Principal Experimental Scientist

U.S. Fusion Energy; Energy (IL); On-site; USD 230,000 - 270,000; Full time

Benefits offered by this job

Medical, Dental, and Vision plans

PTO 31 days

401(k) match up to 5%

Parental leave

Wellness stipend

Job summary

Helion, a fusion power company based in Everett, WA, seeks a Principal Experimental Plasma Scientist to lead the plasma diagnostic effort for its fusion generators. This onsite role reports to the Director of Plasma and Nuclear Science in Everett.

You will own design and deployment of diagnostics, integrate input from physics, engineering and data science, and ensure high data fidelity across campaigns. The position offers a rigorous environment with ownership, urgency, and opportunities to

Qualifications

• PhD in physics/engineering with a focus on plasma science, diagnostics, or high-vacuum instrumentation.
• 10+ years in advanced lab environments with plasma systems and UHV infrastructure.
• Proven use of diagnostic measurements (interferometry, spectroscopy, Langmuir probes, etc.) to drive system improvements.
• Expertise in multiple areas of plasma diagnostics and fusion engineering; operates independently.

Responsibilities

• Own end-to-end design and deployment of plasma diagnostics.
• Integrate input from plasma physics, machine operations, controls, and data science.
• Lead assembly, installation, calibration, and commissioning of diagnostics across campaigns.
• Develop expertise in pre-ionization plasma diagnostics and best practices.
• Analyze diagnostic data in real time to extract insights and inform tuning.
• Partner with leadership on strategy, roadmaps, and long-term vision.

Skills

Plasma diagnostics

Data analysis

Independent researcher

High-vacuum systems

Education

PhD in physics or related field

Tools

Interferometry

Spectroscopy

Langmuir probes

Magnetic coils

Electrostatic diagnostics

Job description

About Helion

We are a fusion power company based in Everett, WA, with the mission to build the world's first fusion power plant, enabling a future with unlimited clean electricity. Our vision is a world with clean, reliable, and affordable energy for everyone.

Location

Everett, WA

Employment Type

Full time

Location Type

On-site

Department

Science

Compensation

$230K – $270K

Overview

We are a fusion power company based in Everett, WA, with the mission to build the world's first fusion power plant, enabling a future with unlimited clean electricity. Our vision is a world with clean, reliable, and affordable energy for everyone. Since Helion's founding in 2013, we have raised $1.5 billion from long-time investors such as Sam Altman, Mithril, and Capricorn Investment Group as well as new investors including Thrive Capital, LightSpeed Venture Capital, SoftBank, and others to propel us forward. Our current prototype, Polaris, has reached record-breaking plasma temperatures of 150 million degrees Celsius (13 keV). Helion is continuing to iterate and on the path to the world's first fusion power plant, Orion. This is a pivotal time to join Helion. You will tackle real-world challenges with a team that prizes urgency, rigor, ownership, and a commitment to delivering hard truths – values essential to achieving what no one has before. Together, we will change the future of energy, because the world can't wait.

What You Will Be Doing

We are looking for a Principal Experimental Plasma Scientist to lead the plasma diagnostic effort of Helion's fusion generators. This is an onsite role that reports directly to our Director of Plasma and Nuclear Science at our Everett, WA office.

You Will

• Own the end-to-end design and deployment of a comprehensive suite of plasma diagnostics, collaborating closely with physicists, engineers, designers, and data analysts to ensure robust, scalable instrumentation that meets both experimental and operational requirements
• Integrate cross-disciplinary technical input from experts across Helion—including plasma physics, machine operations, controls, and data science—to align diagnostic capabilities with real-time operational needs and long-term scientific milestones
• Lead the hands-on execution of assembly, installation, calibration, and commissioning processes for diagnostics across multiple campaigns and testbeds. Ensure high data fidelity through rigorous validation and alignment procedures
• Develop foundational expertise in pre-ionization plasma diagnostics, establishing best practices and internal methodologies that inform next-generation fusion device development optimized for energy gain and power conversion
• Analyze diagnostic data in real time to extract actionable insights about plasma behavior, inform operational tuning, and identify opportunities for performance optimization and system redesign
• Partners with leadership across the organization, contributing to strategic planning, roadmap development, and long-term technical vision

Required Skills

• Ph.D. in physics, electrical engineering, aerospace engineering, or a related discipline, with a focus on plasma science, diagnostics, or high-vacuum instrumentation
• 10+ years of experience working in advanced laboratory environments, with extensive hands-on work involving plasma generation, plasma systems, and UHV vacuum infrastructure
• Demonstrated track record using diagnostic measurements (e.g., interferometry, spectroscopy, Langmuir probes, magnetic coils, electrostatic diagnostics) to evaluate plasma parameters such as density, temperature, and current profiles, directly influencing system improvements
• Deep expertise and unique domain knowledge in multiple areas of plasma diagnostics and fusion engineering. Recognized as a subject matter expert who operates independently

Benefits

• Medical, Dental, and Vision plans for employees and their families
• 31 Days of PTO (21 vacation days and 10 sick days)
• 10 Paid holidays, plus company-wide winter break
• Up to 5% employer 401(k) match
• Short term disability, long term disability, and life insurance
• Paid parental leave and support (up to 16 weeks)
• Annual wellness stipend

Helion is an equal opportunity employer and value diversity at our company. We do not discriminate based on race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. If you need assistance or an accommodation during the interview process, please let us know.

Compensation Range: $230K - $270K