In this week's Chemical and Engineering News, this really interesting article by Craig Bettenhausen on 3He:
The industrial gas giant Air Liquide has signed a long-term agreement to purchase helium-3 (3He) from a Canadian nuclear power firm. The arrangement creates the first significant private supply of the ultra-rare gas, a light isotope of helium used in deep cryogenics, nuclear science, and quantum computing.
Air Liquide will take 3He that Laurentis Energy Partners extracts from a nuclear power byproduct, further purify it, and package it for sale. Jennifer Chapin, director of projects at Laurents, says the initial output will be between 5,000 and 10,000 L per year. “This really does present a shift in terms of market availability,” she says.
Though the gas can be used for medical imaging and other nuclear science, Patrick Wikus, a cryogenics expert at the scientific instrument maker Bruker, expects the main application of the new supply to be in quantum computing, which requires operating temperatures near 0 K.
...Conventional liquid 4He cooling gets down to 1–4 K. To go even colder, scientists mix super-cooled 3He and 4He; the entropy gain from the mixing cools the system down even further. Called 3He-4He dilution, the process can get as low as 5 mK.
Adding 3He to a typical chiller costs $30,000 to $40,000, Wikus says, at a cost today of around $1,000 per L. At that price, recycling is a must. “When I did my PhD, I had 20 L of 3He. If I had lost those, that would have been it for my thesis,” he says.
Read more to find out how the material is extracted (from hydrogen bombs!)