Accelerator science

LLNL’s accelerators are rapidly expanding research capabilities and supporting emerging programmatic needs to produce a series of powerful and complementary beam capabilities. These tools include a deuteron-ion accelerator for neutron imaging, a 55 MeV electron linear accelerator used to study photonuclear reactions, and a mono-energetic gamma-ray test station for developing high-brightness, narrow-band, visible and x-ray beams using Compton scattering.

Learn more about our accelerator science research.

High-energy physics

The discovery of the Higgs boson particle answered a major question of the Standard Model of particle physics: the mechanism for electroweak symmetry breaking. However, there are still many outstanding questions about the structure of the Standard Model itself, as well as observational phenomena that cannot be explained by the model. We aim to answer some of these questions by using innovative techniques to find new particles from proton–proton collisions.

Learn more about our high-energy physics research.

Neutrinoless double-beta decay

What is the mass and nature of the neutrino? This question is among the most important unanswered questions in science. Our unique expertise in time-projection chamber technology has enabled us to lead the effort to answer this question with the nEXO experiment, which will look for an ultra-rare phenomenon called neutrinoless double beta decay. Demonstration of this phenomenon would indicate that the neutrino is its own antiparticle and may have important implications for understanding the imbalance of matter and antimatter in the universe.

Learn more about the nEXO experiment.

Nuclear astrophysics

One of the major goals in nuclear astrophysics is to understand the origin of the elements in the cosmos and our solar system. To this end, we combine knowledge about the nuclear environment in presolar grain analysis with nuclear measurements to identify key reaction networks, which we model using LLNL’s high-performance computing capabilities.

Learn more about our nuclear astrophysics research.

Nuclear fission

Nuclear cross-section measurements provide essential data for stewardship science as well as the design and operation of and commercial nuclear reactors. The accuracy of this data is imperative for modeling nuclear physics applications. We led a collaboration, called the Neutron Induced Fission Fragment Tracking Experiment, to develop a fission time projection chamber (TPC) that can track charged particles in three dimensions. The unparalleled background rejection capabilities of the fission TPC allow the detailed systematic checks needed for precision cross-section measurements.

Learn more about our nuclear fission research.

Nuclear structure

Shape is a fundamental property of an atom’s nucleus. However, one of the emergent properties of the nuclear many-body problem is deformation: nuclei can take on many shapes, from simple forms to more exotic ones. We use the Coulomb excitation technique on accelerated beams of exotic ions to measure the nuclear shape and determine its form and the magnitude of its deformation.

Learn more about our nuclear structure research.

Nuclear reactions

Understanding neutron-induced reactions is necessary for the safe operation of nuclear reactors and can help answer questions about the origins of the elements around us. However, making direct measurements of the neutron-capture cross section is extremely difficult. To address this difficulty, we collaborated with LLNL’s theoretical physicists to develop an indirect technique for constraining the properties of these reactions and calculating the properties of the desired reaction.

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Precision beta decay and neutron spectroscopy

We pioneered the use of beta-decay Paul traps for precision measurements of nuclear beta decays. Our experiments, performed at Argonne National Laboratory, provide measurements with applications in the study of nuclear reactions as well as precision tests of the weak interaction as a problem of physics beyond the Standard Model.

Learn more about our precision beta decay research and our neutron spectroscopy techniques.

Relativistic heavy-ion physics

We seek to better understand the properties of nuclear matter under extreme temperature, density, and pressure through the collisions of high-energy heavy ions. Our research focuses specifically on the properties of the quark–gluon plasma, a state of matter generated through experiments at the Large Hadron Collider (ATLAS) and the Relativistic Heavy Ion Collider (sPHENIX).

Learn more about our relativistic heavy-ion physics research.