Emission-Angle Dependence of Electron Transmission through Thick Layers with Initial Energy of 24.8 MeV

抄録

Electrons of 24.8-MeV energy were incident on thick layers of C, Al, Cu, and Pb. Energy spectra f(E, θ) of transmitted electrons were measured at angles θ of 0°, 5°, 15°, 30°, and 60°. The material thicknesses ranged from ∼1 to ∼3.6 g/cm², or ∼10 to ∼30% of the continuous slowing-down approximation range of the incident electrons in each material. The total number of emerging electrons s(θ), defined as ∫f(E, θ)dE, was evaluated for each material. The angular dependence of s(θ)⁄s(0°) is compared with the Moli\={e}re theory of electron multiple scattering including an energy-loss correction, a large-angle correction, and a modification of screening angle. The experimentally obtained s(θ)⁄s(0°) relative to the calculated one increases as θ increases, and this is more remarkable for materials of low Z than in the case of high-Z materials.