By Joseph Yoniles, Jacob A. Summers, Kara Zielinski1, Cali Antolini, Mayura Panjalingam, Stella Lisova, Frank R. Moss, Maximus Aldo Di Perna, Christopher Kupitz2, Mark S. Hunter2, Lois Pollack3, Soichi Wakatsuki, Peter D. Dahlberg
1. Center for Free-Electron Laser Science 2. SLAC National Accelerator Laboratory 3. Cornell University