A new Thomson scattering diagnostic has recently been installed on the WEST tokamak. It enables the measurement of electron density and temperature along a laser path by collecting photons scattered by the plasma using multiple optical detection systems.

The system relies on a pulsed YAG laser (1064 nm, 5 ns, 30 Hz), whose trajectory must be controlled with millimeter precision to intersect the collection optics lines of sight. The optical path, approximately 15 meters long, includes several mirrors mounted on remotely controlled motorized mounts. After passing through the plasma, the laser beam is absorbed in an instrumented dump.

The objective of this apprenticeship is to develop an automated alignment system for the laser beam in order to optimize measurement quality and ensure a safe, unobstructed beam path.

The project will focus on the following tasks:

• Implementing beam trajectory visualization systems (near-field and far-field sensors, cameras):
  • Optical setup optimization;
  • Camera triggering and synchronization;
  • Real-time image processing to reconstruct the beam trajectory;
    Positioning error and sensitivity analysis.
• Controlling motorized optical mounts and coupling them with beam trajectory computation tools;
• Processing high-frequency (GHz) acquisition data from the detection system:
  • Signal amplitude computation;
  • Implementing feedback control to adjust the laser trajectory and optimize the measured signal.

This project aims to develop a complete control system integrating measurement, analysis, and actuation to enhance Thomson scattering diagnostic performance.

You are currently enrolled in an engineering school with a specialization in instrumentation, optics, or photonics.

Ideally, you have:

• Knowledge of optics and pulsed laser systems;
• Experience or interest in image processing;
• Basics in control systems and optimization;
• Programming skills (Python, C, and/or LabVIEW).