  We present experimental and theoretical studies of magnetic levitation of
hydrogen gas bubble surrounded by liquid hydrogen confined in a
semi-transparent spherical shell of 3 mm internal diameter. Such shells are
used as targets for the inertial confinement fusion (ICF), for which a
homogeneous (within a few percent) layer of a hydrogen isotope should be
deposited on the internal walls of the shells. The gravity does not allow the
hydrogen layer thickness to be homogeneous. To compensate this gravity effect,
we have used a non-homogeneous magnetic field created by a 10 T superconductive
solenoid. Our experiments show that the magnetic levitation homogenizes the
thickness of liquid hydrogen layer. However, the variation of the layer
thickness is very difficult to measure experimentally. Our theoretical model
allows the exact shape of the layer to be predicted. The model takes into
account the surface tension, gravity, van der Waals, and magnetic forces. The
numerical calculation shows that the homogeneity of the layer thickness is
satisfactory for the ICF purposes.
