Engineering Physics Intern (Spring 2026)
Content + Source + Freshness • 14 Dec 2025 • 95% confidence
Offer value
Strong opportunity for students in engineering or physics fields with competitive pay and the chance to contribute to pioneering fusion energy research.
- Competitive intern salary at $55,000/year.
- Hands-on experience in leading-edge fusion technology.
- Strong mentorship from industry experts.
Pros
- Hands-on experience in fusion energy research.
- Mentorship opportunities with experienced professionals in the field.
- Competitive pay for intern positions.
Cons
- Highly technical background required, limiting opportunities for non-engineering candidates.
- On-site work may be challenging for those preferring remote flexibility.
- Pressure to adapt to rapidly shifting priorities.
Who it's for
Internship / Entry-level • On-site
Good fit
- Students in engineering or physics with hands-on experience.
- Individuals eager to work in clean energy innovation.
- Proactive learners wanting to impact scientific advancements.
Not recommended for
- Candidates seeking remote internship opportunities.
- Individuals uninterested in technical fields.
- Those who prefer defined and stable roles with minimal ambiguity.
Motivation fit
Key skills
About the job
About Marathon Fusion
We are building the fuel cycle for fusion energy on climate-relevant timelines to accelerate the deployment of this critical energy resource. By working alongside universities, national labs and industry partners to commercialize critical technologies, we aim to ensure the safe and economic deployment of fusion energy at meaningful speed and scale.
Marathon is supported by some of the energy industry's leading investors, alongside grant funding from the US Department of Energy’s ARPA-E and the Breakthrough Energy Fellows program.
About the team
Kyle and Adam founded Marathon Fusion to remove roadblocks to fusion deployment and meet the demands of the burgeoning industry. Kyle comes from the policy world, previously reporting to the CIO of Schmidt Futures, and with a background in software engineering for machine learning applications. Adam was a research engineer at Otherlab developing high efficiency heat pumps, worked on the DEMO-2 mission at SpaceX to return humans to the ISS, and received his MA from Princeton in Plasma Physics.
Our growing team includes a materials scientist, a computational research engineer, two mechanical engineers and an operations manager working out of our office in San Francisco.
Engineering at Marathon Fusion
The research engineering team is responsible for enabling experimentation, working alongside scientists to understand the objectives and constraints on our devices, and constantly striving to find opportunities to accelerate our R&D roadmap.
During your time, you’ll work to:
Conduct hands on design and rapid prototyping
Integrate power systems, pneumatics, sensors and mechanical subsystems into our prototypes and test bed
Perform mechanical/electrical design in CAD
Uphold standards and requirements for ultra-high vacuum environments
Procure equipment to meet testing requirements, material standards, and project timelines
Job Requirements
Our work requires a willingness to adapt to rapidly changing circumstances and shifting priorities, while keeping an eye on the long-term goals that ultimately drive success. Navigating this environment necessitates effective communication across roles and backgrounds, a high degree of trust between team members, and the willingness to learn and develop new skills on the job. We place particular weight on a team member's ability to be self-directed and proactive.
Ideal candidates will have experience and interests spanning:
Hands on fabrication and rapid prototyping
Engineering analysis
Excellent written and oral communication skills
Progress towards a degree in engineering, physics, or related fields
We are interviewing for interns able to join for at least 10 weeks, any time of year.
We are able to sponsor visas for applicants from outside the U.S.
Marathon Fusion considers all qualified applicants equally for employment. We do not discriminate on the basis of race, color, national origin, ancestry, citizenship status, protected veteran status, religion, physical or mental disability, marital status, sex, sexual orientation, gender identity or expression, age, or any other basis protected by law, ordinance, or regulation.
The salary for this position is $55,000 USD/year, or $26.44/hour. The role is full-time (40 hours a week) and in-person at our San Francisco office.
