FERROELECTRIC HIGH BRIGHTNESS ELECTRON SOURCE

THIS ADDRESSES THE NEED FOR HIGH BRIGHTNESS SOURCESOF HIGH CURRENT PULSED ELECTRON BEAMS THROUGH AN IN DEPTH STUDY OF ELECTRON EMISSION FROM FERROELECTRIC MATERIALS. RECENTLY COPIOUS EMISSION OF ELECTRONS HAS BEEN OBSERVED FROM FERROELECTRIC MATERIALS UPON FAST POLARIZATION CHANGE. USING LEAD ZIRCONIUM TITANATE (PZT) AND LEAD LANTHANAM ZIRCONIUM TITANATE (PLZT) ELECTRON EMISSION CURRENT DENSITIES OF 100A/CM(2) HAVE BEEN OBSERVED. THIS CURRENT DENSITY IS ABOUT AN ORDER OF MAGNITUDE LARGER THAN POSSIBLE WITH THERMIONIC CATHODES AND CLOSE TO THE MAXIMUM OBTAINED WITH LASER DRIVEN PHOTOCATHODES. THE FERROELECTRIC SOURCE IS A ROOM TEMPERATURE EMITTER WITH A THEORETICAL BRIGHTNESS LIMIT OF 3.2X10(12) A/M(2.)RAD(2) WHICH IS AN ORDER OF MAGNITUDE LARGE THAN PRESENT PHOTOCATHODES. PREVIOUS WORK HAS MEASURED THE BEAM EMITTANCE, BRIGHTNESS AND SPATIAL PROFILE Y DURING PHASE I. THIS SIMPLE SOURCE HAS THE POTENTIAL TO REPLACE THERMIONIC AND PHOTOCATHODES IN ADVANCED ACCELERATORS AND RF SOURCES. THE SOURCE IS POTENTIALLY ATTRACTIVE DUE TO THE HIGH BRIGHTNESS OBTAINABLEWITH A SIMPLE SYSTEM AS COMPARED TO THERMIONIC CATHODES REQUIRING PULSE BUNCHING FOR HIGH CURRENTS OR PHOTOCATHODES DRIVEN BY LARGE LASERS.