Energy-Chirp Compensation in a Laser Wakefield Accelerator

Area of Science:

• Plasma Physics
• Particle Acceleration
• Laser-Plasma Interactions

Background:

• Energy spread in laser wakefield accelerators is limited by energy chirp during injection and acceleration.
• Minimizing energy spread is crucial for applications requiring high-quality electron beams.

Purpose of the Study:

• To introduce and validate a novel method for reducing beam chirp.
• To convert broadband electron beams into quasimonoenergetic beams with reduced energy spread.

Main Methods:

• Longitudinal density tailoring of the plasma.
• Quasi-3D particle-in-cell simulations.
• Experimental validation of the proposed method.

Main Results:

• Demonstrated conversion of broadband electron beams to quasimonoenergetic beams.
• Achieved energy spread of ≤10% with beam charge >120 pC.
• Simulations indicate potential for subpercent energy spread in linear/quasilinear regimes.

Conclusions:

• Longitudinal density tailoring is an effective technique for reducing beam chirp.
• The method offers a pathway to high-quality electron beams from laser wakefield accelerators.
• Potential for achieving ultra-low energy spread in specific acceleration regimes.