---
title: 'Director of Fusion Nuclear Science at Xcimer Energy'
canonical: 'https://feeny.ai/job/director-of-fusion-nuclear-science-xcimer-energy-denver-72zcpjkxfa1y'
type: 'job'
last_seen: '2026-09-13'
---

# Director of Fusion Nuclear Science at Xcimer Energy

- **Company:** Xcimer Energy
- **Location:** Denver, CO
- **Compensation:** $220k–$260k
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-08-25
- **Last confirmed live:** 2026-09-13
- **Apply:** https://jobs.lever.co/xcimer/d34ae80a-3bf3-4259-b0e1-6c9b1c5f7ec3

## Job description

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 Director of Fusion Nuclear Science provides strategic, technical, and organizational leadership for the scientific disciplines that enable the realization and industrialization of practical fusion power systems. This leader will define and execute the long‑term scientific roadmap supporting fusion chamber dynamics, blanket multi-physics, tritium science, and other critical fusion nuclear science domains needed to deliver Xcimer’s next‑generation fusion energy platform. The successful candidate will recruit, build, and mentor multidisciplinary world‑class scientific teams; establish long-term scientific roadmap; and ensure that cutting‑edge research translates into validated models, experimental data, and actionable design guidance. This role partners closely with program and engineering leadership, and other science department directors, while serving as the company’s primary authority for fusion nuclear science.

## Responsibilities

- Build, lead and grow the Fusion Nuclear Science department, including hiring, onboarding, mentoring, and professional development of scientific staff.
- Define and own the scientific roadmap for fusion chamber dynamics, blanket multi-physics, tritium science, and supporting fusion nuclear science domains.
- Develop the strategy for scientific tools, modeling frameworks, experimental capabilities, and validation infrastructure.
- Oversee scientific analysis, modeling, code development, and experimental programs with strong emphasis on reproducibility, uncertainty quantification, and model credibility.
- Translate scientific insights, experimental data, and validated models into design guidance for engineering teams responsible for fusion system architecture.
- Collaborate closely with the engineering  and operations divisions, and with other science departments, to ensure strong communication and alignment.
- 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 modeling tools, experimental facilities, or other fusion nuclear science scope.
- Establish department‑wide scientific best practices, documentation standards, review processes, and quality expectations appropriate for industrial fusion systems.
- Identify key scientific risks across fusion nuclear science programs and drive mitigation strategies supporting execution and long‑term scalability.
- Support system troubleshooting, root‑cause investigations, and scientific review of failures or anomalies encountered in development or experimental operations.
- Align fusion nuclear science priorities with company strategy, program schedules, resource constraints, and commercialization goals in partnership with executive leadership.

## Qualifications

- Education: PhD in Nuclear Science, Nuclear Engineering, Nuclear Physics, or a closely related field.
- Experience: 12+ years of experience in analysis, simulation, experimental R&D, or technology development for complex nuclear or fusion systems under extreme thermal and radiation environments.
- Leadership: 6+ years in leadership of multidisciplinary scientific or R&D organizations.
- Deep experience with nuclear analysis tools (e.g., MCNP), multi‑physics simulation software (e.g., COMSOL, ANSYS), and reactor thermohydraulic codes (e.g., RELAP, MELCOR).
- Experience designing and executing experiments that raise component or system technology readiness.
- Proven record of mentoring and growing high-performing technical teams.
- Strong publication and scientific leadership record.
- Ability to operate effectively within a rapidly evolving organization transitioning from startup to industrial scale.
- Ability to balance hands‑on 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

- Experience in fusion chamber research, blanket multi-physics, and tritium fuel cycle analysis.
- Familiarity with fusion safety and regulatory requirements.
- Experience in the commercial nuclear industry or fusion experimental facilities.
- Knowledge of tritium handling systems, molten salt technologies.
- Familiarity with fusion plant design and commercialization efforts.

## 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.

## About Xcimer Energy

## Company Overview
- **One-liner**: Xcimer Energy is building the world’s most powerful excimer lasers to commercialize inertial fusion energy, delivering safe, affordable, and effectively limitless power while also strengthening national security.
- **Entity Type**: Private (Series A; total funding ~$200M)
- **Headquarters**: Denver, Colorado, United States (with manufacturing operations in Tucson, Arizona)
- **Founded**: 2022
- **Founders**: Conner Galloway (CEO, CSO) and Alexander Valys (President, CTO)

## Core Business
- **Primary industry/industries**: Fusion energy (inertial confinement fusion), laser systems, national security/defense
- **Target customers**: B2B / B2G (utilities, government, defense contractors, national laboratories)
- **Mission or purpose statement**: “Transform decades of scientific progress into commercial fusion plants to deliver safe, affordable, and effectively limitless energy—while improving air defense and national security.”

## Products & Services
- **Phoenix (2026)**: Prototype system demonstrating core laser technology and laser architecture in Denver.
- **Anvil (2028)**: 200 kJ, two-sided inertial fusion energy (IFE) excimer beamline demonstrator using Argos laser modules – the largest laser amplifiers in the world.
- **Vulcan (2031)**: Engineering (wall-plug) breakeven demonstration – world’s largest laser, combining many Argos modules to achieve 4 MJ of laser energy on target, upgradeable to 12 MJ.
- **Athena (2035)**: First commercial laser fusion power plant, delivering 400 MW of electricity to the grid.
- **National Security Applications**: Nuclear Weapons Effects Testing (NWET), stockpile stewardship, and directed energy systems.

## Market Standing
- **Valuation/Market Cap**: Not publicly available
- **Key Metric**: Total funding – “nearly $200 million” per FAQ page; “more than $150M raised” per media page (conflicting reports, both cited)
- **Notable Investors/Partners**: Hedosophia, Breakthrough Energy Ventures, Lowercarbon Capital, Prelude Ventures, Emerson Collective, Starlight Ventures, Wireframe Ventures, Leitmotif Ventures, Gigascale Capital. Also partners with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, Oak Ridge National Laboratory, Naval Research Laboratory, MIT, University of Rochester, General Atomics, Westinghouse.
- **Growth Signals**: Headcount of 109 employees (+45.6% YoY), plans to double the team over the next year, 32 open positions across 5 departments, largest laser fusion award from U.S. Department of Energy’s Milestone-Based Fusion Development Program.

## Competitive Advantages
- **Excimer laser architecture (KrF)**: 30x lower cost per joule than the solid-state lasers used at NIF; technology is commercially proven in semiconductor lithography.
- **Scientifically validated approach**: Only fusion method that has achieved scientific breakeven in the laboratory (NIF ignition).
- **Aggressive but grounded roadmap**: Wall-plug breakeven by 2031, grid power by 2035 – one of the fastest timelines in the industry.
- **Dual-use technology**: Fusion energy platform also serves critical national security applications, opening additional funding and partnership avenues.

## Strategic Focus
- Complete Phoenix and Anvil milestones to de-risk laser architecture.
- Hire and scale the team (targeting double the current headcount).
- Secure site for Vulcan and prepare for engineering breakeven demonstration.
- Advance commercial fusion power plant (Athena) design and regulatory pathways.
- Expand defense and government partnerships.

## Why Work Here
- **Culture highlights**: Values precision, creativity, collaboration, and questioning assumptions. Team includes top talent from fusion, energy, defense, aerospace, semiconductor lithography, and academia.
- **Work environment**: Primarily onsite in Denver, CO (engineering roles); flexible work environment, dog-friendly office, free lunch Tuesdays and Thursdays.
- **Notable perks**: Competitive wages, equity compensation plan, comprehensive health/dental/vision insurance, 401k with employer match, up to 12 weeks paid parental leave, 13 paid holidays, generous sick leave and vacation, relocation package, professional growth opportunities.
- **Internship program**: Highly competitive, hands-on experience in fusion science and engineering; strong track record of converting interns to full-time hires.

## Sources
1. [xcimer.energy/company](https://xcimer.energy/company/)
2. [xcimer.energy/careers](https://xcimer.energy/careers/)
3. [xcimer.energy/faq](https://xcimer.energy/faq/)
4. [xcimer.energy/media](https://xcimer.energy/media/)
5. [linkedin.com/company/xcimer-energy-corporation](https://linkedin.com/company/xcimer-energy-corporation)

## Other roles at Xcimer Energy

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