High performance cold cathode CNT x-ray tube

The cold cathode x-ray tube was fabricated using a line-shape carbon nanotube (CNT) field emitter which is made by a free-standing CNT film. The cold cathode x-ray tube indicated a extremely high emission current density and a small focal spot. The high emission current of the CNT field emitter is caused by high density emission sites at the edge of CNT film and the small focal spot is attributed to combination of the line-shape CNT field emitter and an elliptical cavity-shape focusing lens. The cold cathode x-ray tube using CNT field emitter shows high-resolution X-ray images at a lower tube current compared with thermionic X-ray tubes or CNT paste cold cathode X-ray tubes.