Mechanical Engineer

Xcimer Energy leverages decades of research on Inertial Fusion Energy (IFE) combined with groundbreaking new laser architecture. Our mission is to deploy fusion power plants to meet global decarbonization goals as fast as possible. Xcimer has assembled a team of leaders in tough tech, fusion science, and manufacturing with a track record of rapid execution. Supported by leading investors, Xcimer is uniquely positioned to deliver limitless, clean, fusion power to combat climate change. Join us in powering a better world with inertial fusion! 

This is a full-time, onsite role based at our headquarters in Denver, CO. 

As a Mechanical Engineer, you will play a critical role in the design, analysis, build, and operation of laser, pulsed power, vacuum vessel, and ancillary mechanical systems that are central to Xcimer’s excimer‑laser‑based IFE technology. You will contribute across the full product lifecycle—from early prototype systems through the design and demonstration of a power‑producing inertial fusion reactor. We are seeking engineers who bring strong technical depth, hands‑on problem-solving skills, and a passion for building high‑performance hardware that will redefine the future of energy. 

Responsibilities

Create 3D models, detail part drawings, assemblies, P&ID’s and interface control documents.
Design structures and pressure vessels, perform proof-tests to code standards.
Communicate and document design with mechanical, systems, laser and optical engineering and manufacturing team members.
Support procurement of the hardware for the prototype laser amplifiers and optical conditioning equipment.
Selection of sensors and instruments, work with controls team for integration
Oversee and assist assembly by a team of interdisciplinary technicians.
Support ongoing operation of the subject equipment and systems.
Continue above roles and responsibilities to participate in subsequent amplifier up-scaling leading to that which is needed for a power-producing IFE reactor.
Participate in concept studies supporting the use of these lasers in a power-producing IFE reactor, and other applications.
Contribute to authoring work instructions, test plans, specifications, and other documentation for the integration and operation of complex systems of systems
Provide manufacturing and production support and first-time engineering builds
Participate in design reviews and help to streamline engineering processes
Work with cross-functional teams that are responsible for selecting materials, manufacturing processes, and suppliers to produce world class hardware.
Plan, coordinate, conduct tests, and review test data
Maintain and report on activity schedule, budget and technical status
Identify opportunities for improvements and operational cost savings 

Qualifications

Education: B.S. in Mechanical, Nuclear, Aerospace Engineering, or related field.
Experience: 3-5 years in mechanical engineering, with a focus on industrial equipment design (preferred industries include semiconductor, solar, R+D, nuclear, fusion energy, lasers, defense).
Proficiency with 3D CAD software (NX preferred).
Working knowledge of Finite Element Analysis (FEA).
Experience getting design projects over the finish line, built, and qualified.
Strong problem-solving skills and a hands-on approach to troubleshooting and testing.
Interdisciplinary engineering experience is a plus.
Must be a U.S. citizen or national, U.S. permanent resident (current Green Card holder), or lawfully admitted into the U.S. as a refugee of granted asylum  

Desired

• Start-up experience preferred  

Equal Employment Opportunity

Xcimer Energy is proud to be an Equal Opportunity/Affirmative Action Employer and is committed to attracting, retaining, and developing a highly qualified, diverse, and dedicated work force. Xcimer Energy hires and promotes people on the basis of their qualifications, performance, and abilities. We support the establishment and maintenance of a workplace that fosters trust, equality, and teamwork, in which all employees recognize and appreciate the diversity of individual team members. We provide all qualified applicants for employment and employees with equal opportunities for hire, promotion, and other terms and conditions of employment, regardless of their race, color, religion, gender, sexual orientation, gender identity, national origin/ethnicity, age, physical or mental disability, genetic factors, military/veteran status, or any other status or characteristic protected by federal, state, and/or local law. Xcimer Energy will consider for employment qualified applicants with criminal histories in a manner consistent with applicable federal, state, and local laws.

Benefits

Xcimer offers a comprehensive benefits package designed to support employee health, well-being, and long-term success. Benefits include medical, dental, and vision coverage; basic and supplemental life insurance; short- and long-term disability; paid parental leave for employees at the time of birth or adoption; and a 401(k) with a company match of up to 6%. Eligible employees also receive equity, allowing them to share in the company’s long-term success.

Xcimer operates under a flexible Paid Time Off (ATO) approach. Rather than a fixed number of vacation days, employees are trusted to take the time they need to rest and recharge while meeting the expectations of their role and team. In addition, employees receive paid sick time, 13 company-paid holidays, and an annual paid company shutdown. Benefits are available to regular employees, including part-time and fixed-term roles, as well as interns, with eligibility varying by benefit.