Simulation of impurity transport in the peripheral plasma due to the emission of dust in long pulse discharges on the Large Helical Device. (August 2017)

• Record Type: Journal Article
• Authors: Shoji, M.; Kawamura, G.; Smirnov, R.; Pigarov, A.; Tanaka, Y.; Masuzaki, S.; Uesugi, Y.
• Is Part Of: Nuclear materials and energy. Volume 12(2017)
• Page Start: 779
• Page End: 785
• Publication Date: 2017-08
• Subjects: Dust -- EMC3-EIRENE -- DUSTT -- Long pulse discharge; Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2017.07.002
• Languages: English
• ISSNs: 2352-1791

Abstract

Highlights: Simulation of impurity transport induced by dust is performed in a 3-d geometry. The radiation power increases with a dust emission rate by impurities in the dust. The plasma flow in divertor legs is quite effective for preventing the dust effect. Dust emission near the main plasma is dangerous for sustaining plasma discharges. Simulations are consistent with observations in long pulse plasma discharges. Abstract: Two different plasma termination processes by dust emission were observed in long pulse discharges in the Large Helical Device. One is a plasma termination caused by large amounts of carbon dust released from a lower divertor region. The other is termination caused by stainless steel (iron) dust emission from the surface of a helical coil can. The effect of the dust emission on the sustainment of the long pulse discharges are investigated using a three-dimensional edge plasma transport code (EMC3-EIRENE) coupled with a dust transport code (DUSTT). The simulation shows that the plasma is more influenced by the iron dust emission from the helical coil can than by the carbon dust emission from the divertor region. The simulation revealed that the plasma flow in divertor legs is quite effective for preventing dust from terminating the long pulse discharges.