Instrumentation Physicist: Digital Twin

Instrumentation Physicist: Digital Twin Location: Palo Alto, CA (hybrid) 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 what someone can do today; we hire for who they are and who they are becoming.What We Need — and Why It Matters The goal is to be a digital twin of the accelerator. The first step is virtual commissioning: tune a simulated machine to specification using only what its instruments can measure. This role makes each simulated instrument read what the real instrument would read, with the same noise, offsets and calibration errors.The twin is a shared project. Accelerator Physics owns the beam dynamics and the error budget. The ML team owns surrogate models, fast solvers, and anomaly detection. This role is in the Diagnostics team and owns the instrument models.What You'll Do Instrument models - Model each diagnostic from physics, from the beam through the pickup, front-end electronics and digitizer to the processed reading. Include noise, offsets, nonlinearity and calibration errors.- Validate each model against bench and machine data, and report how well it predicts the real readings.- Turn models that others write into tested, reusable parts.Virtual commissioning - Commission the diagnostic systems in simulation before they meet beam: calibration, resolution, and the measurement procedures that use them.- With Accelerator Physics, develop the tuning procedures that depend on these measurements, and test them on simulated machines with unknown errors.Integration - Serve each instrument model through EPICS with the same PVs as the real instrument, so that operator software runs the same against the twin and against the machine.- Connect instrument readout to the twin, with the team's Electrical, FPGA and Controls engineers.Simulation software - Build and maintain the instrument models in the shared twin code base, and keep them correct and fast as the code base grows.- Review code from other contributors, including code written by AI agents.- Contribute to the beam dynamics codes the twin uses (Bmad / Tao, Impact, Genesis) where the instrument models need it.Virtual diagnostics - With the ML team, infer beam properties that no single instrument measures, from several measurements and a model.What We Are Looking For - Ph.D. in Physics or related field, or equivalent experience- Strong software engineering in Python: structure, testing (pytest), packaging, code review, including review of code written by AI agents.- The Python scientific stack: NumPy, SciPy, Matplotlib, etc.- Scientific or numerical computing where the result must be physically correct.- Physics depth, from a degree in physics or a related field or from demonstrated work.- Knowledge of how measurement instruments work, from physical signals through electronics to digitized data, including noise and calibration.- Hands-on measurement with real instruments: bench tests, data acquisition and calibration.- Ability to work closely with other physicists and engineers and learn about new devices quickly.And If You Bring This — Even Better Instruments and signals - Beam position, current or loss monitors- Screens, cameras and optical imaging- Instrument and noise modeling- Signal processing and DSP- RF and analog front endsPhysics and simulation - Bmad / Tao- Genesis / Minerva- Impact- EM simulation of pickups and structures (CST, HFSS)- Monte Carlo methodsControls - EPICS IOCs- pyepics, caproto, PVAccess- Instrument control and DAQSoftware - Fortran or C++ in established simulation codes- GPU or HPC computing- Web front ends for scientific tools- Containers and CIDomain - Accelerator, FEL or synchrotron facility experience- Detector, DAQ or diagnostic systems in particle, nuclear, plasma or fusion physics- Digital twins or hardware-in-the-loop simulationWhat You Can Expect from Us 100% Company-funded health insurance for employeeCompany funded Life Insurance and disability insurance401k contribution. 100% up to 3% of compensation, plus 50% match between 3% and 5%. Immediately vested.Flexible Paid Time-Off, Sick leave and Company HolidaysCompany Paid Two-weeks Winter BreakFlexible Hybrid Work ModelPay 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 100,000/year-145,000/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.