Speaker
Description
Laser-wakefield acceleration (LWFA) occurs when an intense laser pulse drives a high-amplitude plasma wave in under dense plasma, trapping and accelerating electron bunches to relativistic energies over millimeter to centimeter scales. During the acceleration process, transverse electron oscillations within the plasma wakefield produce high-brightness, ultrashort "betatron" x-rays. The small source size and few femtosecond duration of these x-rays is well-suited for time-resolved imaging and absorption spectroscopy, supporting medical diagnostics, laboratory-scale astrophysics, and the study of microstructural dynamics in advanced materials. However, the practical use of betatron sources as a scalable tool for x-ray probing requires minimization of shot-to-shot fluctuations in x-ray flux and pointing.
This work addresses the critical need to improve source stability and characterization for high-throughput imaging applications. We investigate the impact of spatio-temporal laser parameters, specifically Group Delay Dispersion (GDD), Third Order Dispersion (TOD) and Pulse Front Tilt (PFT) on the LWFA process at the Advanced Laser Light Source (ALLS) in Quebec, Canada. Using the Ti:sapphire laser system at ALLS, delivering 3.2J of energy on target at 2.5Hz repetition rate with a pulse duration of ~20 fs, we demonstrate that a careful management of PFT is essential to mitigate off-axis x-ray beam steering and asymmetric electron injection. With such optimized laser conditions, stable betatron x-ray emission supports high-resolution imaging and tomographic scans.
| Keyword-1 | Laser-plasma interactions |
|---|---|
| Keyword-2 | Betatron x-ray generation |