Superfluidity of liquid helium video brief report Wikipedia Kapitsa
Superfluidity is a special state of matter that occurs under the action of very low temperatures, near absolute zero, allowing him through narrow slits and capillaries without friction.
Under the superfluidity understand a specific state of matter (quantum liquid) occurring under the action of very low temperatures near absolute zero (thermodynamic phase), allowing him through narrow slits and capillaries without friction.
Quantum (ideal) fluid is incompressible, no viscosity and heat conduction, there are no shear stresses between two adjacent layers. All of her items are characterized by rectilinear inertial motion and constant speed. The most well-known ideal environments include air, helium, hydrogen and others.
Superfluidity occurs after the test substance phase of the transition and its gradual transformation into the discharged condensate Bose-Einstein. The air superfluidity occurs at the level of 2.70 °K, liquid helium at 2.17 °K, the crystal of helium and hydrogen is 0.15 °K.
To obtain the effect of superfluidity in the laboratory, the scientists resorted to laser. Using a combination of laser cooling and evaporative cooling techniques, they lowered the temperature of the samples up to thousandths of a degree exceeding absolute zero (-273.15 °C).
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