Numerical studies of confinement scalings for the dynamo-free reversed-field pinch
2007 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 47, no 1, 9-16 p.Article in journal (Refereed) Published
In the reversed-field pinch (RFP), tearing modes associated with the dynamo are responsible for reduced energy- and particle confinement. In this study, it is observed that by implementing current profile control (CPC) in the RFP, a dynamo-free state can be achieved. The effect of CPC in the RFP is examined by the use of numerical simulations, and scaling laws are presented for confinement parameters. The model is nonlinear MHD in 3D including finite resistivity and pressure. A linear regression analysis is performed on simulation data from a series of computer runs for a set of initial parameter values. Scaling laws are determined for radial magnetic field, energy confinement time, poloidal beta and temperature. Confinement is improved substantially as compared with the conventional RFP - the temperature reaches reactor relevant levels by ohmic heating alone. It is observed that the configuration spontaneously develops into a quasi single helicity state. The CPC scheme is designed to eliminate the fluctuating electric dynamo field Ef ≤ -〈v × B〉, using feedback of an externally imposed electric field. The focus of this study is on obtaining principal theoretical optimization of confinement in the RFP by implementing CPC and to formulate scaling laws for confinement parameters, thus investigating the reactor viability of the concept.
Place, publisher, year, edition, pages
2007. Vol. 47, no 1, 9-16 p.
Computer simulation, Electric conductivity, Joule heating, Magnetohydrodynamics, Optimization, Plasma confinement, Regression analysis, Scaling laws
Fusion, Plasma and Space Physics
IdentifiersURN: urn:nbn:se:kth:diva-6334DOI: 10.1088/0029-5515/47/1/002ISI: 000243953900005ScopusID: 2-s2.0-33947622628OAI: oai:DiVA.org:kth-6334DiVA: diva2:11019
QC 20100924. Uppdaterad från Accepted till Published (20100924).2006-11-132006-11-132010-09-24Bibliographically approved