Experimental techniques that are useful in the production and study of the fission product rare gases have been developed. The experimental developments reported in this work include a new radiation-resistant fission-gas-emanating compound, a fast technique for the separation of trace quantities of xenon or krypton from a fission gas mixture, and a "charged-wire chamber" used in the continuous removal of decay products from radioactive gas sources.These methods have been applied in the determination, by direct counting techniques, of the half-lives of 138Cs (32.3 ± 0.1 min), 139Cs (9.0 ± 0.15 min), 140Cs (63.8 ± 1.2 sec), 137Xe (3.80 ± 0.05 min), 139Xe (14.1 ± 0.8 min), 139Xe (41.2 ± 0.15 sec), and 140Xe (13.7 ± 0.15 sec). These results compare favorably with the most recently published measurements of these half-lives.