Staff Research Scientist - Advanced Projects

 The Princeton Plasma Physics Laboratory (PPPL) seeks a Staff Research Scientist to lead the commissioning, integration, and scientific exploitation of a femtosecond two-photon absorption laser-induced fluorescence (fs-TALIF) neutral-density diagnostic and the real-time edge Thomson scattering system on the WEST tokamak (CEA Cadarache, France). The successful candidate will deliver real-time, spatially resolved measurements of edge neutral (deuterium) profiles co-located with WEST’s high-resolution Thomson scattering system, and will use these data to develop a quantitative understanding of WEST edge and pedestal dynamics in an ITER-relevant, full-tungsten environment. This is a unique opportunity to build a first-of-a-kind diagnostic capability and contribute directly to the U.S. and international fusion power-exhaust mission. The position is based at PPPL (Princeton, NJ) and will require several  international trips of 2 to 4 weeks per year to WEST.

A U.S. Department of Energy National Laboratory managed by Princeton University, the Princeton Plasma Physics Laboratory (PPPL) is tackling the world’s toughest science and technology challenges using plasma, the fourth state of matter. With more than 70 years of history, PPPL is a leader in the science and engineering behind the development of fusion energy, a potentially limitless energy source. PPPL is also using its expertise to advance research in the areas of microelectronics, quantum sensors and devices, and sustainability sciences. Whether it be through science, engineering, technology or professional services, every team member has an opportunity to contribute to our mission and vision. Come join us!

To develop, commission, and scientifically exploit the femtosecond two-photon absorption laser-induced fluorescence (fs-TALIF) neutral diagnostic on the WEST tokamak, providing the first high-resolution (5 mm spatial, 1 ms temporal) measurements of atomic deuterium neutral density in an ITER-relevant tungsten-wall environment. The Staff Research Scientist will integrate fs-TALIF with WEST’s real-time, high-resolution Thomson scattering (TS) system to obtain simultaneous, co-located profiles of neutral density (n_D), electron density (n_e), and electron temperature (T_e), and will lead edge-profile studies that build a quantitative understanding of WEST edge and pedestal dynamics—including neutral penetration, ionization sourcing, and their role in setting the density transport barrier and divertor performance. These measurements will validate and improve neutral-transport models (e.g., DEGAS 2) critical to ITER and future fusion devices.

• Diagnostic design, integration, and commissioning. Design, bench-test, and deploy the fs-TALIF system on WEST, including the coaxial beam transport that overlaps the Thomson scattering laser, the opto-mechanical and vacuum-window interfaces, UV beam delivery (205 nm), and collection optics; verify beam pointing, pulse duration, and spot size against WEST constraints. (30%)
• Real-time integration and calibration. Synchronize fs-TALIF with the WEST central timing system and the high-resolution Thomson scattering diagnostic, integrate data acquisition with the WEST database, and establish absolute neutral-density calibration using a krypton reference cell to enable real-time edge measurements at up to 1 kHz. (20%)
• Edge-profile studies and physics analysis. Lead measurement campaigns acquiring simultaneous, co-located n_D, n_e, and T_e profiles across L-mode, H-mode, and gas-puff scenarios, impurity dropper, and multiple plasma configurations; analyze WEST edge dynamics, including neutral penetration, the local ionization source, edge parameters, and divertor neutral behavior. (25%)
• Model validation and scientific output. Support the model validation using the measured neutral distributions against DEGAS 2 predictions, deliver datasets to the modeling team, and disseminate results through peer-reviewed publications and conference presentations. (15%)
• Collaboration and project coordination. Coordinate with PPPL, CEA/WEST, and Texas A&M collaborators; mentor students and postdoctoral researchers; and contribute to project reporting and DOE data-management compliance. (10%)

• Ph.D. in plasma physics, applied physics, optical science/engineering, or a closely related field, plus a minimum of 2 years of relevant postdoctoral or research experience.
• Demonstrated experience with laser-based plasma diagnostics (e.g., LIF/TALIF, Thomson scattering, or comparable laser spectroscopy) is required, along with hands-on experience deploying diagnostics on a tokamak or other magnetic-confinement or laboratory plasma device.
• Expertise in laser diagnostics and optical design. Background in Thomson scattering including real time integration in magnetically confined devices.
• Proficiency in scientific programming and data analysis (e.g., Python, MATLAB, or IDL) and real-time data acquisition.
• Ability to design, align, and operate complex opto-mechanical systems in a fusion environment, to integrate diagnostics with machine timing and database systems, and to work effectively within an international, multi-institutional collaboration.
• Excellent written and verbal communication skills, and a record of peer-reviewed publication.
• Willingness and ability to travel internationally and work on-site at WEST (CEA Cadarache, France) for extended periods.

Certifications and/or Licenses:

• None required at hire. Laser safety certification and radiation-worker and site-specific safety training are required and will be provided as a condition of working on-site at PPPL and WEST (CEA Cadarache, France).

Physical Requirements:

• Ability to work in and around experimental laser and experimental facilities, including periods of standing, bending, and working in confined or elevated diagnostic areas.
• Capable of performing precise optical alignment tasks and handling laboratory equipment.
• Must be able to wear required personal protective equipment, including laser safety eye-wear.
• Reasonable accommodation will be provided as required by law.

Working Conditions:

Work is performed in laboratory and experimental-hall environments at the WEST facility (CEA Cadarache, France). The position requires extended international travel and on-site assignments at WEST for diagnostic installation, commissioning, and experimental campaigns. Work may be aligned with the WEST shot cycle and can involve occasional extended or non-standard hours during campaigns. The role involves Class 4 laser systems and requires strict adherence to all laser, electrical, and radiation safety protocols at both PPPL and CEA.

Princeton University is an Equal Opportunity Employer and all qualified applicants will receive consideration for employment without regard to age, race, color, religion, sex, sexual orientation, gender identity or expression, national origin, disability status, protected veteran status, or any other characteristic protected by law.

The University considers factors such as (but not limited to) scope and responsibilities of the position, candidate's qualifications, work experience, education/training, key skills, market, collective bargaining agreements as applicable, and organizational considerations when extending an offer. The posted salary range represents the University's good faith and reasonable estimate for a full-time position; salaries for part-time positions are pro-rated accordingly.

If the salary range on the posted position shows an hourly rate, this is the baseline; the actual hourly rate may be higher, depending on the position and factors listed above.

The University also offers a comprehensive benefit program to eligible employees. Please see this link for more information.

Please be aware that the Department of Energy (DOE) prohibits DOE employees and contractors from participation in certain foreign government talent recruitment programs. All PPPL employees are required to disclose any participation in a foreign government talent recruitment program and may be required to withdraw from such programs to remain employed under the DOE Contract.