ABSTRACTS

Concepts for Realizing a Storage Ring Free Electron Laser Oscillator at the APS-U
Emmanuel Aneke, ASD

Storage Ring Free Electron Lasers (SRFELs) represent a promising next step in the evolution of radiation sources. By combining the continuous stable beam structure and multiple simultaneous experiment capabilities of storage rings with the coherent and high-brightness output of Free Electron Lasers (FELs), the best of both worlds can be imagined. Historically, SRFELs started in the visible wavelength regime in the 1980s at Orsay, progressing into the ultraviolet regime in the 1990s and early 2000s with notable results from Duke University and elsewhere. The subsequent advent of linac-driven X-ray FELs (e.g., FLASH, LCLS), along with the recent emergence of fourth-generation diffraction-limited storage rings (e.g., APS-U, ESRF-EBS, PETRA IV) has rekindled the potential for realizing SRFELs in the X-ray and extreme ultraviolet regimes. Leveraging the APS-U’s recently achieved ultralow emittance, this talk outlines emergent simulation efforts using the ELEGANT and GENESIS codes, combined with a custom optical cavity model, to evaluate SRFEL oscillator feasibility. Preliminary results utilizing PETRA IV parameters are presented, demonstrating initial progress toward addressing key challenges, including energy spread compensation via transverse gradient undulators and robust cavity design. This work sets the stage for further detailed studies and lays a practical foundation for future experimental endeavors at APS-U or elsewhere.

Single-shot Longitudinal Phase-Space Measurements of Photo-Cathode Beam
Timothy Suzuki, ASD

Advancements in particle accelerator technology hinge on our ability to precisely measure and understand the behavior of high-charge particle beams. In our latest work, we have identified the imaging capabilities at the LTP:FL1 fluorescent screen by measuring an optical resolution of approximately 200 μm. This measurement was realized by analyzing images from the LTP:FL1 screen downstream of the transverse cavity (Tcav) and the LTP:B1 spectrometer magnet and utilizing beams from our thermionic-cathode gun (TCG). Using photo-cathode gun (PCG) beam, we expect a longitudinal bunch length of approximately 70 μm. A heightened resolution is necessary for more accurate characterization of the longitudinal phase-space of beams produced by the PCG. Thus, we outline the physics requirements that inform the design of the LTP:FL1 imaging system. Our work contributes to the development of more precise diagnostic tools, facilitating breakthroughs in particle physics research.