Metamaterial-based Radiation Sources with Free Electrons

All-metal metamaterial, as a brand-new high frequency structure, can exhibit unusual electromagnetic properties in radiation sources with free electrons. In this talk, the author reports the recent progress in the reversed Cherenkov radiation, reversed Cherenkov oscillator (RCO), and metamaterial extended interaction klystron. The first experiment shows that the RCO is a really metamaterial-based device because all the dimensions are sub-wavelength. These novel radiation sources have important applications such as in the high power microwave, accelerator, medical imaging, and microwave heating.