Narrow bandwidth, low-emittance positron beams from a laser-wakefield accelerator

Area of Science:

• Particle Physics
• Accelerator Physics
• Plasma Physics

Background:

• Plasma wakefield accelerators (PWFA) show promise for next-generation high-energy colliders.
• Positron acceleration in PWFA is challenging due to wakefield structures.
• Experimental research is limited by the availability of suitable positron beams.

Purpose of the Study:

• To experimentally demonstrate a laser-driven source of ultra-relativistic positrons.
• To produce positrons with quality suitable for injection into a plasma accelerator.
• To enable experimental studies of positron acceleration in laser-driven wakefield accelerators.

Main Methods:

• Utilized a laser-driven approach to generate positron beams.
• Performed experimental measurements of positron beam properties.
• Conducted particle-in-cell (PIC) simulations to validate experimental results and explore future scaling.

Main Results:

• Demonstrated the first experimental source of ultra-relativistic positrons for plasma acceleration.
• Achieved selection and transport of positron beamlets with $$ positrons, 5% bandwidth around 600 MeV, femtosecond duration, and micron-scale emittance.
• PIC simulations confirmed the feasibility of guiding and accelerating these positrons in a laser-driven PWFA.

Conclusions:

• The developed laser-driven positron source meets the quality requirements for plasma accelerator injection.
• This work paves the way for experimental investigations into positron acceleration using PWFA.
• Favorable scaling with PW-scale lasers suggests potential for significant charge and energy increases.