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Commonwealth Fusion Systems

Manager, Materials Mechanical Testing

Join Commonwealth Fusion Systems in Devens, Massachusetts as Manager of Materials Mechanical Testing. Lead a team testing materials for fusion energy projects, ensuring quality and innovation. Enjoy competitive pay, equity, flexible vacation, and professional growth in a cutting-edge fusion energy company.
Commonwealth Fusion Systems
Commonwealth Fusion Systems
Devens, Massachusetts, United States Hybrid Full time USD 110k–185k yearly UTC-05:00

Commonwealth Fusion Systems

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.


Last updated on 2026-02-23 | Report an issue

Job Description

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 we're 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 Manager, Materials Mechanical Testing

The Materials and Processing (M&P) Department at CFS supports design engineers, supply chain, and manufacturing by selecting materials, unambiguously defining materials and processing routes, validating and measuring those materials and their properties, and conducting R&D to develop new materials and processes to enable fusion power deployment. M&P at CFS is organized around three primary thrusts: engineering, test and characterization, and development programs. The work is undertaken in support of delivering SPARC, the net energy tokamak under construction in Devens, MA, and ultimately in designing the ARC fusion power plant. These devices pose unique materials challenges including neutron fluxes produced by deuterium-tritium fusion, high heat loads, molten salt coolant systems, complex component topologies, high magnetic fields, and high mechanical loading in cryogenic conditions.

To support this mission, the CFS Materials Test and Characterization team in M&P is seeking a sub-team lead for the growing group. The manager of the materials mechanical testing team will mentor, coordinate, and grow a team of 2-5 materials test engineers in addition to serving as subject matter expert in mechanical testing of materials and structural testing of sub-components in CFS projects.

What you'll do

  • Mentor, coordinate, and line manage a small team of materials test engineers that conduct evaluation, testing and qualification of materials and components for structural and functional applications for CFS projects
  • Maintain and grow CFS cultural values of integrity, self-critique, impact, and execution while supporting and growing team members
  • Serve as a subject matter expert and individual contributor in one or more of the following areas:
    • Mechanical testing of materials
    • Test design and development
    • Structural testing
    • Mechanical design for test fixture development
  • Create educational resources, guidance documentation, and process flows for the team and broader department audience
  • Provide technical guidance to project team members to ensure efficient execution of design-build-test-learn cycles and retirement of technical risks by translating performance requirements into material property specifications
  • Represent CFS Materials Test & Characterization in TRRs, design and manufacturing reviews
  • Report on team activities and successes
  • Ensure efficient and timely transfer of test data and new insights to engineering design teams
  • Promote a safety-oriented work culture and comply with all CFS guidelines and policies
  • Work closely with other CFS teams including:
    • Safety team to manage chemical/mechanical/environmental hazards in existing and new tests being developed
    • Adjacent R&D teams to optimally share pooled resources including equipment and personnel
    • Supply chain team to procure new equipment and materials

What we're looking for

  • BS in Mechanical Engineering or related field + 3-5 years experience with some technical lead responsibility
  • Experience with materials laboratory failure analysis
  • Experience conducting and understanding standard mechanical property testing
  • Experience conducting structural testing of assemblies and prototype components
  • Understanding of how materials properties impact performance
  • Design of experiments
  • Data analysis, interpretation, and visualization
  • Strong knowledge in CAD (NX, Solidworks, AutoCAD, etc.)
  • Knowledge of process-structure-property relationships in materials and relevant manufacturing processes
  • Experience with lab management / test scheduling
  • Experience delegating complex tasks to operating teams
  • Efficient and effective technical communication skills targeted at a variety of audiences
  • A strong drive for quality and attention to detail
  • Ability to communicate with a wide range of technical and non-technical audiences
  • Ability to clearly express and critique ideas
  • Ability to rapidly execute short turnaround engineering/R&D tasks
  • Strong problem solving skills, ability to approach new problems with creativity
  • Resource estimation and projection

Bonus points for

  • Understanding and experience testing materials in various environments including extreme temperature and high vacuum applications
  • Experience developing novel testing methods
  • Experience documenting processes
  • Experience with project management

Must-have Requirements

  • Perform activities such as typing or sitting for extended periods of time
  • Work in a facility that contains industrial hazards including heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, high current, pressure systems, metallographic etchants and cryogenics
  • Willingness to travel or work required nights/weekends/on-call occasionally

$110,000 - $185,000 a year

Salary range for this full-time position + equity + benefits. The actual salary will depend on level, location, qualifications, and experience. The range displayed on each job posting reflects new hire salaries for the position across all US locations. Benefits include:

  • Competitive compensation with equity
  • 13 Company-wide Holidays
  • Flexible vacation days
  • 10 sick days
  • Generous parental leave policy
  • Health, dental, and vision insurance
  • 401(k) with employer matching
  • 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.

Apply now

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About the role

March 7, 2026

Full time

Company

March 7, 2026

Hybrid

USD 110k–185k yearly

Hydropower

Commonwealth Fusion Systems

cfs.energy

  •  Devens, Massachusetts, United States

3-5 years

UTC-05:00