A digital miniature x-ray tube with a high-density triode carbon nanotube field emitter

We have fabricated a digital miniature x-ray tube (6mm in diameter and 32mm in length) with a high-density triode carbon nanotube (CNT) field emitter for special x-ray applications. The triode CNT emitter was densely formed within a diameter of below 4mm with the focusing-functional gate. The brazing process enables us to obtain and maintain a desired vacuum level for the reliable electron emission from the CNT emitters after the vacuum packaging. The miniature x-ray tube exhibited a stable and reliable operation over 250 h in a pulse mode at an anode voltage of above 25 kV. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4776222]