Polarized 3He targets at MAMI

Abstract

Due to its spin structure polarized 3He serves as a suitable substitute for a polarized neutron target. The 3He‐gas is polarized at pressures of about 1 mbar via the metastability exchange optical pumping method. After compression to 5 bar and filling to target cells the gas is used as a target for scattering experiments at the electron accelerator MAMI in Mainz. The polarizer can provide polarized 3He with a polarization of more than 70 % at a yield of 2 bar⋅1/h. The total relaxation time of the target cells in the electron beam is about 50 h.