Comparison of long term fuel retention in JET between carbon and the ITER-Like Wall

• Published in: Journal of nuclear materials 2013-07, Vol.438, p.S108-S113
• Main Authors: Loarer, T., Brezinsek, S., Philipps, V., Bucalossi, J., Douai, D., Esser, H.G., Grunhagen, S., Hobirk, J., Jachmich, S., Joffrin, E., Kruezi, U., Lowry, C., Matthews, G., Smith, R., Tsitrone, E., Vartanian, S.
• Format: Article
• Language: English
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2013.01.017

Long term fuel retention experiments have been performed in JET with the ITER- Like Wall (JET-ILW) and compared with reference discharges in the preceding phase with carbon wall (JET-C) in ohmic, L and H-mode plasma scenarios. The long term fuel retention is evaluated through global gas balance with an accuracy of 1.2% for series of repetitive pulses (10–25) carried out over a full day of experiments. Compared to carbon wall, with the JET-ILW, for L mode, the retention exhibits also a drop from 1.26×1021Ds−1 to 4–8×1019Ds−1. Finally for Type III and type I ELMy H-mode, the retention decreases from 1.37×1021Ds−1 to 7.2×1019Ds−1 and from 1.7×1021Ds−1 to 2.7×1020Ds−1 respectively. The retention rates with the JET-ILW exhibit a decrease by a factor of about 10 compared to JET-C attributed to a reduction of carbon impurities and less fuel content in Be codeposition.