Dust studies in DIII-D and TEXTOR

D. L. Rudakov, A. Litnovsky, W. P. West, J. H. Yu, J. A. Boedo, B. D. Bray, S. Brezinsek, N. H. Brooks, M. E. Fenstermacher, M. Groth, E. M. Hollmann, A. Huber, A. W. Hyatt, S. I. Krasheninnikov, C. J. Lasnier, A. G. McLean, R. A. Moyer, A. Yu Pigarov, V. Philipps, A. PospieszczykR. D. Smirnov, J. P. Sharpe, W. M. Solomon, J. G. Watkins, C. P C Wong

Tutkimustuotos: LehtiartikkeliArticleScientificvertaisarvioitu

49 Sitaatiot (Scopus)

Abstrakti

Studies of naturally occurring and artificially introduced carbon dust are conducted in DIII-D and TEXTOR. In DIII-D, dust does not present operational concerns except immediately after entry vents. Submicrometre sized dust is routinely observed using Mie scattering from a Nd : Yag laser. The source is strongly correlated with the presence of type I edge localized modes (ELMs). Larger size (0.005-1 mm diameter) dust is observed by optical imaging, showing elevated dust levels after entry vents. Inverse dependence of the dust velocity on the inferred dust size is found from the imaging data. Heating of the dust particles by the neutral beam injection (NBI) and acceleration of dust particles by the plasma flows are observed. Energetic plasma disruptions produce significant amounts of dust; on the other hand, large flakes or debris falling into the plasma may induce a disruption. Migration of pre-characterized carbon dust is studied in DIII-D and TEXTOR by introducing micrometre-size particles into plasma discharges. In DIII-D, a sample holder filled with 30-40 mg of dust is inserted in the lower divertor and exposed, via sweeping of the strike points, to the diverted plasma flux of high-power ELMing H-mode discharges. After a brief dwell (∼0.1 s) of the outer strike point on the sample holder, part of the dust penetrates into the core plasma, raising the core carbon density by a factor of 2-3 and resulting in a twofold increase in the radiated power. In TEXTOR, instrumented dust holders with 1-45 mg of dust are exposed in the scrape-off-layer 0-2 cm radially outside of the last closed flux surface in discharges heated with 1.4 MW of NBI. Launched in this configuration, the dust perturbed the edge plasma, as evidenced by a moderate increase in the edge carbon content, but did not penetrate into the core plasma.

AlkuperäiskieliEnglanti
Artikkeli085022
Sivut1-11
Sivumäärä11
JulkaisuNuclear Fusion
Vuosikerta49
Numero8
DOI - pysyväislinkit
TilaJulkaistu - 2009
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

Sormenjälki Sukella tutkimusaiheisiin 'Dust studies in DIII-D and TEXTOR'. Ne muodostavat yhdessä ainutlaatuisen sormenjäljen.

Siteeraa tätä