Fast magnetization of amorphous metallic cores

Due to their high saturation flux density, amorphous metallic alloys play a key role in linear induction accelerators that require ferromagnetic cores with sufficient volt-seconds to support multiple pulses. As both the shape of the material hysteresis curve and the core losses depend on the magnetization rate, dB/dt, measurements at various rates are necessary in any system model involving these alloys. We present the characterization of two candidate materials, Metglas 2605CO and 2605HB1M, at magnetization rates ranging from 1-6 T/ws. We also compare our results to published data [1].

I. Introduction

Linear induction accelerators (LIAs) contain inductive ferromagnetic cores to maintain a voltage across the cell acceleration gap as the electron beam traverses the path. The time a given voltage can be maintained is given by the total volt-seconds that a core can support. From Faraday's Law,

$$\begin{equation*} V\Delta t=\Delta BA_{\mathrm{c}}, \tag{1} \end{equation*}$$ where and are the accelerating pulse voltage and width, and and are the magnetic induction swing and cross-sectional area of the core, respectively. To maximize available volt-seconds, one must maximize both and . It is therefore advantageous to have material with as high as possible in order to maintain a reasonable accelerator cell size.