@inproceedings{4a2e36ecbca248f5826a94a51c1e718e,
title = "Effect of the minority concentration on ion cyclotron resonance heating in presence of the ITER-like wall in JET",
abstract = "The most recent JET campaign has focused on characterizing operation with the «ITER-like» wall. One of the questions that needed to be answered is whether the auxiliary heating methods do not lead to unacceptably high levels of impurity influx, preventing fusion-relevant operation. In view of its high single pass absorption, hydrogen minority fundamental cyclotron heating in a deuterium plasma was chosen as the reference wave heating scheme in the ion cyclotron domain of frequencies. The present paper discusses the plasma behavior as a function of the minority concentration X[H] in L-mode with up to 4MW of RF power. It was found that the tungsten concentration decreases by a factor of 4 when the minority concentration is increased from X[H] ≈ 5% to X[H] % 20% and that it remains at a similar level when X[H] is further increased to 30%; a monotonic decrease in Beryllium emission is simultaneously observed. The radiated power drops by a factor of 2 and reaches a minimum at X[H] ≈ 20%. It is discussed that poor single pass absorption at too high minority concentrations ultimately tailors the avoidance of the RF induced impurity influx. The edge density being different for different minority concentrations, it is argued that the impact ICRH has on the fate of heavy ions is not only a result of core (wave and transport) physics but also of edge dynamics and fueling.",
keywords = "ICRH, ITER-like wall, impurities, minority heating",
author = "{Van Eester}, D. and E. Lerche and P. Jacquet and V. Bobkov and A. Czarnecka and Coenen, {J. W.} and L. Colas and K. Cromb{\'e} and M. Graham and S. Jachmich and E. Joffrin and Klepper, {C. C.} and V. Kiptily and M. Lehnen and C. Maggi and F. Marcotte and G. Matthews and Mayoral, {M. L.} and {Mc Cormick}, K. and I. Monakhov and Nave, {M. F.F.} and R. Neu and C. Noble and J. Ongena and T. P{\"u}tterich and F. Rimini and Solano, {E. R.} and {Van Rooij}, G.",
year = "2014",
doi = "10.1063/1.4864528",
language = "English",
isbn = "9780735412101",
series = "AIP Conference Proceedings",
publisher = "American Institute of Physics Inc.",
pages = "223--226",
booktitle = "Radiofrequency Power in Plasmas - Proceedings of the 20th Topical Conference",
note = "20th Topical Conference on Radiofrequency Power in Plasmas ; Conference date: 25-06-2013 Through 28-06-2013",
}