Optical Diagnostics Intern (Summer 2026)

Marathon Fusion • San Francisco, CA

2d • $28 - $43

About The Position

Marathon Fusion is building the engineering technologies needed to scale fusion from breakeven experiments into real power plants. While much of the industry is focused on proving new fusion devices, our focus is on the practical systems that will make fusion deployable at climate-relevant scale.
We develop core fuel cycle and plant-level technologies for stable isotope production, fuel cycle closure, and advanced blanket systems that enable both energy generation and high-value co-products.
Founded in 2023, Marathon Fusion is building the components and systems that will help fusion become a practical, abundant, and reliable energy source for the 21st century.
This track combines optical/electro-magnetic diagnostics with hands-on experimentation on a plasma centrifuge apparatus. Successful candidates will work with optical, spectroscopic and electro-magnetic diagnostics to characterize plasma centrifuge.

Requirements

• Studying physics, and have meaningful hands-on experience in experimental physics, optical diagnostics, electro-magnetic probes, vacuum systems operation, or similar.
• Studying applied physics or electrical engineering, and have had meaningful exposure to physics, optical diagnostics and electro-magnetic probes through coursework, internships and projects.
• Studying a combination of both in a physics / engineering program, double major or similar and have exceptional work-ethic, eagerness to learn, and autonomy.
• Excellent written and oral communication
• Ability to think holistically about systems
• Capacity to learn new technical subjects quickly, collaborate cross-functionally, and consider problems from inter-disciplinary perspectives
• Organization and project management
• A high degree of conscientiousness and integrity
• Long-term vision while executing short-term goals
• Comfort with the inherent uncertainty of breakthrough technology
• Experimental mindset, ability to form and test hypotheses

Nice To Haves

• plasma physics
• optics
• spectroscopy
• vacuum systems

Responsibilities

• Experimental Physics: Setting up experiments and coordinating with relevant sub-systems owners: diagnostics, data acquisition and control systems, gas and vacuum equipment, for measurements of plasma properties.
• Diagnostics: Preparing optical and electro-magnetic diagnostics systems and experimental controls for measurements on plasma centrifuge.
• Testing and Iteration: Conducting measurements, collecting and analyzing data, and clearly communicating these results with the team to contribute to the development of plasma diagnostics systems.

What This Job Offers

• Career Level: Intern
• Education Level: No Education Listed