Metallic mirrors will be essential components of all optical systems for plasma diagnosis in ITER. A comprehensive First Mirror Test (FMT) has been carried out in the JET tokamak. The exposure was followed by a characterisation of mirrors and their carriers. The main results obtained by optical and surface analysis methods are: (i) reflectivity of all tested mirrors is degraded either by erosion with charge exchange neutrals or by the formation of thick deposits; (ii) deuterium and carbon are the main elements detected on all mirror surfaces and the presence of beryllium is also found in several cases; (iii) thick deposits show columnar structure; (iv) bubble-like structures are detected in deposits; their formation is a probable reason for deposits' disintegration and peeling-off; (v) the deposition in channels in the divertor cassettes is pronounced at the very entrance and then it sharply decreases with the distance from the plasma, ?5-7 mm.
|Journal||Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|
|Publication status||Published - 2010|
|MoE publication type||A1 Journal article-refereed|
- Diagnostic mirrors
- Erosion and deposition
- Surface analysis
Rubel, M., Coad, J. P., De Temmerman, G., Hakola, A., Hole, D., Likonen, J., Uytdenhouwen, I., & Widdowson, A. (2010). First Mirrors Test in JET for ITER: An overview of optical performance and surface morphology. Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 623(2), 818-822. https://doi.org/10.1016/j.nima.2010.01.069