[Ultra-Intense Seminar] Few-Cycle Probing of Laser-Plasma Accelerators - A Detailled Insight into the Acceleration Processes

durch Prof. Malte Kaluza (Friedrich-Schiller-Universität Jena)

Freitag 04.06.2021, 15:00 → 17:00 Europe/Berlin

Relativistic plasmas generated by high-power laser pulses are a potential candidate for future compact electron and ion accelerators. In a plasma-electron accelerator, the driving laser pulse generates a high-amplitude plasma wave forming the electric field structure (the „wakefield“) which can trap and accelerate electrons to several GeV energies over distances of a few centimeters only. The properties of the generated electron pulses (their energy spectrum, pulse duration, lateral dimensions, emittance…) strongly depend on the parameters and the evolution of this accelerating structure. Therefore, a complete understanding of the physical phenomena underlying the acceleration process is mandatory to improve the controllability of the electron pulses, which will determine their potential applicability in the future.

This presentation will give a short introduction to laser wakefield accelerators, discuss transverse optical probing as a high-resolution diagnostic tool [1,2,3] and present experimental results on the characterization and evolution of the electron pulses [4] and of the plasma wave [5,6].

Furthermore, an example will be given, how such a high-resolution optical diagnostic can also be applied to a laser-driven proton accelerator using 20-µm diameter water droplets as the target. Here, the expansion of the droplets under the irradiation of the laser pulse together with the direct observation of the influence of several experimental parameters on the generated proton pulses is visualized and compared to numerical simulations [7].

 

[1] M. B. Schwab et al., Applied Physics Letters 103, 191118 (2013)

[2] M. C. Downer et al., Reviews of Modern Physics 90, 035002 (2018)

[3] I. Tamer et al., Optics Express 28, 19034 (2020)

[4] A. Buck et al., Nature Physics 7, 543 (2011)

[5] A. Sävert et al., Physical Review Letters 115, 055002 (2015)

[6] E. Siminos et al., Plasma Physics and Controlled Fusion 58, 065004 (2016)

[7] G. A. Becker et al., Scientific Reports 9, 17169 (2019)

YouTube Link