Speed of Second Sound Transverse Waves in Liquid Helium

Michelle Chorn and Lucas Giolas

University of Minnesota

Methods of Experimental Physics Spring 2012

Abstract

Transverse waves, waves propagating perpendicularly to the cylindrical container's vertical axis, were used to measure the speed of second sound in liquid helium near the lambda point. The liquid helium was housed in a flat cylindrical container. Using two electrodes and an aluminum diaphragm, the second sound was driven at a specific frequency by one of the electrodes. The second electrode detected the second sound wave created by the driver. The resonance frequency of the detected wave was then related to the speed of second sound. All final values for the speed of second sound were within 3 standard deviations of the expected values for each temperature.