Powerful diagnostic and imaging accelerators at LLNL enable scientists to produce and detect isotopes, explore nuclear reactions, evaluate unknown material, and peer inside heavily shielded objects.
Using accelerators to understand the universe
Accelerators use electromagnetic fields to propel charged particles, such as protons or electrons, at high speeds into a target or against other particles. We study the resulting collisions to increase our understanding of matter and the origins of the Universe.
LLNL’s accelerators enable us to expand our research capabilities and support emerging programmatic needs through a series of powerful and complementary beam capabilities.
Peering inside shielded material with neutron imaging
LLNL’s accelerator-driven neutron imaging capability is far smaller and less complicated than existing neutron imaging tools at other facilities.
This more compact technology, where neutrons are made through deuteron bombardment, allows us to advance imaging science and support mission-relevant research at LLNL. With its ability to penetrate thick, dense objects and produce radiographic images of interior features, neutron imaging has the potential to revolutionize stockpile stewardship. And as a next-generation radiographic technique, it also can be used for non-destructive evaluation of large, additively manufactured components.
We anticipate that our neutron source will enable research advancements in nuclear cross-section measurements, material assay via gamma-ray spectroscopy, and experiments aimed at understanding the effects of radiation on materials and component performance.
Expanding photonuclear experimental capabilities
We leverage LLNL’s newest electron linear accelerator to study the photonuclear properties of materials. This powerful tool, known as the Photonuclear Reactions for Isotopic Signature Measurements (PRISM) accelerator, propels electrons into a tungsten plate to generate high-energy x rays, which then interact with the nuclei of interest. Radiation detectors measure the particles generated in the reaction.
PRISM can accelerate electrons up to 55 million electron-volts, but it can also be tuned to low-electron energy to study radiation effects, support radiochemistry research, or better understand medical isotope production. We can scan a range of energies to determine photonuclear cross sections, allowing the inference of neutron reactions on unstable nuclei.
We are expanding the breadth of experimental work enabled by photonuclear measurement capabilities. For example, we recently demonstrated the ability to distinguish different isotopes of uranium using delayed-neutron signatures. Future applications include interrogating unknown materials, producing isotopes, and analyzing the nuclear properties of materials, including experiments that will support LLNL’s stockpile stewardship and nonproliferation missions.
MEGa-ray: A versatile imaging tool
LLNL’s mono-energetic gamma-ray (MEGa-ray) test station produces electron bunches that collide head-on with laser photons to generate a powerful and versatile beam. The collision shifts photons from visible light to mono-energetic x rays via Compton scattering.
We can tune or adjust Laser-Compton photons to different wavelengths, enabling us to detect, image, and assay specific objects of interest, such as nuclear waste canisters, nuclear fuel rods, and other objects that might house uranium or plutonium.