Dynamic scaling and ultrasonic attenuation in4He near the superfluid transition point

✍ Scribed by Ken-ichi Tozaki; Akira Ikushima

• Publisher: Springer US
• Year: 1978
• Tongue: English
• Weight: 718 KB
• Volume: 32
• Category: Article
• ISSN: 0022-2291
• DOI: 10.1007/bf00117959

✦ Synopsis

Attenuation of first sound has been measured in "SHe under saturated vapor pressure near the lambda temperature TA at frequencies to/ 2~r ranging from 10.2 to 271 MHz. The frequency dependence of the critical part of the attenuation is determined and the dynamic scaling hypothesis is examined. Above the lambda point, it is found that the critical attenuation is described by a scaling function t~(to, e)=y'+YF (wz), where ~'=zoe -x and e= T/TA -1, with the results x = 1.02:e0.05 and y = 0.33~0.03. The characteristic frequency of the order-parameter fluctuation with the wave number k equal to the inverse correlation length is then proportional to e ~, which is in an excellent agreement with the prediction of dynamic scaling. Below the lambda point, a characteristic relaxation time or times shorter than previously expected at lower frequencies appears to exist in the present frequency range.