Steady state tokamak reactor based on the bootstrap current

A concept of a steady state tokamak fusion reactor based on the bootstrap current is presented. Operation at high poloidal beta (?p ? 2.0) and high q (4?5) with a relatively small limit on ??p (< 0.5) makes it possible to drive a bootstrap current constituting up to 70% of the total plasma current without exceeding the Troyon beta limit. The rest of the plasma current can be driven by the high energy neutral beam with an energy multiplication factor Q of 30. Energy confinement scaling laws predict that the reactor condition is attainable by increasing the major radius up to 9 m in such a high ?p and high q plasma at a relatively low plasma current (12 MA) with a confinement enhancement factor of 2 compared with the L-mode scaling. This reactor has a reasonable size (Vp = 1500 m3) and fusion output power (2.5 GW) and is consistent with present knowledge regarding tokamak plasma physics, namely the Troyon limit, the energy confinement scalings, the bootstrap current and the current drive efficiency (neutral beam current drive with a total power of 70 MW and a beam energy of 1 MeV) with good prospects for the formation of a cold and dense divertor plasma.

[1]  R. S. Devoto,et al.  Numerical analysis of 2D MHD equilibrium with non-inductive plasma current in tokamaks , 1992 .

[2]  D. McCune,et al.  Initial Confinement Studies of Ohmically Heated Plasmas in the Tokamak Fusion Test Reactor , 1984 .

[3]  Bootstrap current theory and experimental evidence , 1988 .

[4]  J. Ramos,et al.  Access to the second stability region in a high shear, low aspect ratio tokamak , 1988 .

[5]  R. Yoshino,et al.  Incremental energy confinement time during H0 beam heating in JT-60 , 1987 .

[6]  N. Fisch.  Confining a Tokamak Plasma with rf-Driven Currents. , 1978 .

[7]  J. Cordey,et al.  Modelling of temperature profiles and transport scaling in auxiliary heated tokamaks , 1987 .

[8]  N. Fujisawa,et al.  Bifurcated confinement solutions for diverted tokamaks , 1985 .

[9]  Tadashi Sekiguchi,et al.  Plasma Physics and Controlled Nuclear Fusion Research , 1987 .

[10]  J. Johner,et al.  A conceptual steady state tokamak reactor with passive current generation , 1989 .

[11]  K. Miyamoto,et al.  Plasma physics and controlled nuclear fusion , 1979 .

[12]  E. G. Hope,et al.  Frequency of the Hydrogen Maser , 1971, Nature.

[13]  M. Honda,et al.  Efficient lower hybrid current drive using a multijunction launcher on JT-60 , 1989 .

[14]  Bell,et al.  Bootstrap current in TFTR. , 1988, Physical review letters.

[15]  R. Gruber,et al.  MHD-limits to plasma confinement , 1984 .

[16]  S. Hirshman,et al.  Neoclassical transport of impurities in tokamak plasmas , 1981 .

[17]  J. G. Cordey,et al.  Beam‐induced currents in toroidal plasmas of arbitrary aspect ratio , 1980 .

[18]  N. H. Brooks,et al.  Impurity reduction and remote radiative cooling with single-null poloidal divertor in Doublet-III , 1982 .

[19]  Robert James Goldston.  Energy confinement scaling in Tokamaks: some implications of recent experiments with Ohmic and strong auxiliary heating , 1984 .