Carbon nanotube x-ray tube with bipolar operation for dental application

This paper investigates a bipolar high voltage driven carbon nanotube-based X-ray tube. For field electron emission, an electric field must be formed between the gate and the cathode, and a strong negative voltage must be applied to the cathode. A circuit capable of field emission and cathode negative voltage application is designed with a negative power supply using only one negative high voltage source and a resistor for this purpose. The CNTs grown on the metal substrate can generate a stable tube current of 3 mA, and X-ray images were obtained using this tube. Both bipolar driving and unipolar driving are tested under the same conditions to determine the difference between the two driving methods. This result confirms that there is no difference in image quality when only the anode is subjected to 60 kV and when the anode and cathode are subjected to +30 kV and -30 kV, respectively. As a result, it has been confirmed that bipolar driving is less prone to arcing and that image quality can be maintained because the burden on the anode is lower than in unipolar driving.