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Precision Milling of Carbon Nanotube Forests Using Low Pressure Scanning Electron Microscopy
Published on: February 5, 2017
A vacuum-sealed compact x-ray tube based on focused carbon nanotube field-emission electrons
Jin-Woo Jeong1, Jae-Woo Kim, Jun-Tae Kang
1Nano Electron-source Creative Research Center, Electronics and Telecommunications Research Institute, Yuseong-gu, Daejeon 305-700, Korea.
Abstract:
We report on a fully vacuum-sealed compact x-ray tube based on focused carbon nanotube (CNT) field-emission electrons for various radiography applications. The specially designed two-step brazing process enabled us to accomplish a good vacuum level for the stable and reliable operation of the x-ray tube without any active vacuum pump. Also, the integrated focusing electrodes in the field-emission electron gun focused electron beams from the CNT emitters onto the anode target effectively, giving a small focal spot of around 0.3 mm with a large current of above 50 mA. The active-current control through the cathode electrode of the x-ray tube led a fast digital modulation of x-ray dose with a low voltage of below 5 V. The fabricated compact x-ray tube showed a stable and reliable operation, indicating good maintenance of a vacuum level of below 5 × 10(-6) Torr and the possibility of field-emission x-ray tubes in a stand-alone device without an active pumping system.
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