Multipactor is a parasitic phenomenon that occurs in devices where a microwave is transmitted under vacuum such as electronic vacuum tubes for electron microscopy, resonant cavities and couplers for particle accelerators and microwave circuits. on board the satellites. It consists of an avalanche of electrons set in motion by a radiofrequency field which can cause, under certain conditions, a disturbance of measurements, damage or even destruction of RF devices.
This phenomenon is directly linked to the emission of so-called secondary electrons from a material when it is irradiated with electrons. The secondary electron production yield (SEY for Secondary Emission Yield) is therefore a crucial parameter if we want to greatly reduce the multipactor phenomenon.
This thesis project aims at the fundamental study of SEY of thin films synthesized by Atomic Layer Deposition (ALD). ALD is a thin film synthesis technique used in the microelectronics, photovoltaic, battery industries…, which allows unparalleled control of thickness and chemical composition down to the atomic level on complex surfaces. This deposition technique is therefore a remarkable tool for 1 / studying separately and in a controlled manner the impact of different alloys (chemical composition), and their thickness on the SEY and 2 / directly applying these optimized structures on "real »RF devices. This thesis will be done in collaboration between CEA and ONERA. It combines at the same time a proven deposition technique, means of spectroscopic surface characterizations of peaks and numerical simulations.