Enhanced coherent Thomson scattering in the few-cycle regime

Area of Science:

• Physics
• Quantum Optics
• Plasma Physics

Background:

• Coherent nonlinear Thomson scattering is a key mechanism for X-ray generation.
• The interaction of intense laser pulses with relativistic electron sheets is crucial for advanced X-ray sources.
• Understanding pulse duration effects is vital for optimizing scattering efficiency.

Purpose of the Study:

• To investigate X-ray production via coherent nonlinear Thomson scattering using few-cycle laser pulses.
• To determine the impact of single-cycle laser pulses on scattering efficiency compared to longer pulses.
• To explore the underlying physics responsible for enhanced X-ray generation.

Main Methods:

• Theoretical calculation of X-ray amplitude in the nonadiabatic regime.
• Numerical simulations using particle-in-cell (PIC) methods.
• Analysis of scattering efficiency for varying laser pulse durations.

Main Results:

• A two-orders-of-magnitude increase in scattering efficiency was observed for single-cycle laser pulses with electron sheets thicker than the X-ray wavelength.
• Suppression of destructive interference and frequency downshift from ultrabroad spectra of single-cycle pulses contribute to the enhancement.
• Calculated X-ray amplitude agrees with PIC simulation results.

Conclusions:

• Single-cycle laser pulses significantly enhance X-ray production efficiency in coherent nonlinear Thomson scattering.
• The findings provide a pathway for designing more intense and shorter attosecond X-ray sources.
• This research opens new possibilities for applications requiring high-brightness, short-wavelength radiation.