Stable Operation of a Free-Electron Laser Driven by a Plasma Accelerator

Area of Science:

• Plasma Physics
• Accelerator Science
• Laser Science

Background:

• Plasma-based accelerators achieve high accelerating fields, enabling compact electron beam generation.
• Free-electron lasers (FELs) can be realized using these compact electron beams.
• Existing self-amplified spontaneous emission (SASE) FELs lack stability and reproducibility.

Purpose of the Study:

• To demonstrate a proof-of-principle for generating stable and reproducible FEL light using plasma-accelerated electron beams.
• To overcome the limitations of SASE FELs for practical user applications.

Main Methods:

• Utilized plasma-accelerated electron beams.
• Employed an external laser to seed the free-electron laser process.
• Measured infrared FEL radiation emitted over six consecutive undulators.

Main Results:

• Successfully generated stable and reproducible FEL light.
• Observed typical exponential energy growth of the FEL radiation.
• Seeded FEL pulses exhibited energies 2 orders of magnitude higher and 3 times greater stability compared to SASE.

Conclusions:

• Plasma-accelerated beams can be used to create seeded FELs with enhanced stability and reproducibility.
• This approach offers a promising alternative to SASE FELs for user-oriented light sources.
• The demonstrated technique paves the way for more reliable and powerful compact light sources.