Optimization of ballasted carbon nanotube array for X-ray source

Ballast resistor under layer can improve reliability and stability of field emission cathode. Utilization of ballast resistor in Spindt cathode has been studied thoroughly. However, due to the significant difference between the Spindt cathode and CNT (carbon nanotube) emitter, studies of ballasted CNT emitter array are rare. Ballasted CNT emitter array has been demonstrated in our early studies. In this article, we use the finite element method to analyses the effect of the geometry parameters of the emission array. Optimized parameters, for example: intertube pitch, connection pad diameter, resistor layer thickness, and height of the CNT, are calculated. These optimized parameters are suitable for ballasted CNT emitter arrays for flat panel X-ray sources.