The soft x-ray free-electron laser FLASH at DESY: beamlines, diagnostics and end-stations

TLDR

FLASH, the Free‑electron LASer in Hamburg, is a unique worldwide source of extremely bright, ultra‑short laser‑like pulses tunable across the extreme ultraviolet and soft x‑ray spectrum, serving a broad user community from atomic and molecular physics to plasma, solid‑state physics, chemistry, and biology. The paper provides a detailed overview of the FLASH user facility, emphasizing the exploitation of its ultra‑short pulses with pump–probe techniques. The facility features efficient radiation transport, novel online photon diagnostics, and optical and THz sources synchronized to FLASH to enable pump–probe experiments. Citation: Ackermann et al., Nature Photonics 1, 336–342.

Abstract

FLASH, the Free-electron LASer in Hamburg, is a worldwide unique source for extremely bright ultra-short laser-like pulses tunable in a wide spectral range in the extreme ultraviolet and soft x-ray region (Ackermann et al 2007 Nat. Photonics 1 336–42). To fully exploit the features of this new generation of light sources, a user facility with efficient radiation transport to the experimental area and novel online photon diagnostics capable of characterizing the unique parameters of the FLASH radiation has been built. It serves a broad user community active in many scientific fields ranging from atomic and molecular physics to plasma and solid state physics as well as chemistry and biology. A special focus is placed on the exploitation of the ultra-short FLASH pulses using pump–probe techniques. Thus, the facility is equipped with optical and THz sources synchronized to FLASH. This paper gives a detailed overview of the FLASH user facility.