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Commonwealth Fusion Systems (CFS)

Intern - R&D Test Engineer (m/w/d)

Become an R&D Test Engineering Intern at Commonwealth Fusion Systems in Somerville and Devens, Massachusetts. Support engineers in designing and building test stands, conducting tests, and analyzing data for fusion energy projects. Enjoy competitive pay, health benefits, and professional growth opportunities.

Commonwealth Fusion Systems (CFS)

Company Overview

Commonwealth Fusion Systems (CFS)

Cambridge, MA, United States

2018

Approximately 430 employees (source: zoominfo.com). Revenue figures vary, with reports indicating $211.3 million or $31.7 million, though as a pre-revenue fusion developer focused on R&D, these may reflect funding or operations rather than sales.

What They Do

Commonwealth Fusion Systems (CFS) is a pioneering private fusion energy company that specializes in tokamak-based magnetic confinement fusion. Founded as a spinout from MIT's Plasma Science and Fusion Center, CFS focuses on utilizing high-temperature superconducting magnets to achieve commercial net energy production (source: cfs.energy). The company has made significant strides in its technology, particularly with the development of compact fusion machines that leverage decades of tokamak science. Their flagship projects, SPARC and ARC, aim to demonstrate net energy gain and commercial viability in the coming years (source: cfs.energy).

Projects & Track Record

CFS is currently engaged in several groundbreaking projects, most notably the construction of SPARC, which is set to be the world's first net-energy fusion machine. Located at their Fusion Energy Campus in Devens, Massachusetts, SPARC aims to demonstrate net energy gain by the late 2020s (source: cfs.energy). Additionally, CFS is planning the ARC project, a 400 MW-class grid-scale tokamak power plant designed for commercial deployment in the early 2030s. These projects are underpinned by significant technological advancements, including the successful testing of the central solenoid magnet module (CSMC) in November 2024, which confirmed the manufacturability of critical components for SPARC (source: zoominfo.com).

Recent Developments

In the past two years, CFS has made remarkable progress, including the opening of its Devens Fusion Energy Campus on February 10, 2023, which was attended by notable figures such as U.S. Secretary of Energy Jennifer Granholm (source: cfs.energy). The company has also secured substantial funding, raising $863 million in August 2024, building on a previous $1.8 billion round in May 2023, bringing total funding to over $2 billion (source: wbjournal.com). Furthermore, CFS announced its first commercial power plant site in Chesterfield County, Virginia, which will be independently financed and operated, with plans for grid connection in the early 2030s (source: zoominfo.com).

Working There

CFS offers a range of roles across various disciplines, including fusion science, engineering, manufacturing, and materials science. The majority of their workforce is based at the Devens campus, which has grown to over 430 employees (source: cfs.energy). The company culture emphasizes rapid execution and transparency, attracting top talent from the fusion and manufacturing sectors. Key executives include Co-Founder and CEO Bob Mumgaard, along with other leaders in operations and science, indicating a strong demand for expertise in tough tech and physics (source: nasdaqprivatemarket.com). While specific benefits are not detailed, the scale-up and investor backing suggest competitive packages for high-caliber roles in a mission-driven environment (source: cfs.energy). Job seekers are encouraged to monitor their careers page for openings related to SPARC and ARC advancements.

Contact


Last updated on 2025-12-26 | Report an issue

Commonwealth Fusion Systems is on a mission to deliver the urgent transition to fusion energy.

Combining decades of research, top talent, and new technologies, we're designing and building commercially viable fusion power plants. And working with policymakers and suppliers to build the energy industry of the future.

We're in the best position to make it happen. Since 2018, we've raised nearly $3 billion in capital, making us the largest and leading private fusion company in the world.

Now we're looking for more thinkers, doers, builders, and makers to join us. People who'll bring new perspectives, solve tough problems, and thrive as part of a team.

If that's you and this role fits, we want to hear from you.

Join the power movement as an R&D Test Engineering Intern

The R&D Intern will work with the TF R&D team primarily at CFS-1, to de-risk SPARC TF magnet components. Responsibilities include supporting engineers in designing and building test stand components/fixtures for testing, as well as conducting tests and analysis to obtain high quality data that informs actionable recommendations on an aggressive schedule supporting magnet technology development.

Program Details

  • 12-16 week internship program
  • 40-50 hours per week with set hourly salary based on year in school
  • Opportunities vary between onsite in Somerville, MA and Devens, MA. If an intern is going to be on site, you will be responsible for your own transportation and housing
  • Specific project assignments and required technical skillset will vary based on the team's existing need.
  • Opportunities available for currently enrolled college students in all levels of schooling from bachelor's degree to PhD
  • Interns must be authorized to work in the United States for any employer

What you'll do

  • Support engineers in building test stands, executing tests and/or projects
  • Responsible for obtaining high quality data and performing high quality data analysis
  • Responsible for the design, build, and commissioning of key pieces of equipment and/or software in support of development, qualification, and production test objectives
  • Work with test engineers in close collaboration across manufacturing, R&D, procurement, and SPARC teams to achieve their test objectives
  • Support design reviews, and test readiness reviews as needed

What we're looking for

  • Pursuing an engineering degree with focus in the fields of Mechanical, Electrical or Aerospace OR pursuing a degree in Physics or Applied Physics
  • Hands-on experience through academic research, project teams, machine shops, hackathons, or industry internships
  • Mechanical design (structural focus), electrical design, instrumentation and control, experience with cryogenics, high currents, high voltage, experimental design, rapid prototyping and testing is a plus
  • Ansys, COMSOL, Python for data analysis, 3D CAD is a plus
  • Demonstration of exceptional results through a range of different pursuits
  • High self-motivation and drive to execute quickly with excellent troubleshooting/problem-solving skills

Must-have Requirements

  • Willingness to travel or work required nights/weekends/on-call occasionally
  • Perform activities such as typing, standing, or sitting for extended periods of time
  • Dedication to safety to mitigate industrial hazards that may include heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, and cryogenics

$23 - $35 an hour

Rates are aligned to your current year in school, ensuring equitable and consistent pay across our intern program.

For BS interns, the hourly rate is $23-$29

For MS/PhD interns, the rate is $32-$35

Benefits included for full-time interns:

  • 40 hours of sick time
  • Health, dental, and vision insurance
  • 401(k) with employer matching (must be 21 years of age to enroll)
  • Professional growth opportunities
  • Team-building activities

At CFS, we excel in fast-paced environments, driven by our values of integrity, execution, impact, and self-critique. As we grow, we're eager to bring on mission-driven folks who offer diverse perspectives and fresh ways to tackle challenges.

We value diversity deeply and are proud to be an equal opportunity employer by choice. We consider all qualified applicants equally, regardless 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.

This role requires compliance with U.S. laws concerning the export of controlled or protected technologies or information (collectively, "Export Control Laws"). Any offer of employment will be contingent on the need for compliance with such Export Control Laws.

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About the role

December 9, 2025

Internship

Company

December 27, 2025

On-site

USD 23–35 per hour

Commonwealth Fusion Systems (CFS)

cfs.energy

  •  Somerville, Massachusetts, United States
  •  Devens, Massachusetts, United States

Currently enrolled college students (bachelor's to PhD)

UTC-05:00

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