X-ray tubes incorporating carbon nanotube cathodes

Oxford Instruments is currently producing tubes with CNT (carbon nanotube) cathodes for compact X-ray sources such as the 30 kV, 12.2 in³ (16.4 cm³) source. This paper provides information on the emission stability, leakage current and reproducibility of the X-ray tubes, and the effects cathode performance has on the tubes. We will also include data from an analyzer that was constructed to measure the angular divergence of the emission from these particular CNT cathodes. These data indicate that the half-angle dispersion of electrons emitted into a uniform electric field is approximately 3°.