Senior Mechanical Engineer - Diagnostics

About the role

Pacific Fusion is a company founded in 2023 dedicated to providing clean power through abundant, affordable, and clean energy. We are currently designing and building a pulser-driven inertial fusion system aimed at achieving net facility gain. Additionally, we are developing essential components for cost-effective fusion systems. With significant funding from investors, we are assembling a team of experts from various fields including fusion science, engineering, and industry. Our goal is to address climate change and meet increasing global energy demands.

Why This Role Matters

Pacific Fusion is seeking an exceptional Senior Mechanical Engineer to contribute to the creation of commercial fusion energy. This role involves owning mechanical scopes, providing technical direction to multidisciplinary teams, and ensuring the successful design, analysis, integration, and validation of mechanical systems and components. The position requires deep technical expertise and innovative problem-solving skills, as well as the ability to collaborate effectively within a dynamic team.

What You'll Do

• Own assigned mechanical scope end-to-end, providing technical direction to multidisciplinary teams to translate system requirements into robust, deliverable designs
• Provide subject matter expertise in mechanical design and analysis for advanced diagnostic instrumentation, from concept through release
• Develop precision motion and thermal management solutions compatible with high-vacuum and radiation environments
• Define and verify mechanical alignment requirements for optical and detector systems, coordinating with metrology and assembly teams
• Apply optomechanical design principles for mirrors, lenses, and optical mounts to ensure precision alignment and performance of diagnostic systems
• Create and maintain 3D CAD models and 2D fabrication drawings with GD&T for machined, sheet-metal, and additive-manufactured components
• Perform FEA (structural, thermal) to validate designs against shock, vibration, and thermal loads expected in pulsed fusion experiments
• Maintain rigorous revision control and configuration management in PDM/PLM systems: part numbering, BOMs, ECOs, and CAD library maintenance
• Mentor early-career engineers and contribute to the technical development of the broader team
• Perform other duties as assigned

What You Bring

• Bachelor’s degree in mechanical engineering or related field; advanced degree a plus
• Strong first-principles engineering instincts and problem-solving skills
• 5+ years’ experience in mechanical design for vacuum-compatible instrumentation, ideally with radiation or high-energy diagnostics
• Expert proficiency in a professional 3D CAD platform (Creo, NX, or SolidWorks), GD&T, and producing detailed manufacturing drawings
• Significant experience with FEA tools (ANSYS, COMSOL) for structural and thermal analysis
• Demonstrated ability to navigate competing design constraints simultaneously: vacuum compatibility, radiation tolerance, thermal management, and tight geometric envelopes internally and between neighboring subsystems
• Proven ability to operate as an effective individual contributor: self-directed and accountable for assigned deliverables end-to-end
• Comfortable driving cross-functional stakeholders — vendors, technicians, and peer engineers — to keep mechanical deliverables on schedule
• Excellent verbal and written communication skills for technical documentation and cross-functional collaboration
• Able to work closely with team members and project manager in fast-paced environment with ambitious deadlines

Bonus Points

• Experience in fusion, plasma physics, accelerator physics, defense, or other high-consequence technical environments
• Familiarity with vacuum systems, cryogenics, high-voltage hardware, or pulsed power components
• Exposure to large-scale structural systems, pressure vessels, or custom capital equipment

Pay Range

$138,100—$263,800 USD Total Compensation & Benefits For Eligible Employees

Industry-competitive salary

Equity plan 6% employer

401k matching

Generous paid time off (including sick leave, vacation, paid family leave)

Medical, Dental, and Vision insurance

Actual base salary offered will be determined by: experience, skills, and work location.

This range is for base salary, our total compensation includes equity and benefits.

We welcome you to apply even if your expectations are outside our listed range.