Density effect of solidified hydrogen isotope particles on Particle Image Velocimetry measurements of HeII flow

Solid H-2, D-2 and H-2/D-2 particles can be generated in He II by solidifying directly from the gas phase. Here we compare these three different particles as tracers for tracking He 11 forced flow in a horizontal channel using the Particle Image Velocimetry (PIV) technique. Slip velocity measurements show that all generated particles are in the micron size range. Steady state velocity fields of the forced flow of He II within a square cross-section channel are measured. By comparing the results obtained from different tracers, we show that the slip velocity caused by non-neutral buoyancy of these particles does not affect the measured velocity profiles of He II forced flow.