  A laser-driven spin-polarized 3He2+ beam source for nuclear-physics
experiments and for the investigation of polarized nuclear fusion demands a
high-density polarized 3He gas-jet target. Such a target requires a magnetic
system providing a permanent homogeneous holding field for the nuclear spins
plus a set of coils for adjusting the orientation of the polarization. Starting
from a transport vessel at a maximum pressure of 3 bar, the helium gas is
compressed for a short time and can be injected into a laser-interaction
chamber through a non-magnetic opening valve and nozzle, thus forming jets with
densities of about a few 10^19 cm-3 and widths of about 1 mm. The target
comprises a 3D adjustment system for precise positioning of the jet relative to
the laser focus. An auxiliary gas system provides remote target operation and
flushing of the gas lines with Ar gas, which helps to reduce polarization
losses. The design of the target, its operation procedures and first
experimental results are presented.
