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

2021 ◽  
Author(s):  
Jiang Yueling ◽  
Dong Quanlin

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.

1987 ◽  
Vol 51 (6) ◽  
pp. 409-411 ◽  
Author(s):  
S. A. Lee ◽  
L.‐U. A. Andersen ◽  
J. J. Rocca ◽  
M. Marconi ◽  
N. D. Reesor

Particles ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 238-252 ◽  
Author(s):  
Siriwan Krainara ◽  
Shuya Chatani ◽  
Heishun Zen ◽  
Toshiteru Kii ◽  
Hideaki Ohgaki

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.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1836 ◽  
Author(s):  
Ik-Soo Kwon ◽  
Sun-Jin Kim ◽  
Mansoor Asif ◽  
Bang-Wook Lee

The influx of a switching impulse during DC steady-state operations causes severe electrical stress on the insulation of HVDC cables. Thus, the insulation should be designed to withstand a superimposed switching impulse. All major manufacturers of DC cables perform superimposed switching impulse breakdown tests for prequalification. However, an experimental approach to study space charge dynamics in dielectrics under a switching impulse superposed on DC voltage has not been reported yet. This is because, unlike the DC stress, it is not possible to study the charge dynamics experimentally under complex stresses, such as switching impulse superposition. Hence, in order to predict and investigate the breakdown characteristics, it is necessary to obtain accurate electric field distribution considering space charge dynamics using a numerical approach. Therefore, in this paper, a numerical study on the switching impulse superposition was carried out. The space charge dynamics and its distribution within the dielectric under DC stress were compared with those under a superimposed switching impulse using a bipolar charge transport (BCT) model. In addition, we estimated the effect of a superimposed switching impulse on a DC electric field distribution. It was concluded that the temperature conditions of dielectrics have a significant influence on electric field and space charge dynamics.


2013 ◽  
Vol 652-654 ◽  
pp. 2391-2394
Author(s):  
Dong Hui Zhang ◽  
Chun Dong Liu ◽  
Jian Ming Liang ◽  
Chang Sheng Li

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.


2014 ◽  
Vol 602-605 ◽  
pp. 2986-2990
Author(s):  
De Wang

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.


Sign in / Sign up

Export Citation Format

Share Document