NBI Scientist (Computational Beam Physicist)

Madison, WI

Bridge simulation and experiment to help advance the next generation of fusion technology. The

NBI Scientist (Computational Beam Physicist) will lead the scientific-code stack connecting fast beam models, high-fidelity simulations, and experimental validation. This role will develop and integrate computational tools used to model beam behavior, evaluate system performance, and compare simulation results with experimental data. Working closely with scientists and engineers, this position will help translate modeling results into actionable insights that guide beam-system design, optimization, and experimental planning.

Key Responsibilities

1. Take primary responsibility for RealBeam™ architecture, implementation quality, and verification, ensuring the modeling framework is reliable, maintainable, and supports Realta’s beam-physics needs.

2. Connect RealBeam™ and WarpX workflows, establishing consistent model inputs, outputs, and computational approaches across WHAM and Narsil.

3. Develop and maintain the validated modeling pipeline that connects beam simulations with experimental results and supports Genesis surrogate modeling and technical decision-making.

4. Develop, test, and improve scientific software and numerical tools used for beam modeling, simulation, analysis, and comparison with experimental data.

5. Perform computational studies and parameter scans to evaluate beam behavior, system performance, and design alternatives.

6. Work closely with scientists and engineers to translate simulation results into clear technical recommendations that support experimental planning and system design.

7. Partner closely with members of the NBI team, providing software, computational, and numerical expertise that complements their beam-physics and experimental validation work.

Background and Experience

• PhD or equivalent experience in Computer Science, Applied Mathematics, Plasma Physics, or related field. Background in beam physics, plasma physics, particle transport, computational physics, or a closely related field.
• Strong foundation in physics, scientific Python, and numerical methods; experience with C++, HPC, and GPU computing is highly desirable.
• Experience developing and maintaining scientific software, including version control, testing, verification, documentation, and reproducible workflows.
• Ability to develop and integrate parameter scans, uncertainty studies, optimization methods, and surrogate-model workflows while maintaining a strong understanding of the underlying physics.
• Experience working with large-scale simulations, computational modeling, and analysis of complex physical systems.
• Experience with PIC, Monte Carlo, beamline, or multiphysics simulation codes is preferred.
• Ability to work collaboratively with scientists and engineers and clearly communicate computational results and recommendations.

Compensation and Benefits

What we are working on is hard… and hugely important. Realta Fusion is assembling a talented team bound together by a passion to solve humanity's biggest challenge with first-of-a-kind technology. Additionally, Realta offers:

• Competitive compensation package, including equity stock options
• Comprehensive benefits including health, dental, and vision insurance, plus a retirement savings plan
• Flexible paid time off (PTO) to support work-life balance
• Work and live in Madison, Wisconsin — one of America's most livable and vibrant cities

We value diversity as a critical factor in innovation and believe a diverse team is necessary to solve the toughest problems. We aim to create an inclusive environment that unleashes the full creativity of our team members from a wide variety of backgrounds and experiences. We provide equal employment opportunities to all individuals based on merit and without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, veteran status, or any other protected status under applicable laws.