Historical background to stellarators at the Australian National University

Toroidal plasma studies started at Australian National University, under the late Bruce Liley, in 1964 with a versatile, capacitor-bank- powered apparatus known eventually as LT-3. This had a high-resistivity (Inconel) toroidal vacuum vessel, major radius 40 cm, minor 10 cm, inside a 10mm-thick copper shell (to provide equilibrium and gross stability) upon which were wound close-fitting toroidal-field windings. Ohmic heating plasma currents induced via an iron core provided the poloidal field, the arrangement being termed a 'θ-z pinch' apparatus since it could operate over a wide range of toroidal to poloidal magnetic field ratios, i.e., from q << 1 to q >> 1. It soon showed better results when the toroidal field rather than the poloidal was dominant to form the 'diffuse pinch' configuration with q > 1 rather than a Zeta-like compressed pinch with q << 1, ie as a tokamak. This independently established the only line of tokamak research outside USSR until the Dubna meeting of 1969 led to its global spread. Copyright (2002) Australian National University- Research School of Physical Sciences and Engineering