攜帶式X光影像機之射線激發管的電子光學系統之設計

過去，X光大量的使用於醫療中，X光射線愈來愈受到重視，而使用X光時要如何控制輻射劑量，卻又能夠達到良好的曝光效果是值得去研究地，而X光的產生是藉由電子束撞擊靶面產生，因此如何讓電子束撞擊靶面後能夠更有效率的產生X光，並且能夠達到更好的聚焦效果顯的極為重要。過去所使有的X光射線管多為熱陰極，而熱陰極本身需具備較大的空間已達到良好的散熱效果。攜帶式X光機在近年被提出，由於攜帶式X光機的可攜性，攜帶式X光機可以進行更多元的檢測。冷陰極X光射線管的優點是所需空間較小，且耗損能量較少，由於以上的優點使得冷陰極被廣泛運用到攜帶式X光管中。冷陰極是使用奈米碳管進行場發射來達到激發電子束的效果，傳統的熱陰極與冷陰極發射原理有著極大的不同。因此本篇論文針對冷陰極X光射線管的部分進行研究與探討。本論文中將X光分成兩個部分進行探討，首先利用CST PARTICLE STUDIO針對如何藉由改變物件外觀以產生適當地電子透鏡，使電子束能夠達到良好的聚焦效果，並且能夠來使陽極端接收電流能達到最大值來進行探討。在進行電子束的探討之後，我們再針對電子束激發的X光利用ROSI來進行X光成像模擬。

關鍵字

X光射線激發管；電子光學；攜帶式影像機

並列摘要

In recent years, X-ray has been used in medical. X-ray becomes more and more attention. How to control the dose of X-ray but to achieve good results when you are using it becomes an important study. Because X-ray is generated by electron beam hit the metal target surface, using the electron beam to generate X-ray more efficiently and getting better results on focus are important. In the past, hot cathode had been used in the X-ray tube for a long time. It needs a big space for hot cathode to low down the temperature. The portable X-ray machines have been proposed in recent years. Due to the portability of the portable X-ray machines, the portable X-ray machine can be used in more studies. The advantages of the X-ray tube which use cold cathode requires less space and less energy, so the cold cathode has been applied to portable X-ray tube. It emerges the electron beams by Carbon nanotubes. It is lots of difference between hot cathode and cold cathode. We study how to change the shape of grids of X-ray tube to generate a good electron lens to focus the electron beams and improve the incident current on anode by using CST PARTICLE SYUDIO in the first part. The second part is using the results which come from the first part on the X-ray imaging by using ROSI which is a program by using Monte Carlo method.

並列關鍵字

Electron-optics ； Portable imaging systems ； X-ray tube

參考文獻

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[5] H. Makishimia, H. Imura, M. Takahashi, H. Fukui, and A. Okamoto, “Remarkable Improvements of Microwave Electron Tubes Through The Development of Cathode Materials,” in Proc. 10th Int. Vac. Microelectron. Conf., Kyongju, Korea, pp. 194–199, 1997.

[6] C.O.Bozler, et al., “Gated Field-Emitter Arrays for Microwave-Tube Applications,” IVMC'95 Technical Digest, pp. 118- 122, 1995.

[7] Wei Lei, Xiaobing Zhang, Jing Chen, Zhiwei Zhao, Yiping Cui, and Baoping Wang, “Very High Field Emission from A Carbon Nanotube Array with Isolated Subregions and Balanced Resistances,” IEEE Transactions on Date of Publication on Electron Devices, pp. 3616 – 3621, Oct. 2011.

國際替代計量

攜帶式X光影像機之射線激發管的電子光學系統之設計

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