Attenuation and velocity of first sound in a saturated3He-4He mixture at very low temperatures and high magnetic field

✍ Scribed by S. A. J. Wiegers; R. Jochemsen; C. C. Kranenburg; G. Frossati

• Publisher: Springer US
• Year: 1988
• Tongue: English
• Weight: 725 KB
• Volume: 71
• Category: Article
• ISSN: 0022-2291
• DOI: 10.1007/bf00115042

✦ Synopsis

We present experimental results on the attenuation and velocity of first sound in a saturated (X = 0.064) JHe-4He mixture. The measurements were performed at very low temperature (3.5 < T< 20 mK) with relatively low frequencies (around 1 MHz) at saturated vapor pressure, using a CW technique. Though the results are found to be in qualitative agreement with the theory for acoustic transmission in degenerate mixtures, they are not quantitatively consistent with theory. A phenomenological explanation is offered for this discrepancy. We compare our data with recent measurements at higher temperatures and frequency. We have also performed the measurements in a magnetic field of 9 T. Within our experimental accuracy we cannot detect any systematic difference from the measurements in zero feld. This is expected from theory.