GYRAC

The ''GYRAC'' concept is based on cyclotron resonance in a magnetic field that is increasing slowly in time. Others have shown that this results in an autoresonance in which the wave provides a synchronous acceleration of the electrons. Using a simple model makes it possible to design a particularly compact, cyclic electron accelerator; in a cavity with a 1-m radius and final magnetic field of 5 T, electron energy reaches 680 MeV, giving rise to synchrotron radiation at 1keV. Assuming uniform fields and rescaling time, the authors arrive at a Hamiltonian system which has one degree of freedom and which, in a first order approximation, is time independent. In a second-order approximation, the authors find a slow damping of autoresonant oscillation. A paraxial model for beam and fields enables us to evaluate the charge effects-the GYRAC then resembles the betatron. Finally, these results are illustrated by numerical 3-D simulations