High spatial coherence and short pulse duration revealed by the Hanbury Brown and Twiss interferometry at the European XFEL

Ruslan Khubbutdinov; Natalia Gerasimova; Giuseppe Mercurio; Dameli Assalauova; Jerome Carnis; Luca Gelisio; Loïc Le Guyader; Alexandr Ignatenko; Young Yong Kim; Benjamin E Van Kuiken; Ruslan P Kurta; Dmitry Lapkin; Martin Teichmann; Alexander Yaroslavtsev; Oleg Gorobtsov; Alexey P Menushenkov; Matthias Scholz; Andreas Scherz; Ivan A Vartanyants

doi:10.1063/4.0000127

High spatial coherence and short pulse duration revealed by the Hanbury Brown and Twiss interferometry at the European XFEL

Struct Dyn. 2021 Aug 23;8(4):044305. doi: 10.1063/4.0000127. eCollection 2021 Jul.

Authors

Ruslan Khubbutdinov, Natalia Gerasimova¹, Giuseppe Mercurio¹, Dameli Assalauova², Jerome Carnis², Luca Gelisio³, Loïc Le Guyader¹, Alexandr Ignatenko², Young Yong Kim², Benjamin E Van Kuiken¹, Ruslan P Kurta¹, Dmitry Lapkin², Martin Teichmann¹, Alexander Yaroslavtsev¹, Oleg Gorobtsov⁴, Alexey P Menushenkov⁵, Matthias Scholz², Andreas Scherz¹, Ivan A Vartanyants

Affiliations

¹ European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany.
² Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg, Germany.
³ Center for Free-Electron Laser Science, DESY, Luruper Chaussee 149, D-22761 Hamburg, Germany.
⁴ Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14850, USA.
⁵ National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe shosse 31, 115409 Moscow, Russia.

Abstract

Second-order intensity interferometry was employed to study the spatial and temporal properties of the European X-ray Free-Electron Laser (EuXFEL). Measurements were performed at the soft x-ray Self-Amplified Spontaneous Emission (SASE3) undulator beamline at a photon energy of 1.2 keV in the Self-Amplified Spontaneous Emission (SASE) mode. Two high-power regimes of the SASE3 undulator settings, i.e., linear and quadratic undulator tapering at saturation, were studied in detail and compared with the linear gain regime. The statistical analysis showed an exceptionally high degree of spatial coherence up to 90% for the linear undulator tapering. Analysis of the measured data in spectral and spatial domains provided an average pulse duration of about 10 fs in our measurements. The obtained results will be valuable for the experiments requiring and exploiting short pulse duration and utilizing high coherence properties of the EuXFEL.