Propagation of thermal shock wave in compressed He II induced by a gasdynamic shock wave impingement

摘要

Strong thermal shock waves in compressed He II induced by a gasdynamic shock wave impingement onto the free surface are investigated by measuring the temperature variation with superconductive temperature sensors. It is found from the experimental result that in the immediate vicinity of the vapor-He II interface region no thermal shock wave is excited. Instead, a thermal boundary layer with a large temperature gradient is formed there and grows up to several mm in thickness immediately after the impingement. It is considered that a thermal shock wave is generated just below the thermal boundary layer and a little later than the impingement.