A high-performance carbon nanotube-based field emission x-ray tube for commercial dental imaging

We developed a fully vacuum-sealed carbon nanotube (CNT)-based field emission x-ray tube with commercial-level performance for dental imaging application. The CNT x-ray tube was designed in a triode configuration with the focus-functional gate and had a compact size, much smaller than the conventional hot-cathode tubes. The small size of CNT x-ray tubes along with no cathode heating enables us to make a very compact portable dental imaging system. We have obtained a quite good x-ray image of a human tooth phantom by operating the CNT x-ray tube in an anode voltage of 65 kV, an emission current of 3 m A, and a pulse duration of 0.5 s, which is comparable to that of the conventional commercial hot-cathode tube.