  In laboratory experiments we observe that ice particles (\leq100 \mu m)
entrained in a low pressure atmosphere (~1 mbar) get trapped by temperature
gradients between three reservoirs at different tempertature. Confining
elements are a peltier element at 250 K (bottom), a liquid nitrogen reservoir
at 77 K (top) and the surrounding vacuum chamber at 293 K. Particle levitation
and trapping is modeled by an interplay of thermophoresis, photophoresis and
gravity. A number of ice particles are trapped simultaneously in close spatial
distance to each other at least up to minutes and are accessible for further
experiments.
