Is there any way to actually produce helium other than nuclear fusion? I would assume not, but I'm not an expert in this field.
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Helium is produced naturally by radioactive decay underground. There is no way to artificially produce it in useful quantities.
But we can capture more of it from natural gas wells. Today much helium is just vented off and wasted at wellheads. As the price rises it makes sense to invest in cryogenic helium capture equipment for more wells.
Terrestial helium isn't produced by nuclear fusion. It's produced by nuclear decay. As you may know, you get alpha, beta and gamma radiation from decay. Gamma rays are just energetic photos. You typically need thick lead and/or concrete to shield you from them. Beta radiation is high energy electrons. A thin sheet of steel will shield you from those.
And lastly we have alpha radiation, which is just a Helium nucleus. A sheet of paper will generally block alpha radiation.
Some materials are really strong alpha emitters. A good example is Polonium-210 where almost all of its energy from decay is in the form of alpha radiation. This is why Po-210 is so lethal when ingested, which has been used for that purpose [1].
But this means if you produce a lump of Polonium-210, it's basically radiating Helium. The source of almost all of the Earth's Helium is from uranium and thorium decay.
[1]: https://en.wikipedia.org/wiki/Poisoning_of_Alexander_Litvine...
> Gamma rays are just energetic photos
They are indeed. The average planet busting Gamma Ray Burst is just a Vogon trying to "get the whole family in".
I would think that lighting a Vogon family picture would be about as advisable as recording a Vogon speech. That is to say not at all.
Helium exists in great quantities in the 4 big planets, which unlike Earth have strong enough gravity to retain it.
Others have mentioned that some helium exists on the Moon, where it comes from the solar wind. The use of the helium 3 from there has been suggested for nuclear fusion, if the fusion of helium 3 became possible (it is much more difficult than the fusion of tritium with deuterium, which is the main approach attempted for now).
However, for fusion relatively small amounts could still be useful. For other uses the amount of lunar helium might not be enough, even when ignoring how expensive it would be to transport it from there.
If you have something that emits a lot of alpha particles as it decays, you could surround it with a source of electrons, I suppose. The details would have to be left as an exercise, and I doubt you'd get enough helium to be very useful unless you were dealing with large amounts of ridiculously-radioactive substances.
Same with fusion. Due to the implications of E=mc^2, fusion yields a lot of energy and a uselessly-small amount of matter. There don't seem to be many good ways to get a lot of helium besides either waiting millions of years for it to show up naturally, or carefully recycling what we already have.
> you could surround it with a source of electrons, I suppose
Water would be the best for this. The cross-section is good and water can ionise easily. But yeah, you would not get a lot of it.
It can form during radioactive decay of uranium and thorium.
And that's where all of our helium actually comes from. Any radioactive decay that emits alpha particles generates helium, since alpha particles are just helium nuclei. When that happens underground, the helium can get trapped. It tends to get trapped in the same places that natural gas gets trapped, so natural gas extraction often encounters helium as well.
Similar to oil and gas (although a completely different mechanism), it takes deep time to accumulate, but can be extracted much, much faster. So although new helium is being generated underground all the time, we can still run out in a practical sense.
Dumb question, but is there any world where a fission reactor could reasonably genrate waste with a short enough half-life to produce meaningful amounts of helium as a side-gig?
I'd say no, although the amount of helium that's produced is small enough that it's not quite as absurd as I would have thought. Worldwide helium production is something around 25,000 tons/year. A nuclear power plant produces about 25 tons of waste per year. There are about 440 nuclear power plants in the world. If their waste consisted entirely of helium, that would be roughly 44% of total world helium production. More than I guessed! But, of course, only a tiny, tiny, tiny fraction of that waste ever turns into helium, so even if you somehow made it decay all at once, it would be be pretty insignificant on a world scale.
The reason helium can't be produced chemically (like hydrogen can be produced e.g. from water) is that there are no natural chemical compounds which contain helium. That's because it doesn't form those compounds in the first place, since it's a noble gas.
Not at any temperature nor pressure found on Earth:
> These could exist in planets like Neptune or Uranus.
It's also formed similarly to oil over millions of years underground if I understand correctly so can be a byproduct of natural gas mining.
It's often found alongside natural gas because the rock structures that can trap methane can also trap other gasses, but the original source is different - thermal decomposition of organic matter for natural gas and radioactive decay, mostly of uranium and thorium, for helium.
I agree that the "accumulation over millions of years" is similar (and similarly a potential problem if we burn through all that accumulation).
Helium will leak out of some structures that hold methane. Shale will trap methane and let helium escape. Layers of salt trap both. Thus horizontal drilling and fracking to recover oil and methane from shale produces very little helium.
Which is exactly 100% of Earth's helium. Every single helium atom we use is a result of alpha decay, as a very good approximation there isn't any primordial or stellar helium on or in Earth.
Atmospheric extraction on Earth would require massive amounts of energy and infrastructure.
Gas giant atmosphere extraction sounds very far future