Progress at HERMES: Preparations for measurements of nucleon spin structure functions

A new experiment, designed to measure spin-dependent lepton-nucleon deep inelastic scattering, is being built on the HERA electron storage ring at DESY, Hamburg. The HERMES experiment will use a windowless internal gas cell of polarized H, D, or 3He nuclei as a target for the stored 27 GeV electron (or positron) beam. The pure target, coupled with a high luminosity, will enable greater statistical precision and much smaller systematic errors that has been possible thus far in previous measurements at CERN and SLAC. The construction of the experiment is underway. At the same time, a test experiment is being conducted on the HERA ring, using an unpolarized gas cell and prototypes of the detectors. This report briefly summarizes the results of the test run and the status of the construction of the full experiment