Paramagnetic Materials for PASER and Tunable RF Absorption

We report on the use of paramagnetic active media for the PASER (Particle Acceleration by Stimulated Emission of Radiation) and for dielectric loaded accelerating structures with tunable absorption for high order modes. The dielectric is doped with a material exhibiting high paramagnetic resonance, e.g. ruby with Cr3+. The absorption frequency can be tuned by a magnetic field.