Summer 2026 Internship - Physics

Xcimer Energy • Denver, CO

13d • $25 - $35 • Onsite

About The Position

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! Join Xcimer’s engineering internship program and gain hands-on experience in designing and building cutting-edge laser-driven inertial fusion hardware and software. As an intern, you will be integral to developing the systems needed for the world’s first commercial fusion energy power plant. We have multiple internship opportunities available across various disciplines, including Mechanical Engineering, Electrical Engineering, Physics, and Software Development. Please apply to the posting that best matches your background and interests. During this 12-week program at our headquarters in Denver, CO, you’ll work alongside an industry expert mentor to tackle complex, real-world challenges in fields such as structures, mechanisms, optics, pulsed power, computational engineering, plasma physics, and manufacturing. We are seeking interns who are passionate about applying their technical skills, problem-solving abilities, and commitment to quality to drive the future of clean energy! Application close date: 12/31/2025

Requirements

• Qualified candidates must be enrolled in a Bachelor's, Master’s or PhD degree program from an accredited college or university in mechanical engineering, electrical engineer, physics, nuclear engineering, or other related engineering discipline.
• Application of technical skills outside of the classroom (examples include: extracurricular projects, volunteering, personal projects, laboratory research, or prior internship/work experience).
• Proficiency in CAD software for 3D modeling and simulation.
• Strong written, verbal, communication, and interpersonal skills.
• Passion for fusion energy!
• Ability to work full-time onsite through the duration of the 12 week internship program in Denver, CO.
• 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.

Responsibilities

• Mechanical design and hardware development
• Mechanical and thermal analysis using finite element analysis
• Systems engineering
• Manufacturing engineering
• Electrical engineering (pulsed power)
• Control systems engineering
• Computational and software engineering (simulations)
• Nuclear engineering
• Optical engineering
• Plasma physics

Benefits

• Employee Benefits include: Medical, dental, vision, basic and supplemental life insurance, paid parental leave (must be employed at time of birth or adoption), short and long-term disability, 401(k) with a company match of up to 6%.
• Paid Time Off: 15 days per year based on weekly scheduled hours, 10 paid sick leave, and 13 company-paid holidays for all regular employees (including part-time), fixed-term, and interns.
• Equity will be granted to eligible employees. Equity is designed to allow employees to share in company results and success.

What This Job Offers

• Job Type: Full-time
• Career Level: Intern