DYNAMICALLY POLARIZED TARGET FOR THE g_2~p AND G_E~p EXPERIMENTS AT THE JEFFERSON LAB

摘要

Recently, two experiments were concluded in Hall A at the Jefferson Lab which utilized a newly assembled, solid, polarized hydrogen target. The primary components of the target are a new, high cooling power ~4He evaporation refrigerator, and a repurposed, superconducting split-coil magnet. It has been used to polarize protons in irradiated NH_3 at a temperature of 1 K and at fields of 2.5 and 5.0 tesla. Maximum polarizations of 55 and 95％ were obtained at those fields, respectively. To satisfy the requirements of both experiments, the magnet had to be routinely rotated between angles of 0, 6, and 90° with respect to the incident electron beam.