Design and Characterization of TiO2 Nanotube Based X-Ray Tube with Single Focusing Electrode
Y Alivov1*, Y Feng2, M Klopfer1, S Molloi1, (1) University of California, Irvine, Irvine, CA, (2) Lawrence Berkeley National Laboratory, Berkeley, CATU-A-218-10 Tuesday 8:00:00 AM - 9:55:00 AM Room: 218
Purpose: To study the effect of geometrical and electrical parameters on focal spot size (FSS) of TiO2 nanotube field emission X-ray tube. The X-ray tube parameters were optimized to achieve the smallest FSS for different cathode sizes and anode voltages.
Methods: The simulations were performed using the industry standard commercial software SIMION 80.1 3D. FSS was simulated as a function of the distance between gate electrode and focusing electrode (dG-L), focusing electrode opening diameter (dL), thickness of the focusing electrode (HL), distance between focusing electrode and anode (dL-A), and anode diameter (dA). The anode voltage was varied between 20-120 kV. dL was varied from 4 to 24 mm with 4 mm increments, and at each dL value FSS and focusing voltage (Vf) were studied as a function of TiO2 nanotube sample size dS. Simulations were followed by experiments to build X-ray tube with optimized parameters.
Results: The effect of various X-ray tube parameters on the focusing properties of electron optics system was investigated in the search for the smallest FSS for different TiO2 nanotube sample sizes. In particular, it is found that FSS grows with dS for all dL values. FSS grows fast at the beginning with the average growth rate of 183 µm/mm until dS reaches approximately 1 mm for all dL values. Then, FSS becomes weekly dependent on dS and later, as dS approaches dL, it starts growing fast again with average growth rate of 193 µm/mm. An X-ray tube was built with optimized from simulations parameters and its performance was tested.
Conclusions: A set of geometrical and electrical parameters have been established for different anode voltages and cathode sizes that provide the smallest focal spot size. An X-ray tube has been built and tested with optimized parameters.