On the Production of Electron Pairs in the Field of an Electron

The ratio, $R=\frac{\sigma -\mathrm{pairs}}{\sigma -}\mathrm{triplets}=\frac{C{\left(Z^2\right)}_{\mathrm{ef}}}{Z_{\mathrm{ef}}}$ for three gases, C${\mathrm{H}}_4$, air, and argon, has been studied and C found to be 3.63, 3.97, and 4.11, respectively. The average value of C from these data is 3.92±0.26. The gamma-rays from ${\mathrm{F}}^{19}(p,\alpha )\gamma {\mathrm{O}}^{16}$ were used in this experiment. The measured energies of the gamma-rays as deduced from pairs formed in C${\mathrm{H}}_4$ are 6.13±0.06 and 7.12±0.07 Mev. Data on the energy distribution of the low energy negative electron of the triplet are included.