Preliminary investigations of a compact polarized electron/positron linac for scattering experiment off rare isotopes*

Ongoing workshops on existing and new possible future storage rings using rare isotopes for nuclear astrophysics applications have occurred within the past decades. While the ones in developments are primarily in the low energy regime (few 10s MeV/u), the Facility for Rare Isotope Beams (FRIB) is starting some investigations that would include both a low and high energy (few 100s MeV/u) rings. Coupling an electron linac with a storage ring would not only extend past and current scattering experiments from stable nuclei to exotic nuclei, but also open new physics opportunities not accessible previously. Such facilities are under developments in Japan (SCRIT at RIKEN) and in Europe (ELISE at FAIR and DERICA in Dubna). Recent technology advancements in both RF cavities (such as the Nb₃Sn design at Cornell) and highly polarized electron/positron beams (such as the PEPPo concept at JLab) make a unique combination for the possibility of a high energy polarized e^± linac that could be coupled with the high intensity, large rare isotope selection beams of the possible storage rings at FRIB.  A preliminary study on the feasibility and performances of such linac will be presented and discussed.