大束流场发射阴极X射线管的阳极设计
Design of Large Beam Field Emission Cathode X-ray Tube Anode
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摘要: 采用蒙特卡罗软件和有限元分析软件分析了固定阳极X射线管中电子轰击阳极靶的能量沉积和热量传输过程，固定阳极由铜棒和钨片组成。研究了在不同形状、尺寸和占空比的电子束脉冲轰击下，阳极靶面不同厚度的钨片和相邻铜棒的温度上升过程。结果表明，钨片厚度存在最优值，但最优值与具体使用条件相关；在脉冲成像方式下，固定阳极靶能承受更强束流强度的轰击。因此，采用固定阳极靶方案，研制140 kV高压、10 mA以上电流、直径1 mm以下有效焦点的场发射阴极X射线管是可行的。Abstract: In this paper, the Monte Carlo method and finite element analysis software were used to analyze electronic energy deposition and heat transfer process during the electron bombardment of the target in the fixed anode X-ray tube. The anode is made up of copper rod and tungsten film. With different duty cycles, sizes and shapes, the focal temperature rising process of tungsten film with different thicknesses and the adjacent copper was calculated. The result shows that there is an optimal value of tungsten film thickness depending on the working conditions. In pulse imaging mode, the fixed anode is able to withstand large beam intensity. Therefore, the development of a field emission cathode X-ray tube with maximum voltage of 140 kV, maximum current above 10 mA, effective focal spot diameter below 1 mm is feasible.
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Keywords:
- large beam X-ray tube ,
- Monte Carlo ,
- anode design
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