Polarization Build up in Compass 6LiD Target

The CERN COMPASS experiment uses a large double 424 cm³ cell polarized ⁶LiD target for the muon program. High nuclear spin polarization |P| > 50 % is obtained, typically in five days. The high cooling power of the COMPASS dilution refrigerator helps to build up the polarization fast at temperatures around 300 mK. At lower microwave power with lower spin and lattice temperatures, the polarization build up is slower. We discuss these features of the dynamic nuclear polarization of our ⁶LiD target.