Abstract
In the past few years, we have been witnessing an increased interest for studying materials properties under non-equilibrium conditions. Several well established spectroscopies for experiments in the energy domain have been successfully adapted to the time domain with sub-picosecond time resolution. Here we show the realization of high resolution resonant inelastic X-ray scattering (RIXS) with a stable ultrashort X-ray source such as an externally seeded free electron laser (FEL). We have designed and constructed a RIXS experimental endstation that allowed us to successfully measure the d-d excitations in KCoF3 single crystals at the cobalt M2,3-edge at FERMI FEL (Elettra-Sincrotrone Trieste, Italy). The FEL-RIXS spectra show an excellent agreement with the ones obtained from the same samples at the MERIXS endstation of the MERLIN beamline at the Advanced Light Source storage ring (Berkeley, USA). We established experimental protocols for performing time resolved RIXS experiments at a FEL source to avoid X ray-induced sample damage, while retaining comparable acquisition time to the synchrotron based measurements. Finally, we measured and modelled the influence of the FEL mixed electromagnetic modes, also present in externally seeded FELs, and the beam transport with ~120 meV experimental resolution achieved in the presented RIXS setup.
Highlights
IntroductionThere is only one publication on FEL-based high resolution RIXS experiment to study the low energy excitations in correlated materials[8]
We have measured for the first time the high resolution EUV RIXS at a seeded FEL on a KCoF3 single crystal
We were able to measure the d-d excitations from KCoF3 using EUV RIXS spectroscopy with ~120 meV resolution in an overall detection time comparable to the synchrotron measurements
Summary
There is only one publication on FEL-based high resolution RIXS experiment to study the low energy excitations in correlated materials[8] This experiment by Rusydi et al was performed at the PG1 beamline of FLASH FEL (DESY, Hamburg), with the typical SASE (self amplified spontaneous emission)-FEL pulses that have an energy bandwidth on the order of 10−1 (ΔE/E). Extended data acquisition times are needed to achieve a suitable signal statistics to analyze RIXS spectra To overcome this problem, an externally seeded FEL, like FERMI (Elettra, Trieste), can be used since it generates quasi-transform limited pulses with stable photon energy and extremely narrow bandwidth (on the order of ~10−3) at pulse-to-pulse intensity fluctuation below 20% rms[10]. The results presented here are important steps on the road towards time-resolved EUV RIXS experiments at seeded FELs with high energy and time resolution
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
