GeV Electron Acceleration by Trapezoidal Laser Pulse Envelope Under Combined Effect of Frequency Chirp and Axial Magnetic Field in Vacuum

Abstract

In the present article, we have investigated efficient electron acceleration by employing trapezoidal laser pulse envelope under the combined effect of linear chirp and external axial magnetic field in vacuum. In this envelope, the electric signal linearly rises to a certain level, stay there, and then falls back to its initial level. So, there will be an opportunity to increase the interaction time between laser pulse and electron for efficient energy transfer, which has been reflected in this study. A few megaelectronvolt electrons have been injected axially to the front of a trapezoidal short laser pulse. In all calculations, the front end of each laser pulse captures electron at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$t= 0$ </tex-math></inline-formula> . The dynamics arise from analytical and numerical solutions of Newton–Lorentz force equations of motion. Electron energy gain has been calculated for initial laser phase varying from 0 to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\pi $ </tex-math></inline-formula> . For the optimum set of laser parameters, we have observed electro’s energy gain of the order of GeV.