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arXiv · 2307.13689

All-optical GeV electron bunch generation in a laser-plasma accelerator via truncated-channel injection

A. Picksley·J. Chappell·E. Archer·N. Bourgeois·J. Cowley·D. R. Emerson·L. Feder·X. J. Gu·O. Jakobsson·A. J. Ross·W. Wang·R. Walczak·S. M. Hooker
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Abstract

We describe a simple scheme, truncated-channel injection, to inject electrons directly into the wakefield driven by a drive pulse guided by an all-optical plasma channel. We use this approach to generate dark-current-free 1.2 GeV, 4.5 % relative energy spread electron bunches with 120 TW laser pulses guided in a 110-mm-long hydrodynamic optical-field-ionized (HOFI) plasma channel. Our experiments and particle-in-cell simulations show that high-quality electron bunches were only obtained when the drive pulse was closely aligned with the channel axis, and was focused close to the density down-ramp formed at the channel entrance. Start-to-end simulations of the channel formation, and electron injection and acceleration show that increasing the channel length to 410 mm would yield 3.65 GeV bunches, with a slice energy spread $\sim 5 \times 10^{-4}$.

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A. Picksley, J. Chappell, E. Archer, N. Bourgeois, J. Cowley, D. R. Emerson, L. Feder, X. J. Gu, O. Jakobsson, A. J. Ross, W. Wang, R. Walczak, S. M. Hooker. 2023-07-25. All-optical GeV electron bunch generation in a laser-plasma accelerator via truncated-channel injection. https://doi.org/10.1103/physrevlett.131.245001

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