Two-fluid tokamak equilibria with reversed magnetic shear and sheared flow
Φόρτωση...
Ημερομηνία
Συγγραφείς
Poulipoulis, G.
Throumoulopoulos, G. N.
Tasso, H.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Journal of Plasma Physics
Όνομα βιβλίου
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Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The aim of the present work is to investigate tokamak equilibria with reversed magnetic shear and sheared flow, which may play a role in the formation of internal transport barriers (ITBs), within the framework of the two-fluid model in cylindrical geometry. The study is based on exact self-consistent solutions by means of which the impact of the magnetic shear, s, and the 'toroidal' (axial) and 'poloidal' (azimuthal) ion velocity components, v(iz) and v(i theta), on the radial electric field, E(r), its shear, vertical bar dE(r)/dr vertical bar, and the shear of the E x B velocity, omega(ExB) ( vertical bar)d/dr(E x B/B(2))vertical bar, is examined. For a wide parametric regime of experimental concern it turns out that the contributions of the v(iz), v(i phi) and pressure gradient (del P(i)) terms to E(r), vertical bar E(r)'vertical bar and omega(ExB) are of the same order of magnitude. The contribution of the del P(i) term is missing in the framework of magnetohydrodynamics (MHD) (G. Poulipoulis et al. 2004 Plasma Phys. Control. Fusion 46, 639). The impact of's on omega(ExB) through the del P(i) term is stronger than that through the velocity terms; in particular for constant B(z) the ion pressure gradient contribution to omega(ExB) at the point where dE(r)/dr = 0 scales as (1 - s)(2 - s), whereas the ion flow contributions to omega(ExB) Scale as (1 - s). The results indicate that, like MHD, the magnetic shear and the sheared toroidal and poloidal velocities act synergetically in producing electric fields and therefore omega(ExB) profiles compatible with the ones observed in discharges with ITBS; owing to the del P(i) term, however, the impact of s on Er, vertical bar Er'vertical bar and omega(ExB) is stronger than that in MHD.
Περιγραφή
Λέξεις-κλειδιά
internal transport barriers, steady-state operation, ideal magnetohydrodynamic equilibria, radial electric-field, asdex upgrade, incompressible flows, stability, jet, confinement, plasmas
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000247516800007
http://journals.cambridge.org/download.php?file=%2FPLA%2FPLA73_03%2FS0022377806004673a.pdf&code=3568ea592f9528b2bcc11dafcdd37ae9
http://journals.cambridge.org/download.php?file=%2FPLA%2FPLA73_03%2FS0022377806004673a.pdf&code=3568ea592f9528b2bcc11dafcdd37ae9
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών