To reach that point, they have to be cooled by liquid helium, which is expensive to make and manage.
The superfluid transition in liquid helium is an example of this.
An early application was to the study of liquid helium.
Zaphod started with fear and his blood seemed to turn to liquid helium.
His further research suggests the anomaly may indeed be coming from liquid helium in the setup.
Such technologies, not quite practical when liquid helium is necessary, may now be within reach.
It is usually used at 4.2 K, the boiling point of liquid helium.
Once inside, it would be frozen in liquid helium.
The space between the suits was filled with liquid helium.
These magnets have to be very cold to work and they are cooled by liquid helium.
