Design of an FPGA zero-crossing algorithm for density measurement

Vacancy details

General information

Organisation

The French Alternative Energies and Atomic Energy Commission (CEA) is a key player in research, development and innovation in four main areas :
• defence and security,
• nuclear energy (fission and fusion),
• technological research for industry,
• fundamental research in the physical sciences and life sciences.

Drawing on its widely acknowledged expertise, and thanks to its 16000 technicians, engineers, researchers and staff, the CEA actively participates in collaborative projects with a large number of academic and industrial partners.

The CEA is established in ten centers spread throughout France
  

Reference

2026-40252  

Position description

Category

Intrumentation, metrology and control

Contract

Work-Study contract

Contract duration (months)

12

Job description

In tokamaks such as WEST, one of the main diagnostics used to measure plasma density is a laser interferometer. It relies on the phase difference between a probing beam passing through the plasma and a reference beam. This phase shift is directly related to the electron density of the plasma.

The objective of this apprenticeship is to develop a robust real-time phase comparison system based on a zero-crossing detection algorithm implemented on a Red Pitaya board equipped with an FPGA.

Your main tasks will include:

  • Designing and implementing an FPGA-based zero-crossing algorithm for phase measurement;
  • Developing real-time error detection and correction mechanisms (signal loss, fringe jumps, anomalies);
  • Improving fringe jump detection methods;
  • Benchmarking the developed solution against the existing diagnostic system;
  • Validating the algorithms through simulations and Python-based analysis tools.

Initially, the work will focus on laboratory testing of the FPGA implementation. Depending on progress, validation using real plasma data may also be performed.

 

This project is also part of a broader European framework (Eurofusion – WP-DTT) and addresses key challenges for future fusion devices.

 

Expected deliverables:

  • FPGA code implementing phase measurement on the Red Pitaya platform;
  • Python scripts for testing and data analysis;
  • Final report summarizing the work;
  • Presentation of results to the WEST team.

Applicant Profile

You are currently pursuing a Master’s degree or an engineering degree in electronics, instrumentation, or embedded systems.

Ideally, you have:

  • Knowledge of System-on-Chip (SoC) and FPGA programming;
  • Background in signal processing and time series analysis;
  • Python programming skills for data analysis;
  • Interest in electronics and embedded systems.

Position location

Site

Cadarache

Job location

France, Provence-Côte d'Azur, Bouches du Rhône (13)

Location

  Saint Paul lez Durance

Candidate criteria

Languages

English (Intermediate)

Prepared diploma

Bac+5 - Diplôme École d'ingénieurs

Requester

Position start date

01/06/2026