What Would A Scifi Antimatter/Matter Reactor Be Like?

[Spacescifi]

Supposedly... aren't star trek warp cores this more or less?

My Scifi scenario: A neutral solid material is made that won't go kaboom upon touching antimatter. The only issue is that this is not a passive process but requires a constant flow of electrical input into the material to ensure it won't go kaboom with the anti-matter. Fortunately the amount of power required is not great... just make sure you have a bunch of auxiliary back ups so it never loses power.

Main question: Assuming someone made this fictional material and hired engineers to go about making an anti-matter/matter reactor from it how would they do it?

Let's also presume mankind has reached the point of making antimatter at an efficient rate as well as safely (in no small part due to the scifi material that does not go ka-boom from touching antimatter).

 

Edited March 31 by Spacescifi

[DDE]

23 minutes ago, Spacescifi said:

A neutral solid material is made that won't go kaboom upon touching antimatter. The only issue is that this is not a passive process but requires a constant flow of electrical input into the material to ensure it won't go kaboom with the anti-matter.

So why do you have to posit a non-existent material when you're just describing something akin to a Joffe trap that is entirely physics-compliant?

[DareMightyThingsJPL]

46 minutes ago, Spacescifi said:

Let's also presume mankind has reached the point of making antimatter at an efficient rate as well as safely (in no small part due to the scifi material that does not go ka-boom from touching antimatter).

Well, there is a limit. Put simply, antimatter isn't a fuel, it is an energy transport mechanism. A fuel is something that can be mined. An energy transport mechanism is something that has to be artificially made - and with antimatter, the efficiency of creating it is abysmal.

Currently, our best methods of production achieve 0.000002% efficiency. The late Dr. Robert Forward states that efficiencies of 0.01 could be achieveable (the logic being that engineers aren't physicists and physicists aren't engineers, but if you could get them to work together you could get stuff to work better). The theoretical maximum would be 50%, due to the pesky law of Conservation of Baryon Number (when  energy is turned into matter, equal amounts of matter and antimatter must be created)

[Spacescifi]

1 hour ago, DDE said:

So why do you have to posit a non-existent material when you're just describing something akin to a Joffe trap that is entirely physics-compliant?

Probably because I never heard of a Joffe trap lol. Second because I don't want to assume anything about what we have not achieved yet.... so scifi methods it is.

1 hour ago, DareMightyThingsJPL said:

Well, there is a limit. Put simply, antimatter isn't a fuel, it is an energy transport mechanism. A fuel is something that can be mined. An energy transport mechanism is something that has to be artificially made - and with antimatter, the efficiency of creating it is abysmal.

Currently, our best methods of production achieve 0.000002% efficiency. The late Dr. Robert Forward states that efficiencies of 0.01 could be achieveable (the logic being that engineers aren't physicists and physicists aren't engineers, but if you could get them to work together you could get stuff to work better). The theoretical maximum would be 50%, due to the pesky law of Conservation of Baryon Number (when  energy is turned into matter, equal amounts of matter and antimatter must be created)

 

Yes I know it cannot be mined, even though I read there are regions of  outer space even in our solar system where the probability of producing it is fairly high if you know what you're doing

Read that Saturns rings are bombarded with enough cosmic radiation that antimatter is created.. just not enough to do anything substantial besides a lot of radiation.

Antimatter is a great way to transfer a LOT of energy if you had a way to store it... hence the scifi solid material.

Edited March 31 by Spacescifi

[DareMightyThingsJPL]

40 minutes ago, Spacescifi said:

Antimatter is a great way to transfer a LOT of energy if you had a way to store it... hence the scifi solid material.

The thing is... you can. There are Penning traps, and concepts that suspend frozen antihydrogen masses in magnets, which use UV lasers to melt it for transport on-demand. Thing is, keeping that antihydrogen cool and confined is very expensive in terms of both mass and in electricity. 

40 minutes ago, Spacescifi said:

Read that Saturns rings are bombarded with enough cosmic radiation that antimatter is created.. just not enough to do anything substantial besides a lot of radiation.

Yes, this is true for any planet with a magnetosphere - specifically Earth and Saturn, and possibly Jupiter, Uranus and Neptune (either their magnetospheres are to strong or to weak). Only antiprotons are captured in these fields, though, and in VERY small amounts. Enough to use in catalyzed microfission or initiated microfusion, though.

Edited March 31 by DareMightyThingsJPL
Grammar correction

[Spacescifi]

1 minute ago, DareMightyThingsJPL said:

The thing is... you can. There are Penning traps, and concepts that suspend frozen antihydrogen masses in magnets, which use be UV lasers to melt it for better transport on-demand. Thing is, keeping that antihydrogen cool and confined is very expensive in terms of both mass and in electricity. 

Yes, this is true for any planet with a magnetosphere - specifically Earth and Saturn, and possibly Jupiter, Uranus and Neptune (either their magnetospheres are to strong or to weak). Only antiprotons are captured in these fields, though, and in VERY small amounts. Enough to use in catalyzed microfission or initiated microfusion, though.

 

Which is exactly why a posited the scifi solid material  A lot easier to work with since all you need is electricity and worrying about keeping it frozen is not a concern or a factor.

[DareMightyThingsJPL]

1 minute ago, Spacescifi said:

Which is exactly why a posited the scifi solid material  A lot easier to work with since all you need is electricity and worrying about keeping it frozen is not a concern or a factor.

That is true, and I can see the point of view. 

[Spacescifi]

21 minutes ago, DareMightyThingsJPL said:

That is true, and I can see the point of view. 

 

Perhaps the more important question is would our understanding of physics allow for a solid material that... when powered up, would not react catastrophically with antimatter?

Don't know really. Probably not

I mean... if you had a way of literally freezing time upon a solid then antimatter would not react with it at all even if in contact... because things only happen if time passes... not when time is frozen.

And I know that is even more farfetched...but it would also work lol.

Time frozen solid armor.... who knew?

Edited March 31 by Spacescifi

[RCgothic]

Anti-hydrogen would love to escape containment in much the same way that hydrogen does, and neutral materials couldn't be compelled to remain separate from matter, so whatever it was would need to have a charge of some sort.

I went down a bit of a rabbit hole of suggesting using a plasma of anti-Beryllium or anti-Flourine.

They both only have one stable isotope and are significantly more massive than hydrogen, which simplifies the plasma dynamics.

But plasma containments remain horrendously leaky in the grand scale of things, and Anti-Be and Anti-F are both very hard to fabricate from anti-H:

I believe Be is primarily made from spalling a larger element with cosmic rays, and Flourine needs a rare branch of supernova fusion.

 

So back to the drawing board!

No Plasma. We use solid anti-carbon in diamond form for it's vacuum stability, and we then give it a charge and suspend it electrically in a vacuum. Safe, vacuum-stable antimatter storage! Power would be extracted by bombarding the solid antimatter with a matter beam. This would probably top up the charge as well, as the matter beam would need to be charged.

Carbon can be formed from 3 helium atoms fused in short succession before the intermediate Beryllium 8 has time to realise it's unstable and decay. It's a very not easy process and we are nowhere near being able to do that ourselves, but it's necessary if we want anything solid with decent vacuum stability.

A civilisation capable of fusing to anti-carbon would need to have significant energy abundancy, and would probably only use this process for extremely demanding applications, such as interstellar travel.

Edited March 31 by RCgothic

[Spacescifi]

53 minutes ago, RCgothic said:

Anti-hydrogen would love to escape containment in much the same way that hydrogen does, and neutral materials couldn't be compelled to remain separate from matter, so whatever it was would need to have a charge of some sort.

I went down a bit of a rabbit hole of suggesting using a plasma of anti-Beryllium or anti-Flourine.

They both only have one stable isotope and are significantly more massive than hydrogen, which simplifies the plasma dynamics.

But plasma containments remain horrendously leaky in the grand scale of things, and Anti-Be and Anti-F are both very hard to fabricate from anti-H:

I believe Be is primarily made from spalling a larger element with cosmic rays, and Flourine needs a rare branch of supernova fusion.

 

So back to the drawing board!

No Plasma. We use solid anti-carbon in diamond form for it's vacuum stability, and we then give it a charge and suspend it electrically in a vacuum. Safe, vacuum-stable antimatter storage! Power would be extracted by bombarding the solid antimatter with a matter beam. This would probably top up the charge as well, as the matter beam would need to be charged.

Carbon can be formed from 3 helium atoms fused in short succession before the intermediate Beryllium 8 has time to realise it's unstable and decay. It's a very not easy process and we are nowhere near being able to do that ourselves, but it's necessary if we want anything solid with decent vacuum stability.

A civilisation capable of fusing to anti-carbon would need to have significant energy abundancy, and would probably only use this process for extremely demanding applications, such as interstellar travel.

 

Nice work. I guess particle beams of regular matter could be used to react with equally small amounts of antimatter to release energy.

A lot of energy is released as gamma rays, so I imagine any true antimatter reactor will need  thick walls that can catch or absorb the gamna rays and collect them as an energy source as well.

In other words... not like the glowy long tube warp cores Star Trek is famous for.

[AckSed]

Lots of theoretical work has been done in rocketry in confining unstable, high-energy matter. Whether it be antimatter, metastable helium, metallic hydrogen or single-atom hydrogen, people have seen the performance and wanted it.

Fortunately, the creator of the High Frontier boardgame (which you may have heard me go on about in the past) is just this kind of rocket scientist, and included an appendix explaining the technology behind the game's thruster and reactor cards - with citations.

Concepts for the design of an antimatter annihilation rocket (D. L. Morgan, British Interplanetary Society, 1982): https://ntrs.nasa.gov/api/citations/19820013176/

This gives a good rundown on what antimatter is, how a reactor utilising it could be made and so on. The important thing is that antimatter is the opposite charge of its matter, so a positron (antimatter electron) has a positive charge, and an antiproton has a negative charge.

This means that both can form 'atoms' with its matter counterpart: protonium is a proton electrically-bound to an antiproton, and positronium is a positron bound to an electron.

Which brings us to the next design. Positronium can be stored. Not easily, but easier than straight antimatter. tl;dr if pinned with magnetic fields & stretched apart with electric fields, and stored in supercooled quantum dot chips (approximately 10 to the power of 11 Ps atoms may be stored per 1cm x 1cm chip), they have a lifetime of over a year instead of nanoseconds. Further, "the binding energy of this state is quite large, resulting in a ground state that is both stable against direct annihilation and against ionization by low frequency background radiation."

Downsides? It's unlikely to have any big annihilation booms, but rather must be laser-excited in a steady stream into an attenuating matrix with hydrogen flowing through it. The stated performance on the "Positronium Bottle Reactor" is 300MW of thermal energy with 2.7 kiloNewtons thrust at 8,000 seconds of delta-V.

Propulsion and Power With Positrons (K. Edwards, Air Force Research Laboratory, 2004): https://bravenewclimate.com/files/files/library/meetings/fellows/mar04/edwards_kenneth.pdf

Positronium in crossed electric and magnetic fields: the existence of a long-lived ground state (J. Shertzer, J. Ackermann, P. Schmelcher, 1997): https://arxiv.org/abs/physics/9712028

Edited March 31 by AckSed

[ColdJ]

A lot of real world physics people commenting here, can't compete with that so just SciFi.

Usually they claim magnetic field containment.

My Question. How do you take the massive release of energy and turn it into usable energy?

Otherwise nuclear reactors would be using the particles released to knock electrons out of orbits to create current, rather than just heat water.

[adsii1970]

5 minutes ago, ColdJ said:

A lot of real world physics people commenting here, can't compete with that so just SciFi.

Usually they claim magnetic field containment.

My Question. How do you take the massive release of energy and turn it into usable energy?

Otherwise nuclear reactors would be using the particles released to knock electrons out of orbits to create current, rather than just heat water.

 

[RCgothic]

Mind a little bit blown by the idea of Protonium, Positronium, and Muonium, but on looking them up they're all super-unstable and decay by annihilation within a hundredth of a second of production.

Edited March 31 by RCgothic

[AckSed]

3 hours ago, ColdJ said:

My Question. How do you take the massive release of energy and turn it into usable energy?

Otherwise nuclear reactors would be using the particles released to knock electrons out of orbits to create current, rather than just heat water.

Helion Energy's fusion reactor is supposed to use the pulses of electromagnetic energy released by expanding fusion plasma to generate electricity directly, but that's not what you're asking.

So I'm going to be a terrible swot and ask, "What is usable energy?"

This has a scientific term: exergy.

Quote

Energy and exergy are two related but distinct concepts in the field of thermodynamics. Energy refers to the ability to do work or produce heat, and it can exist in various forms such as mechanical, thermal, or electrical energy. On the other hand, exergy is a measure of the quality or usefulness of energy. It takes into account the irreversibilities and inefficiencies in energy conversion processes. While energy is conserved in any thermodynamic system, exergy is not, as it is lost due to irreversibilities. Therefore, exergy analysis provides a more comprehensive understanding of the efficiency and sustainability of energy conversion systems, allowing for the identification of potential areas for improvement and optimization.

To really trim it down, the exergy of an antimatter reactor is low if all you want is to generate power. This doesn't quite matter because the energy release is so great even compared to nuclear fission or fusion, but the form of the energy is difficult to utilise, as the charged particles decay, and the positrons react with the electrons produced, leaving you with nothing but ghostly neutrinos and hard gamma rays.

Spoiler

To put it in percentages, of the energy from an initial proton/antiproton annihilation event:

37.77% is expressed in decay of the neutral pions into gamma rays, and this happens almost immediately;

67.33% is left in the energy of the positive and negative charged pions, and if we can't use that, that loses 14.68% just in neutrinos as they decay into charged muons;

52.65% left, which, if left unused, slightly less soon decays into equal amounts of positrons, electrons, and a whopping 31.59% in more neutrinos;

21.06% left, which if we don't separate or harvest the electrons or positrons, annihilates with itself into more gamma rays.

And the best use we have so far of using that gamma ray energy... is to let it slam into a block or pool of mass to heat it up so we can utilise the heat, or let it escape into space.

Ain't fair, is it?

For reaction exhaust, the charged muons are capable of being diverted with a magnetic nozzle to provide thrust, as they're moving at 0.94c, but capturing that charge is... well, I know of no way to accomplish it right now.

However...

How does one feel about using absurdly powerful lasers to create antimatter out of nothing, then compress it with magnetic fields so you can use an unbelievably powerful gamma ray laser as a rocket sound? Good? https://www.centauri-dreams.org/2016/08/02/the-evolution-of-antimatter-propulsion/

[RCgothic]

So about 1010 MeV is actually recoverable from the initial 1880MeV, (about 54%) and then in the form of heat we can turn that into electricity at about 40% efficiency with a steam cycle, for just over 20% of the initial input. 

Antimatter is a really inefficient storage medium, but it's so powerful and energy dense that you probably don't care about inefficient conversion factors.

(Although be sure to vent byproduct heat somewhere or you'll need to start caring quick!)

I think I've already hinted at the huge inefficiency in getting to antimatter in the first place, so yeah, lose a lot of energy both ways.

Edited March 31 by RCgothic

[Nuke]

i bet solid anti-lithium might make things easier. you can use its paramagnetic properties to suspend it in a vacuum chamber. granted anti-lithium is going to be a lot harder to make than run of the mill anti-hydrogen. but if you can get the mass of containment down a lot, and come up with a means to transport it from containment and "burn" it in a reactor, then you have an ultimate antimatter rocket with solid isp. it gives you the means for sublight interstellar transfers.

cool thing is if your containment needs maintenance, you can just put the block of anti-lithium outside while you work on the reactor, engine, etc. hydrogen is problematic enough when it doesn't try to annihilate with everything.

Edited March 31 by Nuke

[ColdJ]

3 hours ago, AckSed said:

"What is usable energy?"

Well in this case I am thinking either propulsion or electricity. Although how you use it as propulsion without vapourising the ship, I am not sure.

3 hours ago, RCgothic said:

(Although be sure to vent byproduct heat somewhere or you'll need to start caring quick!)

Venting heat in Space, ahh what fun.

It seems that with our current understandings, that creating antimatter for anything but wiping out the entire planet very quickly is rather futile.

In SciFi you can create any magical science you like to make the plot work.

One of the problems I have with Star Trek Discovery when it went into the future, is the Badges that can teleport you instantly with no external help and to any co-ordinate with barely any input.

The power of that one badge could power the entire planet Earth. The computational power would be astronomical. And it somehow transports itself along with the person.

I mean what, does it make a copy of itself out of pure energy, transfer control to the copy and get it to take over?

[Nuke]

discovery went to far i think. plausible technology is one thing but they turned it into space magic. then add to that the fact that everyone acts like a teenager. then you have insufferable space magic.

[magnemoe]

22 hours ago, ColdJ said:

A lot of real world physics people commenting here, can't compete with that so just SciFi.

Usually they claim magnetic field containment.

My Question. How do you take the massive release of energy and turn it into usable energy?

Otherwise nuclear reactors would be using the particles released to knock electrons out of orbits to create current, rather than just heat water.

That is part of the tricks, you want charged plasma from the matter anti matter reaction, this can be used to generate electricity directly or generate trust in a rocket. 
an hydrogen-anti hydrogen impact just leave very hard gamma rays. Antimatter engines has lots of the same issues as fusion engines, you want charged particles. 
But fusion is safe, yes its radiation then its running and liner get radioactive because of neutrons but you can simply turn it off. 
Antimatter only safe mode is dumping it overboard if on an spaceship.  

[Codraroll]

A simple question with a simple answer. You specifically say "scifi", which means it could look like anything you want. Make stuff up as it suits your wishes. That's what the "fi" part of the word means. Fiction. Use the imagination and do whatever.

[DareMightyThingsJPL]

8 hours ago, Codraroll said:

A simple question with a simple answer. You specifically say "scifi", which means it could look like anything you want. Make stuff up as it suits your wishes. That's what the "fi" part of the word means. Fiction. Use the imagination and do whatever.

I remember I wrote sci-fi a bit ago. I liked being scientifically accurate, but some things have to be handwaved (TL;DR: no interstellar civilization if there isn't FTL). My word of advice for sci-fi is, learn and understand what science permits and does not. Once you know that, you know where you need to break scientific accuracy for story purposes

[AckSed]

6 hours ago, DareMightyThingsJPL said:

My word of advice for sci-fi is, learn and understand what science permits and does not. Once you know that, you know where you need to break scientific accuracy for story purposes

This, this and thrice this.

Airily saying that it doesn't matter gets to me. The whole point of the scientific method is to have rigor in your observations of reality such that your predictions can be reproduced; it's skinning the hide of science to cover your bamboo framework and leaving the soul.

We don't want a stiff, dead, taxidermied pseudoscientific animal with glowy lights, we want a Frankenstein's monster that has some semblance of agreement with life and the world, one that can actually speak to us.

I do write (fanfic, but still) and you can speak to human experiences and be successful, because we do like to hear about ourselves. The very best science-fiction authors allowed what they know about the world to drive their stories, to let the environment warp their characters because they were speculating via the scientific method. E.g. Robert Heinlein's The Menace From Earth frankly gets some important details wrong, and its appeal is in the very human characters, but it is still true that with Earth-normal strength and a bit more air-pressure humans on the Moon wearing wings and a tail can fly under their own power. It ignited my imagination and drove me to write my own short story set on the Moon, based upon what we know now.

You say people don't care? I care. I'm people.

Spacescifi, please post examples of your stories, so I can see where you have put the effort in and the advice we have given. I don't like feeling like we're being used more as an oracle by the lazy, or worse - market research.

Edited April 3 by AckSed

[DDE]

20 minutes ago, AckSed said:

Spacescifi, please post examples of your stories, so I can see where you have put the effort in and the advice we have given. I don't like feeling like we're being used more as an oracle by the lazy, or worse - market research.

I think they may fall into a trap very familiar to me - lazy doodling masquerading as 'continuous worldbuilding'. There's nothing wrong with it per se, but one should not masquerade it (especially to themselves) as something it's not.

[darthgently]

One possible advantage to good AI is the end of would be sci-fi writers picking the brains on the internet for ideas and details