Autoresonant accelerator concept

We present a new ion accelerator idea which combines the basic concepts of traveling wave and collective acceleration. The lower cyclotron mode of a relativistic electron beam along a spatially decreasing magnetic field $B$ constitutes the traveling wave, the wave phase velocity varying inversely with $B$. The negative energy character of the wave allows automatic extraction of energy from the electron beam for the acceleration process. Typical ion energy versus current outputs are estimated.