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TY - UNPB AU - Tan, C.J. AU - Du, Y. C. AU - Huang, W.-H. AU - Jin, Q.X. AU - Liu, D.H. AU - Luo, L. AU - Tang, C.-X. ED - Schaa, Volker RW ED - Ji, Daheng ED - Li, Lu ED - Zhao, Ning TI - Beam Dynamics of Grided Electron Gun in Distributed X-ray Sources J2 - Proc. of SAP2017, Jishou, China, 28-30 August 2017 C1 - Jishou, China T2 - Symposium on Accelerator Physics T3 - 13 LA - english AB - Distributed X-ray sources, a single vacuum chamber containing multiple x-ray sources, open the way to innovative system concepts in x-ray and CT. This paper proposed a novel electron beam focusing scheme for distributed x-ray sources. The sources used dispenser cathode as electron emitter, mesh grid to control emission current, and two electrostatic lenses for beam shaping, focusing and deflecting or not. Because the mesh is a non-linear optical system, after beam passes the mesh, the beam emittance grows. In order to minimize this emittance growth, the first lens was placed behind the mesh. The second lens, called focusing lens, with two semi-ellipses opening make the beam shaping, deflecting or not. If the voltages of two semi-elliptical electrodes are different, the beam will deflect after passing through the focusing lens. The voltage difference between the two semi-elliptical focusing lens is set to +V, 0, -V. Then three focal spots will be obtained on the anode target. So that we can use fewer cathodes to get more sources, thereby reducing cost and the difficulty of thermal management, increasing the count of focal spots and improving the image quality. PB - JACoW CP - Geneva, Switzerland ER -