1. Department
of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States
2. Department
of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065,
United States
3. Department
of Physics, Cornell University, Ithaca, New York 14853, United States
4. Cornell High Energy Synchrotron
Source (CHESS), Cornell University, Ithaca,
New York 14853, United States