P o S ( P S T P 2 0 1 7 ) 0 0 8 A dynamically polarized target for CLAS 12

The 12 GeV physics program in Hall B at Jefferson Lab will be centered on the newly commissioned, high acceptance spectrometer CLAS12 and will utilize a variety of nuclear targets, including a dynamically polarized solid target for experiments on longitudinally polarized protons, deuterons, and lithium nuclei. The target, under construction in a collaborative effort between the Jefferson Lab Target Group, Christopher Newport University, Old Dominion University, and the University of Virginia, is designed with a number of innovative features. These include multiple target cells for reduced systematic uncertainties, internal superconducting shim coils to adjust the polarizing magnetic field, and a 1 K evaporation refrigerator with an integrated load lock system for the target samples. The current status of the system’s design, construction, and various R&D efforts are described.