Laser and electron deflection from transverse asymmetries in laser-plasma accelerators

Area of Science:

• Plasma physics
• Laser-driven particle acceleration

Background:

• Laser-plasma accelerators (LPAs) are crucial for generating high-quality electron beams.
• Controlling electron beam pointing is essential for LPA applications.
• Laser pulse front tilt and plasma density gradients are known to influence beam dynamics.

Purpose of the Study:

• To investigate and model the deflection of laser pulses and accelerated electrons in LPAs.
• To quantify the effects of laser pulse front tilt and transverse plasma density gradients on beam steering.
• To demonstrate controllable beam deflection for potential applications in electron beam pointing control.

Main Methods:

• Development of quantitative models for laser and electron steering.
• Validation of models using particle-in-cell (PIC) simulations.
• Experimental verification using the BELLA Petawatt Laser.

Main Results:

• Asymmetry in plasma refractive index causes laser steering via density gradients or spatiotemporal coupling.
• Skewed plasma waves induce transverse forces, deflecting electrons relative to the laser.
• Experiments demonstrated controllable laser and electron beam deflection (0.1-1 mrad) by laser pulse front tilt.

Conclusions:

• Laser pulse front tilt and plasma density gradients provide a mechanism for steering laser pulses and electron beams in LPAs.
• The proposed models accurately predict laser and electron deflection.
• Controllable beam deflection via pulse front tilt has significant potential for precise electron beam pointing control in LPAs.