Metallic Coatings in the Diagnosis of Run‐Away Electrons in Magnetic Confinement Fusion Facilities

Abstract The article presents the application of a low‐temperature plasma technique accomplished by controlled arc discharges in ultra‐high vacuum deposition of metallic coatings on ceramic substrates. Such metallic coatings are very important in the diagnostic devices within the magnetic confinement fusion facilities, especially in small and medium‐sized tokamaks. The application of molybdenum coating on the diamond substrate necessary for Cherenkov‐type detectors applied as a runaway electron diagnosis is an example of such an application in diagnostic techniques. Presented research focused on the structural analysis of molybdenum coatings and the influence of different synthesis parameters on coatings' diverse structures and thicknesses. The stability of molybdenum coatings is explored using the Rod Plasma Injector IBIS2 facility. Pulsed plasma interactions induced noticeable surface changes, mirroring the destruction observed after exposure to up to 10 plasma pulses. In addition, the characteristics of Cherenkov detector molybdenum coating destruction after experimental campaigns are presented.