Frozen spin target system for high intensive gamma-ray source at DFELL of TUNL
The UVa group in collaboration with the TUNL group is currently building a frozen spin target system for the high intensity gamma-ray source (HIγS) at the Duke Free Electron Laser Laboratory (HIFROST). The heart of the system is a dilution refrigerator which we rebuilt from the one originally designed by T. Niinikoski and used at CERN and subsequently at GKSS (now HGZ), Germany. The use of a polarized target together with ∼100% polarized beams available at HIγS make the HIγS facility ideal for double polarization experiments. The first experiment will utilize a polarized deuteron target with the ∼100% circularly polarized gamma-ray beams to measure the Drell-Hearn-Gerasimov sum rule integrand for the deuteron below pion threshold. We report the status of developing this system and describe the first experiment using HIFROST.
