Mirror test for International Thermonuclear Experimental Reactor at the JET tokamak: An overview of the program

Metallic mirrors will be essential components of all optical spectroscopy and imaging systems for plasma diagnosis that will be used at the next-step magnetic fusion experiment, International Thermonuclear Experimental Reactor (ITER). Any change of the mirror performance, in particular, reflectivity, will influence the quality and reliability of detected signals. At the instigation of the ITER Design Team, a dedicated technical and experimental activity aiming at the assessment of mirror surface degradation as a result of exposure to the plasma has been initiated on the JET tokamak. This article provides a comprehensive overview of the mirror test program, including design details of the mirror samples and their supports, their locations within JET, and the issue of optical characterization of the mirrors both before and after exposure. The postexposure characterization is particularly challenging in JET as a consequence of an environment in which both tritium and beryllium are present.

[1]  C. Gil,et al.  Analyses of metallic first mirror samples after long term plasma exposure in Tore Supra , 2006 .

[2]  A. E. Costley,et al.  Technological challenges of ITER diagnostics , 2005 .

[3]  Marek J. Rubel,et al.  Diagnostics for studying deposition and erosion processes in JET , 2005 .

[4]  V. Philipps,et al.  Exposure of metal mirrors in the scrape-off layer of TEXTOR , 2005 .

[5]  H. Kugel,et al.  Time Resolved Deposition Measurements in NSTX , 2004 .

[6]  G. Matthews,et al.  Quartz microbalance: a time resolved diagnostic to measure material deposition in JET , 2003 .

[7]  A. Donné,et al.  Key issues in diagnostics for burning plasma experiments , 2003, IEEE Transactions on Plasma Science.

[8]  G. Matthews,et al.  Erosion/deposition in JET during the period 1999-2001 , 2003 .

[9]  G. Matthews,et al.  Beryllium and carbon films in JET following D-T operation , 2003 .

[10]  G. Matthews,et al.  Erosion/Deposition Issues at JET , 2001 .

[11]  C. H. Skinner,et al.  Plasma-material interactions in current tokamaks and their implications for next step fusion reactors , 2001 .

[12]  A. F. Bardamid,et al.  Some problems of the material choice for the first mirrors of plasma diagnostics in a fusion reactor , 1999 .

[13]  E. Palik.  Handbook of Optical Constants of Solids , 1997 .

[14]  A. C Rolfe,et al.  Remote handling on fusion experiments , 1997 .

[15]  H. E. Bennett.  Specular Reflectance of Aluminized Ground Glass and the Height Distribution of Surface Irregularities , 1963 .

[16]  J. Contributors,et al.  Institute of Physics Publishing Plasma Physics and Controlled Fusion Material Erosion and Migration in Tokamaks , 2005 .

[17]  G. Matthews,et al.  Carbon Deposition in the Inner JET Divertor Measured by Means of Quartz Microbalance , 2004 .

[18]  A. D. Kudlenko,et al.  Ion Fluence and Energy Effects on the Optical Properties of SS Mirrors Bombarded by Hydrogen Ions , 2003 .