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Theoretical Physicist

Mid-Senior Level | Full-time
Physical Life Sciences | livermore, CA | 02/18/2022

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Company Description

Join us and make YOUR mark on the World!

Are you interested in joining some of the brightest talent in the world to strengthen the United States’ security? Come join Lawrence Livermore National Laboratory (LLNL) where our employees apply their expertise to create solutions for BIG ideas that make our world a better place.

We are committed to a diverse and equitable workforce with an inclusive culture that values and celebrates the diversity of our people, talents, ideas, experiences, and perspectives. This is essential to innovation and creativity for continued success of the Laboratory’s mission.

Job Description

We have an opening in the Nuclear Security Physics Group for a Theoretical Physicist to work on developing new nuclear diagnostic capabilities and on problems related to the statistical theory of fission chains. This work will support the nation’s ability to counter, respond to, and if necessary, mitigate a nuclear or radiological incident quickly. This critical mission is the responsibility of the U.S. Department of Energy, National Nuclear Security Administration’s (DOE/NNSA) JTOT (Joint Technical Operation Team) Program—an agile, task-organized unit, ready to react at a moment’s notice to support nuclear and radiological weapons of mass destruction incidents.

This position will be filled at either level based on knowledge and related experience as assessed by the hiring team. Additional job responsibilities (outlined below) will be assigned if hired at the higher level.

In this role you will 

  • Develop theories and mathematical models to predict results of a radiation measurement of a nuclear weapon.
  • Lead research in identifying and developing possible new diagnostic methods.
  • Use nuclear data and the results of simulations made with radiation transport codes (e.g. MCNP or GEANT4) to unravel the details of a measurement.
  • Prepare proposals for agencies that fund research in this mission space
  • Work as part of an interdisciplinary team with experimental physicists, computational physicists, and statisticians to reconcile measurements with theories and to refine the theories, hardware, and measurements.
  • Lead technical efforts with responsibility for budgets, schedules, deliverables, and resource allocation
  • Document and publish research results in peer-reviewed scientific publications and present results at external conferences, seminars and/or technical meetings
  • Perform other duties as assigned.

Additional job responsibilities, at the SES.4 level

  • Determine project scope, schedule and budget and lead a team of multidisciplinary personnel who conduct analysis under your direct supervision.
  • Propose and execute development plans to meet medium/long term objectives in the nuclear diagnostics domain.
  • Manage multi-disciplinary teams of scientists and technical personnel.


  • Ability to secure and maintain a U.S. DOE Q-level security clearance, which requires U.S. Citizenship.
  • Ph.D. in theoretical physics or related field or the equivalent combination of education and related experience.
  • Understanding of theoretical physics and analytic methods of mathematical physics; knowledge of computational techniques (e.g. Bill Press’ Numerical recipes).
  • Familiarity with radiation and neutron transport.
  • Ability to develop independent research projects as demonstrated through publication of peer-reviewed literature
  • Documented publication record in peer-reviewed literature with experience presenting research results to a large audience.
  • Advanced verbal and written communication skills necessary to author technical and scientific reports and publications and deliver scientific presentations.
  • Initiative and interpersonal skills with desire and ability to work in a collaborative, multidisciplinary team environment.

Additional qualifications at the SES.4 level

  • Significant experience managing projects and teams.
  • Significant experience collaborating across research (university or national laboratory) and commercial (industry) institutions.
  • Significant experience effectively managing concurrent technical tasks with competing priorities.

Qualifications We Desire

  • Experience with radiation measurement instruments, systems, and analysis.
  • Understanding of the principles of radiation detection and signal processing.
  • Ability to coordinate complex tasks by interacting independently with other team members in the execution of the mission.

Additional Information

All your information will be kept confidential according to EEO guidelines.

Position Information

This is a Career Indefinite position. Lab employees and external candidates may be considered for this position.

Why Lawrence Livermore National Laboratory?

  • Included in 2022 Best Places to Work by Glassdoor!
  • Work for a premier innovative national Laboratory
  • Comprehensive Benefits Package
  • Flexible schedules (*depending on project needs)
  • Collaborative, creative, inclusive, and fun team environment

Learn more about our company, selection process, position types and security clearances by visiting our Career site

COVID-19 Vaccination Mandate

LLNL demonstrates its commitment to public safety by requiring that all new Laboratory employees be immunized against COVID-19 unless granted an accommodation under applicable state or federal law. This requirement will apply to all new hires including those who will be working on site, as well as those who will be teleworking.

Security Clearance

This position requires a Department of Energy (DOE) Q-level clearance.  If you are selected, we will initiate a Federal background investigation to determine if you meet eligibility requirements for access to classified information or matter. In addition, all L or Q cleared employees are subject to random drug testing.  Q-level clearance requires U.S. citizenship.  For additional information, please see DOE Order 472.2

Pre-Employment Drug Test

External applicant(s) selected for this position will be required to pass a post-offer, pre-employment drug test. This includes testing for use of marijuana as Federal Law applies to us as a Federal Contractor.

Equal Employment Opportunity

LLNL is an affirmative action and equal opportunity employer that values and hires a diverse workforce. All qualified applicants will receive consideration for employment without regard to race, color, religion, marital status, national origin, ancestry, sex, sexual orientation, gender identity, disability, medical condition, pregnancy, protected veteran status, age, citizenship, or any other characteristic protected by applicable laws.

If you need assistance and/or a reasonable accommodation during the application or the recruiting process, please submit a request via our online form

California Privacy Notice

The California Consumer Privacy Act (CCPA) grants privacy rights to all California residents. The law also entitles job applicants, employees, and non-employee workers to be notified of what personal information LLNL collects and for what purpose. The Employee Privacy Notice can be accessed here.

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