• Ash, R.; Abhari, Z.; Candela, R.; Welke, N.; Murawski, J.; Gardezi, S.M.; Venkatasubramanian, N.; Munawar, M.; Siewert, F.; Sokolov, A.; LaDuca, Z.; Kawasaki, J.; Bergmann, U.: X-FAST: A versatile, high-throughput, and user-friendly XUV femtosecond absorption spectroscopy tabletop instrument. Review of Scientific Instruments 94 (2023), p. 073004/1-10

Open Access Version  (available 01.07.2024)

We present the X-FAST (XUV Femtosecond Absorption Spectroscopy Tabletop) instrument at the University of Wisconsin-Madison. The instrument produces femtosecond extreme ultraviolet photon pulses via high-harmonic generation in the range of 40–72 eV, as well as optical pump pulses for transient-absorption experiments. The system implements a gas-cooled sample cell that enables studying the dynamics of thermally sensitive thin-film samples. This paper provides potential users with specifications of the optical, vacuum, data acquisition, and sample cooling systems of the X-FAST instrument, along with performance metrics and data of an ultrafast laser-induced phase transition in a Ni2MnGa Heusler thin film.