Director of Heating and Fueling

About Thea Energy: Thea Energy is leveraging recent breakthroughs in stellarator physics and engineering to create a faster and simpler approach to commercializing fusion energy. The company is reinventing the stellarator using computer-controlled arrays of planar coils thereby replacing the intricate, complex modular magnets required in all other stellarator architectures. Thea Energy is on a mission to create a limitless source of zero emission energy for a sustainable future.

Position Overview: Thea Energy is seeking a Director of Heating and Fueling to lead the research, design, engineering, prototyping, and qualification of auxiliary plasma heating and core/edge fueling systems across both the Eos and Helios development programs. This leader will guide an interdisciplinary team advancing the technical basis for system design of:

• Microwave Heating Systems: High-power, Electron Cyclotron Resonance Heating (ECRH) and associated transmission/launching infrastructure.
• Advanced Fueling & Particle Injection: High-frequency, cryogenic pellet injection and associated transmission/launching infrastructure. As part of a rapidly growing team, you will shape the organizational build-up of a leading fusion energy company. This role demands a high degree of autonomy and the technical decisiveness required to navigate engineering trade-offs rapidly in a high-velocity startup environment.

Key Responsibility Areas: Strategic Leadership & Program Execution

• Own the technical roadmap and milestones for microwave heating systems, cryogenic pellet injection, and supporting infrastructure for Eos and Helios from pre-conceptual physics design through hardware fabrication, testing, and operational commissioning.

• Lead and mentor a team of RF/microwave physicists, high-voltage electrical engineers, beam-line specialists, cryogenic engineers, and computational modelers.

• Establish budget, resource allocation, and vendor engagement strategies, balancing rapid in-house prototyping and test stand development with key institutional and national laboratory partnerships.

• Electron Cyclotron Heating Physics and Engineering

• Serve as design authority on the physics design and hardware integration of multi-megawatt steady-state electron cyclotron heating systems tailored to planar-coil stellarator geometries, including microwave sources, ECRH transmission lines, and steerable launchers.

• Oversee comprehensive ray-tracing, full-wave modeling, and Fokker-Planck simulations (e.g., TORAY, TRAVIS, GENRAY, AORSA) to evaluate wave absorption profiles, heating, and core-edge deposition.

• Establish requirements for high-voltage power supplies, transmission waveguides, and vacuum windows.

• Interface with Plasma Controls and Operations group to optimize real-time control and protection of electron cyclotron systems.

• Oversee development of techniques and controls to mitigate localized microwave heat deposition on plasma-facing components. Fueling Systems Physics and Engineering

• Serve as the design authority on the physics design, engineering and qualification of deep-core fueling systems, focusing on continuous, high-repetition-rate cryogenic deuterium-deuterium and deuterium/tritium (D-T) pellet injectors.

• Direct the design of boundary gas puffing and/or supersonic molecular beam injection (SMBI) to support density ramp-up and plasma start-up.

• Interface with Plasma Controls and Operations group to optimize real-time control and protection of cryogenic pellet injection systems.

• Collaborate closely with the Divertor & PMI and Fuel Cycle teams to optimize particle throughput, burn fraction, neutral pumping efficiency, and overall fuel cycle inventory.

Ideal Experience & Skillsets: Education

• Ph.D. or Master’s degree in Plasma Physics, Nuclear Engineering, Electrical Engineering, Applied Physics, or a closely related discipline.

• 7+ years of direct experience in the design, development, commissioning, or operation of auxiliary heating (ECRH, ICRF, NBI) or cryogenic fueling systems on magnetic confinement fusion devices (stellarators or tokamaks). Technical Expertise

• Deep domain knowledge in wave-particle interactions, RF transmission and antenna-plasma coupling, or pellet ablation/penetration dynamics.

• Clear understanding of the operational trade-offs between physics performance (heating efficiency, core transport, wave propagation and absorption) and engineering feasibility (launcher survivability, RF breakdown limits, remote maintainability, high-voltage reliability).

• Sufficient familiarity with ECRH modeling packages (e.g., TRAVIS, TORAY, GENRAY, TRANSP, ASCOT) and electromagnetic and thermal-mechanical multiphysics tools (e.g., CST Studio, ANSYS, COMSOL) to direct physics/engineering teams. Core Competencies

• Decisive technical judgment: ability to balance scientific precision with the aggressive timelines and milestones of private fusion commercialization.

• Exceptional cross-disciplinary communication skills, with the ability to convey complex heating and wave-mechanics trade-offs to coil designers, mechanical engineers, executive leadership, and external partners. Preferred Qualifications

• Direct experience engineering or operating heating or fueling systems in 3D/non-axisymmetric magnetic fields

• Hands-on experience developing or commissioning multi-megawatt steady-state RF transmission components (mirrors, polarizers, diamond windows) or cryogenic pellet extrusion barrels.

• Familiarity with diagnostics coupled to heating and fueling performance (e.g., interferometry, microwave reflectometry, Thomson scattering, neutron spectrometers).

Company Benefits:

• Salary range $165,000-$230,000
• Comprehensive health benefits (e.g. medical/dental/vision)
• Employee equity stock options
• 20 days PTO

It’s not necessary to meet all of the skillsets outlined above. Please feel free to send us a note and tell us why you would still be a great fit for this role or Thea Energy.

Diversity and Inclusion: Thea Energy is an equal opportunity employer committed to creating a company of diverse backgrounds. By creating a diverse environment, we will bring new ideas and approaches to solving some of the world’s hardest (and most important) problems. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, gender, sexual orientation, gender identity or expression, national origin, family or marital status, age, disability, veteran’s status, or other characteristic protected by applicable laws and regulations.