A vacuum-sealed compact x-ray tube based on focused carbon nanotube field-emission electrons
A vacuum-sealed compact x-ray tube based on focused carbon nanotube field-emission electrons
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DOI：
10.1088/0957-4484/24/8/085201
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发表时间：
2013-03-01
期刊：
影响因子：
3.5
通讯作者：
Song, Yoon-Ho
中科院分区：
文献类型：
--
作者：
Jeong, Jin-Woo;Kim, Jae-Woo;Song, Yoon-Ho
我们报道了一种基于聚焦碳纳米管(CNT)场发射电子的全真空密封紧凑型X射线管，用于各种射线照相应用。特别设计的两步钎焊工艺使我们在没有任何主动真空泵的情况下，实现了良好的真空水平，使X射线管稳定可靠地运行。此外，场发射电子枪中集成的聚焦电极有效地将来自碳纳米管发射器的电子束聚焦到阳极靶上，获得了约0.3 mm的小焦斑，大电流超过50 mA。通过X射线管阴极的有源电流控制，实现了X射线剂量的快速数字调制，电压低于5V。制作的紧凑型X射线管运行稳定可靠，表明在没有主动抽运系统的情况下，场发射X射线管的真空度保持在5×10(-6)Torr以下。
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 x 10(-6) Torr and the possibility of field-emission x-ray tubes in a stand-alone device without an active pumping system.