Energy positive? That made me laugh. Making antimatter is more energy negative than building a 747 out of gold. They burn through enough power to light a town in order to capture a literal handful of antimater particles.

In a rocket it would not be useful. It has the energy but would emit it as all sorts of highly penetrating radiation rather than hot gas for a rocket nozzle to turn into thrust.

One particle has enough energy to, maybe, if it hit a speck of dust it might result in a perceptible twitch of that speck of dust... if you were watching the spec under a good optical microscope.

Positrons aren’t useful because they annihilate to produce gamma rays, which can’t be contained. However, anti-proton annihilation produces a bunch of particles, including pions, which could be contained in a magnetic bottle and directed for thrust.

In this case they are using 22Na that produces positrons. A quick search says that they cost like $50-$300. (I guess I'm in yet another list now.) I used one in the physic lab a few years ago. They are good enough to get a few blips in a Geiger counter or something similar.

I agree that if someone wants to make enough antiprotons and positrons to make enough antimater to power a rocket, the cost is prohibitive and there is absolutely no hope to make it cost efficient.

They really missed out on a chance to go with 'negatrons' instead of antiprotons.

That would too easily get confused with positrons (anti-electrons).

Or even "notorp". Notorps could have been a thing.

I know you’re being facetious but a 747 made out of gold is going to be ~24 billion dollars if you are doing a weight conversion. A 747 by itself is ~$400 million. The entire CERN annual electricity cost is $~25-50M.

No way this experiment had that kind of funding. I would bet the experiment itself had a few million dollars in funding at most + another few for the salaries. Max 10M all in. Probably closer to 2-5M. Expensive but not prohibitive like a 747. But for a single particle.

Scaling up no one really knows because we only do this for single particles and that’s really inefficient. At scale it’s unclear what it could look like.

But electrons/positrons cannot become fuel. Positrons repel each other. So to make any real amount of antimater, beyond counting individual particles, you need anti-protons to keep the positrons happy and containable at scale. Creating the sort of anti-hydrogen one might want to collect as fuel, THAT requires golden 747s of energy.

I could be wrong but my understanding is that’s purely a function of our technological limitations in how we create antimatter, not in the fundamental energy required. Our tech of a particle acceleration is ~1e9 times less efficient than the actual energy required because most of the energy is lost, not converted. A gram would be $~6.2M/gram if we could get to 1% energy conversion efficiency. No one bothers of course to even try because it’s not worth it - expensive, difficult, and huge energy losses. Fusion reactors for space ships will probably come before antimatter gets cracked as a battery source.

I appreciate your comment as it sets expectations on what the technology can do today.

What would need to be true for the capability of creating and using antimatter to become feasible?

Veritasium made a video about CERN's "antimatter factory"

https://m.youtube.com/watch?v=jjp3WC8Unj8

“A literal handful of antimater particles” would be quite potent, even if your hands are very tiny.