Effect of charging-up and regular usage on performance of the triple GEM detector to be employed for plasma radiation monitoring

After the problem of high-temperature plasma confinement, construction of diagnostics that is able to identifyplasma contamination with impurities and to determine impurity distribution is another critically importantissue. Solution of this problem would enable progress towards the success in controlled thermonuclear fusion. Anew diagnostics, based on Gas Electron Multiplier (GEM) technology, has been recently developed for poloidaltomography focused on radiation of the metal impurities by monitoring in Soft X-Ray (SXR) region. GEM baseddetectors would undergo much less damage by neutrons than standard semiconductor diodes which results inbetter operational stability. This paper emphasizes the results of the latest examination of this type of detectors,showing influence of the charging-up effect on the detector performance and its physical properties for expectedplasma radiation intensity. In addition, an undesired influence of aging of the detector window’s material on theperformance of the GEM detector is also shown: regular (moderate or active) usage could lead to changes ofmaterial’s morphology as well as its composition. This study confirms the importance of further research intomaterial’s optimization of GEM detectors used as a base for SXR tomographic diagnostics aimed to work underdifferent plasma radiation conditions.