Density peaking in low collisionality ELMy H-mode in JET
2004 (English)In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 46, no 12, 1877-1889 p.Article in journal (Refereed) Published
Low collisionality, low particle source. ELMy H-modes (type-III) with sawteeth are produced in JET in order to address the question of density profile evolution in the reference q(95) = 3 ITER scenario. The paper focuses on particle transport in the core zone around the mid-radius. The pedestal region including ELMs and the region affected by sawteeth are not considered. By replacing a significant part of the neutral beam heating by RF power the beam particle flux at mid-radius has been reduced to Gamma(Beam)/n(e) = 0.07 m s(-1). The additional flux due to wall neutrals is estimated as Gamma(Wall)/n(e) = 0.12 m s(-1). Density profiles are found to be modestly peaked under these conditions with a relative density difference of Deltan/(n) = 0.23 across the zone not affected by sawteeth and ELMs. In a region around the mid-radius the ratio of effective particle diffusivity to electron thermal diffusivity is found to be D-e,D-eff/chi(e) approximate to 0.2, which might indicate an anomalous pinch provided the particle diffusivity D-e is sufficiently lame. The measured values of D-e,D-eff/chi(e) are at the lower end of the range used in ITER models.
Place, publisher, year, edition, pages
2004. Vol. 46, no 12, 1877-1889 p.
transport, plasma, confinement, profile, core, flux
IdentifiersURN: urn:nbn:se:kth:diva-23992DOI: 10.1088/0741-3335/46/12/006ISI: 000226127400007ScopusID: 2-s2.0-10844272475OAI: oai:DiVA.org:kth-23992DiVA: diva2:342691
QC 201005252010-08-102010-08-10Bibliographically approved