Collective Deceleration of Laser-Driven Electron Bunches

Area of Science:

• Plasma Physics
• Accelerator Physics
• Laser-Plasma Interactions

Background:

• Laser wakefield acceleration (LWFA) generates high-quality electron bunches.
• Plasma wakefields (PWFs) are crucial for advanced acceleration techniques.
• Traditional PWF studies often require large-scale radio frequency (RF) accelerators.

Purpose of the Study:

• To investigate the capability of few-femtosecond electron bunches from LWFA to drive PWFs.
• To explore the potential of tabletop LWFA electron sources for studying PWF physics.
• To demonstrate a compact method for generating and studying PWFs.

Main Methods:

• Propagation of few-femtosecond electron bunches through 2 mm of underdense plasma (10^18 cm^-3).
• Experimental observation of electron bunch deceleration and self-driven PWF excitation.
• Analysis of the acceleration gradient and its dependence on plasma density.

Main Results:

• Efficient driving of PWFs by few-fs electron bunches was confirmed.
• A strong, density-insensitive deceleration of electron bunches was observed.
• An average accelerating gradient of 5.1 GV/m was achieved, attributed to self-driven PWFs.
• The results indicate that tabletop LWFA electron sources can be used to study PWF physics.

Conclusions:

• Few-femtosecond electron bunches from LWFA are effective drivers of plasma wakefields.
• Compact LWFA systems offer a viable platform for studying fundamental PWF physics.
• This approach bypasses the need for large-scale RF accelerators in certain PWF research.