▎ 摘　　要

A method for the effective excitation of Highly Confined Surface Plasmon Polaritons (HC SPPs) that can generate x-rays is presented based on the electron beam excitation of hot carriers and the graphene hot carrier quantum Cherenkov effect. Compared with the widely used methods of HC SPPs' excitation, in this method, no periodic structure is needed, so it is possible to achieve a miniaturized system; it can also excite monochromatic HC SPPs with a guide wavelength as small as 1/300 of the vacuum wavelength. The working point of HC SPPs is not sensitive to the velocity of the electron beam and can be dynamically tuned through the Fermi energy of graphene. At the same time, the working efficiency can be significantly improved (to about 37.28%). Based on the above-mentioned characteristics, when the HC SPPs and the electron beam in this method are used in the electron-plasmon scattering system, x-ray emission can be achieved with rather low electron beam energy (35 KeV). Since the electron beam can simultaneously act as the SPPs' source and the scatterer, it is possible to integrate an x-ray source and the HC SPPs' emitter that drives the x-ray source in the same cavity, realizing a unified system.