Brillouin Light Scattering from Superfluid Helium under Pressure
We have used Brillouin scattering1,2 to study both thermally excited first and second sound in pure liquid 4He at a pressure of 25 atm. We have measured the high-frequency velocity and damping of both modes at a wavelength of 4.34 × 10−5 cm and at temperatures between 1.4 and 2.2°K. The ratio of the intensity of the light scattered from second sound to that scattered from first sound has also been determined and is reported here for the temperature region 10−5 < T λ — T < 10−1 °K.
KeywordsEntropy Attenuation Helium Compressibility Germanium
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- 1.V.L. Ginsburg, J. Phys. (SSSR) 7, 305 (1943).Google Scholar
- 5.W.F. Vinen, in Physics of Quantum Fluids, R. Kubo and F. Takano, ed., Syokabo, Tokyo (1971).Google Scholar
- 8.G. Winterling, F.S. Holmes, and T.J. Greytak (to be published).Google Scholar
- 9.T.J. Greytak, this volume.Google Scholar
- 14.G. Ahlers, private communication.Google Scholar