1. Department of Physics, Stanford University, Stanford, California 94305, USA
2. SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
3. Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
4. Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
5. Department of Applied Physics, Stanford University, Stanford, California 94305, USA