A HIGHLY SENSITIVE BREIT-RABI TYPE POLARIMETER FOR AN INTERNAL POLARIZED HYDROGEN AND DEUTERIUM TARGET

A Breit-Rabi type polarimeter for thermal hydrogen and deuterium atomic beams has been developed, which allows to measure the relative occupation numbers n(i) of the hfs states. The n(i) are derived from ratios of measured intensities, while switching on and off certain rf transitions. As an essential part, so-called medium-field transitions have been applied for hydrogen and deuterium for the first time. A precision of DELTA-n =0.02 is obtained in 120 s of measurement time at an intensity of 2 X 10(13) atoms/s into the cross-beam ion source of the quadrupole mass spectrometer.