title: Enhanced confinement and quasi-single-helicity regimes induced by poloidal current drive.
abstract: Enhanced confinement regimes with quasihelical symmetry are reproducibly obtained in the modified reversed field pinch eXperiment (RFX)-mod by reducing the level of internal chaos through the combination of a smooth magnetic boundary (through a virtual shell scheme) and the oscillating poloidal current drive technique. The plasma moves from a chaotic multiple helicity towards a quasi-single-helicity regime with a magnetic island showing high temperature and soft x-ray emissivity. The chaos reduction involves also the plasma outside the island allowing for a global enhanced confinement with an improvement up to 50%.
authors.affiliation: Consorzio RFX, Associazione Euratom-ENEA sulla Fusione-Corso Stati Uniti, 4, I-35127 Padova, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Terranova
authors.forename: A
authors.initials: A
authors.lastname: Alfier
authors.forename: F
authors.initials: F
authors.lastname: Bonomo
authors.forename: P
authors.initials: P
authors.lastname: Franz
authors.forename: P
authors.initials: P
authors.lastname: Innocente
authors.forename: R
authors.initials: R
authors.lastname: Pasqualotto