Nuclear polarization measurement of H/D atoms extracted from a storage cell with a Lamb-shift polarimeter

The occupation numbers of the individual hyperfine substates in a beam of hydrogen or deuterium atoms are measured with a Lamb-shift polarimeter. Therefore, the nuclear polarization of an atomic beam can be determined with high precision of about 0.5 % within 20 s. The measurements are carried out with the atomic beam source for the internal polarized storage-cell gas target of ANKE ( I ∼ 7 × 10 16 atoms/s). The polarization of a slow (500–2000 eV) ion beam with currents higher than 1 nA can be measured as well. When the intensity of the atomic beam is reduced by a factor of 100, the Lamb-shift polarimeter still provides a precise measurement with an error of about 2% within 30 s. Thus, it is thought possible to determine the nuclear polarization of the atomic gas inside the storage cell, when a sample of these atoms effuse into the Lamb-shift polarimeter through a sample tube. results obtained with a simple Teflon cell, a new ionizer with an internal getter pump, a newly designed Wien filter and a larger photomultiplier are presented. Planned studies to optimize the polarization measurement are discussed as well.