coal powerplant exhaust, which is what they're used for right now), so if you can use these gammas and pions to make hot gas, you can use them for MHD, as well.

Oh yeah, that completely slipped my mind . Still beam cores might run into in efficiency issues with energy conversion with less reaction mass that can absorb the gamma (another reason why AM thermal is pretty good). AM thermal is a really good propulsion system, especially where high TWR is required and when antimatter is hard to come by. Just figured with the large amounts proposed in the OP that you might as well use it (that amount would also be ideal for a plasma core).

Speaking of, just some math on the power requirements to produce 1 ton of antimatter every two months at various tech levels. Basically a swarm of specialized factories inside mercury's orbit should be able to crank it out no problem, just not today.

At current efficiencies. (1E-13 %) Pretty ridiculous: 1.7E28 W, 9E14x Global power output, 44x Output of the Sun.

Specialized facilities a billion times more efficient (0.0001%) Pretty reasonable for an advanced civ: 1.7E19 W, 900000x Global power output, 0.000004x Output of Sun.

Pair production from black hole hawking radiation (~30%) Easily doable, assuming you can make and maintain the 5-10 Mt black holes: 5.7E13 W,  1100x Global power output.

Max efficiency from Andreev Reflection in quark nuggets (~85%) Trivial, quark nuggets not included: 2E13 W, 380x Global power output.

Edited April 10, 2020 by wafflemoder