A high density polarized hydrogen gas target for storage rings

A storage cell target of polarized hydrogen gas was installed in a storage ring to study the target characteristics (nuclear polarization, target thickness, radiation resistance). The density of the target gas was enhanced by cooling the cell. Using a weak transverse guide field (5 G), the nuclear polarization of the target was measured to be 0.80±0.02 when atoms in a single hyperfine state were selected. The areal density of the target under these conditions was 5.5⋅1013 H↘/cm2 (T=115 K), while for two spin states (applicable to experiments in high energy rings, where a strong magnetic field can be applied to the target) the target thickness was found to be 8.2⋅1013 H↘/cm2.