English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

ELM mitigation by nitrogen seeding in the JET gas box divertor

MPS-Authors
/persons/resource/persons109017

Eich,  T.
Experimental Plasma Physics 1 (E1), Max Planck Institute for Plasma Physics, Max Planck Society;

/persons/resource/persons109371

Herrmann,  A.
Experimental Plasma Physics 1 (E1), Max Planck Institute for Plasma Physics, Max Planck Society;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Rapp, J., Eich, T., von Hellermann, M., Herrmann, A., Ingesson, L. C., Jachmich, S., et al. (2002). ELM mitigation by nitrogen seeding in the JET gas box divertor. Plasma Physics and Controlled Fusion, 44(6), 639-652.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0027-4101-F
Abstract
One of the most severe problems for fusion reactors is the power load on the divertor target plates. Technically only power loads of less than 10 MW m(-2) are acceptable. However, strong edge localized mode (ELM) activity can lead to power loads in excess of 800 MW m-2. In order to reduce the steady- state heat flux and the transient heat flux due to ELMS, radiation cooling experiments were performed at JET Nitrogen was puffed into the divertor up to a radiative power fraction of 90%. This was achieved at a density of 0.85 times the Greenwald density (Greenwald M 1988 Nucl. Fusion 28 2199), while maintaining an H-factor of f(H98) = 0.82. The Z(eff) in all those discharges stayed around 2.0. At approximately 55% radiative power fraction, the ELM characteristic changes from type I to type III, resulting in a loss of confinement of about 25% due to a degradation of the edge pedestal and hence a reduction of the ELM power load to the divertor tiles. By increasing the radiative power fraction to values of about 90%, the heat flux is reduced to 2 MW m(-2).