{"schemaVersion":"jobsearcher.job.v1","id":"f1e89f479fbb2b79f2e1039d","url":"https://jobsearcher.com/jobs/f1e89f479fbb2b79f2e1039d","canonicalUrl":"https://jobsearcher.com/jobs/f1e89f479fbb2b79f2e1039d","title":"Mechanical Engineer, RF Systems","description":"About Commonwealth Fusion Systems:\n\nCommonwealth Fusion Systems is on a mission to deliver the urgent transition to fusion energy.\n\nCombining decades of research, top talent, and new technologies, we’re designing and building commercially viable fusion power plants. And we're working with policymakers, suppliers, and many others to build the energy industry of the future.\n\nWe’re in the best position to make it happen. Since 2018, we’ve raised $4 billion of capital, making us the largest and leading fusion company in the world.\n\nNow 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.\n\nIf that’s you and this role fits, we want to hear from you.\n\nJoin the power movement as an Mechanical Engineer, RF Systems\n\nSPARC sustains fusion reactions by feeding >25MW of 120MHz RF power into the tokamak to heat the plasma to 100 million Kelvin. We need a Mechanical Engineer to design the critical physical infrastructure that routes this massive power, from coax transmission lines that span the entire plant to the intricate cooling plates required for high-power electronics.\n\nAt this level, you will own the physical design and integration of robust mechanical systems, translating requirements into manufacturing-ready hardware. You will design everything from large-scale utility interfaces and custom bellows to sheet metal parts and custom heat sinks, taking designs from ideation and CAD modeling through fabrication and direct plant integration.\n\nFor more information on the SPARC RF plant, see the SPARC journal papers here:\n\nOverview of the SPARC tokamak\nPhysics basis for the ICRF system of the SPARC tokamak\nWhat you'll do:\nDesign specialized RF Heating plant components working closely with RF Engineers. These include large-diameter coaxial transmission lines and devices such as stub tuners and RF testing loads\nDecompose high-level system requirements into actionable mechanical specifications, owning the mechanical designs for the RF Heating system\nCollaborate daily with a dedicated CAD drafting team, providing clear guidance to detail, rigorously reviews, and releases\nPartner cross-functionally with RF engineers, electronics engineers, process engineers, and other disciplines\nArchitect thermal management solutions by integrating complex water and air cooling loops directly into high-power electronics enclosures and plant systems\nDevelop large sheet metal components, precise mounting hardware for custom printed circuit board assemblies, cold plates, and more\nPerform structural loads analysis and thermal analyses to ensure design viability\nWhat we’re looking for:\nBachelor’s degree in Mechanical Engineering, Physics, or a related field\n5+ years of hands-on mechanical design experience in industrial, heavy machinery, high-power electronics, electric vehicle, or aerospace environments\nDemonstrated experience as the primary creator and owner of mechanical design architectures, operating as a core design engineer\nDirect experience performing structural loads analysis and thermal analyses to validate mechanical designs\nHigh proficiency in 3D CAD software and creating detailed manufacturing drawings utilizing GD&T standards\nPossess a strong fundamental understanding of heat transfer, structural mechanics, and fluid dynamics\nBonus points for:\nExperience using Siemens NX for 3D modeling and Teamcenter for product lifecycle management and drawing release workflows\nBackground decomposing complex system requirements into clear mechanical hardware specifications\nExperience designing large-scale pipe routing, coaxial transmission lines, flanges, bellows, or active water and air cooling systems\nExperience with complex electronics assemblies and the thermal management of such assemblies\nDeep familiarity with sheet metal fabrication processes, machining capabilities, and communicating directly with contract manufacturers\nMust-have Requirements:\nAbility to lift up to 50lbs\nPerform activities such as stooping, climbing, standing, typing or sitting for extended periods of time\nWillingness to travel or work required nights/weekends/on-call occasionally\nWork in a facility that contains industrial hazards including heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, high current, pressure systems, and cryogenics\nSalary 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.\n\nBenefits include:\n• Competitive compensation with equity\n• 13 Company-wide Holidays\n• Flexible vacation days\n• 10 sick days\n• Generous parental leave policy\n• Health, dental, and vision insurance\n• 401(k) with employer matching\n• Professional growth opportunities\n• Team-building activities\n#LI-Onsite\n\nAt 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.\n\nWe 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.\n\nThis 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.","company":"Commonwealthfusionsystems5","rawCompany":"commonwealthfusionsystems5","city":"Devens","state":"MA","isRemote":false,"isActive":false,"createdAt":"2026-09-25T11:33:18.076Z","occupations":[{"code":"17-2141.00","title":"Mechanical Engineers","slug":"mechanical-engineers"},{"code":"17-2199.00","title":"Engineers, All Other","slug":"engineers-all-other"},{"code":"17-3013.00","title":"Mechanical Drafters","slug":"mechanical-drafters"}],"industries":[{"code":"333248","title":"All Other Industrial Machinery Manufacturing","slug":"all-other-industrial-machinery-manufacturing"},{"code":"541330","title":"Engineering Services","slug":"engineering-services"},{"code":"541715","title":"Research and Development in the Physical, Engineering, and Life Sciences (except Nanotechnology and Biotechnology)","slug":"research-and-development-in-the-physical-engineering-and-life-sciences-except-nanotechnology-and-biotechnology"}],"jobPosting":{"@context":"https://schema.org","@type":"JobPosting","title":"Mechanical Engineer, RF Systems","description":"About Commonwealth Fusion Systems:\n\nCommonwealth Fusion Systems is on a mission to deliver the urgent transition to fusion energy.\n\nCombining decades of research, top talent, and new technologies, we’re designing and building commercially viable fusion power plants. And we're working with policymakers, suppliers, and many others to build the energy industry of the future.\n\nWe’re in the best position to make it happen. Since 2018, we’ve raised $4 billion of capital, making us the largest and leading fusion company in the world.\n\nNow 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.\n\nIf that’s you and this role fits, we want to hear from you.\n\nJoin the power movement as an Mechanical Engineer, RF Systems\n\nSPARC sustains fusion reactions by feeding >25MW of 120MHz RF power into the tokamak to heat the plasma to 100 million Kelvin. We need a Mechanical Engineer to design the critical physical infrastructure that routes this massive power, from coax transmission lines that span the entire plant to the intricate cooling plates required for high-power electronics.\n\nAt this level, you will own the physical design and integration of robust mechanical systems, translating requirements into manufacturing-ready hardware. You will design everything from large-scale utility interfaces and custom bellows to sheet metal parts and custom heat sinks, taking designs from ideation and CAD modeling through fabrication and direct plant integration.\n\nFor more information on the SPARC RF plant, see the SPARC journal papers here:\n\nOverview of the SPARC tokamak\nPhysics basis for the ICRF system of the SPARC tokamak\nWhat you'll do:\nDesign specialized RF Heating plant components working closely with RF Engineers. These include large-diameter coaxial transmission lines and devices such as stub tuners and RF testing loads\nDecompose high-level system requirements into actionable mechanical specifications, owning the mechanical designs for the RF Heating system\nCollaborate daily with a dedicated CAD drafting team, providing clear guidance to detail, rigorously reviews, and releases\nPartner cross-functionally with RF engineers, electronics engineers, process engineers, and other disciplines\nArchitect thermal management solutions by integrating complex water and air cooling loops directly into high-power electronics enclosures and plant systems\nDevelop large sheet metal components, precise mounting hardware for custom printed circuit board assemblies, cold plates, and more\nPerform structural loads analysis and thermal analyses to ensure design viability\nWhat we’re looking for:\nBachelor’s degree in Mechanical Engineering, Physics, or a related field\n5+ years of hands-on mechanical design experience in industrial, heavy machinery, high-power electronics, electric vehicle, or aerospace environments\nDemonstrated experience as the primary creator and owner of mechanical design architectures, operating as a core design engineer\nDirect experience performing structural loads analysis and thermal analyses to validate mechanical designs\nHigh proficiency in 3D CAD software and creating detailed manufacturing drawings utilizing GD&T standards\nPossess a strong fundamental understanding of heat transfer, structural mechanics, and fluid dynamics\nBonus points for:\nExperience using Siemens NX for 3D modeling and Teamcenter for product lifecycle management and drawing release workflows\nBackground decomposing complex system requirements into clear mechanical hardware specifications\nExperience designing large-scale pipe routing, coaxial transmission lines, flanges, bellows, or active water and air cooling systems\nExperience with complex electronics assemblies and the thermal management of such assemblies\nDeep familiarity with sheet metal fabrication processes, machining capabilities, and communicating directly with contract manufacturers\nMust-have Requirements:\nAbility to lift up to 50lbs\nPerform activities such as stooping, climbing, standing, typing or sitting for extended periods of time\nWillingness to travel or work required nights/weekends/on-call occasionally\nWork in a facility that contains industrial hazards including heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, high current, pressure systems, and cryogenics\nSalary 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.\n\nBenefits include:\n• Competitive compensation with equity\n• 13 Company-wide Holidays\n• Flexible vacation days\n• 10 sick days\n• Generous parental leave policy\n• Health, dental, and vision insurance\n• 401(k) with employer matching\n• Professional growth opportunities\n• Team-building activities\n#LI-Onsite\n\nAt 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.\n\nWe 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.\n\nThis 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.","datePosted":"2026-09-25T11:33:18.076Z","dateModified":"2026-09-25T11:33:18.076Z","hiringOrganization":{"@type":"Organization","name":"Commonwealthfusionsystems5","sameAs":"https://jobsearcher.com"},"jobLocation":{"@type":"Place","address":{"@type":"PostalAddress","addressLocality":"Devens","addressRegion":"MA","addressCountry":"US"}},"identifier":{"@type":"PropertyValue","name":"JobSearcher","value":"f1e89f479fbb2b79f2e1039d"},"url":"https://jobsearcher.com/jobs/f1e89f479fbb2b79f2e1039d"}}