[en] Cesium and sodium in vapor form are used in two of the approaches to negative-ion production for neutral-beam research. Since fusion reactors are sensitive to the presence of high-Z impurities, it is important to monitor the extent to which the cesium and sodium migrate in the beam direction, or travel as part of the beam itself. Two techniques have been developed for the trace identification of either cesium or sodium on targets placed in vacuum. One of these involves neutron activation, and the other alpha-backscattering, to provide quantitative identification. Three types of targets have been employed, polyethylene which is suitable for the activation technique, beryllium which is useful for the alpha-backscatter analysis, and glassy carbon which is usable with either technique, and therefore, for cross comparison