Diagnostics Mechanical Engineer
Confirmed on the employer's own hiring board on Nov 5, 2026. First seen by Alion on Nov 4, 2026. Commonwealth Fusion Systems scores A on the Alion truth index.
Join the power movement as a Diagnostics Mechanical Engineer
Commonwealth Fusion Systems is assembling the high-field SPARC tokamak, which aims to be the first magnetic fusion device to achieve net fusion energy, and is predicted to be able to achieve high gain and fusion power up to 140 MW. We are completing the design and have begun the assembly and installation of diagnostic systems that will be used to control the plasma and deliver the scientific data necessary to complete the design of ARC. These include approximately 40 sub-systems covering magnetics, interferometry, neutral pressure, x-ray to visible spectroscopy, camera imaging, bolometry, neutrons, Thomson scattering, electron cyclotron emission, reflectometry, Langmuir probes and structural temperature and strain sensing. A more detailed overview can be found at: https://pubs.aip.org/aip/rsi/article/95/10/103518/3317155.
CFS is looking to grow the SPARC team in order to complete the mechanical design and integration of these diagnostic systems as they move through design closeout, analysis, procurement, test, and installation. At present we’re finalizing the design and starting assembly for many of the front-end, in vacuum measurement devices and are looking to add multi-faceted support to help carry those designs across the finish line, take on engineering challenges associated with their build and test, and help design the structural components associated with ex-vessel data transmission to our diagnostic labs. Candidates will work as part of an integrated diagnostic team along with fusion scientists and other engineers to demonstrate net energy from a tokamak for the first time. CFS encourages applications from both senior and early career engineers and those interested in cross-industry career changers to help us build a diverse team to meet our mission goals.
What you'll do:
- Shepherd SPARC diagnostic sub-systems through design closeout, test, and procurement, working with a team of scientists, designers, analysts and engineers
- Integrate technical input from experts on the team to ensure diagnostic designs will survive SPARC’s harsh environments and be usable to achieve SPARC’s scientific mission goals
- Coordinate with manufacturing engineers to align on build and test strategy for complex integrated systems, and support builds in the field to maintain quality and speed
- Contribute to a strong safety culture
What we're looking for:
- Bachelor’s degree in a relevant engineering field (mechanical, aerospace, civil or nuclear)
- 5+ years of relevant experience designing and delivering mechanical systems
- Demonstrated examples of delivering cradle-to-grave mechanical design with nuanced environmental or performance requirements
- Experience designing for manufacturing and assembly, and collaborating with partners to oversee or carry out integrated builds
- Bias toward action, and a balance of engineering intuition and technical rigor that allows for robust, simple designs to be generated with speed
- First principles based approach to engineering and ability to understand concepts and tradeoffs that bridge engineering and physics
- Strong communication skills to gather inputs and distribute information across several partner teams
Bonus points for:
- Experience with Siemens NX, Teamcenter, or Ansys as CAD, PLM, and analysis tools
- Experience with software development, particularly in Python
- Experience designing large equipment requiring lifting/rigging tools to assemble
- Experience with design of systems for exposure to high stress, UHV, high temperature, high magnetic field, and/or radiation environments
Must-have requirements:
- Ability to occasionally lift up to 50 lbs
- Perform activities such as climbing, typing, standing, or sitting for extended periods of time
- Willingness to travel or work required nights/weekends/on-call occasionally
- Work in a facility that contains industrial hazards including heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, high current, pressure systems, and cryogenics