Induction accelerator efficiency at 5 Hz

We stimulate fusion power plant driver efficiency by pulsing small inductio n cores at 5Hz (a typical projected power plant repetition rate), with a re sistive load in the secondary winding that is scaled to simulate the beam l oading for induction acceleration. Starting from a power plant driver desig n that is based on other constraints, we obtain the core mass and accelerat ion efficiency for several energy ranges of the driver accelerator and for three magnetic alloys. The resistor in the secondary is chosen to give the same acceleration efficiency, the ratio of beam energy gain to energy input to the core module (core plus acceleration gap), as was computed for the d river. The pulser consists of a capacitor switched by FETs, Field Effect Tr ansistors, which are gated on for the desired pulse duration. The energy to the resistor is evaluated during the portion of the pulse that is adequate ly flat. We present data over a range of 0.6-5 mus pulse lengths. With 1 mu s pulses, the acceleration efficiency at 5 Hz is measured to be 75%, 52%, a nd 32% for thin-tape-wound cores of nanocrystalline, amorphous, and 3% sili con steel materials respectively, including only core losses. The efficienc y increases for shorter pulse durations. (C) 2001 Elsevier Science B.V. All rights reserved.