Acknowledgments

This work was supported by the Office of Nonproliferation Research and Engineering, Chemical and Biological National Security Program (CBNP), of the National Nuclear Security Administration (NNSA) under U.S. Department of Energy Contract No. DE-AC03-76SF00098.

More information on DOE-sponsored security research can be found at http://www.energy.gov/security.

Additional research that contributed to the web site was performed at the University of California, Berkeley, Department of Civil and Environmental Engineering.