Discoveries: Science of Signatures

Signatures found in raw signals and downstream data are key to useful knowledge.

Signatures are the unique elements that allow us to locate threats within their environments and describe them – for example, the pattern variation that lets us distinguish spinach from poison ivy.

Los Alamos scientific leadership in signatures extends from nuclear and radiological to chemical and materials, biological, energy, earth systems, and space signatures. Our scientific strategy is to discover new signatures, revolutionize the measurement of signatures, and engineer and deploy advanced signature-related technologies from the lab to the field.

Biomedical Isotopes

Both stable and radioactive isotopes, produced and isolated at Los Alamos, benefit biomedical research and medical procedures.

Since the Lab’s inception, the science of isotopes (atoms with the same number of protons but different numbers of neutrons) has been core to our mission. We apply both stable and radioactive isotopes to a range of biomedical science. The large-scale isolation of stable isotopes of oxygen, carbon, and nitrogen required distillation columns up to 700 feet high. The isotopes enabled techniques like nuclear magnetic resonance (NMR) to map out biological molecules, and frontier research like pharmacokinetics, tracking the speed of interactions between medicines and the body. Short-lived radioactive isotopes are used for medical imaging and therapy. For example, strontium-82, used for cardiac imaging, was delivered from Los Alamos Neutron Science Center starting in the 1970s. Strontium-82 production has successfully been transferred to industry, while the Lab has shifted focus to a new suite of radioisotopes for medical imaging and treatment for a broad spectrum of diseases.  

Contributing authors

Kevin John and Jill Trewhella

References

Los Alamos was a major supplier of Strontium-82 for years:

1. Production of strontium-82 for the Cardiogen® PET generator: A project of the Department of Energy Virtual Isotope Center, Phillips, Dennis, E. J. Peterson, Wayne Taylor, et al. Radiochimica Acta 88 (2000): 149–155.

Dynamic Imaging

High speed photography and x-ray and proton radiography are essential to looking deep into weapons-relevant systems. These tools, invented at Los Alamos, include LANSCE/prad and DARHT. 

Summary

High-speed photography and radiography are essential to certifying the stockpile without nuclear testing. These imaging tools were pioneered during the Manhattan Project, for example, rotating mirror cameras. Flash radiography matured with the 1963 PHERMEX accelerator, measuring high-explosive equations of state, terminal ballistics, and weapon-related experiments. Ultimately, PHERMEX was replaced with DARHT and the underground CYGNUS facility.  

Proton radiography (pRad) at LANSCE uses the unique properties of high-energy protons to look into objects too dense for gamma-rays to penetrate. Solid-state, high-speed cameras, including the R&D 100 award-winning “Camera On A Chip” (2007), made x-ray film obsolete.

Modern detectors collect up to 20 million frames per second, and are large enough to collect data on full-sized (mock) assemblies using large, segmented scintillators. The billion-dollar Scorpius facility is scheduled to augment DARHT and CYGNUS (2030) by combining their unique capabilities in one underground location.  

Contributing author

Scott Watson 

References

Flash radiography as applied to DARHT. The detector technology associated with flash radiography has advanced well beyond x-ray film.  Modern detectors capture millions of frames per second with remarkable efficiency and image quality.

1. The DARHT Camera, Watson, S. A., Los Alamos Science, 28 (2003): 92–95.

The science of flash radiography originated with the Manhattan Project.  Significant advances like Prad, Cygnus, DARHT and Scorpious continue to this day.

2. The Development of Flash Radiography. Cunningham, G. S., C. and Morris. Los Alamos Science, 28 (2003): 76–91.

PHERMEX was the world’s first major, purpose-built, flash radiographic facility (see photo) and included many unique technological advances including the world’s largest RF cavities.

3. Phermex: A Pulsed High-Energy Radiographic Machine Emitting X-Rays. Venable, Douglas, D. O.Dickman, J. N. Hardwick, et al. “” Los Alamos Scientific Laboratory report LA-3241 (1967).

Proton Radiography is a relatively new imaging concept first pioneered by Los Alamos Nobel Laureate Louis Alvarez.  Because it utilizes charged particles, instead of photons, Prad’s characteristics are distinct from, and often complementary to Roentgen’s x-ray radiography.

4. The Proton Radiography Concept. Ziock, H.-J., K. J. Adams, K. R. Alrick, et al. Los Alamos National Laboratory report LA-UR-98-1368 (1998).

Quantum Information

Los Alamos leads the way in understanding our quantum world, opening the door to quantum applications for computing and security. 

Summary

Nature at the smallest scales is dominated by quantum effects. Although quantum mechanics is over a century old, its foundations are still not settled, and quantum applications are just at the threshold of changing the world. Los Alamos has led the way in quantum science and applications. LANL scientists developed theories of quantum mechanical decoherence that explained how interactions between a quantum system and its environment can rapidly destroy its quantum properties. Los Alamos research then opened the door to quantum computing with theoretical and experimental demonstrations of quantum error correction, showing that the inevitable errors occurring in quantum computers can be overcome. LANL’s pioneering theoretical scheme for efficient optical quantum computation is one of today’s most promising approaches to useful quantum computation. Finally, LANL physicists demonstrated that quantum cryptographic systems were practical, leading to programs that address the security needs of several federal agencies, such as securing power grids.

Contributing author

Malcolm Boshier 

References

The emerging understanding of quantum mechanical decoherence was reported in:

• Decoherence and the Transition From Quantum To Classical. Zurek, W. H.  Physics Today 44 (1991): 36.
• Decoherence, Einselection, and the Quantum Origins of the Classical. Zurek, W. H. Review of Modern Physics 75 (2003): 715

Quantum computing with linear optics was reported in:

• A Scheme for Efficient Quantum Computation with Linear Optics. Knill, E.,  R. Laflamme, and G. J. Milburn. Nature 409 (2001): 46.

Quantum error correction was reported in:

• Theory of Quantum Error-correcting Codes. Knill, E., and R. Laflammee. Physical Review A 55 (1997): 900.

Long-range quantum cryptography was reported in:

• Practical Free-space Quantum Key Distribution Over 10 km in Daylight and at Night. Hughes, R. J., J. E.  Nordholt, D. Derkacs, and C. G. Peterson. New Journal of Physics 4 (2002): 43.
• Several aspects of quantum information, including decoherence, error correction, and quantum key distribution are discussed in a special issue of Los Alamos Science  (No. 27, 2002) entitled  “Information, Science, and Technology in a Quantum World”, Los Alamos Science, available at Los Alamos Science | Research Library (lanl.gov).