Planar permanent magnet edge-field quadrupoles for use in particle accelerating machines and in insertion devices designed to generate spontaneous or coherent radiation from moving charged particles are disclosed. The invention comprises four magnetized rectangular pieces of permanent magnet material with substantially similar dimensions arranged into two planar arrays situated to generate a field with a substantially dominant quadrupole component in regions close to the device axis.
This invention was made with government support under Grants No. DE-AC03-82-ER1300, DE-FG06-85-ER13309, and DE-AC03-76SF0015, awarded by the Department of Energy, and Grant No. AFOSR-85-0326 awarded by the Department of Defense. The government has certain rights in this invention .