High resolution sound velocity measurement in liquid3He using path length modulation technique

Abstract

Employing path length modulation technique, we are able to make high resolution sound velocity measurements (≈ 10 ppm) with a relatively short path length. We present new values ofF 2 3 calculated from zeroand first-sound velocity measurements at 12.6 MHz in liquid3He over the pressure range of 0.6 to 14 bar. We also report a newly observed behavior in high frequency zero-sound velocity at 113 MHz near the superfluid transition temperature at 0.6 bar.