The effect of cesium vapour on the bulk conductivity of plasma. Sprayed alumina

We have shown that Cs vapour is able to easily penetrate the bulk of plasma-sprayed alumina, leading to large increases in the bulk conductivity of the material. We have determined the temperature and pressure dependencies over a significant and technologically relevant range. In contrast to the surface conductivity we have found that the bulk conductivity exhibits a significant dependence on Cs pressure, varying approximately linearly with PCs. We believe that this effect represents a potentially significant degradation mechanism for single cell thermionic fuel elements which utilize this material. (author)