Nuclear & Chemical

On the frontier of nuclear physics, particle physics, and chemistry

LLNL’s Nuclear and Chemical Sciences Division (NACS) offers deep expertise in physics and chemistry, allowing the advancement of scientific understanding, capabilities, and technologies in nuclear and particle physics, radiochemistry, forensic science, and isotopic signatures.

Every day, we focus on fundamental science, such as developing cutting-edge tools to uncover new chemical signatures or studying plasma effects on nuclear reactions. Combined with our experience conducting programmatic work in nuclear and chemical science, we provide innovative solutions for a range of national security problems.

Our world-class capabilities in radiation detection, chemical and nuclear forensic science, isotope geochemistry, and environmental radiochemistry also contribute to scientific advancements that help make the world safer.

We explore the chemistry of heavy elements (and discover new ones), chase elusive new particles, and answer important scientific questions about dark matter, neutrino physics, nuclear structure, nucleosynthesis, and the origins of the universe.

In addition to our technical mission, we actively build our expertise by collaborating with the scientific community, organizing summer schools, working closely with the Glenn T. Seaborg Institute, and hiring postdocs.

Explore this page to learn more about the people, research, and resources that support our mission.


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Research Areas

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Chemical & Isotopic Signatures

Group Leader: Mike Kristo

Our researchers analyze nuclear, geological, and extraterrestrial materials, with the aim of understanding their provenance and the processes involved in their formation.

Nuclear forensics is a key focus area for our group, providing decision makers and law enforcement with technical information for nuclear security purposes. This information includes reliable, high-quality analytical data that is legally defensible in a court of law, while advancing the state-of-the-art in nuclear forensics analysis. Our nuclear forensics toolbox includes a wide range of techniques to determine the isotopic, elemental, molecular, and physical characteristics of a nuclear forensics sample.

Our dynamic research program also focuses on cosmochemical investigations of early solar system processes. Additional research areas include nuclear non-proliferation, environmental geochemistry, nuclear fallout formation, and material science.

The broad range of bulk and in situ analytical techniques we use, and our interpretation of the results, have resulted in numerous high-impact publications. Our group provides cutting-edge scientific contributions to the international community as one of the premier nuclear forensics laboratories in the world.

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Environmental Isotope Systems

Group Leader: Jennifer Pett-Ridge

We are a diverse group of systems biologists, geochemists, and radiochemists who focus on multidisciplinary approaches to understanding natural and human-impacted environments.

Areas of research include:

  • How subsurface biogeochemistry controls transport of actinides in the environment
  • The role of microbial and viral communities in the terrestrial carbon cycle and negative carbon dioxide emissions
  • Tracing groundwater and contaminants to predict climate change impacts on water resources
  • Identifying how microbiomes shape productivity of bioenergy-relevant plant and algal crops

We also work on environmental proliferation detection and monitor radionuclides in air, water, and soil on LLNL campuses.

Our research involves a wide variety of radio- and stable-isotope enabled methods and inorganic mass spectrometric techniques, including NanoSIMS isotopic imaging, noble gas mass spectrometry, and stable isotope mass spectrometry. Many projects emphasize use of novel techniques and new methods, including new isotope-enabled tracing methods for microbial, soil, and groundwater systems and the development of new mass spectrometry-based techniques for nuclear forensics applications.

Our research is primarily funded by the Department of Energy Office of Biological and Environmental Research and the National Nuclear Security Administration.

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Forensic Sciences & Assessments

Group Leader: Katelyn Mason

We provide key scientific and technological subject matter expertise to the Laboratory’s Forensic Science Center (FSC) and Intelligence Program. In the FSC, we:

  • Research the physicochemical and physiological effects of chemical threat agents
  • Evaluate novel chemical synthesis methods and specific chemical signatures associated with these methods
  • Develop analytical methods to determine and support source forensics studies
  • Investigate biomedical exposure signatures
  • Manage consequences and related activities
  • Create new approaches to traditional forensic methods
  • Develop environmental and medical countermeasures

Through our participation in the Laboratory’s Intelligence Program, we provide comprehensive technical assessments and operational support to U.S. weapons of mass destruction counterproliferation and counterterrorism missions.

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Nuclear & Particle Physics

Group Leader: Nick Scielzo

Our group is dedicated to probing fundamental interactions of elementary particles and nuclei while also using our skills to address emerging national and global security challenges within the evolving landscape for nuclear security. We employ and recruit scientists with expertise in accelerator physics, detector design and construction, and complex data analysis, and who draw on state-of-the-art engineering and high-performance computing facilities.

To learn more about our group, visit the Nuclear and Particle Physics Group website.


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Nuclear & Radiochemistry

Group Leader: Tim Rose

We perform fundamental and applied research and development in nuclear science, including developing and implementing advanced experimental methods, radiochemical separations techniques, and data evaluation and interpretation capabilities.

We support the National Ignition Facility (NIF), stockpile stewardship, nuclear forensics, nuclear energy, and intelligence programs at LLNL. We also collaborate with national and internal groups in areas such as the chemistry and physics of the heaviest elements, automated radiochemistry, NIF radiochemical measurements, post-detonation debris diagnostics, and fireball condensation chemistry.

We specialize in radiochemical separations to isolate subtle nuclear signatures from a wide variety of matrices, as well as in the preparation and exploitation of unique target materials for nuclear data measurements.

Our responsibilities include:

  • Radiochemical diagnostics at NIF, including operational analytic measurements and the conduct of dedicated laser shots to assess specific isotope properties within extraordinary plasma environments.
  • Radiochemical evaluations of nuclear device performance in support of the stockpile stewardship and post-detonation nuclear forensics missions, providing essential data to constrain the design physics models developed by LLNL’s Strategic Deterrence and Global Security directorates.
  • Leading the detailed forensic analyses of real-world nuclear smuggling samples interdicted (or otherwise obtained) by law-enforcement and intelligence-community agencies.
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Nuclear Data & Theory

Group Leader: Sofia Quaglioni

We research nuclear theory to provide a fundamental understanding of atomic nuclei, their role in the universe, and how they impact LLNL’s national security missions.

Utilizing LLNL’s high-performance computing resources and building on innovations in machine-learning and quantum computing, we explore the nuclear many-body problem, beginning with the glue that binds quarks into protons and neutrons and how these protons and neutrons bind into the nuclei that make up most of the visible matter in the universe.

We develop new theories and computational tools to describe nuclear reactions ranging from fusion to fission, which are responsible for powering the stars, forging the elements in the cosmos, and are the source of energy in nuclear weapons. We not only characterize these reactions with fundamental theories, but we also tabulate them in extensive numerical libraries using ground-breaking formats for use in transport codes and provide enhanced support for high-fidelity uncertainty quantification studies.

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Nuclear Security Physics

Group Leader: Jonathan Dreyer

The security of nuclear and radiological weapons and materials is a major concern for LLNL. Improved capabilities are needed to address nuclear proliferation detection, arms control verification, nuclear safeguards, nuclear terrorism prevention, and consequence management.

Our mission is to apply nuclear physics, high energy physics, and astrophysics science, technology, and expertise to address the illicit production or diversion of special nuclear material and related threats. Our domain expertise, as well as knowledge we’ve obtained from participating with and training first responders, allows us to develop better instrumentation, improved signatures, and new analysis techniques for the detection, classification, identification, localization, tracking, and defeat of the unauthorized use of nuclear materials.

We are a conduit between the nuclear and high energy physics communities and LLNL’s Global Security Directorate research needs. Within LLNL, we communicate program needs to NACS science and technology staff while helping to make NACS capabilities accessible to the programs. Outside of LLNL, we recruit expertise from and foster collaborations with the nuclear science and engineering communities, publish results in peer-reviewed scientific journals, and track placement opportunities in universities, national laboratories, and industry.

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Rare Event Detection

Group Leader: Nathaniel Bowden

In both fundamental and applied nuclear physics, researchers and users of radiation detection equipment are often confronted with the problem of extracting a weak signal from a copious background. Broadly, this area of research is sometimes referred to as rare event detection.

Our group develops advanced methods for measuring a relatively narrow class of rare events: keV-MeV scale energy depositions arising from neutral particles, including gamma-rays, neutrons, neutrinos, and the vanishingly rare—and still hypothetical—dark matter particle. Neutral particle detectors in this energy range are crucial for fundamental science, especially particle astrophysics, but also for applied nuclear science, including nuclear nonproliferation, arms control, and nuclear materials monitoring.

Nuclear security applications and fundamental nuclear science may appear disparate but are in reality closely connected. Our training in both areas allows us and the Laboratory to effectively exploit the strong technological synergies that exist between them.

We lead or participate in ongoing international fundamental science collaborations, including:

  • The LUX/LZ Dark Matter experiment
  • The ADMX axion dark matter search experiment
  • The development of large water Cherenkov detectors for fundamental science and remote reactor monitoring, including the WATCHMAN and WATCHBOY detectors and the Advanced Instrumentation Testbed for neutrino detection concepts
  • The PROSPECT sterile neutrino search experiment
  • The Project 8 neutrino mass measurement experiment
  • The BeEST sterile neutrino search experiment

With different optimizations, the same concepts allow us to develop innovative gamma-ray, neutron, and antineutrino detectors to improve International Atomic Energy Agency safeguards, to verify nuclear arms control agreements, and to screen and characterize nuclear material in a wide range of monitoring contexts. Examples include passive and active gamma-ray tomographic systems for spent fuel, segmented scintillator arrays for precise characterization of fissile content in shielded materials, remote monitoring and exclusion of nuclear reactors using antineutrino detectors, and novel detectors for characterizing the fissile content of spent fuel using information derived from antineutrino spectra.

More information about our research is available on the Neutrino Physics at LLNL website.

Our work was featured in a Science Friday spotlight titled “Looking at Light for Signs of Dark Matter.”

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Safeguards, Nonproliferation, & Response

Group Leader: Bryan Bandong

With a staff of nuclear scientists, engineers, radiochemists, health physicists, and radiation safety and protection subject matter experts, our group is uniquely positioned to support mission-critical programs in nuclear counterterrorism, nuclear security and nonproliferation, and emergency response and consequence management.

Our research and development activities focus on advanced radiation detection and nuclear measurements for applications in:

  • Technical nuclear forensics and countermeasures
  • Next generation technical safeguards and global threat reduction initiatives
  • Arms control and nuclear compliance verification, including assisting the U.S. government in interagency and international treaty negotiations

We are engaged in the development of concepts of operations (CONOPS) and in researching, testing, and evaluating field systems in support of various international and regional organizations (such as the International Atomic Energy Agency, EURATOM) and national agencies (Department of Energy, Department of Defense, Department of Homeland Security) programs in nuclear safeguards infrastructure and technology, nuclear and radiological emergency response, consequence management, preventive radiological and nuclear detection architectures and system engineering, and the interdiction of illicit transport of nuclear and radiological materials.

Our activities include:

  • Development, setup, testing, and evaluation of land-based or aerial/marine-borne detection systems customized to the needs and applications of federal, state, and local law-enforcement agencies
  • Outreach, training, and field exercises for first responders on the use of portable or fieldable detection systems with national and international partners
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  • Modeling and simulation of radiation detector response
  • Measurements and improvements in nuclear decay data and reaction cross sections
  • Fabrication of high-fidelity realistic surrogate tests and exercises for radiological/nuclear materials for use with analytical method development and validation as well as laboratory proficiency testing

Career Opportunities

Our exciting work would not be possible without dedicated staff. We’re always looking for talented scientists to join our multidisciplinary teams.

Browse our open positions or read about our internship programs.

In the News

Capabilities & Facilities

Our researchers utilize world-class scientific capabilities and modern high-performance computing facilities to support Laboratory programs. Listed below are some of LLNL’s state-of-the-art capabilities commonly used by our scientists.