Stable femtosecond X-rays with tunable polarization from a laser-driven accelerator

Area of Science:

• Physics
• Laser-driven particle acceleration
• X-ray generation

Background:

• High-peak-power lasers enable compact, intense radiation sources.
• Laser wakefield acceleration produces X-rays via electron oscillation (betatron radiation).
• Existing betatron sources suffer from poor control and stability, limiting applications.

Purpose of the Study:

• To demonstrate reliable production of X-ray beams with tunable polarization.
• To improve the control and stability of betatron X-ray sources.

Main Methods:

• Utilizing ionization-induced injection in a gas mixture to control electron orbits.
• Employing high-peak-power lasers to drive electron acceleration and X-ray emission.

Main Results:

• Achieved reproducible electron orbits, leading to reduced signal and beam profile fluctuations.
• Demonstrated significantly improved beam pointing stability (variation < 1/10th of divergence).
• Obtained X-ray beams with a polarization ratio up to 80%, with easily rotatable polarization axis.

Conclusions:

• Reliable and controllable production of polarized X-ray beams from laser-driven betatron sources is now possible.
• Enhanced stability and tunable polarization open new avenues for innovative applications.
• This advancement promises broad impact across various scientific and technological fields.