Simple Contour Analysis of Ignition Conditions and Plasma Operating Regimes in Tokamaks

摘要

Contour plots of ignition, auxiliary power requirements, heating and operating windows, optimal path to ignition, ignition margin, etc., are generated analytically in terms of a small number of parameters (aB sub 02 /q/sub */, R sub 0 /B sub 0 , , etc.) for classes of devices with equivalent performance. Numerical studies are carried out to map the physics design space. Considering both the Murakami density limit (approx.B sub 0 /R sub 0 ) and the Troyon beta limit (approx.I/aB sub 0 ), results from analytic calculations indicate that in a standard tokamak geometry (A approx. 2.5 to 3.5, kappa = b/a approx. 1.6 to 1.7, q/sub psi/ approx. 2.6) devices with aB sub 02 /q/sub */ approx. 20 should be ignitable provided confinement does not degrade with heating (ohmic + alpha + auxiliary, etc.) power; however, aB sub 02 /q/sub */ approx. 30 (25) may be required for minimal ignition for a typical L- (H-) mode confinement scaling. Increased plasma elongation (kappa approx. 2) may help to reduce these requirements. (ERA citation 11:008095)