Testing the role of molecular physics in dissipative divertor operations through helium plasmas at DIII-D

Loading...
Thumbnail Image
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2017-05-01
Major/Subject
Mcode
Degree programme
Language
en
Pages
Series
Physics of Plasmas, Volume 24, issue 5
Abstract
Recent experiments in DIII-D helium plasmas are examined to resolve the role of atomic and molecular physics in major discrepancies between experiment and modeling of dissipative divertor operation. Helium operation removes the complicated molecular processes of deuterium plasmas that are a prime candidate for the inability of standard fluid models to reproduce dissipative divertor operation, primarily the consistent under-prediction of radiated power. Modeling of these experiments shows that the full divertor radiation can be accounted for, but only if measures are taken to ensure that the model reproduces the measured divertor density. Relying on upstream measurements instead results in a lower divertor density and radiation than is measured, indicating a need for improved modeling of the connection between the divertor and the upstream scrape-off layer. These results show that fluid models are able to quantitatively describe the divertor-region plasma, including radiative losses, and indicate that efforts to improve the fidelity of the molecular deuterium models are likely to help resolve the discrepancy in radiation for deuterium plasmas.
Description
Keywords
Other note
Citation
Canik , J M , Briesemeister , A R , McLean , A G , Groth , M , Leonard , A W , Lore , J D & Moser , A L 2017 , ' Testing the role of molecular physics in dissipative divertor operations through helium plasmas at DIII-D ' , Physics of Plasmas , vol. 24 , no. 5 , 056116 . https://doi.org/10.1063/1.4982057