Has anyone on the forum worked with magnetic refrigeration?
Magnetic refrigeration is a cooling technology based on the magnetocaloric effect. This technique can be used to attain extremely low temperatures.
When a medium is magnetized its magnetic moments get aligned and the heat of magnetization is released. Vice versa, if the medium is demagnetized its temperature drops.
My understanding is that the benefit is avoiding all of the annoying aspects of fluid compression refrigeration at near-zero temperature (ie non-existent vapor density), but otherwise is massively energy intensive. I would categorize this as one of the many technologies that literally only works in a vacuum.