Wave Particle Cherenkov Interactions Mediated via Novel Materials

Currently there is an increasing interest in dielectric wall accelerators. These work by slowing the speed of an EM wave to match the velocity of a particle beam, allowing wave-beam interactions, accelerating the beam. However conventional dielectric materials have limited interaction regions, so wave-beam energy transfer is minimal. In this paper we consider Artificial Materials (AMs), as slow wave structures, in the presence of charged particle beams to engineer Inverse-Cherenkov acceleration. AMs are periodic constructs whose properties depend on their subwavelength geometry rather than their material composition, and can be engineered to give an arbitrary dispersion relation. We show that Metamaterials, one example of an AM, can mediate an Inverse-Cherenkov interaction, but break down in high power environments due to high absorption. We consider AMs with low constitutive parameters and show they can exhibit low absorption whilst maintaining the ability to have a user defined dispersion relation, and mediate a wavebeam interaction leading to Inverse-Cherenkov acceleration.