RF Systems Mechanical Engineer – High-Power Thermal Design

Fusion Energy Base; Harvard (MA); On-site; USD 90,000 - 145,000; Full time

Benefits offered by this job

Equity

Health insurance

401(k) with employer matching

Generous vacation policy

Sick days

Parental leave

Job summary

Commonwealth Fusion Systems in Devens, MA is seeking a Mechanical Engineer, RF Systems to own the mechanical design of the RF heating plant, from large-diameter coax lines to cooling plates required for high‑power electronics.

You will collaborate with RF engineers, electronics and process teams, decompose requirements into actionable specifications, and produce manufacturing‑ready drawings with GD&T while validating thermal and structural performance.

Qualifications

• Bachelor’s degree in Mechanical Engineering, Physics, or a related field.
• 5+ years of hands-on mechanical design experience in heavy machinery or high-power electronics.
• Experience owning mechanical design architectures from concept to manufacturing release.
• Strong CAD skills and ability to produce GD&T-compliant drawings.

Responsibilities

• Design RF Heating plant components, including large-diameter coaxial transmission lines and loads.
• Translate high-level requirements into mechanical specifications and own RF system designs.
• Collaborate with CAD drafting team to create detailed manufacturing drawings and releases.
• Architect thermal management by integrating water and air cooling loops in enclosures and plant systems.
• Develop large sheet metal parts, mounting hardware, and cold plates for PCB assemblies.
• Perform structural loads and thermal analyses to verify design viability.
• Work with RF engineers, electronics engineers, process engineers and other disciplines.

Skills

Mechanical design

3D CAD

Thermal analysis

Structural analysis

GD&T

Cross-functional collaboration

Education

Bachelor’s degree in Mechanical Engineering, Physics, or related field

Tools

Siemens NX

Teamcenter

Job description

Commonwealth Fusion Systems in Devens, MA is seeking a Mechanical Engineer, RF Systems to own the mechanical design of the RF heating plant, from large-diameter coax lines to cooling plates required for high‑power electronics.

You will collaborate with RF engineers, electronics and process teams, decompose requirements into actionable specifications, and produce manufacturing‑ready drawings with GD&T while validating thermal and structural performance.