Te/Ti effects on JET energy confinement properties
Abstract
Lately the question has been raised if a modification of the energy-confinement scaling law with respect to the electron to ion temperature ratio, Te/Ti, is required. Theoretically, like in e.g. the Weiland model, the confinement is thought to degrade with Te/Ti and studies of the hot-ion (Ti>/Te) mode seems to corroborate this. In this paper, it is shown that due to a number of effects that cancel each other out, the energy confinement time remains constant for Te/Ti>~1. The numerical study relies on a series of JET shots specifically designed to reveal an effect of Te/Ti in the hot-electron (Te>Ti) mode. A distinct effort was made to keep all current scaling-law parameters constant, including the total heating power. The effects that provide the constant confinement times have therefore nothing to do with the global properties of the plasma, but are rather due to variations in the temperature gradients which affects the transport locally.
Keywords
Cite
@article{arxiv.physics/0410184,
title = {Te/Ti effects on JET energy confinement properties},
author = {Elina Asp and Jan Weiland and Xavier Garbet and Paola Mantica and Vassili Parail and Wolfgang Suttrop},
journal= {arXiv preprint arXiv:physics/0410184},
year = {2007}
}
Comments
12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France)