Measurement of 129Xe-Cs binary spin-exchange rate coefficient -: art. no. 061401

We report the first measurement of the spin-exchange rate coefficient for binary collisions between Cs and Xe-129 atoms in the temperature range 110<T<150 degreesC at a 9.4-T magnetic field. Under these conditions, binary spin-exchange collisions dominate the longitudinal nuclear spin-relaxation rate 1/T-1 of Xe-129 gas. We measured 1/T-1 of a thermally polarized Xe gas using the saturation-recovery of conventional nuclear magnetic resonance. We also directly measured the Cs atomic number density [Cs] by using Faraday rotation of the linear polarization of a probing laser beam passing through the sample. The measured rate coefficient is kappa(9.4 T)=d(1/T-1)/d[Cs]=(2.81+/-0.2)x10(-16) cm(3)/s, which is about a factor of 1.6 higher than the previously measured spin-exchange rate coefficient of Xe-129-Rb binary collisions. Using a calculated magnetic decoupling factor, we extrapolate our result to zero magnetic field: kappa(0 T)=(4.1+/-0.3)x10(-16) cm(3)/s.