TY  - JOUR
AU  - Mertens, Philippe
AU  - Boman, Romain
AU  - Dickheuer, Sven
AU  - Krasikov, Yury
AU  - Krimmer, Andreas
AU  - Leichtle, Dieter
AU  - Liegeois, Kim
AU  - Linsmeier, Christian
AU  - Litnovsky, Andrey
AU  - Marchuk, Oleksander
AU  - Rasinski, Marcin
AU  - De Bock, Maarten
TI  - On the use of rhodium mirrors for optical diagnostics in ITER
JO  - Fusion engineering and design
VL  - 146
IS  - B
SN  - 0920-3796
CY  - New York, NY [u.a.]
PB  - Elsevier
M1  - FZJ-2019-02743
SP  - 2514-2518
PY  - 2019
AB  - The first mirrors of optical diagnostics in ITER are exposed to high radiation and fluxes of particles which escape the plasma, in the order of $10^{20} m^{−2}s^{−1}$. At the position of the mirror, the flux may still reach about $10^{18} m^{−2}s^{−1}$. First mirrors are thus the most vulnerable in-vessel optical components, being subject to erosion, esp. by fast charge-exchange neutrals, or to deposition of impurities at flux rates which can reach 0.05 nm/s. The material selected for the reflecting surface must combine a high optical reflectivity in a wide spectral range and a sufficient resistance to physical sputtering during normal operation and during mirror cleaning discharges, if any is installed. Rhodium ($^{103}Rh$) was identified early as a possible or even promising candidate. It combines several attractive properties, for instance a mass which leads in most cases to low sputtering yields together with an optical reflectance ($\mathscr{R}_{Rh}≈75\%$) which is much higher than of some other options. $\mathscr{R}_{Rh}$is insensitive to large temperature changes. Rhodium is fairly inert and its low oxidation is an appreciable advantage in case of steam ingress events.The core-plasma CXRS diagnostic in ITER (UPP 3) have now turned to Rh as a baseline. The aim is to procure monocrystalline rhodium (SC-Rh) to mitigate the increase of the diffuse reflection with the damage due to physical sputtering.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000488313700241
DO  - DOI:10.1016/j.fusengdes.2019.04.031
UR  - https://juser.fz-juelich.de/record/862421
ER  -