Method of rapid determination of MHD equilibrium properties with the modified version of the SURFAS code

Autor: D.K. Lee, M. Okabayashi, Y.C. Sun, M.F. Reusch, S.P. Hirshman
Rok vydání: 1993
Předmět:
DOI: 10.2172/10189893
Popis: Rapid determination of MHD eqilibrium properties of tokamak plasmas is carried out by means of an approximation method based on the use of database files. These are computed a priori from MHD equilibrium solutions obtained by performing reconstruction to match experimental measurements, which include motional Stark effect (MSE) data. The procedure carries out a single iteration of Newton`s method to determine the poloidal variation of the toroidal plasma current density in the equilibrium form j{sub {phi}} = {minus}2{pi}({mu}{sub 0}Rp{prime} + FF{prime}/R) by representing p{prime}({psi}) and F({psi})F{prime}({psi}) in series expansions of Chebyshev polynomials. The polynominal expansion coefficients are obtained through a least-squares data fitting process similar to that used in the equilibrium reconstruction. Knowing the current density j{phi} allows the determination of the internal q-profile from the MSE data. This important stability parameter is generally unavailable from a current filament model. Numerical results calculated in this approach are compared with those determined from an accurate solution of the Grad-Shafranov equation, subject to a similar set of magnetic and pressure measurement constraints.
Databáze: OpenAIRE