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Register a new userGenerating high quality ultra-relativistic electron beams using an evolving electron beam driver
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Added by
Thamine Dalichaouch
Publication date
2019
fields
Physics
and research's language is
English
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A new method of controllable injection to generate high quality electron bunches in the nonlinear blowout regime driven by electron beams is proposed and demonstrated using particle-in-cell simulations. Injection is facilitated by decreasing the wake phase velocity through varying the spot size of the drive beam and can be tuned through the Courant-Snyder (CS) parameters. Two regimes are examined. In the first, the spot size is focused according to the vacuum CS beta function, while in the second, it is focused by the plasma ion column. The effects of the driver intensity and vacuum CS parameters on the wake velocity and injected beam parameters are examined via theory and simulations. For plasma densities of $sim 10^{19} ~text{cm}^{-3}$, particle-in-cell (PIC) simulations demonstrate that peak normalized brightnesses $gtrsim 10^{20}~text{A}/text{m}^2/text{rad}^2$ can be obtained with projected energy spreads of $lesssim 1%$ within the middle section of the injected beam, and with normalized slice emittances as low as $sim 10 ~text{nm}$.
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A unique facility for laser plasma physics and advanced accelerator research has been built recently at Tsinghua Universtiy. This system is based on Tsinghua Thomson scattering X-ray source (TTX), which combining an ultrafast TW laser with a synchronized 45MeV high brightness linac. In our recent laser wakefield acceleration experiments, we have obtained 10~40MeV high quality monoenergetic electron beams by running the laser at 5TW peak power. Under certain conditions, very low relative energy spread of a few percent can be achieved. Absolute charge calibration for three different scintillating screens has also been performed using the linac system.
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