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  • Liquid helium - Wikipedia

    Liquefaction. Helium was first liquefied on July 10, 1908, by the Dutch physicist Heike Kamerlingh Onnes at the University of Leiden in the Netherlands. At that time, helium-3 was unknown because the mass spectrometer had not yet been invented. In more recent decades, liquid helium has been used as a cryogenic refrigerant, and liquid helium is produced commercially for use in superconducting ...

  • Introduction to Liquid Helium - NASA

    11-9-2014  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. (It varies slightly with pressure.) Helium I, the "warm" form, acts more or less like a conventional liquid. Helium II has some strange properties.

  • Superfluid helium-4 - Wikipedia

    OverviewPropertiesFilm flowSuperfluid hydrodynamicsFountain pressureHeat transportTheoryBackground

    Figure 1 is the phase diagram of He. It is a pressure-temperature (p-T) diagram indicating the solid and liquid regions separated by the melting curve (between the liquid and solid state) and the liquid and gas region, separated by the vapor-pressure line. This latter ends in the critical point where the difference between gas and liquid disappears. The diagram shows the remarkable property that He is liquid even at absolute zero. He is only solid at pressures above 25 bar.

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  • Superfluid helium - YouTube

    5-8-2007  Ben Miller experiments with superfluid helium - Horizon: What is One Degree? - BBC Two - Duration: 4:13. BBC 901,495 views. ... Liquid Helium and Party Balloons - Periodic Table of Videos ...

  • 作者: ryanhaart
  • Helium II chemical isotope Britannica

    Other articles where Helium II is discussed: cryogenics: K, however, it abruptly becomes helium II, a liquid with such low viscosity that it can literally crawl up the side of a and flow through microscopic holes too small to permit the passage of ordinary liquids, including helium I. (Helium I and helium II are, of course, chemically

  • AMD Phenom II Overclocked to 6.5GHz - New World

    14-2-2013  AMD Phenom II Overclocked to 6.5GHz - New World ... use a combination of liquid nitrogen and liquid helium to reach CPU tempertures of -232 degrees Celsius in order to attain CPU clock speeds ...

  • 作者: AMDUnprocessed
  • Conceptual Physics: ALL ABOUT HELIUM-I HELIUM-II

    Liquid He-II can creep along solid surfaces in the form of high mobile film generally known as "Rollin" (also called as Rollinsimon) film. The properties of film were investigated by Daunt and Mendelsohn. If a tube containing Helium-II is placed in Helium-II bath a) If liquid level inside tube is less, flow of liquid takes place from bath to tube.

  • Questions and Answers About Liquid Helium WIRED

    You put the liquid helium into the NMR and it keeps the magnet cold. Of course, it does this because some of the helium makes the phase transition from a liquid to a gas and that takes energy.

  • Flow of Liquid Helium II Nature

    1-1-1938  A SURVEY of the various properties of liquid helium II has prompted us to investigate its viscosity more carefully. One of us1 had previously deduced an upper limit of 10−5 C.G.S. units for the ...

  • Cited by: 334
  • Liquid Helium II - The Superfluid - TIB

    Experiment zur Demonstration der Eigenschaften von Helium II und Helium I. Versuchseinrichtung (Isoliergefäß), Verhalten am 2-Punkt (2,17 K), Wärmeleitfähigkeit und Viskosität, normale und superflüssige Komponente des Helium II, innere Reibung und Wärmetransport.

  • Flow of Liquid Helium II - NASA/ADS

    A SURVEY of the various properties of liquid helium II has prompted us to investigate its viscosity more carefully. One of us 1 had previously deduced an upper limit of 10 -5 C.G.S. units for the viscosity of helium II by measuring the damping of an oscillating cylinder. We had reached the same conclusion as Kapitza in the letter above; namely, that due to the high Reynolds number involved ...

  • Two Fluid Model of Superfluid Helium (He II, Superfluidity)

    Liquid helium remains in the liquid phase under its own vapor pressure and would apparently do so right down to absolute zero temperature (Figure 1). Due to the small mass and extremely weak forces between the helium atoms, pressure is required to produce solid helium (25 atmospheres or more). Figure 1. Phase Diagram of Liquid Helium

  • The two-fluid theory and second sound in liquid helium

    Helium II Helium I Phonons Figure 1. Properties of liquid helium. (a)The specific heat of liquid helium has an anomalous jump near 2.2 K. The “lambda transition” between the superfluid phase (helium II) at lower temperatures and the normal phase (helium I) at higher temperatures is so named because the anomaly resembles the Greek letter λ.

  • The Rotation of Liquid Helium II - Institute of Physics

    The Rotation of Liquid Helium II To cite this article: D V Osborne 1950 Proc. Phys. Soc. A 63 909 View the article online for updates and enhancements. Related content Second Sound in Liquid Helium II D V Osborne-Schwinger Potential in Nuclear Forces F C Barker-The Theory of the Propagation in Liquid Helium II of `Temperature-Waves' of Finite ...

  • Liquid Helium II: The Hydrodynamics of the Two-Fluid

    Exact non-linear equations of motion for reversible processes in the two-fluid model of liquid He II are obtained from a variational principle of the type first introduced by Eckart in a different connection. Transitions between the two fluids are taken into account. Except for a term giving the effect of these transitions the equations obtained are substantially identical with those given by ...

  • Lattice Model of Liquid Helium, II Progress of ...

    The partition function of the lattice model of liquid helium introduced in the preceding paper is calculated by making use of the Kikuchi's approximation. Setting two parameters, the effective mass m = 1/7 m 0 ( m 0 is the mass of He atom), and the lattice spacing d = 3.1Å, an excellent agreement of the density dependence of λ-temperature with experiment is obtained.

  • Properties of liquid helium II - ScienceDirect

    Physica VIII, no 7 Juli 1941 PROPERTIES OF LIQUID HELIUM II by A. BIJL, J. DE BOER and A. MICHELS (71th publication of the Van tier Waals Fund, Van der Waals-laboratorium, Gemeente-Universiteit, Amsterdam) Summary The theory of the degeneration phenomena of an ideal B o s e-E i n- s t e i n gas is modified so as to make it more in accordance with the thermal phenomena of liquid helium II.

  • NON-EQUILIBRIUM THERMODYNAMICS AND LIQUID HELIUM II

    NON-EQUILIBRIUM THERMODYNAMICS AND LIQUID HELIUM II 693 usually accepted for liquid helium II, that no "normal" atoms can pass through a narrow capillary s). The present paper can also be considered as a refinement of the calculation made by one of us 4), where liquid helium II was con-

  • helium Definition, Properties, Uses, Facts Britannica

    Properties. Helium-4 is unique in having two liquid forms. The normal liquid form is called helium I and exists at temperatures from its boiling point of 4.21 K (−268.9 °C) down to about 2.18 K (−271 °C). Below 2.18 K, thermal conductivity of helium-4 becomes more than 1,000 times greater than that of copper.This liquid form is called helium II to distinguish it from normal liquid helium ...

  • On the fountain effect in liquid helium II

    On the fountain effect in liquid helium II To cite this article: R J Atkin and N Fox 1977 J. Phys. C: Solid State Phys. 10 4945 View the article online for updates and enhancements. Related content Non-linear waves in helium II R J Atkin and N Fox-On the experimental verification of Landau's theory of superfluid helium R J Atkin and N Fox-

  • TeamLiquid StarLeague 5 - Liquipedia - The StarCraft II ...

    The TeamLiquid StarLeague 5, announced on April 20, 2020, is the third TSL event held for StarCraft II, returning after an 8 years long hiatus.. Format [] Qualifiers []. The qualifiers are divided into Korean server qualifiers and North American/European server qualifiers (global qualifiers).

  • Air Liquide Gas AB

    Air Liquide är världens ledande leverantör av gaser, teknik och tjänster för industri och sjukvård. Verksamheten finns representerad i 80 länder, har ca 66 000 medarbetare och över 3,6 miljoner kunder och patienter. Air Liquide i Norden utgör en del av Air Liquide-koncernen.

  • THEORY OF LIQUID HELIUM - dspace.mit.edu

    A quasi-thermodynamic theory of liquid helium is developed based on four very general postulates. The results are in excellent agreement with experiment, in particular with the measurements of the temperature waves (second sound), the existence of which was predicted by the theory. The Bose-Einstein liquid intro-

  • The rotation of liquid helium II I. Experiments on the ...

    An experimental investigation of the propagation of second sound in uniformly rotating resonators filled with liquid helium II has been made. It is found that in the uniformly rotating liquid the velocity of the second sound is not changed by more than 01%, but there is an excess attenuation which is, except near the λ point, proportional to the angular velocity ω, independent of second ...

  • Viscosity of Liquid Helium below the λ-Point Nature

    We are making experiments in the hope of still further reducing the upper limit to the viscosity of liquid helium II, but the present upper limit (namely, 10 −9 C.G.S.) is already very striking ...

  • Buy Helium Gas or Purchase Liquid Helium (He) Praxair,

    At Praxair, we deliver gas and liquid helium (He) in a variety of purities up to 99.999%. Explore the chart below to view the spec sheets and safety data sheets for our pure helium products and a few of our popular welding mixtures.

  • Liquid helium - Questions and Answers in MRI

    In the 1990's helium-only systems were developed and by the early 2000's refrigeration systems had become so sophisticated and efficient that liquid helium needed to be added only every 2-3 years. Over the last decade zero boil off ( ZBO ) refrigeration systems have become standard, allowing essentially unlimited normal operation without need for helium refill.

  • (PDF) Roton Excitation Spectrum in Liquid Helium II

    The energy-momentum spectrum of the excitations in liquid helium II has been measured in a neutron scattering experiment. At T=1.1°K, data were obtained in the momentum range p/ℏ=0.55 to 2.36 A-1.

  • The Rotation of Liquid Helium II - ResearchGate

    Download Citation The Rotation of Liquid Helium II An experiment is described in which the free surface of rotating liquid helium II is studied. It is shown that the results, which are the ...

  • The rotation of liquid helium II II. The theory of mutual ...

    The rotation of liquid helium II II. The theory of mutual friction in uniformly rotating helium II. Henry Edgar Hall. Google Scholar. Find this author on PubMed . Search for more papers by this author . and . William Frank Vinen. Google Scholar. Find this author on PubMed .

  • Vortex lines in liquid helium II - ScienceDirect

    Two VORTEX LINES IN LIQUID HELIUM II S 15 experiments of this type were reported at the 1957 Low Temperature Physics conference in Madison, but at that time neither had been success- ful is) 18). However, the repetition of one of these experiments with a recon- structed apparatus has since led to some success, and this work will now be described (the reason for the original failure is unknown).

  • NASA Awards Two Contracts for Supply of Gaseous, Liquid

    NASA has awarded contracts to Air Products and Chemicals, Inc. of Allentown, Pennsylvania, and Messer LLC of Bridgewater, New Jersey, to supply gaseous and liquid helium.

  • Liquid Helium II: The Superfluid - segment 3of5 - video ...

    8-4-2015  Liquid Helium II: The Superfluid - segment 3of5. Report. Browse more videos. Playing next. 5:59. Liquid Helium II: The Superfluid - segment 5of5. Lavon Pollock ...

  • 作者: Lavon Pollock
  • Excitation Energy of Liquid Helium. II (pdf) Paperity

    Excitation Energy of Liquid Helium. II 0 Department of Physics and Astronomy Louisiana State University , Baton Rouge, Louisiana 70803 The excitation spectrum of liquid Helium II is re-examined using the formalism developed by Sunakawa et a!.

  • HEAT CURRENTS IN LIQUID HELIUM II (Journal Article)

    Authors: Vicentini-Missoni, M.; Cunsolo, S. Publication Date: Fri Apr 01 00:00:00 EST 1966 Research Org.: Univ., Rome OSTI Identifier: 4548390 NSA Number: NSA-20-019761

  • THE KINEMATIC VISCOSITY OF LIQUID HELIUM II (Journal ...

    28-4-2020  Authors: Woods, A D.B.; Hallett, A C.H. Publication Date: Fri Aug 01 00:00:00 EDT 1958 Research Org.: Univ. of Toronto Sponsoring Org.: USDOE OSTI Identifier: 4302665

  • The Absorption of Sound in Liquid Helium II

    The absorption of sound in liquid heliumi II BY K. DRANSFELD,* J. A. NEWELLt AND J. WILKS Clarendon Laboratory, Oxford (Commumnicated by N. Kurti, F.R.S.-Received 31 July 1957) The absorption of sound in liquid helium ii has been measured in the temperature range down to 0.40 K, at frequencies of 6-0 and 14-4 Me, and under pressures of up to 25 ...

  • Air Liquide A world leader in gases, technologies and ...

    Air Liquide is present in 80 countries with approximately 67,000 employees and serves more than 3.7 million customers and patients.

  • Heat Transport in Liquid Helium II SpringerLink

    The superfluidity of liquid helium II is equally unique physically. At present, the development of commercial uses which depend upon the unusual thermomechanical properties of liquid helium II is not as advanced. This is partially due to its inconveniently low temperature.

  • The Detection of Single Quanta of Circulation in Liquid ...

    The detection of single quanta of circulation in liquid helium ii BY WV. F. VINEN The Royal Society Mond Laboratory, University of Cambridge (Communicated by D. Shoenberg, P.R.S.-Received 29 June 1960) [Plate 1] An apparatus is described for detecting single quanta of superfluid circulation round a fine wire in liquid helium Ii.

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