Fabrication and Simulation of Self-Focusing Field Emission X-ray Tubes
AbstractA self-focusing field emission (FE) X-ray tube with a large-area cathode design was simulated and fabricated. The designed X-ray tube had a cylindrically symmetric geometry; the diameter of the cathode and the anode was 15 mm, and the cathode-anode distance was 20 mm. Owing to the unique cup-shaped design of the cathode, the electron beam emitted from the large-area cathode was focused onto the anode without using magnetic lenses or extra biased electrodes. Carbon nanocoils, which were grown on the bottom of the circular cup-shaped cathode, were used as electron emitters because of their excellent FE properties. A simulation of the electron trajectories for various cup heights revealed that the optimal focal spot size (0.1 mm) was obtained at a cup height of 5 mm when a voltage of 50 kV was applied. To verify this result, an X-ray tube was fabricated and tested. An X-ray photograph of the tested tooth and electric circuits showed good resolution and X-ray intensity. The large cathode area effectively reduces the current density and thereby improves the lifetime of the cathode. View Full-Text
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Cheng, K.; Chou, Y.-P.; Youh, M.-J.; Liu, Y.-M.; Ger, M.-D.; Hou, K.-H.; Pu, N.-W. Fabrication and Simulation of Self-Focusing Field Emission X-ray Tubes. Appl. Sci. 2015, 5, 942-954.
Cheng K, Chou Y-P, Youh M-J, Liu Y-M, Ger M-D, Hou K-H, Pu N-W. Fabrication and Simulation of Self-Focusing Field Emission X-ray Tubes. Applied Sciences. 2015; 5(4):942-954.Chicago/Turabian Style
Cheng, Kevin; Chou, Yi-Ping; Youh, Meng-Jey; Liu, Yih-Ming; Ger, Ming-Der; Hou, Kung-Hsu; Pu, Nen-Wen. 2015. "Fabrication and Simulation of Self-Focusing Field Emission X-ray Tubes." Appl. Sci. 5, no. 4: 942-954.