Secondary Electron Yield from Al by High-Energy Primary Electrons

The yield of secondary electrons from thin (1.71 mg/${\mathrm{cm}}^2$) aluminum foils by high-energy primary electrons is reported. The value is 0.0397±0.0003 secondary electron per primary electron from both sides of the foil. The result is independent of the primary-electron energy in the range 111-235 Mev.