Sr Mechanical Engineer (Vacuum Systems)

Avalanche is a Seattle-based start-up developing compact fusion machines for clean, energy-dense power generation at a scale you can hold in your hands.  Our unique approach allows us to build, test, break, learn and iterate in days.  The modular design is designed to provide power to applications from austere environments to deep sea vehicles and maritime transport to lunar power. 

We know we have an incredibly ambitious mission, and that it requires a wide combination of skills, attitude, and grit to make it happen. If you have a passion for abundant energy, and how we can improve life with it, we want to have a chat with you.

Avalanche might be fit for you if: You are self-motivated, energized by problem solving and working closely with hardware. You enjoy hands-on, creative collaboration with a small, tight-knit team you can work with, laugh with, and learn with on a wide variety of topics.  You can learn and pivot between priorities when necessary and you can slide the headphones on, focus, and auger deep into a single topic as needed.  You thrive in an atmosphere of development, and you are an ardent learner who’s always looking for ways to grow and improve.

About the Role

Avalanche Energy is seeking a Mechanical Engineer to design, build, and maintain the mechanical systems that support our compact fusion devices. You will work directly on vacuum hardware, structural assemblies, thermal management systems, and supporting laboratory infrastructure, contributing to experiments that are designed, built, and iterated rapidly.

This is a deeply hands-on role. You will be responsible for everything from CAD modeling and component selection to fabrication, assembly, testing, and troubleshooting under demanding conditions. The work spans precision vacuum systems, structural design, thermal and high-voltage management, and integration with experimental hardware. You will be working with materials ranging from stainless steels to refractory metals and ceramics. This is not a desk job or a simulation-first role—this is lab-centered engineering focused on getting complex mechanical systems to work, reliably and repeatably.

Responsibilities

• Design, build, and maintain mechanical and vacuum systems supporting fusion experiments, diagnostics, and laboratory infrastructure.

Mechanical Engineer

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• Work alongside physicists and engineers to conceive, implement, and refine mechanical systems for experimental hardware, from initial concept through fabrication, assembly, and iteration.

• Specify, procure, fabricate, and test mechanical hardware including vacuum vessels, structural mounts, thermal interfaces, feedthroughs, and precision mechanical assemblies.

• Perform hands-on troubleshooting of mechanical and vacuum systems, diagnosing issues related to leaks, thermal performance, structural loading, alignment, and hardware fit-up.

• Support experiment operation by setting up, validating, and maintaining mechanical systems, vacuum hardware, and associated diagnostics.

• Provide mechanical insight into experimental results, helping interpret hardware performance, system behavior, and failure modes.

• Contribute to continuous improvement of lab mechanical practices, documentation, fabrication standards, and build processes.

Required Qualifications

• B.S. degree or higher in mechanical engineering, aerospace engineering, or a closely related field.

• 2-5 years of post-degree experience in hands-on mechanical engineering roles, preferably in a laboratory or experimental hardware environment.

• Strong command of mechanical engineering fundamentals, including structural analysis, thermal systems, fluid mechanics, and materials selection.

• Proficiency in 3D CAD tools (e.g., SolidWorks, CATIA, or equivalent) for design, assembly modeling, and drawing generation.

• Experience designing, assembling, and operating vacuum systems, including familiarity with pumping systems, gauging, and leak checking.

• Experience with thermal management design, including heat transfer analysis, cooling system design, and thermal interface materials.

• Experience working with machine shops and fabrication processes, including tolerance specification, GD&T, and hands-on assembly of precision mechanical hardware.

• Familiarity with FEA tools for structural or thermal analysis (e.g., ANSYS, Abaqus, or equivalent).

• Comfort working directly with physical hardware in a laboratory or machine shop environment, including hands-on assembly, installation, and test.

Desired Qualifications

• Experience designing or building hardware for laboratory experiments, research programs, or scientific instruments.

• Experience working with design or fabrication using ceramic materials, including MACOR or Alumina.

• Experience with high-vacuum or ultra-high-vacuum (HV/UHV) systems, including system design, bakeout, and troubleshooting.

• Familiarity with plasma physics hardware or fusion-related systems, such as magnetic coils, ion sources, beam optics, or high-voltage electrical feedthroughs.

• Experience with precision machining or direct hands-on fabrication, including lathe, mill, or other shop equipment.

• Experience working with cryogenic systems, high-pressure hardware, or other mechanically demanding environments.

Additional Considerations

Location: Prefer onsite to support hands-on laboratory work and close integration with experimental teams.
Sites: Tukwila or Richland, Washington.
Travel: Occasional travel for equipment procurement, integration, or collaboration as needed.
Schedule: Standard business hours, with flexibility during experimental campaigns or critical test periods.

Benefits

• Excellent medical, dental, and vision benefits.

• 10 paid holidays and a company-wide December holiday break.

• Generous paid vacation and sick time.

• Small, tight-knit team with low barriers to action.

• Exposure to a wide range of challenging, hands-on engineering problems.

• Meaningful equity in the form of stock options.

We value people of all backgrounds. We are an equal opportunity employer, and you do not need to match every listed qualification to apply. If you like being hands-on, all over the system, and making difficult hardware work in the real world, we encourage you to apply.

This position may require access to export-controlled information. In order to comply with U.S. export control laws, applicants must be a “U.S. person” as defined by U.S. trade control laws (U.S. citizen, lawful permanent resident, or protected individual).

Benefits:

• Excellent medical, dental and vision benefits: We pay 100% of your premiums

• 10 paid holidays and company-wide December holiday break

• Generous paid vacation and sick time

• Small, tight-knit team with low barriers to action

• Exposure to a wide variety of problems for unparalleled, hands-on professional growth

• Weekly employer provided team meals, a well-stocked kitchen, and employee events on and off-site

• Opportunity for Equity

Avalanche values people of all races, ethnicities, genders, ages, religions, and sexual orientations. We also acknowledge the value that different life experiences bring to our organization. Avalanche is an equal opportunity employer, and you do not need to match every listed expectation to apply for this position. We encourage all individuals who are excited about delivering fusion energy to the world to apply.

Notice to Recruitment Agencies

Avalanche Energy does not accept unsolicited resumes or candidate submissions from staffing agencies, search firms, or third-party recruiters. Agencies should not submit candidate information through our careers site or directly to hiring managers or employees without prior authorization from our Talent Acquisition team.

Avalanche Energy will not be responsible for placement fees or other charges associated with unsolicited submissions. Agency partnerships and candidate submissions must be authorized in advance and supported by a signed agreement with Avalanche Energy.