Observation of second-sound-rarefaction shock waves in superfluid helium
Mezhov-Deglin L. P. , Iznankin A. Yu., Mineev V. P.
In addition to a second-sound-compression shock wave, a rarefaction shock wave can be observed at distances of the order of several centimeters from the radiator when a short, high-power, thermal pulse propagates in superfluid helium.