Calculation and interpretation of analytic high-beta poloidal equilibria in finite aspect ratio tokamaks
- Department of Physics, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, California 90024 (United States)
The validity of the analytic large aspect ratio, high-{Beta} equilibria developed by Cowley {ital et al}. [Phys. Fluids B {bold 3}, 2066 (1991)] is extended to include finite aspect ratio equilibria with {ital q}{sup 2}{much_lt}1, where {ital q} is the safety factor. These high-{Beta} equilibria have two regions. Most of the volume lies in the {open_quote}{open_quote}core region,{close_quote}{close_quote} where {psi}={psi}({ital R}). The flux surfaces close in the {open_quote}{open_quote}boundary layer region,{close_quote}{close_quote} which has thickness {delta}. The solutions are valid when {delta}/{ital a}{approximately}O({radical}{epsilon}/{Beta}{ital q}{sup 2}) is small, where {ital a} is the minor radius. Thus, finite {epsilon} is allowed when {ital q}{sup 2} is large. The equilibria are completely specified by the midplane profiles of pressure {ital p}({ital R}) and poloidal magnetic field {ital B}{sub {ital P}}({ital R}) and the shape of the plasma boundary, all of which can be measured experimentally. Note the departure from customary specification of {ital p}({psi}), {ital q}({psi}), or {ital F}({psi}). A fast numerical code, requiring a few seconds to execute, has been written to compute and illustrate the analytic high-{Beta} equilibria. The qualitative features of high-{Beta}{sub {ital P}} tokamaks are discussed in detail. {copyright} {ital 1996 American Institute of Physics.}
- DOE Contract Number:
- FG03-93ER54224
- OSTI ID:
- 254915
- Journal Information:
- Physics of Plasmas, Vol. 3, Issue 1; Other Information: PBD: Jan 1996
- Country of Publication:
- United States
- Language:
- English
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