Speaker
Description
In the last years, the visualization of structural dynamics, which take place on time scales as short as few femtoseconds has been complemented by pump-probe techniques that employ relativistic electrons as probes, e.g. ultrafast electron diffraction (UED). These applications demand not only extreme beam quality in 6‑D phase space such as few nanometer transverse emittances and femtosecond bunch lengths, but also equivalent beam stability. Although these utmost requirements have been demonstrated by a compact setup with a high‑gradient electron gun with state‑of‑the‑art laser technologies, this approach is fundamentally restricted by its nature for compressing the electron bunches in a short distance by a ballistic bunching method while also suppressing the time-of-flight jitter of the electrons. Here, we propose a new methodology that pushes the limit of timing jitter and bunch compression simultaneously beyond the state‑of‑the‑art by utilizing consecutive RF cavities. This accelerator layout already exists for energy recovery linear accelerator demonstrators such as SEALAB in Helmholtz-Zentrum Berlin. Furthermore, the superconducting nature of the RF cavities in the beam-line is capable of providing MHz repetition rates, which are out of reach for most conventional high‑gradient electron guns. Hence, the proposed accelerator layout offers a new scientific case for similar ERL demonstrators without significant modifications, while providing enhanced signal to noise performance when compared to other purpose-built UED accelerators.
