  Maintaining high levels of 3He polarization over long periods of time is
important to many areas of fundamental and particle beam physics. Long
measurement times are often required in such experiments and the data quality
is a function of the 3He polarization. This is the case for neutron scattering
where the 3He can be used to analyze the spin of a scattered neutron beam and
relatively small fluxes of polarized neutrons leads to experiment times longer
than several days. Consequently the J\"ulich Centre for Neutron Science (JCNS)
is developing spin-exchange optical pumping (SEOP) systems capable of
polarizing the 3He gas in place on a typical neutron instrument. Using a
polarizer device we constructed a high level of 3He polarization of 81 % \pm2%
was maintained with good time stability. Such levels of polarization maintained
over time will be able to reduce the measurement times for such experiments and
eliminate time dependent data corrections.
