Time-resolved RIXS experiment with pulse-by-pulse parallel readout data collection using X-ray free electron laser

H Lu; A Gauthier; M Hepting; A S Tremsin; A H Reid; P S Kirchmann; Z X Shen; T P Devereaux; Y C Shao; X Feng; G Coslovich; Z Hussain; G L Dakovski; Y D Chuang; W S Lee

doi:10.1038/s41598-020-79210-4

Time-resolved RIXS experiment with pulse-by-pulse parallel readout data collection using X-ray free electron laser

Sci Rep. 2020 Dec 17;10(1):22226. doi: 10.1038/s41598-020-79210-4.

Authors

H Lu¹, A Gauthier¹, M Hepting¹, A S Tremsin², A H Reid³, P S Kirchmann^{1

4}, Z X Shen^{1

4}, T P Devereaux^{1

4

5}, Y C Shao⁶, X Feng⁶, G Coslovich³, Z Hussain⁶, G L Dakovski³, Y D Chuang⁶, W S Lee⁷

Affiliations

¹ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Stanford University, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.
² Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, 94720, USA.
³ Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.
⁴ Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA, 94305, USA.
⁵ Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA.
⁶ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
⁷ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Stanford University, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA. leews@stanford.edu.

Abstract

Time-resolved resonant inelastic X-ray scattering (RIXS) is one of the developing techniques enabled by the advent of X-ray free electron laser (FEL). It is important to evaluate how the FEL jitter, which is inherent in the self-amplified spontaneous emission process, influences the RIXS measurement. Here, we use a microchannel plate (MCP) based Timepix soft X-ray detector to conduct a time-resolved RIXS measurement at the Ti L₃-edge on a charge-density-wave material TiSe₂. The fast parallel Timepix readout and single photon sensitivity enable pulse-by-pulse data acquisition and analysis. Due to the FEL jitter, low detection efficiency of spectrometer, and low quantum yield of RIXS process, we find that less than 2% of the X-ray FEL pulses produce signals, preventing acquiring sufficient data statistics while maintaining temporal and energy resolution in this measurement. These limitations can be mitigated by using future X-ray FELs with high repetition rates, approaching MHz such as the European XFEL in Germany and LCLS-II in the USA, as well as by utilizing advanced detectors, such as the prototype used in this study.

Grants and funding

DE-AC02-76SF00515/U.S. Department of Energy (DOE)