Generation of X-rays by relativistic electrons in waveguide structures

Abstract

Experimental investigations aimed at studying the fundamental properties of x-ray generation by relativistic electrons in waveguide structures are presented. Both simple triple-layer W/C/W waveguide and complex waveguide structures such as non-uniform and uniform photonic crystals created on thick Si substrates were used. The W/C/W waveguide effect proved in x-rays distributions as an additional narrow peak inside a wide cone of ordinary Bremsstrahlung. Yield and angular density of the x-rays exited in the waveguide and then emitted from the waveguide channel is much less than that of Bremsstrahlung emitted from whole bulk of the waveguide radiator. But the waveguided x-rays are emitted only from the waveguide channel having very small width. X-ray generation in non-uniform photonic crystal (a multilayer having a channel inside) combines the effect of x-ray generation in the layered substructures of the multilayer (the layered walls of the channel) and waveguide effect for the generated radiation passing the waveguide channel in the guided modes due to both multiple Bragg and multiple full external reflections.