Abstract
Since the ITER-like wall in JET (JET-ILW) came into operation, dedicated ITER-like plasma current (Ip) ramp-up (RU) and ramp-down (RD) experiments have been performed and matched to similar discharges with the carbon wall (JET-C). The experiments show that access to H-mode early in the Ip RU phase and maintaining H-mode in the Ip RD as long as possible are instrumental to achieve low internal plasma inductance (li) and to minimize flux consumption. In JET-ILW, at a given current rise rate similar variations in li (0.7–0.9) are obtained as in JET-C. In most discharges no strong W accumulation is observed. However, in some low density cases during the early phase of the Ip strong core radiation due to W influx led to hollow electron temperature (Te) profiles. In JET-ILW Zeff is significantly lower than in JET-C. W significantly disturbs the discharge evolution when the W concentration approaches 10−4; this threshold is confirmed by predictive transport modelling using the CRONOS code. Ip RD experiments in JET-ILW confirm the result of JET-C that sustained H-mode and elongation reduction are both instrumental in controlling li.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.