Wiktionary
n. (context physics English) The liquified form of helium that does not solidify even at absolute zero; it shows unusual properties, such as superfluidity, due to quantum effects.
Wikipedia
At standard pressure, the chemical element helium exists in a liquid form only at the extremely low temperature of −269 °C (about 4 K or −452.2 °F). Its boiling point and critical point depend on which isotope of helium is present: the common isotope helium-4 or the rare isotope helium-3. These are the only two stable isotopes of helium. See the table below for the values of these physical quantities. The density of liquid helium-4 at its boiling point and a pressure of one atmosphere (101.3 kilopascals) is about 0.125 grams per cm, or about 1/8th the density of liquid water.
Usage examples of "liquid helium".
When he boiled helium under reduced pressure, the liquid helium went to a new form—.
The infrared detectors themselves were immersed in huge vessels of liquid helium.
We did not know that the bells with their frozen occupants had been partly crushed by the glacier, or that at the site they were placed into thermos cylinders with liquid helium and immediately transported by shuttle to our ship.
Laran serves two very useful functions that of being the most remote outpost in die system, and of being toe site of the Revonan helium conversion facility This facility pro vides the liquid helium.
Rick continued to breathe normally, except that he was now breathing from his supply of liquid helium and liquid oxygen.
There might be another ocean deep below those thousands of kilometers of metallic hydrogen, an ocean of liquid helium.
Finally, at the very top, there's a slick of liquid helium, which is funny stuff.