Luminous, relativistic, directional electron bunches from an intense laser driven grating plasma


Amit D. Lad , ... , Z. M. Sheng , K. A. Tanaka, G. Ravindra Kumar and H. Habara [ ]

Bright, energetic, and directional electron bunches are generated through efficient energy transfer of relativistic intense (~ 1019 W/cm2), 30 femtosecond, 800 nm high contrast laser pulses to grating targets (500 lines/mm and 1000 lines/mm), under surface plasmon resonance (SPR) conditions. Bi-directional relativistic electron bunches (at 40o and 150o) are observed exiting from the 500 lines/mm grating target at the SPR conditions. The surface plasmon enhances the electron flux and temperature by factor of 6.0 and 3.6, respectively, compared to that of the plane substrate. Particle-in-Cell simulations indicate that fast electrons are emitted in different directions at different stages of the laser interaction, which are related to the resultant surface magnetic field evolution. This study suggests that the SPR mechanism can be utlized to generate multiple, bright, ultrafast relativistic electron bunches for a variety of applications. High energy particle bunches are a major tool in modern science and technologies.

This figure shows clear increase of bi-directional electrons in the case of grating target (500 lines/mm) at 40 and 150 degrees compared to the plane normal.