Few-cycle pulse generation in an x-ray free-electron laser

Area of Science:

• Physics
• Quantum Mechanics
• Laser Science

Background:

• Free-electron lasers (FELs) are powerful tools for generating coherent radiation.
• Current FEL technology has limitations in producing ultra-short pulse durations.
• Investigating methods to shorten pulse durations is crucial for advanced scientific research.

Purpose of the Study:

• To propose and simulate a novel method for generating few-cycle x-ray pulses.
• To achieve pulse durations significantly shorter than current FEL capabilities.
• To enhance research opportunities in ultrafast atomic and nuclear dynamics.

Main Methods:

• Utilizing a compact
• afterburner
• extension with multiple undulator sections and chicane delays.
• Employing advanced simulations to model the generation of few-cycle x-ray pulses.
• Operating within the hard x-ray regime (wavelength ~0.1 nm, photon energy ~10 keV).

Main Results:

• Achieved root mean square pulse durations of approximately 700 zeptoseconds (zs).
• Obtained peak powers approaching gigawatt (GW) levels, near FEL saturation.
• Demonstrated a discretely multichromatic spectrum with a bandwidth envelope increased by two orders of magnitude compared to unseeded FELs.

Conclusions:

• The proposed afterburner method enables the generation of unprecedentedly short x-ray pulses.
• This advancement significantly expands research capabilities in ultrafast atomic and nuclear dynamics.
• The technique offers a pathway to push the boundaries of scientific exploration in attosecond science.