Study of recycling impurity retention in Alcator C-mod

This work was aimed at reproducing experimental results in impurity compression of Ar, as well as the screening of recycling and non-recycling impurities from reaching the core plasma. As part of the study the code was upgraded in order to track the impurity flow from source till it reaches the core, include the energy dependence on recycled impurity atoms, and allow for more realistic impurity recycling in the SOL. This added capability allows the determination of which source locations are dominant in determining the core impurity level, where they cross the separatrix into the core and where they leave the core. The modeling reproduces within a factor of 2 the experimentally observed compression of Ar in the divertor of Alcator C-Mod. In addition it was found that under attached conditions recycling at the outer plasma edge (limiters located there) was the dominant source of Ar ions reaching the core (over 60%). For detached conditions divertor recycling replaces the outer edge in supplying the majority of Ar ions reaching the core.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Nuclear Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Chung, Taekyun

Advisor dc:contributor.advisor

• Ian H. Hutchinson and Bruce Lipschultz.

• Nuclear Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/33644

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/33644