Studying a kind of portable ultra-bright microfocus x-raysource
Wang Kai-Ge(王凯歌)a)b), Wang Lei(王雷)c), and Niu Han-Ben(牛憨笨)b)†
aInstitute of Photonics & Photonic Technology, Northwest University, Xi'an 710069, China; b Institute of Optoelectronics, Shenzhen University, Shenzhen 518060, China; c Xi'an Institute of Applied Optics, Xi'an 710065, China
Abstract This paper studies the properties of a kind of portable ultra-bright microfocus x-ray source with the Monte-Carlo method in detail. The new x-ray source consists of an electron-emission system, an electrostatic focusing system and a metal target. A crystal Lanthanum Hexaboride cathode, a Wehnelt grid and an extracted electrode compose the triode electrode electron-gun system. Two equal radius cylinder electrodes form the focusing system. The key factors determining the focus properties of the electron beam such as the ratio Dw/H, grid bias Vg, and the properties of the extracted electrode are numerically studied. The calculated results reveal that when Dw/H, Vg, the length of the extracted electrode, and the distance between the grid and the extracted electrode equals 5, --0.6 kV, 10 mm, and 8 mm respectively, the electron beam focal spot can be concentrated down to 9 μm in radius and a reasonable focal length about 72.5 mm can be achieved, at the same time, the cathode emission currents can be as high as 30 mA.
Received: 19 September 2008
Revised: 15 October 2008
Accepted manuscript online:
(X- and γ-ray sources, mirrors, gratings, and detectors)
Fund: Project supported by the Major
Program of the National Natural Science Foundation of China (Grant
No 60532090), and the National Natural Science Foundation of China
(Grant No 60771048).
Cite this article:
Wang Kai-Ge(王凯歌), Wang Lei(王雷), and Niu Han-Ben(牛憨笨) Studying a kind of portable ultra-bright microfocus x-raysource 2009 Chin. Phys. B 18 1807
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