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Antimatter has been transported for the first time

nature.com

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Re: Antimatter has been transported for the first time

#51

Post by d_silin »

wiredfool wrote: post #47
d_silin wrote: post #39

Earlier quoted context omitted.

Very tough engineering problem. Amount transported is 92 atoms. A mole (1 gram) of anti-hydrogen is 6.23x10^23 atoms.

When I visited CERN, they mentioned that there were some large number of protons in the ring at a time, and the runs would last a significant amount of wall clock time. (Don’t remember the exact numbers, but I think it was like 10^19 atoms of H, and days of wall clock) The upshot was, it was likely that less than a mol of hydrogen had been run through the ring.

If humanity doesn't perish in the next hundred year and masters interplanetary spaceflight, antimatter drive is the logical next step in propulsion after fusion.

Interstellar spaceflight will become (barely) feasible once spaceships can reach velocity between 0.02 to 0.1c are possible. Even assuming non-100% conversion efficiency, antimatter has enough energy density to provide this capability.

Re: Antimatter has been transported for the first time

#52

Post by yibg »

csense wrote: post #37

From a layman's point of view antimatter seems like an ideal spacecraft fuel. It's as energy dense as E = mc^2 allows, and if you have infrastructure to make it, the only input you need to produce it is electricity. Being able to transport it seems like an important piece of that puzzle. Production and storage would need to be scaled by many orders of magnitude, but that's merely an engineering problem...right?

Not familiar with the subject so genuine question. HOW would antimatter be used as fuel? There is energy released in matter antimatter annihilation, but where would the force to move a spacecraft come from?

Re: Antimatter has been transported for the first time

#55

Post by tczMUFlmoNk »

nikhilisvalid wrote: post #49
voidUpdate wrote: post #5

Earlier quoted context omitted.

Wolfram Alpha says its approximately the kinetic energy of a mosquito in flight

Wolfram Alpha says it's approximately _one-sixth_ the kinetic energy of a mosquito in flight

When we're talking scales like 10^-23, "one" and "one sixth" are comparable enough to warrant an "approximately".

Re: Antimatter has been transported for the first time

#57

Post by goda90 »

yibg wrote: post #52
csense wrote: post #37

From a layman's point of view antimatter seems like an ideal spacecraft fuel. It's as energy dense as E = mc^2 allows, and if you have infrastructure to make it, the only input you need to produce it is electricity. Being able to transport it seems like an important piece of that puzzle. Production and storage would need to be scaled by many orders of magnitude, but that's merely an engineering problem...right?

Not familiar with the subject so genuine question. HOW would antimatter be used as fuel? There is energy released in matter antimatter annihilation, but where would the force to move a spacecraft come from?

Use the antimatter as an electricity source to power ion thrusters, maybe?

Re: Antimatter has been transported for the first time

#58

Post by dodobirdlord »

isolli wrote: post #48
PowerElectronix wrote: post #34

Earlier quoted context omitted.

It would depend on how it's distributed. If it's very homogeneous, totally anihilated. If there are galaxies of matter and galaxies of antimatter, more or less like us with a bit more background radiation.

How do we know there are no antimatter galaxies far away from us?

Mass in the universe appears to be (very) roughly uniformly distributed, so even if there are large bodies of antimatter far away in the universe there would have to be a transition boundary somewhere between here and there where the universe goes from being mostly matter to being mostly antimatter. The universe is big and stuff would sometimes cross this boundary and get annihilated, and if this happened it would be the brightest thing in the sky, briefly outshining entire galaxies. We’ve been watching the sky for a while now and have never observed a bright visual event with the spectral signature of a matter/antimatter annihilation, so we assume there is not such a transition boundary, and by extension that the universe is made up of mostly matter out to the edge of the observable universe.

Re: Antimatter has been transported for the first time

#59

Post by throwaway894345 »

adrianN wrote: post #50
csense wrote: post #37

From a layman's point of view antimatter seems like an ideal spacecraft fuel. It's as energy dense as E = mc^2 allows, and if you have infrastructure to make it, the only input you need to produce it is electricity. Being able to transport it seems like an important piece of that puzzle. Production and storage would need to be scaled by many orders of magnitude, but that's merely an engineering problem...right?

Black holes are good star ship engines because they turn everything into Hawking radiation.

Can you elaborate? Why is HR useful for starship engines?

Re: Antimatter has been transported for the first time

#60

Post by jjmarr »

yibg wrote: post #52
csense wrote: post #37

From a layman's point of view antimatter seems like an ideal spacecraft fuel. It's as energy dense as E = mc^2 allows, and if you have infrastructure to make it, the only input you need to produce it is electricity. Being able to transport it seems like an important piece of that puzzle. Production and storage would need to be scaled by many orders of magnitude, but that's merely an engineering problem...right?

Not familiar with the subject so genuine question. HOW would antimatter be used as fuel? There is energy released in matter antimatter annihilation, but where would the force to move a spacecraft come from?

> Various antiproton-powered rocket systems have been proposed. All of which rely on the particles released to supply direct thrust or to heat a working fluid by interparticle collisions or by heating a solid core first [14]. There is also the possibility to use the heated working fluid to generate electricity for electric propulsion systems [14].

> Following Fig. 9, beam core and plasma core configurations can produce direct thrust by directing the charged particles produced into an exhaust beam using a magnetic nozzle. Gas core systems use the energy released from the reaction to heat a gas that is exhausted for thrust. Finally, solid core configuration heats a metal core like Tungsten that acts as a heat exchanger to a propellant that is then exhausted from a regular nozzle.

Not the same paper, but goes into more detail.

https://www.sciencedirect.com/science/article/pii/S266620272...

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