Free-electron lasing at 27 nanometres based on a laser wakefield accelerator

Area of Science:

• Physics
• Accelerator Science
• Photon Science

Background:

• X-ray free-electron lasers (XFELs) provide intense, coherent radiation crucial for structural biology and chemistry.
• Current XFEL facilities rely on large, costly radio-frequency accelerators.
• Compact and economical accelerator options are highly sought after.

Purpose of the Study:

• To demonstrate the feasibility of using laser wakefield accelerators (LWAs) for XFEL applications.
• To overcome the challenge of poor electron beam quality from LWAs for lasing.
• To achieve exponential gain in undulator radiation using LWA-driven electron beams.

Main Methods:

• Experimental setup utilizing three undulators.
• Generation of electron beams via laser wakefield acceleration.
• Measurement of amplified undulator radiation characteristics.

Main Results:

• Successful experimental demonstration of undulator radiation amplification in the exponential-gain regime.
• Achieved peak radiation energy of approximately 150 nanojoules at 27 nm.
• Observed a 100-fold power gain in the third undulator, confirming lasing.

Conclusions:

• Proof-of-principle for free-electron lasing using laser wakefield accelerators.
• Paves the way for developing compact and economical XFELs.
• Broadens potential applications of XFEL technology through miniaturization.