What term describes the explosive conversion of liquid helium to gaseous helium?

The term that describes the explosive conversion of liquid helium to gaseous helium is "quench." In cryogenics, a quench refers to a rapid process where liquid helium, which is maintained at a very low temperature, suddenly converts to gas when exposed to a higher temperature or when the pressure is reduced. This transformation occurs quickly and can produce a loud noise and a violent outburst of gas, which makes it distinct from more gradual processes.

Expansion, condensation, and evaporation do not accurately characterize this specific process. Expansion refers to the increase in volume of a substance as it changes phase or temperature, which does not emphasize the rapid, explosive nature of the transition. Condensation is the process where a gas turns into a liquid, which is the opposite of what is occurring here. Evaporation describes the gradual transformation of liquid to gas at lower temperatures, without the sudden energy release and associated phenomena that characterize a quench. Thus, "quench" uniquely captures the sudden and explosive nature of the conversion from liquid helium to gaseous helium.