Matched Guiding and Controlled Injection in Dark-Current-Free, 10-GeV-Class, Channel-Guided Laser Plasma Accelerators

A. Picksley; J. Stackhouse; C. Benedetti; K. Nakamura; H. E. Tsai; R. Li; B. Miao; J. E. Shrock; E. Rockafellow; H. M. Milchberg; C. B. Schroeder; J. van Tilborg; E. Esarey; C. G. R. Geddes; A. J. Gonsalves

arXiv · 2408.00740

Matched Guiding and Controlled Injection in Dark-Current-Free, 10-GeV-Class, Channel-Guided Laser Plasma Accelerators

A. Picksley·J. Stackhouse·C. Benedetti·K. Nakamura·H. E. Tsai·R. Li·B. Miao·J. E. Shrock·E. Rockafellow·H. M. Milchberg·C. B. Schroeder·J. van Tilborg·E. Esarey·C. G. R. Geddes·A. J. Gonsalves

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Abstract

We measure the high intensity laser propagation throughout meter-scale, channel-guided LPAs by adjusting the length of the plasma channel on a shot-by-shot basis, showing high quality guiding of 500 TW laser pulses over 30 cm in a hydrogen plasma of density $n_0 \approx 1 \times 10^{17} \, \mathrm{cm^{-3}}$. We observed transverse energy transport of higher-order modes in the first $\approx 12 \, \mathrm{cm}$ of the plasma channel, followed by quasi-matched propagation, and the gradual, dark-current-free depletion of laser energy to the wakefield. We quantify the laser-to-wake transfer efficiency limitations of currently available PW-class laser systems, and demonstrate via simulation how control over the laser mode can significantly improve accelerated beam parameters. Using just 21.3 J of laser energy, and triggering localized electron injection into the accelerator, we observed electron bunches with single, quasimonoenergetic peaks, relative energy spreads as low as 3 % and energy up to 9.2 GeV with charge extending beyond 10 GeV.

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A. Picksley, J. Stackhouse, C. Benedetti, K. Nakamura, H. E. Tsai, R. Li, B. Miao, J. E. Shrock, E. Rockafellow, H. M. Milchberg, C. B. Schroeder, J. van Tilborg, E. Esarey, C. G. R. Geddes, A. J. Gonsalves. 2024-08-01. Matched Guiding and Controlled Injection in Dark-Current-Free, 10-GeV-Class, Channel-Guided Laser Plasma Accelerators. https://arxiv.org/abs/2408.00740

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