Design of internal superconducting holding magnet for the JLAB Hall-B frozen spin polarized target

We present the results of our investigation of a series of internal holding magnets for longitudinal and transverse polarizations. These magnets will be placed inside a polarizing refrigerator designed for frozen spin targets. The studied magnets will provide the holding field in the range 0.3–0.5 T. The total thickness of the superconducting coils is of the order 0.5 mm. The frozen spin target is under construction for use in photo-nuclear experiments in concert with the JLAB Hall-B CLAS detector.