Speaker
Description
Controlling the longitudinal phase space of high-brightness relativistic electron beams is crucial for advanced accelerator concepts. A key method for this involves manipulating the photoemission laser’s temporal distribution, though picosecond-level precision remains challenging. In this work, we demonstrate that applying a controlled longitudinal ramp to a flattop laser distribution can counteract accelerator-induced distortions. Implemented at the LCLS-II superconducting injector via spatiotemporal shaping of the UV photocathode laser, this technique provides deterministic control over the longitudinal electron phase space. We show that this optical asymmetry pre-compensates for downstream resistive wall wakefields in the ~80 pC charge regime. This approach linearizes the phase space and suppresses nonlinear energy chirp while preserving resonable emittance. Our results highlight spatiotemporal laser shaping as a robust, generalizable strategy for mitigating collective effects and directly optimizing beam brightness at the source for next-generation accelerators.
Zhou et al., PRAB 24, 073401 (2021)
**Hirschman et al., arXiv:2603.15996 (2026)
Zhang et al., arXiv:2601.03580 (2026)
****Lemons et al., Ultrafast Sci. 5, 0112 (2025)
Funding:
Work supported by DOE BES under DE-AC02-76SF00515, DE-SC0022559, DE-FOA-0002859, DE-FG02-86ER13491; NSF 2231334, 2431903, 2436343; AFOSR FA9550-23-1-0409.
| Working group | WG5 |
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