A SPIN-FILTER POLARIMETER FOR LOW-ENERGY HYDROGEN AND DEUTERIUM ION-BEAMS

An efficient polarimeter which reveals populations of individual hyperfine states of nuclear-spin-polarized H+/- (or D+/-) ion beams has been tested. This device is based on unique properties of a three-level interaction in the 2S1/2 and 2P1/2 states of hydrogen (or deuterium) atoms, created when the incident, polarized ion beams undergo electron pickup in cesium vapour. Used on a polarized ion source, its efficiency facilitates both rapid optimization and continual monitoring of parameters that affect the beam polarization. With such sources, and perhaps in applications with polarized gas jet targets, the device has potential for an absolute accuracy of better than 2%.