Image
The structure of the droplets
used in the quest for superfluidity
in hydrogen. The core is an OCS
molecule surrounded by 1416
molecules of parahydrogen. (a) With
an outer coating of some 8000
helium-4 atoms, the droplet reaches
a temperature of 0.38 K. (b)
With about 500 helium-4 atoms, and
some 10 000 helium-3 atoms as an
outer coating, the increased
evaporative cooling lowers the
temperature of the droplet to
0.15 K.