Director of Fusion Nuclear Science

Xcimer Energy leverages decades of research on Inertial Fusion Energy (IFE) combined with groundbreaking new laser architecture. Our mission is to deploy fusion power plants to meet global decarbonization goals as fast as possible. Xcimer has assembled a team of leaders in tough tech, fusion science, and manufacturing with a track record of rapid execution. Supported by leading investors, Xcimer is uniquely positioned to deliver limitless, clean, fusion power to combat climate change.

Join us in powering a better world with inertial fusion!

This is a full-time, onsite role based at our headquarters in Denver, CO.

The Director of Fusion Nuclear Science provides strategic, technical, and organizational leadership for the scientific disciplines that enable the realization and industrialization of practical fusion power systems. This leader will define and execute the long‑term scientific roadmap supporting fusion chamber dynamics, blanket multi-physics, tritium science, and other critical fusion nuclear science domains needed to deliver Xcimer’s next‑generation fusion energy platform.

The successful candidate will recruit, build, and mentor multidisciplinary world‑class scientific teams; establish long‑term scientific roadmap; and ensure that cutting‑edge research translates into validated models, experimental data, and actionable design guidance. This role partners closely with program and engineering leadership, and other science department directors, while serving as the company’s primary authority for fusion nuclear science.

• Build, lead and grow the Fusion Nuclear Science department, including hiring, onboarding, mentoring, and professional development of scientific staff.
• Define and own the scientific roadmap for fusion chamber dynamics, blanket multi-physics, tritium science, and supporting fusion nuclear science domains.
• Develop the strategy for scientific tools, modeling frameworks, experimental capabilities, and validation infrastructure.
• Oversee scientific analysis, modeling, code development, and experimental programs with strong emphasis on reproducibility, uncertainty quantification, and model credibility.
• Translate scientific insights, experimental data, and validated models into design guidance for engineering teams responsible for fusion system architecture.
• Collaborate closely with the engineering and operations divisions, and with other science departments, to ensure strong communication and alignment.
• Evaluate emerging scientific opportunities and integrate advances from academia, national laboratories, and international fusion programs.
• Manage relationships with external laboratories, university collaborators, and vendors providing modeling tools, experimental facilities, or other fusion nuclear science scope.
• Establish department‑wide scientific best practices, documentation standards, review processes, and quality expectations appropriate for industrial fusion systems.
• Identify key scientific risks across fusion nuclear science programs and drive mitigation strategies supporting execution and long‑term scalability.
• Support system troubleshooting, root‑cause investigations, and scientific review of failures or anomalies encountered in development or experimental operations.
• Align fusion nuclear science priorities with company strategy, program schedules, resource constraints, and commercialization goals in partnership with executive leadership.

• Education: PhD in Nuclear Science, Nuclear Engineering, Nuclear Physics, or a closely related field.
• Experience: 12+ years of experience in analysis, simulation, experimental R&D, or technology development for complex nuclear or fusion systems under extreme thermal and radiation environments.
• Leadership: 6+ years…