Emission of radiation induced by bombardment of slow electrons from a clean (100) surface of tungsten

The mechanism of emission of radiation from a clean W (100) surface bombarded by electrons of about 1 keV has been studied. The radiation spectra in the range from 610 to 240 nm and their dependences on light polarization, observation angle, and incident electron energy have been systematically measured at room temperature. The experimental results are compared qualitatively with the calculation performed in the framework of classical electrodynamics. It is concluded that both transition radiation (or reflection radiation) and bremsstrahlung contribute to the observed radiation, and dominant mechanisms can be distinguished under selected conditions.