SECTION I · THE BRIEF
Brief #68343Updated 20 AUG 2026DEVENS, MALeverKHOSLA VENTURES
Employbl Company Profile

Principal Scientist - Radio Frequency Plasma Heating

Commonwealth Fusion Systems (CFS) is an American company founded in 2018 aiming to build a compact nuclear fusion power plant based on the ARC tokamak reactor concept. The company is based in Cambridge, Massachusetts,…

Location
Devens, MA
Company size
500–2,000
Posted
1w ago
Via
Lever
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Principal Scientist - Radio Frequency Plasma Heating · Commonwealth Fusion Systems

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Job title
Principal Scientist - Radio Frequency Plasma Heating
Job location
Devens, MA
Job description
About Commonwealth Fusion Systems:
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, suppliers, and many others to build the energy industry of the future.
We’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.
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 a Principal Scientist - Radio Frequency Plasma Heating

CFS is looking for an enthusiastic experimental RF Scientist/Engineer to join the team to operate the SPARC ion cyclotron heating system and study RF physics/engineering in SPARC and ARC.

The SPARC tokamak aims to be the first magnetic confinement device to achieve net energy and is predicted to have up to Q=11 in DT, producing up to 140 MW of fusion power. The sole auxiliary heating for SPARC is a 120 MHz, 25 MW (coupled) Ion Cyclotron Resonance Heating (ICRH) system that will launch into SPARC via an array of 14 4-strap ICRH antennas. The novel, solid-state 120 MHz sources and the ICRH antennas are already in production.

The Ion Cyclotron Discharge Cleaning (ICDC) System provides one of several mechanisms to clean and condition the exposed surfaces within the Tokamak confinement vessel, including boronization of plasma facing components. The ICDC System is similar in design but wholly distinct from the ICRF, with its own transmitter, transmission network, and antennas.

The Scientist – Radio Frequency Plasma Heating will be vital to the successful commissioning and operation of both the ICRH and ICDC systems. They will prepare for commissioning via simulations of the antennas and the plasmas and then will be a key part of the team to operate SPARC and to design ARC.
What you'll do:
  • Simulate the SPARC ICRH antennas and RF network system to inform commissioning and operation
  • Contribute to testing of ICRH/ICDC components
  • Inform the implementation of the RF control system and operator interfaces
  • Contribute to the development of commissioning and operation plans and procedures for the ICRH/ICDC system
  • Commission the SPARC ICRH/ICDC system into early plasmas
  • Operate the SPARC ICRH system during Q>1 and high power DT plasmas
  • Study the physics of radio frequency waves in SPARC
  • Provide input to ARC design through simulation and modeling efforts
  • Work with multi-institutional team of collaborators from universities and national labs
  • What we’re looking for:
  • PhD in plasma physics or a closely related discipline
  • 7+ years experience (post degree) working with radio frequency heating, current drive or discharge cleaning systems in fusion plasmas (this may include ion cyclotron, lower hybrid, helicon, or other similar wave systems)
  • Experience running experiments on tokamaks, stellarators, or similar plasma confinement devices
  • Experience developing hardware for plasma physics experiments
  • Experience working with COMSOL, ANSYS HFSS, CST, or similar finite element tools
  • A desire for active participation in tokamak design and operations
  • A drive toward practical solutions to integrated physics and engineering challenges
  • Expertise in ICRF, plasma physics, fusion engineering, and fusion power plant design
  • Bonus points for:
  • 10+ years experience in operating and/or simulating RF heating of plasmas
  • Experience with Python
  • Experience designing ICRH system, RF diagnostics, control and operation tools and procedures for radio frequency heating
  • Experience modelling ICDC physics
  • Must-have Requirements:
  • Perform extended activities such as typing, standing, sitting, etc.
  • Willingness to travel or work required nights/weekends/on-call regularly; expected to travel 1-2 times per year for conferences
  • 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
  • View job listing ↗
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    Where this role is based

    Devens, MA

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    Commonwealth Fusion Systems headquarters

    Cambridge, MA

    Company size

    5002,000 employees

    Founded

    2018

    Total raised

    $3,877,000,000

    View company profile ↗

    Funding rounds