RELAXATION OF ELECTRON POLARIZATION FOR OPTICALLY PUMPED RUBIDIUM ATOMS

Relaxation time constants of electron polarization, [S-z], for optical ly pumped rubidium atoms in a drifilm coated glass cell have been inve stigated with the Faraday rotation method. The dependence of the [S-z] relaxation time on pump cell temperature, rubidium density and applie d magnetic field has been determined with high precision. The measurem ents allow the determination of the local magnetic field on the surfac e, alkali-wall binding energy and wall-dwell time. Furthermore, the ch ange of relaxation time caused by admixtures of molecular hydrogen, ni trogen and oxygen has been investigated. No influence due to the addit ion of hydrogen could be detected up to a density of 3.3x10(14) cm(-3) at typical rubidium densities of several 10(11) cm(-3). The cross sec tion for depolarizing collisons with molecular oxygen has been determi ned to be 7.50x10(-15) cm(2). The corresponding cross section for nitr ogen was found to be two orders of magnitude lower. The experimental r esults are discussed in respect to the performance of spin exchange so urces for nuclear polarized hydrogen and deuterium. (C) 1998 American Institute of Physics. [S0021-8979(98)06810-8].