First Mirrors Test in JET for ITER : An overview of optical performance and surface morphology

• 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, lambda similar to 5-7 mm.

Ämnesord

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Nyckelord

Diagnostic mirrors

Surface analysis

Reflectivity

Erosion and deposition

JET

ITER

Atomic and molecular physics

Atom- och molekylfysik

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)