Attenuation of First Sound Near the Lambda Transition of Liquid Helium

摘要: The attenuation of first sound near the lambda point can be interpreted as being due to two phenomena: (1) a relaxation process described by Pokrovskii and Khalatnikov occurring only below point, having time $\frac{\ensuremath{\xi}}{{C}_{2}}$ where ${C}_{2}$ is velocity second $\ensuremath{\xi}$ coherence length magnitude $1.36\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}{({T}_{\ensuremath{\lambda}}\ensuremath{-}T)}^{\frac{\ensuremath{-}2}{3}}$ cm; (2) critical which nonsingular symmetrical about ${T}_{\ensuremath{\lambda}}$.