Converging second sound shock waves in superfluid helium

Abstract

A spherical heater and conical channel are used to produce converging second sound shock waves. Arrival time and temperature jump data verify the validity of the weak shock relations. The calculated relative velocities (around 10 m/sec) are the largest ever produced in bulk superfluid helium. Comparison of converging and straight channel experiments shows unambiguously that the phenomena associated with the breakdown of superfluidity in second sound shock experiments occur near the heater, not in the bulk fluid.