Generation of 9 MeV γ-rays by all-laser-driven Compton scattering with second-harmonic laser light

Area of Science:

• High-energy physics
• Laser-driven particle acceleration
• Photonics

Background:

• Inverse Compton scattering (ICS) is a key mechanism for generating high-energy photons.
• Laser-wakefield acceleration (LWFA) provides relativistic electron beams for ICS.
• Optimizing laser parameters is crucial for efficient ICS photon production.

Purpose of the Study:

• To develop a novel laser system for independently optimizing two laser pulses for ICS gamma-ray generation.
• To mitigate detrimental effects on electron beam focusing in nonlinear optics.
• To achieve efficient production of gamma-ray photons with energy exceeding 9 MeV.

Main Methods:

• Utilized a single laser system to generate two distinct laser pulses.
• One pulse was used for laser-wakefield acceleration of electrons (~450 MeV).
• The second pulse (3 eV) was inverse Compton scattered off the electron beam to produce gamma rays (>9 MeV).
• Independently optimized optical properties of both laser pulses.
• Mitigated nonlinear optical effects impacting beam focusing.

Main Results:

• Successfully produced gamma-ray photons with energies greater than 9 MeV.
• Demonstrated independent optimization of laser pulses for electron acceleration and scattering.
• Minimized deleterious effects on electron beam focusing associated with high-peak-power nonlinear optics.
• Achieved efficient gamma-ray generation through optimized ICS.

Conclusions:

• A novel, dual-pulse laser system enables independent optimization for enhanced gamma-ray production via ICS.
• This approach improves control over the ICS process and mitigates beam degradation.
• The developed method offers a pathway for efficient generation of high-energy photons for scientific applications.