Liquid helium, superfluidity - HyperPhysics
A remarkable transition occurs in the properties of liquid helium at the temperature 2.17K, called the "lambda point" for helium. Part of the liquid becomes a "superfluid", a zero viscosity fluid which will move rapidly through any pore in the apparatus.
Introduction to Liquid Helium - NASA
2014年9月11日 · For helium 4, crogenicists distinguish two liquid forms: helium I and helium II. Helium I is the warmer form; helium II is the colder. The transition temperature, called the "lambda point", is 2.17 K.
Strange but True: Superfluid Helium Can Climb Walls
2009年2月20日 · Onnes found that helium (technically, the helium 4 isotope) began to readily conduct heat below –455.67 degrees F (–270.92 degrees C), also known as the lambda point.
52.11: Superfluids - Physics LibreTexts
When liquid helium-4 ( \({ }^{4} \mathrm{He}\) ) is cooled below a critical temperature of \(2.17 \mathrm{~K}\) (called the lambda point), a sudden phase transition occurs, and the helium becomes an exotic fluid called helium II. \({ }^{5}\) Helium II is the best-known example of a superfluid — a fluid with odd properties that are governed by ...
Understanding Liquid Helium, The Superfluid | FTLOScience
2017年3月16日 · In order for liquid helium to diverge from the rules of classical mechanics, it has to be further cooled past a critical point known as its lambda (λ) point (Fig. 1). Once below the λ point, liquid helium spontaneously rises up the sides and out of its containers.
Helium shows the particularity that it has no triple point, it may solidify only at pressures above 2.5 MPa. The commonly given lambda point refers to the transition from normal to superfluid helium.
Early research with liquid helium showed that it had re-markable new properties, especially below the so-called a normal fluid that was responsible for phenomena such as lambda transition near 2.2 K, where there is a sharp, narrow the damping of pendulums immersed in the fluid. That rev-peak in the specific heat (see figure 1a).
Lambda point - (Thermodynamics) - Vocab, Definition ... - Fiveable
The lambda point for helium-4 occurs at approximately 2.17 K (-270.98 °C), marking the onset of superfluidity. Near the lambda point, helium exhibits behavior like climbing up the walls of containers and flowing through tiny pores without resistance.
Lambda point - chemeurope.com
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].
Superfluid - University of Oregon
A superfluid is the unusual properties of liquid helium when it is cooled below 2.18 K (-270.97 C), called the lambda point.
- 某些结果已被删除