TRANSFORMER RATIO DEPENDENCE ON BUNCH LENGTH AT NON-LINEAR WAKEFIELD EXCITATION IN PLASMA BY ELECTRON BUNCH WITH GAUSSIAN CHARGE DISTRIBUTION

MAXIMUM TRANSFORMER RATIO AT WAKEFIELD EXCITATION AT BLOWOUT REGIME IN PLASMA BY ELECTRON BUNCH UNDER SEMI-GAUSSIAN CHARGE DISTRIBUTION

10.46813/2020-127-062 ◽

2020 ◽

pp. 62-67

Author(s):

D.S. Bondar ◽

V.I. Maslov ◽

I.N. Onishchenko

Keyword(s):

Numerical Simulation ◽

Relativistic Electron ◽

Charge Distribution ◽

Electron Bunch ◽

Maximum Value ◽

Transformer Ratio ◽

Constant Charge

Using 2d3v code LCODE, the numerical simulation of nonlinear wakefield excitation in plasma by shaped relativistic electron bunch with charge distribution, which increases according to Gaussian charge distribution up to the maximum value, and then decreases sharply to zero, has been performed. Transformer ratio, as the ratio of the maximum accelerating field to the maximum decelerating field inside the bunch, and accelerating the wakefield have been investigated taking into account nonlinearity of the wakefield. The dependence of the transformer ratio and the maximum accelerating field on the length of the bunch was investigated with a constant charge of the bunch. It was taken into account that the length of the nonlinear wakefield increases with increasing length of the bunch. It is shown that the transformer ratio reaches its maximum value for a certain length of the bunch. The maximum value of the transformer ratio reaches six as due to the profiling of the bunch, and due to the nonlinearity of the wakefield.

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Electron bunch length monitors using spatially encoded electro-optical technique in an orthogonal configuration

Applied Physics Letters ◽

10.1063/1.3266919 ◽

2009 ◽

Vol 95 (23) ◽

pp. 231106 ◽

Cited By ~ 6

Author(s):

X. Yang ◽

T. Tsang ◽

T. Rao ◽

J. B. Murphy ◽

Y. Shen ◽

...

Keyword(s):

Electron Bunch ◽

Bunch Length ◽

Optical Technique

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

Particles ◽

10.3390/particles1010018 ◽

2018 ◽

Vol 1 (1) ◽

pp. 238-252 ◽

Cited By ~ 1

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.

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