Author Affiliations

L. Fang,^1,* M. Hoener,¹ M. Guehr,² C. Blaga,³ C. Bostedt,⁴ J. D. Bozek,⁴ P. Bucksbaum,² C. Buth,^5,2 R. Coffee,⁴ J. Cryan,² L. DiMauro,³ O. Gessner,⁶ J. Glownia,² E. Hosler,⁶ E. P. Kanter,⁷ O. Kornilov,⁶ E. Kukk,⁸ B. K. McFarlan,² B. Murphy,¹ S. T. Pratt,⁷ D. Rolles,⁹ and N. Berrah¹

¹Department of Physics, Western Michigan University, Kalamazoo, MI 49008

²PULSE Institute, SLAC, Menlo Park, CA 94025 USA

³Department of Physics, The Ohio State University, Columbus, OH 43210 USA

⁴LCLS, Menlo Park, CA, 94025 USA

⁵Louisiana State University, Baton Rouge, LA 70803 USA

⁶Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA

⁷Argonne National Laboratory, Argonne, IL 60439 USA

⁸Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland

⁹Max Planck ASG, CFEL, 22761 Hamburg, Germany

^*Corresponding author: lifang@slac.stanford.edu