Ranges of Secondary Electrons in Magnesium

An investigation of the range or absorption characteristics of secondary electrons in magnesium by means of examining (with high energy primary electrons) the secondary electron emission ratio $\delta$ as a function of the thickness $x_1$ of magnesium layers evaporated on a carbon backing has led to an expression $l_{1s}=l_{01s}{E}^2$ for the ranges of secondary electrons as a function of the energy $E$ of the secondary electrons at the point of production in the solid. An analysis of the results yields relations between $\delta$ and $x_1$ (for the primary energies used) as well as the separate contributions of backing and layer to the total secondary emission. Values of $l_{01s}$ obtained from this experiment on magnesium for two, four, six, and eight kilovolts are 1.3, 1.7, 2.2, 2.3×${10}^{-9\mathrm{}}$ cm/${\mathrm{}\left(\mathrm{volt}\right)\mathrm{}}^2$, respectively. The depth of origin of secondary electrons in the energy range from 10 volts to 200 volts will vary from 2×${10}^{-7\mathrm{}}$ cm to 4×${10}^{-5\mathrm{}}$ cm.