Study of Electron Beam Space Charge Effect of Electrostatic Focusing

2014 ◽  
Vol 602-605 ◽  
pp. 2986-2990
Author(s):  
De Wang
Keyword(s):  
Electron Beam ◽  
Space Charge ◽  
Computer Aided Design ◽  
Space Charge Effect ◽  
Charge Effect ◽  
Distribution Method ◽  
Beam Focusing ◽  
Computer Aided ◽  
Aided Design

The influence of space charge in the space electron beam focusing system is introduced.Then charge-quantity distribution method which is used to calculate the density of space charge and the Computer Aided Design (CAD) method are put forward The result by programming calculation shows that the method is correct.

scholarly journals Manipulation of Laser Distribution to Mitigate the Space-Charge Effect for Improving the Performance of a THz Coherent Undulator Radiation Source

Particles ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 238-252 ◽  
Author(s):  
Siriwan Krainara ◽  
Shuya Chatani ◽  
Heishun Zen ◽  
Toshiteru Kii ◽  
Hideaki Ohgaki
Keyword(s):  
Electron Beam ◽  
Space Charge ◽  
Electron Bunch ◽  
Beam Quality ◽  
Space Charge Effect ◽  
Bunch Length ◽  
Charge Effect ◽  
Simulation Code ◽  
Undulator Radiation ◽  
Radiated Power

A THz coherent undulator radiation (THz-CUR) source has been developed at the Institute of Advanced Energy, Kyoto University. A photocathode Radio-Frequency (RF) gun and a bunch compressor chicane are used for generating short-bunch electron beams. When the electron beam energy is low, the space-charge effect strongly degrades the beam quality, such as the bunch length and the energy spread at the high bunch charge condition at around 160 pC, and results in the reduction of the highest frequency and the maximum radiated power of the THz-CUR. To mitigate the space charge effect, we have investigated the dependence of the electron beam quality on the laser distribution in transverse and longitudinal directions by using a numerical simulation code, General Particle Tracer GPT. The manipulation of the laser distribution has potential for improving the performance of the THz-CUR source. The electron bunch was effectively compressed with the chicane magnet when the laser transverse distribution was the truncated Gaussian profile, illuminating a cathode. Moreover, the compressed electron bunch was shortened by enlarging the laser pulse width. Consequently, an enhancement of the radiated power of the THz-CUR has been indicated.

Study of Displacement Value of the Electron-Beam in the Electron Gun in Electron-Beam Furnace

2013 ◽  
Vol 652-654 ◽  
pp. 2391-2394
Author(s):  
Dong Hui Zhang ◽  
Chun Dong Liu ◽  
Jian Ming Liang ◽  
Chang Sheng Li
Keyword(s):  
Mathematical Model ◽  
Electron Beam ◽  
Space Charge ◽  
Molten Metal ◽  
Space Charge Effect ◽  
Electron Gun ◽  
Ideal Condition ◽  
Charge Effect ◽  
Beam Spot ◽  
The Ideal

The concept of maximal and minimal displacement value of the electron-beam was proposed considering the influence of space charge effect based on the displacement value of the electron-beam in the process of magnetic deflection scanning in the ideal condition. The deduction of mathematical model of the maximal and minimal displacement value was accomplished. The position of the beam spot can be more accurately controlled by the model, thus it is made sure that un-molten metal is bombarded by the beam spot accurately, which can increase the melt quality.

Electron beam modeling and analyses of the electric field distribution and space charge effect

2021 ◽  
Author(s):  
Jiang Yueling ◽  
Dong Quanlin
Keyword(s):  
Electron Beam ◽  
Electric Field ◽  
Space Charge ◽  
Field Distribution ◽  
Electric Field Distribution ◽  
Space Charge Effect ◽  
Electron Beam Current ◽  
Field Calculation ◽  
Charge Effect ◽  
Cross Sectional

Abstract In electron beam technology, the critical focus of research and development efforts is on improving the measurement of electron beam parameters. The parameters are closely related to the generation, emission, operation environment, and role of the electron beam and the corresponding medium. In this study, a field calculation method is proposed, and the electric field intensity distribution on the electron beam’s cross-section is analyzed. The characteristics of beam diffusion caused by the space charge effect are investigated in a simulation, obtained data are compared with the experiment. The simulation demonstrated that the cross-sectional electric field distribution is primarily affected by the electron beam current, current density distribution, and electron beam propagation speed.

scholarly journals Geometric focusing of intense pulsed ion beams from racetrack type magnetically insulated diodes

1985 ◽  
Vol 3 (2) ◽  
pp. 119-155 ◽  
Author(s):  
K. Yatsui ◽  
A. Tokuchi ◽  
H. Tanaka ◽  
H. Ishizuka ◽  
A. Kawai ◽  
...  
Keyword(s):  
Space Charge ◽  
Incident Angle ◽  
Ion Beam ◽  
Close Correlation ◽  
Diagnostic Techniques ◽  
Space Charge Effect ◽  
Divergence Angle ◽  
Charge Effect ◽  
Time Resolved ◽  
Beam Focusing

Focusing properties and mechanisms are experimentally investigated of an intense pulsed light-ion beam or a medium-mass ion beam extracted from racetrack type magnetically insulated diodes. Quantitative determinations are made for three factors that affect the focusing ability of the beam, i.e., local divergence angle, deviation angle from ideal trajectory and space-charge effect. Behaviour of electrons in an anodecathode gap as well as neutralizing process of the ion beam by electrons are studied in connection with beam focusing. It is found that there is a close correlation between ion yield and electron irradiation on the anode. By adopting a perforated cathode instead of a vane cathode to ensure good uniformity of electric field in the accelerating gap, we have succeeded in significantly reducing the divergence angle. Several new diagnostic techniques and methods have been developed, yielding information such as the time-resolved trajectory and profile or incident angle of the beam. Electron temperature of the anode plasma is theoretically anticipated from the ions observed experimentally. From an estimate of beam divergence due to a space-charge effect, it is suggested that ‘breakeven’ can be achieved without using conventional z-discharged plasma channels if a bunch of boron beams is utilized.

Bitmap generation from computer-aided design for potential layer-quality evaluation in electron beam additive manufacturing

2020 ◽  
Vol 26 (5) ◽  
pp. 941-950
Author(s):  
Hay Wong
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Quality Assessment ◽  
Process Monitoring ◽  
Computer Aided Design ◽  
Reference Image ◽  
Cad Model ◽  
Content Type ◽  
Computer Aided ◽  
Aided Design

Purpose Electron beam additive manufacturing (EBAM) is a popular additive manufacturing (AM) technique used by many industrial sectors. In EBAM process monitoring, data analysis is focused on information extraction directly from the raw data collected in-process, i.e. thermal/optical/electronic images, and the comparison between the collected data and the computed tomography/microscopy images generated after the EBAM process. This paper aims to postulate that a stack of bitmaps could be generated from the computer-aided design (CAD) at a range of Z heights and user-defined region of interest during file preparation of the EBAM process, and serve as a reference image set. Design/methodology/approach Comparison between that and the workpiece images collected during the EBAM process could then be used for quality assessment purposes. In spite of the extensive literature on CAD slicing and contour generation for AM process preparation, the method of bitmap generation from the CAD model at different field of views (FOVs) has not been disseminated in detail. This article presents a piece of custom CAD-bitmap generation software and an experiment demonstrating the application of the software alongside an electronic imaging system prototype. Findings Results show that the software is capable of generating binary bitmaps with user-defined Z heights, image dimensions and image FOVs from the CAD model; and can generate reference bitmaps to work with workpiece electronic images for potential pixel-to-pixel image comparison. Originality/value It is envisaged that this CAD-bitmap image generation ability opens up new opportunities in quality assessment for the in-process monitoring of the EBAM process.

Computer aided design of computer generated holograms for electron beam fabrication

1989 ◽  
Vol 28 (16) ◽  
pp. 3387 ◽  
Author(s):  
Kristopher S. Urquhart ◽  
Sing H. Lee ◽  
Clark C. Guest ◽  
Michael R. Feldman ◽  
Hamid Farhoosh
Keyword(s):  
Electron Beam ◽  
Computer Aided Design ◽  
Computer Aided ◽  
Computer Generated Holograms ◽  
Aided Design
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