Senior Molten Salt Scientist

U.S. Fusion Energy; Illinois; On-site; USD 170,000 - 210,000; Full time

Benefits offered by this job

Equity

401(k) with company match

Paid time off

Job summary

Xcimer Energy, a leader in inertial fusion energy research, seeks a PhD‑level Laboratory Lead to establish and run the Molten Salt Laboratory in Denver, CO. You will design, build, and operate salt test facilities, driving experimental programs that inform fusion power plant development.

The role requires deep molten salt expertise, hands‑on lab leadership, and the ability to scale capabilities from first pots to integrated test loops. Equal commitment to safety and innovation is essential.

Qualifications

• PhD required in a relevant engineering field.
• 12+ years of experience in experimental high-temperature fluids or related R&D.
• Deep experience with molten salts or liquid metals and high-temperature systems.

Responsibilities

• Lead planning, design, build, commissioning and operation of the Molten Salt Laboratory.
• Define and own the development roadmap for molten salt capabilities from small pots to large test loops.
• Develop timelines for prototypical thermal-hydraulic test environments and associated tests.
• Collaborate with science and engineering teams to translate results into design requirements.
• Establish laboratory best practices, documentation standards, and quality expectations.
• Manage relationships with external labs, vendors, and collaborators.

Skills

Molten salt

High temperature fluids

Laboratory leadership

Experimental design

Project management

Education

PhD in Mechanical Engineering, Nuclear Engineering, or Chemical Engineering

Tools

Laboratory equipment

Job description

Denver, CO

Science – Nuclear Science /

Full-Time /

On-site

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.

The successful candidate will be responsible for building the company's technical capability in Flibe (Li₂BeF₄) and other molten salts, including chemistry control, materials compatibility, corrosion, thermophysical properties, tritium behavior, impurity control, salt processing, and measurements/instrumentation for advancing the technology development of our fusion plant power systems.

This individual will lead the design, commissioning, and management of the Molten Salt laboratory, establish experimental capabilities and procedures, and develop a research program that directly informs the design and operation of the company's fusion power plant. The role will work closely with other science departments and with engineering teams to translate experimental results into requirements and design solutions.

The role will work closely with other science departments and with engineering teams to translate experimental results into requirements and design solutions.

The ideal candidate will combine deep technical expertise in molten salts with hands‑on laboratory experience and the ability to establish a new experimental capability from the ground up.

Responsibilities

• Lead the planning, design, build, commissioning, and operation of the Molten Salt Laboratory including sourcing materials and equipment, mentoring science and engineering teams, and developing molten salt operational experience and expertise.
• Define and own the development roadmap for molten salt capabilities including science and engineering workscopes from small pots of static molten salt all the way to large, forced flow integrated effects test loops.
• Develop the timeline for key prototypical thermal-hydraulic test environments including fabrication methods, corrosion tests, jet nozzle design and testing, and mass and heat exchanger design and testing.
• Partner with other Science departments and with the Engineering and Operations divisions to ensure strong communication, and to align on scientific, engineering, and operational goals for fusion power systems development.
• Translate scientific insights, experimental data, and hands-on-experience into design guidance for teams responsible for fusion system architecture.
• Evaluate emerging scientific opportunities and integrate advances from academia, national laboratories, and international fusion programs.
• Manage relationships with external laboratories, university collaborators, and vendors providing materials, pumps, and fabricated components for high temperature salt systems.
• Establish molten salt laboratory research best practices, documentation standards, review processes, and quality expectations.
• Support system troubleshooting, root‑cause investigations, and engineering review of failures or anomalies encountered in development of experimental operations.

Qualifications

• Education: PhD in Mechanical Engineering, Nuclear Engineering, Chemical Engineering, or a closely related field.
• Experience: 12+ years of experience in experimental high temperature fluids (molten salts or liquid metals), experimental R&D, or technology development for complex nuclear or fusion systems under extreme thermal and radiation environments.
• Deep experience with high temperature fluids, thermal-hydraulics, and industrial scale systems.
• Demonstrated hands-on laboratory experience and the ability to establish a new experimental capability from the ground up.
• Experience designing and executing experiments that raise component or system technology readiness.
• Demonstrated leadership of multidisciplinary scientific or R&D organizations.
• Proven record of mentoring and growing high-performing technical teams.
• Strong publication and scientific or engineering leadership record.
• Ability to operate effectively within a rapidly evolving organization transitioning from startup to industrial scale.
• Ability to balance hands‑on engineering and scientific leadership with high‑level strategic direction and organizational oversight.
• 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 or granted asylum.

Desired

• Familiarity with fusion safety and regulatory requirements.
• Experience working under and adhering to beryllium safety requirements.
• Experience in the commercial nuclear industry or fusion experimental facilities.
• Familiarity with fusion plant design and commercialization efforts.

$170,000 - $210,000 a year

Candidates may be considered for other positions at Xcimer Energy, and our actual base salary will be determined on an individual basis and may vary based on job‑related knowledge and skills, education, and experience. The range is published in accordance with Colorado Equal Pay for Equal Work Act and California Equal Pay Act.

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. For more information on “EEO Is the Law,” please see here and here.

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.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.