This is one of the worlds most specialist refrigerators - to within 0.1*C of Absolute Zero.

The original title:

"We Turned A Thermonuclear Bomb Into A Refrigerator"

I changed it to something less misleading and more accurate.

It's a special refrigerator, that is actually using the radioactively decayed Tritium (Hydrogen Isotope) that becomes Helium 4 and Helium 3 (Helium Isotopes), to create 0.3*Kelvin (almost absolute zero) or around MINUS 273*C - this refrigerator is to cool special astronomical cameras to detect infrared - that only super cooled cameras can detect.

It's one hell of a specialist device with SO much cleverness, in it's development and preceeding it's development.

So I thought I should share the information with you.

I am not sure of everything - but these kinds of devices are in the James Webb telescope camera - one of them - like this gets into really specialist stuff and really technical stuff and information that is kind of rare and hard to come across..


https://en.wikipedia.org/wiki/Isotopes_of_helium


Helium-3
Main article: Helium-3

3He is the only stable isotope other than 1H with more protons than neutrons. There are many such unstable isotopes, such as 7Be and 8B. There is only a trace (~2ppm)[16] of 3He on Earth, mainly present since the formation of the Earth, although some falls to Earth trapped in cosmic dust.[7] Trace amounts are also produced by the beta decay of tritium.[27] In stars, however, 3He is more abundant, a product of nuclear fusion. Extraplanetary material, such as lunar and asteroid regolith, has traces of 3He from solar wind bombardment.

To become superfluid, 3He must be cooled to 2.5 millikelvin, ~900 times lower than 4He (2.17 K). This difference is explained by quantum statistics: 3He atoms are fermions, while 4He atoms are bosons, which condense to a superfluid more easily.



Helium-4
Main article: Helium-4

The most common isotope, 4He, is produced on Earth by alpha decay of heavier elements; the alpha particles that emerge are fully ionized 4He nuclei. 4He is an unusually stable nucleus because it is doubly magic. It was formed in enormous quantities in Big Bang nucleosynthesis.

Terrestrial helium consists almost exclusively (all but ~2ppm)[16] of 4He. 4He's boiling point of 4.2 K is the lowest of all known substances except 3He. When cooled further to 2.17 K, it becomes a unique superfluid with zero viscosity. It solidifies only at pressures above 25 atmospheres, where it melts at 0.95 K.