Research Scientist - Advanced Projects

Staff Research Scientist

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…