TY  - CONF
AU  - Litnovsky, A.
AU  - Krasikov, Yu.
AU  - Rasinski, M.
AU  - Kreter, A.
AU  - Linsmeier, Ch.
AU  - Mertens, Ph.
AU  - Unterberg, B.
AU  - Breuer, Uwe
AU  - Wegener, T.
TI  - First direct comparative test of single crystal rhodium and molybdenum mirrors for ITER diagnostics
JO  - Fusion engineering and design
VL  - 123
SN  - 0920-3796
CY  - New York, NY [u.a.]
PB  - Elsevier
M1  - FZJ-2017-03387
SP  - 674-677
PY  - 2017
AB  - All optical and laser diagnostics in ITER will use mirrors to observe the plasma radiation. In the ITER environment, mirrors may become contaminated with plasma impurities hampering the performance of corresponding diagnostics. An in-situ mirror cleaning is proposed, which relies on ion sputtering of the contaminants and the affected mirror material. Previous research demonstrated the advantages of single crystal (SC) molybdenum (Mo) under sputtering conditions over polycrystalline concepts. Recently, the first single crystal rhodium (Rh) mirrors became available and tests have been started at the Forschungszentrum Jülich.In a direct test, SC Rh and SC Mo mirrors were exposed under identical conditions in steady-state helium plasmas in the linear plasma device PSI 2. The energy of impinging ions was ∼100 eV matching conditions expected in the in-situ cleaning system in ITER. During exposure, molybdenum mirrors lost 420–500 nm due to sputtering. Rhodium mirrors lost about 1 μm. Exposure corresponded to 50–100 cleaning cycles in ITER. Nevertheless, rhodium mirrors have preserved their specular reflectivity, showing the maximum degradation of less than 7% at 250 nm. Molybdenum mirrors demonstrated a moderate decrease of specular reflectivity of 12–25%. Results open new perspectives for the use of single crystals in ITER diagnostics.
T2  - 29th Symposium on Fusion Technology (SOFT 2016)
CY  - 5 Sep 2016 - 9 Sep 2016, Prague (Czech Republic)
Y2  - 5 Sep 2016 - 9 Sep 2016
M2  - Prague, Czech Republic
LB  - PUB:(DE-HGF)16 ; PUB:(DE-HGF)8
UR  - <Go to ISI:>//WOS:000418992000140
DO  - DOI:10.1016/j.fusengdes.2017.03.053
UR  - https://juser.fz-juelich.de/record/829753
ER  -