Computational Physicist

xLight Inc.; San Francisco (CA); Hybrid; USD 125,000 - 180,000; Full time

Benefits offered by this job

Health insurance

Life insurance

Disability insurance

401k

Paid time off

Winter break

Flexible hybrid work

Job summary

xLight Inc. is advancing free-electron laser technology for industrial lithography and metrology. The Computational Physicist will translate theoretical models into practical engineering solutions in an interdisciplinary R&D setting.

The role emphasizes developing large-scale simulations, optimizing system performance, and collaborating with accelerator physicists, RF engineers, and experimental teams to validate models and drive innovations in FEL design.

Qualifications

• PhD in Physics or closely related field or equivalent research experience.
• Strong foundation in mechanics, electromagnetism, accelerator physics, and numerical methods.
• 5+ years developing computational models for complex physical systems.
• 5+ years experience in scientific computing, data processing, and visualization.

Responsibilities

• Develop computational models and simulations of particle accelerator and FEL systems.
• Perform beam dynamics simulations including particle tracking and collective effects.
• Model and analyze electromagnetic fields, RF structures, and beam–field interactions.
• Develop simulations for Free Electron Laser physics including electron–photon interactions.

Skills

Python

C++

Beam dynamics

Numerical methods

Scientific computing

Communication

Education

PhD in Physics or related field

Tools

Bmad

Elegant

Genesis

ASTRA

WarpX

OPAL

IMPACT

MAD-X

Job description

Reports To: Director, Accelerator Physics

About xLight

xLight is building the world's most powerful laser to revolutionize semiconductor lithography, metrology, and other critical applications. Our approach is to harness the power of free-electron lasers by building on accelerator technology currently used at scientific facilities around the world. In extending this technology, we are developing industrial-grade light sources, engineered for continuous operation to meet the sophisticated demands of next-generation patterning, metrology, and inspection applications. Join us in this new revolution!

At xLight, we hire exceptional talent and exceptional means more than a strong résumé. How we achieve results is just as important as the results themselves, which is why attitude and character matter as much as technical skill. We believe great talent is widely distributed and not confined to a particular school or background. We seek individuals who demonstrate ownership, a spirit of collaboration, technical curiosity, and a genuine willingness to learn and grow - guided by our core values of Respect, Integrity, Creativity, and Engineering Excellence. We don't just hire for what someone can do today; we hire for who they are and who they are becoming.

What We Need and Why It Matters

The Computational Physicist will develop and apply computational models to understand, predict, and optimize the behavior of particle beams, electromagnetic fields, accelerator components, and Free Electron Lasers.

This role will work closely with accelerator physicists, FEL scientists, RF engineers, controls engineers, and experimental teams to turn theoretical models into practical engineering solutions. The ideal candidate combines strong fundamentals in physics with advanced numerical modeling, scientific computing, and a hands‑on approach to solving complex problems.

What You’ll Do

• Develop computational models and simulations of particle accelerator and FEL systems.
• Perform beam dynamics simulations, including particle tracking, longitudinal and transverse dynamics, and collective effects.
• Model and analyze electromagnetic fields, RF structures, accelerator components, and beam–field interactions.
• Develop simulations for Free Electron Laser physics, including electron–photon interactions, gain, bunching, and FEL performance.
• Conduct numerical studies to optimize accelerator and FEL parameters and system performance.
• Develop physics‑based models to investigate system sensitivity, stability, tolerances, and sources of performance degradation.
• Implement and improve computational methods for large-scale numerical physics problems.
• Analyze simulation and experimental data and establish correlation between computational predictions and measured system performance.
• Build automated simulation and optimization workflows to accelerate engineering and scientific design cycles.
• Work with experimental teams to define measurements and experiments that validate computational models.
• Communicate simulation results, assumptions, limitations, and recommendations to both technical and cross‑functional teams.
• Contribute to the development of internal computational tools, simulation frameworks, and physics models.
• Document models, methodologies, simulation results, and technical conclusions.
• Stay current with advances in accelerator physics, FEL technology, computational physics, and scientific computing.

What We Are Looking For

• Ph.D. in Physics, Computational Physics, Accelerator Physics, Applied Physics, or a closely related field; or equivalent advanced research experience.
• Strong foundation in classical mechanics, electromagnetism, accelerator physics, and numerical methods.
• 5+ years experience developing computational models for complex physical systems.
• 5+ Experience with scientific computing, numerical analysis, data processing, and visualization.
• Strong programming skills in Python and/or C++.
• Experience working with simulation or particle‑tracking codes.
• Ability to independently formulate physics problems, develop computational approaches, and interpret simulation results.
• Strong analytical and problem‑solving skills.
• Excellent written and verbal communication skills.
• Ability to work effectively in a highly interdisciplinary, fast‑paced R&D environment.

And If You Bring This Even Better

• Experience with Free Electron Laser (FEL) physics or high‑brightness electron beams.
• Experience with accelerator simulation and modeling tools such as Bmad, Elegant, Genesis, ASTRA, GPT, WarpX, OPAL, IMPACT, MAD-X, or comparable tools.
• Experience with particle‑in‑cell (PIC) or other electromagnetic simulation techniques.
• Experience with RF accelerator physics and superconducting RF systems.
• Experience with undulator physics and electron–photon interactions.
• Experience with beam dynamics, collective effects, space charge, wakefields, CSR, or beam instabilities.
• Experience with optimization, parameter scans, uncertainty quantification, or machine‑learning‑assisted modeling.
• Experience working with high‑performance computing (HPC), parallel computing, GPUs, or distributed simulation.
• Familiarity with Linux‑based scientific computing environments and Git‑based software development.
• Experience correlating computational models with experimental accelerator or FEL data.

What You Can Expect from Us

• 100% Company‑funded health insurance for employee
• Company funded Life Insurance and disability insurance
• 401k contribution. 100% up to 3% of compensation, plus 50% match between 3% and 5%. Immediately vested.
• Flexible Paid Time‑Off, Sick leave and Company Holidays
• Company Paid Two‑weeks Winter Break
• Flexible Hybrid Work Model

Pay transparency

The pay range for this position reflects the minimum and maximum target for new hire salaries at commencement of employment and is expected to be between USD 125,000/year-180,000/year. However, base pay offered may vary depending on multiple factors, including location, role, job‑related knowledge, skills, relevant education and experience. The total compensation package for this position may also include other elements, including equity, and a full range of benefits. Details of all benefits will be provided if an employee receives an offer of employment.

EEO Statement

xLight Inc. is an Equal Opportunity Employer. Our policy is clear: there shall be no discrimination on the basis of age, disability, sex, race, religion or belief, gender reassignment, marriage/civil partnership, pregnancy/maternity, or sexual orientation. We are an inclusive organization and actively promote equality of opportunity for all with the right mix of talent, skills and potential. We welcome all applications from a wide range of candidates. Selection for roles will be based on individual merit alone.