Development of CNT Based Field Emission X-Ray Source And Imaging System For Biomedical And Industrial Applications

X-ray radiation is widely used for medical and industrial imaging applications. Current x- ray tubes use thermionic cathodes to produce the electron beams which bombard on metal targets to generate x ray. The design has several intrinsic limitations. In this talk we demonstrate that diagnostic x-ray radiation can be generated using a carbon nanotube based field emission cathode. The device can readily produce both continue and pulsed x-ray with a programmable waveform and repetition rate. The x-ray intensity is sufficient to image human extremity. Pulsed x-ray with a repetition rate greater than 100 kHz was readily achieved by programming the gate voltage. The performance of this cold-cathode x-ray tube will be discussed and compared with the conventional thermionic systems. We will also present imaging systems/modalities enabled by the field emission x-ray source.