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Ghost Imaging Approach to Photon Energy Resolved Velocity Map Imaging

POSTER

Abstract

Correlating measurements of x-ray observables with properties of the incident beam is a powerful approach to improving measurements with noisy x-ray free electron laser (XFEL) sources. In particular, spectral-domain ghost imaging techniques can facilitate sub-bandwidth resolution in spectroscopic measurements at XFELs, greatly enhancing the scope of time-resolved x-ray absorption and photoelectron studies. Time-resolved experiments using velocity map imaging (VMI) spectrometers also face the limitation of broad bandwidth fundamentally linked to the requisite time-resolution. Here we present a novel approach that combines photon spectrum correlation analysis with the reconstruction of three-dimensional momentum distribution from velocity map images in an efficient, single-step procedure. We demonstrate its efficacy with results on the photoelectron spectra of Argon (Ar 2p) and CS$_{2}$ (S 2p) using the CAMP VMI spectrometer at beamline BL1 of the free-electron laser FLASH. Distinct features are observed despite having splittings that are exceeded by the average bandwidth of the ionizing XFEL pulses. As high-resolution photoelectron spectrum is informative about local chemical environment, our approach can be a powerful tool for studying dynamics in molecular systems.

Presenters

  • Jun Wang

    LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, USA, Department of Applied Physics, Stanford University; Stanford PULSE Institute, SLAC National Lab

Authors

  • Jun Wang

    LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, USA, Department of Applied Physics, Stanford University; Stanford PULSE Institute, SLAC National Lab

  • Taran Driver

    SLAC, SLAC - Natl Accelerator Lab, LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, USA, Stanford PULSE Institute, SLAC National Lab; LCLS, SLAC National Lab, PULSE Institute, SLAC National Accelerator Laboratory

  • Felix Allum

    Stanford Univ, SLAC National Accelerator Laboratory, Stanford University, Stanford PULSE Institute, SLAC National Lab; LCLS, SLAC National Lab

  • Christopher Passow

    Deutsches Elektronen-Synchrotron DESY

  • Christina Papadopoulou

    Deutsches Elektronen-Synchrotron DESY

  • Günter Brenner

    Deutsches Elektronen-Synchrotron DESY

  • Siqi Li

    LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, USA, Stanford PULSE Institute, SLAC National Lab; LCLS, SLAC National Lab, PULSE Insitute, SLAC National Accelerator Laboratory

  • Stefan Düsterer

    Deutsches Elektronen-Synchrotron DESY

  • Atia Tul Noor

    Deutsches Elektronen-Synchrotron DESY

  • Sonu Kumar

    Deutsches Elektronen-Synchrotron DESY

  • Philip H Bucksbaum

    Stanford Univ, Department of Applied Physics, Stanford University, Department of Physics, Stanford University; Department of Applied Physics, Stanford University; Stanford PULSE Institute, SLAC National Lab, Stanford University

  • Benjamin Erk

    DESY, Deutsches Elektronen-Synchrotron DESY

  • James P Cryan

    SLAC National Lab, LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, USA, Stanford PULSE Institute, SLAC National Lab; LCLS, SLAC National Lab, SLAC National Accelerator Laboratory

  • Ruaridh Forbes

    SLAC - Natl Accelerator Lab, Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford PULSE Institute, SLAC National Lab; LCLS, SLAC National Lab; Department of Physics, Stanford University, SLAC National Accelerator Laboratory