Success in our mission requires breakthroughs in underlying science and technology. Livermore scientists and engineers continually “dig deeper” to understand complex physical phenomena. Progress relies on interweaving new theoretical ideas with results from high-fidelity computer simulations and data from experiments. To keep up with the tremendous progress being made in scientific and engineering simulations, we need measurements at much higher resolution and greater sophistication to provide data for our models and to validate that they accurately simulate reality.
This issue of Science & Technology Review features four wide-ranging examples of experimental activities at the Laboratory. The stories highlight efforts largely directed at developing innovative new ways to collect data that are important to our missions and that help advance scientific knowledge.
The feature story A Bright Idea for Microscopy describes improvements made to the dynamic transmission electron microscope (DTEM). Livermore scientists began developing this technology about a decade ago as a means to take snapshots of dynamic processes on the scale of nanometers and nanoseconds. DTEM uses a short burst of electrons rather than light rays in the microscope. The data recorded show either the diffraction pattern or real-space image made by the scattered electrons as they pass through the thin target sample being viewed. DTEM, which received an R&D 100 Award in 2008, has been used for a wide range of applications in support of Laboratory missions, providing insights into material deformation, phase transitions, nucleation, and growth. DTEM studies have also revealed the activity of catalysts and radiation effects in biology.
Laboratory scientists have now developed movie-mode DTEM (MM-DTEM) to record multiple frames of dynamic processes in action rather than a single shot in time. An R&D 100 Award winner in 2013, MM-DTEM fires up to nine pulses of electrons to sequentially capture fast, irreversible changes in materials at the nanometer scale. Early applications of the technology are described in the feature article, and the possibilities seem limitless. Livermore has partnered with Integrated Dynamic Electron Solutions to make the technology broadly available to the scientific community.
The highlight Trapped Ions Reveal the Undetected: A New Approach for Nuclear Decay Science describes a novel approach we have developed to study radioactive decay processes, which are important to numerous Laboratory mission areas. Many nuclear decay mechanisms are poorly characterized because some of their reaction products are difficult to track. Rather than deploying large, expensive detectors to hunt for missing particles, our tabletop device “traps” the unstable nuclei under study and uses small-scale detectors to view the “trackable” particles. Researchers can then apply the principles of energy conservation and momentum to deduce information about the missing particles. The technique, tested in collaboration with colleagues from Argonne National Laboratory, has exciting applications for studying the operation of nuclear power plants, unresolved issues in nuclear weapons stockpile stewardship, and the creation of heavy elements by stars.
Two other highlights describe innovative experimental work that supports our nuclear-nonproliferation mission. NIF Experiments Track Weapons Effects to Improve Nuclear Forensics discusses experiments at the National Ignition Facility that are exploring nuclear-effects-based forensics tools for use in the event a nuclear device were detonated. These experiments replicated the weapons effects of a 2.5-kiloton nuclear explosive at one-billionth of the volume scale. Gravity Detector Applies Outside-the-Box Thinking to Show What’s Inside the Box describes a novel approach to detect heavily shielded nuclear materials in vehicles. Effective shielding requires considerable mass, and the demonstrated concept is to detect the gravitational pull of the very heavy container.
These experimental efforts differ widely in scale, underpinning technologies, and purpose. However, they share common attributes: ingenuity resulting in unique capabilities, focus on important Laboratory missions, and benefits accrued from the many interactions with the broader scientific community and industry. Livermore’s mission-focused research—from basic science to engineering prototype development—and a multidisciplinary approach to problem solving make all of these successes possible.