Progress report on the Hermes experiment

The HERMES experiment at HERA is introducing a new technique and new kinds of experimental information to the study of spin structure of the nucleon. To measure spin independent deep inelastic scattering from the proton and neutron, HERMES utilizes polarized internal gas targets of hydrogen, deuterium and 3He in the longitudinally polarized electron beam of the HERA storage ring. Key features are zero dilution of the target by unpolarized nuclei, and rapid reversal of the target spin. The χ dependencies of the proton and neutron spin-dependent structure functions are being measured with high precision. But most importantly, the large acceptance HERMES spectrometer detects and identifies leading hadrons in coincidence with the scattered electron. This will provide crucial additional information on the individual contributions of the valence and sea quarks to the nucleon spin, The 1995 running period is being dedicated to the 3He target. (author)