The 'Lambda point' is the
temperature (approximately 2.17
K) below which normal fluid
helium (helium I) transitions to
superfluid helium II. More precisely, there is a lower lambda point at 2.172 K, 0.0497
atm, and an upper one at 1.76 K, 29.8 atm
[1].
The point's name derives from the graph that results from plotting the
specific heat capacity as a function of
temperature (for a given pressure), which resembles the
Greek letter
lambda. The specific heat capacity tends towards
infinity as the temperature approaches the lambda point.
External links
★
What is superfluidity? (includes a graph)