Kyle Jensen will present his defense topic, “Novel Laser-Driven Electron Acceleration and Next-Generation Light Sources” via Zoom.

Abstract: Laser-plasma accelerators (LPAs) provide a small-scale alternative to costly, kilometer-scale conventional accelerator facilities. Capable of sustaining orders of magnitude higher accelerating gradients compared to conventional radio-frequency accelerators, high-quality electron bunches can be accelerated to relativistic energies over millimeter-scale interactions. Due to their intrinsic ultrashort properties and temporal synchronization to the driver laser, LPA electron bunches are of particular interest in the development of novel high-brightness and tunable secondary light sources. Maturation of laser-driven X-ray sources, namely betatron sources, has led to applications across various domains, including spectroscopy, high-resolution imaging, and studies of ultra-fast dynamics. While LPAs make large steps towards improving the scalability and accessibility of particle acceleration as opposed to conventional accelerators, the state-of-the-art electron acceleration and secondary radiation schemes impose strict requirements on viable high-power laser technologies that, in turn, limit scalability to high-repetition rate operation and accessibility to the broader scientific community. The work presented in this thesis aims to address these limitations through studies of existing electron acceleration mechanisms, development of a novel electron acceleration mechanism, and enhancement of a high-brightness betatron radiation source.
??????Enhanced laser-driven betatron radiation is demonstrated through manipulation of the betatron oscillation amplitude and electron injection process. Using a tailored plasma density profile, typically complex and coupled processes regarding laser evolution, electron injection, and radiation generation are largely decoupled. This allows for a high-degree of optimization and tunability of the X-ray source and spectral characteristics. To accompany development of the radiation source, studies of existing spectral reconstruction methods from differential filter arrays and the development of a novel method with improved numerical stability are discussed.
??????A study of established electron injection mechanisms is discussed which provides insight into chromatic correlations of electron bunch source properties and propagation through an advanced charge beam transport line to a high-brightness focus. Insight of the study benefits the pursuit of electron beam coupling to small-apertured accelerating or radiating structures.
??????Development of a novel electron acceleration mechanism is discussed. This highly promising mechanism leverages the stimulated Raman scattering plasma instability at the quarter-critical plasma density for highly efficient generation of high-brightness electron beams while significantly relaxing the requirements of the driving laser system.