The COMPASS polarized target

The COMPASS experiment runs the largest polarized target system ever built to study the spin structure of the nucleon by the deep inelastic muon scattering process. This target, largely reusing the Spin Muon Collaboration target apparatus, consists of two cells opppositely polarized in a 2.5T field, and filled up with granulated (LiD)-Li-6 as a deuteron target. The excellent stability and polarization performance of the target system allowed two (LiD)-Li-6 world polarization records to be set under these conditions between 2001 and 2004.