MEASUREMENT OF THE TOTAL CROSS-SECTION FOR ELECTRON-IMPACT ON Cs USING COLD TRAPPED ATOMS D. M. B. P. Milori, J. R. Garbin, A. M. Tuboy and V. S. Bagnato Instituto de F\'{\i}sica de S\~ao Carlos Universidade de S\~ao Paulo Cx. Postal 369 - S\~ao Carlos -SP - Brasil 13.560 - 970 Using a sample of cold trapped Cs-atoms and an electron gum, we have measured the total cross-section for electron scattering in the range from 80 to 500 eV. In this presentation we show details of the technique and the obtained results.