1. A particle accelerator comprising:a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles within the cavity, the cavity having a magnetic field causing the particles to move orbitally within the cavity;
an extraction channel to receive the particles from the cavity and to output the received particles from the cavity; and
a regenerator to provide a magnetic field change within the cavity to thereby change orbits of particles within the cavity so that, eventually, the particles output to the extraction channel, the regenerator comprising an edge comprising a non-orthogonal intersection of two faces;
wherein the magnetic field in a center of the cavity is at least 6 Tesla.