The most intense group of Auger electrons due to x-rays associated with $K$-capture in ${\mathrm{Zn}}^{65}$ would have energies lying in a narrow band within about 300 ev of a maximum value of 7056 ev ($H\rho 284$). These would arise from $K-L^2$ transitions in the resulting Cu atom. Electrons from the $K-LM$ transitions would be about $\frac{1}{3}$ as numerous, lying within about 300 ev of a maximum value of 8016 ev ($H\rho 302$). The soft electrons which are emitted copiously from ${\mathrm{Zn}}^{65}$ were found to have an absorption limit in collodion of 0.15±.03 mg/${\mathrm{cm}}^2$, approximately 7500 ev. When samples were placed 0.6 to 1.3 cm from the screen of a screen wall-counter filled with ${\mathrm{H}}_2$ at 2 cm Hg pressure, the upper limit (by inspection) was found to be at $H\rho 302\pm 30$ (8000±1700 ev). Scattering in the counter gas and absorption in the sample are believed negligible. These data are consistent with the hypothesis that the soft electrons from ${\mathrm{Zn}}^{65}$ are Auger electrons resulting from $K$-capture. Similar results, in less detail, were obtained in deflection experiments with ${\mathrm{Fe}}^{55}$.

• Received 10 May 1945

DOI:https://doi.org/10.1103/PhysRev.67.309