Impact of Beam Structuring on Electron Acceleration in Preformed Plasma Channels

This study presents a comprehensive comparative theoretical analysis of electron acceleration by four types - Gaussian, Cosine hyperbolic Gaussian (ChG), Hermite-Gaussian (HG), and Hermite-Cosh-Gaussian (HC-G) laser pulses in a preformed ion channel within a subcritical density plasma. The interaction dynamics are examined considering both the direct laser field of radially polarized (RP) laser pulses and the electrostatic field formed by the ion channel. Key parameters, including the decentered parameter ‘b’ of the Cosh function, the Hermite mode index ‘s’, and the ion density ‘n’, are systematically analyzed to understand their impact on electron acceleration and energy gain. Results reveal that the combination of Hermite functions with RP-Ch-G laser pulses and the impact of the ion channel can greatly boost electron energy gain, reaching up to GeV levels with laser intensity (a 0 = 25) and ion density channels (~10 22 m -3 ) with optimized decentered parameters (b~2.0). The study underscores the sensitivity of electron acceleration to the spatial profiles of laser pulses and highlights the advantages of H-Ch-G pulses in achieving superior energy enhancement, making them a promising candidate for advanced laser-driven electron acceleration applications.