SPIN-EXCHANGE PUMPED HE-3 TARGETS - PROGRESS AND PROSPECTS

Polarized He-3 has been used as a spin filter for neutron polarization , as a target to probe neutron structure, and in combination with Xe-1 29 for precision measurement of fundamental physics. Spin exchange pum ped masers of one and two species have run for weeks and allow CW meas urement with precision trending as steeply as tau(-3/2). At SLAC, a pr ogram of experiments has studied the neutron spin-dependent structure function in deep inelastic scattering, exploiting the large neutron po larization in a polarized He-3 target. Data from the most recent exper iment provide new precise data with Bjorken x down to 0.014. Among the conclusions is the need to consider Q(2) dependence in interpretation of the data and determination of sum rules (sums over the full range in x).