Rollin film

Rollin film
Helium II will "creep" along surfaces in order to find its own level - after a short while, the levels in the two containers will equalize. The Rollin film also covers the interior of the larger container; if it were not sealed, the helium II would creep out and escape.
The liquid helium is in the superfluid phase. As long as it remains superfluid, it creeps up the inside wall of the cup as a thin film. It comes down on the outside, forming a drop which will fall into the liquid below. Another drop will form—and so on—until the cup is empty.

A Rollin film, named after Bernard V. Rollin, is a 30 nm-thick liquid film of helium in the helium II state. It exhibits a "creeping" effect in response to surfaces extending past the film's level (wave propagation). Helium II can escape from any non-closed surface via creeping toward and eventually evaporating from capillaries of 10−7 to 10−8 meters or greater.

Rollin films are involved in the fountain effect where superfluid helium leaks out of a container in a fountain-like manner. They have high thermal conductivity.

The ability of superfluid liquids to cross obstacles that lie at a higher level is often referred to as the Onnes-Effect, named after Heike Kamerlingh Onnes. The Onnes-Effect is enabled by the capillary forces dominating the gravity- and viscous forces.

Waves propagating across a Rollin film are governed by the same equation as gravity waves in shallow water, but rather than gravity, the restoring force is the Van der Waals force. These waves are known as third sound.

See also

References

External links



Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Rollin-Film — Helium II kriecht an der Wand des inneren Gefäßes hoch nach einer gewissen Zeit würden sich die Flüssigkeitsstände in den Behältern angleichen. Der Rollin Film bedeckt auch die Wand des großen Behälters, wäre er nicht geschlossen , so würde der… …   Deutsch Wikipedia

  • rollin film — ˈrälə̇n noun Usage: usually capitalized R Etymology: probably from the name Rollin : a very thin film produced by capillary creeping of liquid helium II over a solid surface …   Useful english dictionary

  • Rollin — can refer to:* Bernard Rollin, American philosopher, ethicist, and author * Charles Rollin, French historian and educationist * Rollin , 1974 album by the Bay City Rollers * Rollin (Air Raid Vehicle) , song by Limp Bizkit on the 2000 album… …   Wikipedia

  • Rollin — ist der Familienname folgender Personen: Alexandre Ledru Rollin (1807–1874), französischer Politiker Charles Rollin (1661–1741), französischer Autor Dominique Rollin (* 1982), kanadischer Radrennfahrer Jean Rollin (1938–2010), französischer… …   Deutsch Wikipedia

  • Rollin' with the Nines — Infobox Film name = Rollin with the Nines writer = Julian Gilbey, Will Gilbey starring = Vas Blackwood Terry Stone Billy Murray Simon Webbe Jason Flemyng Robbie Gee director = Julian Gilbey producer = Geoff Austin casting director = Lee Dennison… …   Wikipedia

  • Film d'exploitation — Le film d exploitation est un type de film réalisé en évitant les dépenses des productions de qualité et en visant l exploitation commerciale en attirant un public voyeur, excitant ses intérêts lubriques. Les films d exploitation comptent… …   Wikipédia en Français

  • Rollin, Jean — (Jean Michel Rollin Roth le Gentil / November 3, 1938, Neuilly sur Seine, Hauts de Seine, France )    He entered films in 1955 and collaborated in the creation of animated films. Earning his living as a TV editor and assistant director (1962 Un… …   Encyclopedia of French film directors

  • Fascination (film, 1979) — Pour les articles homonymes, voir Fascination. Fascination est un film fantastique français réalisé en 1979 par Jean Rollin et mettant notamment en scène Brigitte Lahaie et Franca Maï. Sommaire 1 Synopsis 2 …   Wikipédia en Français

  • Jean Rollin — Jean Michel Rollin Le Gentil (born November 3, 1938 in Neuilly sur Seine, Paris, France) is a French auteur (filmmaker), actor, and novelist best known for his films in the fantastique genre. Rollin is credited as having made the first French… …   Wikipedia

  • Jean Rollin — Données clés Nom de naissance Jean Michel Rollin Roth Le Gentil Surnom Michel Gentil, Michael Gentle, J.A. Laser, J.A. Lazar, J.A. Lazer, Jean Pierre Sammut, Robert Xavier Naissance 3 novembre 1938 Neuilly sur Seine (France) Nationalité …   Wikipédia en Français

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”