Abstract
We have measured the sticking probability of atomic hydrogen on a superfluid He4 surface for atom energies between 100 K and 1 mK. The sticking probability shows little variation with energy over this interval, and is close to the value 0.2. The studies were carried out using a magnetic trap that produced a density of 8×1013 cm-3 at a temperature of 100 K. © 1991 The American Physical Society.