1. Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
2. Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
3. Biophysics Program, Stanford University School of Medicine, Stanford, California 94305, USA
4. Stanford Synchrotron Radiation Lightsource (SSRL), SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA