Electron beam acceleration in the self-injection undulating plasma bubble regime of LWFA

These experiments investigate the potentially highly efficient electron trapping in the Expanding Phase-controlled Undulating Bubble (EPUB) [1] regime of Laser Wakefield Acceleration (LWFA). Unlike conventional LWFA schemes that rely on localized injections, the EPUB approach enables multiple, high-charge electron injections within the plasma, governed by controlled bubble undulations. In this regime, super-ponderomotive effects accompanied by laser pulse steepening in the plasma induce bubble undulations controlled by the Carrier Envelope Phase (CEP) offset [1,2]. The EPUB regime requires ultra-relativistic laser intensities (𝑎₀ ≫ 1), high plasma density (>10¹⁹ cm^-3), and short pulse durations (<30 fs). Experimental results obtained at the ELI-NP 100 TW laser facility will be discussed focusing on absolute electron charge production and its dependence on gas jet density and laser pulse duration, for nozzle diameters of 1 mm and 2 mm.

1. Kim J. et al., Polarization and phase control of electron injection and acceleration in the plasma by a self-steepening laser pulse, New J. Phys. 25 03300 (2023)
   
   Kostyukov I., Nerush E., A. Pukhov and V. Seredov, Electron Self-Injection in Multidimensional Relativistic-Plasma Wake Fields, Phys. Rev. Lett. 103, 175003 (2009)