000231280 001__ 231280
000231280 005__ 20190228220014.0
000231280 0247_ $$2doi$$a10.1088/0741-3335/55/12/125010
000231280 037__ $$aARTICLE
000231280 245__ $$aImaging of molybdenum erosion and thermography at visible wavelengths in Alcator C-Mod ICRH and LHCD discharges
000231280 269__ $$a2013
000231280 260__ $$c2013
000231280 336__ $$aJournal Articles
000231280 520__ $$aWe describe results from imaging observations of atomic line and continuum emission in the 550.6 nm region on Alcator C-Mod. Both the 550.6 nm neutral molybdenum emission and the adjacent 549 nm continuum emission are imaged separately to isolate line emission. A few complications of using imaging to infer erosion in this wavelength region are discussed including subtraction of continuum emission and determination of an appropriate S/XB coefficient. Diagnostics of surface erosion and thermography using these emissions are briefly reviewed, and used to study phenomenology during ohmic operation, ion cyclotron range of frequencies heating (ICRH), and lower hybrid current drive (LHCD). In addition to broadening of Mo I emission regions in the outer divertor and main limiter during ICRH compared to ohmic operation, mid-plane localized heating of the main limiter associated with fast-ion impact is observed which exceeds the divertor heat flux. During LHCD operation, several localized regions of increased brightness associated with hot spots are interpreted as heating due to localized density peaking, which re-iterates the importance of imaging continuum emission for subtraction. These sources of surface heating exacerbate plasma–material interactions at the device wall and may require additional mitigation if they cannot be avoided in future machines.
000231280 700__ $$aJames, A.N.
000231280 700__ $$aBrunner, D.
000231280 700__ $$aLaBombard, B.
000231280 700__ $$aLau, C.
000231280 700__ $$aLipschultz, B.
000231280 700__ $$aMiller, D.
000231280 700__ $$aReinke, M.L.
000231280 700__ $$aTerry, J.L.
000231280 700__ $$0240123$$g176719$$aTheiler, C.
000231280 700__ $$aWallace, G.M.
000231280 700__ $$aWhyte, D.G.
000231280 700__ $$aWukitch, S.
000231280 700__ $$aSoukhanovskii, V.
000231280 773__ $$j55$$tPlasma Phys. Control. Fusion$$q125010
000231280 909CO $$ooai:infoscience.tind.io:231280
000231280 909C0 $$0252028$$pSPC
000231280 909CO $$pSB$$particle
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000231280 917Z8 $$x176719
000231280 917Z8 $$x173008
000231280 937__ $$aEPFL-ARTICLE-231280
000231280 973__ $$rREVIEWED$$sPUBLISHED$$aOTHER
000231280 980__ $$aARTICLE