Influence of gas puff location on the coupling of lower hybrid waves in JET ELMy H-mode plasmas
2012 (English)In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 54, no 7, 074004- p.Article in journal (Refereed) Published
Reliable coupling of the lower hybrid current drive (LHCD) to H-mode plasmas in JET is made feasible through a dedicated gas injection system, located at the outer wall and magnetically connected to the antenna (Pericoli Ridolfini et al 2004 Plasma Phys. Control. Fusion 46 349, Ekedahl et al 2005 Nucl. Fusion 45 351, Ekedahl et al 2009 Plasma Phys. Control. Fusion 51 044001). An experiment was carried out in JET in order to investigate whether a gas injection from the top of the torus, as is foreseen for the main gas injection in ITER, could also provide good coupling of the LH waves if magnetically connected to the antenna. The results show that a top gas injection was not efficient for providing a reliable LHCD power injection, in spite of being magnetically connected and in spite of using almost twice the amount of gas flow compared with the dedicated outer mid-plane gas puffing system. A dedicated gas injection system, set in the outer wall and magnetically connected to the LHCD antenna, is therefore recommended in order to provide the reliable coupling conditions for an LHCD antenna in ITER.
Place, publisher, year, edition, pages
2012. Vol. 54, no 7, 074004- p.
Current Drive, Pam Launcher, Tokamak, Lhcd, Iter, Edge, Ftu
IdentifiersURN: urn:nbn:se:kth:diva-99404DOI: 10.1088/0741-3335/54/7/074004ISI: 000305891500005ScopusID: 2-s2.0-84863309523OAI: oai:DiVA.org:kth-99404DiVA: diva2:542175
QC 201207302012-07-302012-07-302012-07-30Bibliographically approved