Comparison of coherent Smith-Purcell radiation generated by 6.1 MeV electron beam in metal and dielectric lamellar gratings

摘要

Coherent Smith-Purcell radiation generated by bunched electron beam in thelamellar metal and dielectric gratings in the millimeter wavelength range wascompared theoretically and experimentally. For theoretical estimation a simplemodel suitable for both dielectric and metal gratings was developed.Experimental comparison was carried out using extracted bunched 6.1 MeVelectron beam of the microtron at Nuclear Physics Institute (Tomsk PolytechnicUniversity). Both theoretical estimations and experimental data showed thedifference of the radiation characteristics from the lamellar metal anddielectric gratings. The radiation from the dielectric grating had peakstructure not monotonic one and was more intense comparing with metal gratingradiation in the wavelength less than coherent threshold. These differences maybe useful for research and development of new compact monochromatic radiationsources in sub-THz and THz region.