FIRST EXPERIMENTAL-VERIFICATION OF SPIN TEMPERATURE EQUILIBRIUM IN A HIGH-FLOW SPIN-EXCHANGE SOURCE FOR POLARIZED HYDROGEN-ATOMS

In a spin-exchange source a large number of hydrogen atoms can be elec tron spin polarized through spin-exchange collisions with optically pu mped alkali atoms. It has been predicted that in spite of a high exter nal magnetic field, which is necessary for an efficient optical pumpin g, polarization can be transferred to the nuclei by frequent spin-exch ange collisions. We have designed and built such a source and have exp erimentally demonstrated that for the chosen geometry the hydrogen ato ms are in spin temperature equilibrium so that the nuclear polarizatio n equals the electron polarization.