Patent ID: 7638957

Claim:
A betatron magnet, comprising: a first guide magnet having a first pole face and a second guide magnet having a second pole face and both said first guide magnet and said second guide magnet having a centrally disposed aperture, wherein said first pole face is separated from said second pole face by a guide magnet gap; a core disposed within said centrally disposed apertures, in an abutting relationship with both said first guide magnet and said second guide magnet, said core having at least one core gap; a drive coil wound around said first pole face and said second pole face; an orbit control coil having a contraction coil portion wound around said at least one core gap and a bias coil portion wound around both said first pole face and said second pole face, said contraction coil portion and said bias coil portion are connected but in opposite polarity; wherein magnet fluxes in said core and said first and said second guide magnets return through one or more peripheral portions of the betatron magnet; a circuit effective to provide voltage pulses to said drive coil and to said orbit control coil; and an electron acceleration passageway located within said guide magnet gap.