title: Demonstration of a time-resolved x-ray scattering instrument utilizing the full-repetition rate of x-ray pulses at the Pohang Light Source.
abstract: We report on the development of a new experimental instrument for time-resolved x-ray scattering (TRXS) at the Pohang Light Source (PLS-II). It operates with a photon energy ranging from 5 to 18 keV. It is equipped with an amplified Ti:sappahire femtosecond laser, optical diagnostics, and laser beam delivery for pump-probe experiments. A high-speed single-element detector and high trigger-rate oscilloscope are used for rapid data acquisition. While this instrument is capable of measuring sub-nanosecond dynamics using standard laser pump/x-ray probe techniques, it also takes advantage of the dense 500 MHz standard fill pattern in the PLS-II storage ring to efficiently record nano-to-micro-second dynamics simultaneously. We demonstrate this capability by measuring both the (fast) impulsive strain and (slower) thermal recovery dynamics of a crystalline InSb sample following intense ultrafast laser excitation. Exploiting the full repetition rate of the storage ring results in a significant improvement in data collection rates compared to conventional bunch-tagging methods.
authors.affiliation: Frontier in Extreme Physics, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600, South Korea.
authors.forename: Wonhyuk
authors.initials: W
authors.lastname: Jo
authors.affiliation: Pohang Accelerator Laboratory, Pohang 790-784, South Korea.
authors.forename: Intae
authors.initials: I
authors.lastname: Eom
authors.affiliation: Department of Physics, DePaul University, Chicago, Illinois 60614, USA.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Landahl
authors.affiliation: Frontier in Extreme Physics, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600, South Korea.
authors.forename: Sooheyong
authors.initials: S
authors.lastname: Lee
authors.affiliation: Pohang Accelerator Laboratory, Pohang 790-784, South Korea.
authors.forename: Chung-Jong
authors.initials: CJ
authors.lastname: Yu