Joséphine Monzac, passionate about physics

« From what I had seen during my internships and in discussions with former students, I understood that ENSTA graduates could very quickly be called upon to take on managerial responsibilities. It's great that the ENSTA degree is so highly valued in the working world, but personally, I preferred to continue studying physics. So the idea of pursuing a PhD naturally came to mind. »

After completing a third year as a substitute in the advanced physics program at École Polytechnique, Joséphine Monzac feels perfectly equipped to begin a doctoral thesis. She will be working at the Laboratoire d'optique appliquée, one of the ENSTA laboratories (CNRS-ENSTA-École Polytechnique-UMR 7639) under the supervision of Jérôme Faure

One of the LOA's research topics is laser-plasma acceleration, one of the most promising applications of lasers for the coming decades. The idea is to interact an ultra-short laser with plasma (a state of matter in which electrons are separated from atoms) to accelerate electrons to a speed close to that of light over an extremely short distance, on the order of a centimeter.

This fantastic acceleration capacity far exceeds that of conventional particle accelerators, which still require several tens of meters of acceleration to achieve the same result.

Joséphine Monzac's work has improved the performance of the LOA's high-frequency laser-plasma accelerator, known as the “Orange Room.” The energy of the electrons produced has increased from 3 to 7 MeV while maintaining a kHz frequency by using hydrogen plasma instead of nitrogen, with a very good explanation of the mechanism causing this gain when changing gases.

The good performance in terms of stability and energy, and the high repetition rates achieved, made it possible to produce a first electron diffraction image, paving the way for a novel method of investigating the organization and behavior of materials at the atomic scale.