Determination of Carbon Release Mechanisms in the DIII-D Divertors from Analysis of C I Line Profiles
- ORNL
- General Atomics, San Diego
- University of Toronto Institute for Aerospace Studies
During typical operation of the DIII-D tokamak, physical and chemical sputtering are the most important mechanisms for release of carbon at the divertor targets [Nuclear Fusion 42 614 (2002)]. Modeling of C I spectral line profiles is discussed as a technique for evaluating the relative contribution of each mechanism and is applied to several types of DIII-D discharges. The line shapes are symmetric and have shifts of about -0.03 if they are produced solely from molecular dissociation, but they exhibit distinct asymmetries and shifts approaching -0.20 if generated by physical sputtering. Modeled profiles must, in general, take account of both mechanisms in order to match experimental data. An alternate approach to distinguishing between the two processes, which relies on the relative intensities of C I, CD, and C2 emissions, is examined in light of conclusions drawn from the line-shape analysis.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 967085
- Journal Information:
- Physics of Plasmas, Journal Issue: 14
- Country of Publication:
- United States
- Language:
- English
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