A 1 GJ pulsed homopolar generator technology demonstration for the IGNITEX ignition experiment

Abstract

Summary form only given. Conceptual design of a TF (toroidal field) coil HPG (homopolar generator) module (~1-GJ energy storage and 12.5-MA peak current) for IGNITEX is presented. The HPG power supply, designed to provide a 150-MA, 12-GJ, 10-s-long pulse to the TF magnet, is accomplished with a modular approach where several generators are used in parallel. The PF (poloidal field) coil power supply requirements are less demanding in terms of energy storage (2.6 GJ) and peak current (22 MA) than those of the TF coil generators. The PF circuits are underdamped to provide ringing and thereby lower peak currents. Active control of all magnet currents during an experiment is provided by continuous adjustments to the HPG excitation fields. The proposed machine consists of a conventional iron-core HPG for voltage generation and current collection and a fiberglass reinforced epoxy-composite flywheel which provides most of the energy storage function. Titanium web structures are used to attach the flywheel to the rotor shaft and a face spline provides coupling to the ferromagnetic rotor. A successful demonstration of the proposed HPG module will provide the power supply capability required for ohmic fusion ignition