Neutronics Jobs (NOW HIRING)

Description
Job Title Spallation Physics & Target Neutronics - Postdoctoral Researcher
Location Los Alamos, NM, US
Organization Name P-2 / Applied & Fundamental Physics (Radiation Effects & Radiography Team)
Minimum Salary
Maximum Salary
What You Will Do
Join the Radiation Effects & Radiography team supporting operations at the Los Alamos Neutron Science Center (LANSCE), a premier experimental facility at Los Alamos National Laboratory (LANL). LANSCE's high-power linear accelerator drives 800-MeV (≉0.84c) protons onto tungsten spallation targets, producing neutrons from thermal energies up to several hundred MeV. These beams enable a broad portfolio of national-impact science and technology.
LANSCE's high-energy proton beams power five user facilities:

• Lujan Center
• Weapons Neutron Research (WNR)
• Ultra-Cold Neutron (UCN) Source
• Proton Radiography (pRad)
• Isotope Production Facility (IPF)

Within P-2, the Spallation Physics Team designs and optimizes spallation targets, radiological shielding, neutron transport, and background reduction across experimental areas, while supporting daily facility operations.
As a postdoctoral researcher, you will help optimize next-generation spallation targets-delivering thermal/epithermal neutrons to Lujan Center instruments and versatile fast-neutron spectra to multiple WNR flight paths. A major focus is modernizing our end-to-end simulation workflow, from as-built geometry capture to high-fidelity transport:

• As part of the Spallation Physics Team, run end-to-end Monte Carlo (MCNP) simulation campaigns using as-built geometry to optimize spallation-target and beamline setups.
• Integrate laser-tracker/LiDAR scans into CAD; generate analysis-ready meshes and use MCNP Unstructured Mesh / hybrid geometry for high-fidelity neutron-transport simulations.
• Operate simulations on the local HPC (~6,000 cores + GPUs).
• Validate MCNP simulations against measurements; perform sensitivity analyses; collaborate with teammates and MCNP developers; document and present results.
• Develop Python-based, reproducible MCNP simulation pipelines for pre/post-processing, meshing, input generation, and results reduction.
• Apply ML/AI (surrogate models, Bayesian optimization, active learning) and computer vision to accelerate MCNP simulation-driven optimization and prepare scan/mesh inputs.

Key Responsibilities

• Develop and maintain CAD and mesh-based models informed by 3D scans (LiDAR, laser tracker).
• Design and simulate spallation targets, moderators, reflectors, and shielding using MCNP (or comparable transport codes).
• Analyze experimental and simulation data; validate models against measurements.
• Automate workflows with Python; maintain reproducible analyses using Git.
• Document methods and results; present to internal reviews and external users.
• Support safe, reliable operations in LANSCE experimental areas

What You Need
Minimum Job Requirements

• Strong desire to learn and grow technically; proactive, solution-oriented mindset.
• Effective communication and teamwork in a multidisciplinary environment.
• Demonstrated experience with MCNP or other particle-transport codes (e.g., Geant4, FLUKA, PHITS).
• Data-analysis experience (experimental and/or simulation).
• Excellent writing and presentation skills.
• Proficiency in Python (core to our workflows).

Preferred Qualifications

• Comfortable with UNIX/Linux environments.
• Contributions to both experimental (hands-on) and simulation work.
• Strong scripting: Bash and Python; familiarity with Fortran, C/C++, or Perl is a plus.
• Skilled with CAD (e.g., SolidWorks, Inventor, SpaceClaim).
• Practical experience with 3D scanning/meshing/CAD and 3D printing.
• Experience using LiDAR or laser trackers.
• Uses Git for version control and team workflows.
• Demonstrated creative, unconventional problem-solving.
• Robotics exposure (not required).
• ML/AI in scientific workflows: experience with one or more of
• surrogate/emulator modeling and Bayesian optimization for design;
• computer vision for point-cloud/mesh/scan processing;
• uncertainty quantification or active learning;
• common libraries/tools (e.g., scikit-learn, PyTorch or TensorFlow, OpenCV).

We value learning and problem-solving over a perfect résumé match. If our mission resonates with you, please apply-even if you don't meet every requirement. Robotics experience and deeper ML/AI expertise are strong pluses, but they're not gatekeepers; curiosity, initiative, and a willingness to learn matter most, and we encourage candidates to apply even if they're missing some of the required items.
Salary : Competitive salaries are based on the date the PhD degree requirements were completed or the degree was awarded. Starting salary for a new graduate is currently $97,000. For more information go to Postdoc Program website at https://www.lanl.gov/careers/career-options/postdoctoral-research/index.php
Education
Ph.D. in physics, engineering, or a closely related field, earned within the last five years (or soon to be completed)
Work Location: The work location for this position is located in Los Alamos, NM.
Notes to Applicants
Interested candidates must submit their application (CV and cover letter) through the online application system and send a CV, cover letter, and three recommendation letters to svoboda@lanl.gov
For further technical information, please contact J. Svoboda at svoboda@lanl.go
Due to federal restrictions contained in the current National Defense Authorization Act, citizens of the People's Republic of China-including the special administrative regions of Hong Kong and Macau-as well as citizens of the Islamic Republic of Iran, the Democratic People's Republic of Korea (North Korea), and the Russian Federation, who are not Lawful Permanent Residents ("green card" holders) are prohibited from accessing facilities that support the mission, functions, and operations of national security laboratories and nuclear weapons production facilities, which includes Los Alamos National Laboratory.
Where You Will Work
Located in beautiful northern New Mexico, Los Alamos National Laboratory (LANL) is a multidisciplinary research institution engaged in strategic science on behalf of national security. Our generous benefits package includes:

• PPO or High Deductible medical insurance with the same large nationwide network
• Dental and vision insurance
• Free basic life and disability insurance
• Paid maternity and parental leave
• Award-winning 401(k) (6% matching plus 3.5% annually)
• Learning opportunities and tuition assistance
• Flexible schedules and time off (paid sick, vacation, and holidays)
• Onsite gyms and wellness programs
• Extensive relocation packages (outside a 50 mile radius)

Additional Details
Directive 206.2 - Employment with Triad requires a favorable decision by NNSA indicating employee is suitable under NNSA Supplemental Directive 206.2 . Please note that this requirement applies only to citizens of the United States. Foreign nationals are subject to a similar requirement under DOE Order 142.3A.
*Eligibility requirements: To obtain a clearance, an individual must be at least 18 years of age; U.S. citizenship is required except in very limited circumstances. See DOE Order 472.2 for additional information.
No Clearance: Position does not require a security clearance. Selected candidates will be subject to drug testing and other pre-employment background checks.
New-Employment Drug Test: The Laboratory requires successful applicants to complete a new-employment drug test and maintains a substance abuse policy that includes random drug testing. Although New Mexico and other states have legalized the use of marijuana, use and possession of marijuana remain illegal under federal law. A positive drug test for marijuana will result in termination of employment, even if the use was pre-offer.
Equal Opportunity: Los Alamos National Laboratory is an equal opportunity employer and supports a diverse and inclusive workforce. All employment practices are based on qualification and merit, without regard to race, color, national origin, ancestry, religion, age, sex, gender identity, sexual orientation, marital status or spousal affiliation, physical or mental disability, medical conditions, pregnancy, status as a protected veteran, genetic information, or citizenship within the limits imposed by federal laws and regulations. The Laboratory is also committed to making our workplace accessible to individuals with disabilities and will provide reasonable accommodations, upon request, for individuals to participate in the application and hiring process. To request such an accommodation, please send an email to applyhelp@lanl.gov or call 1-505-664-6947 option 2 and then option 3.
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Employment Status Full Time
Appointment Type Postdoc
Postdoc
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