Magnetic core test stand for energy loss and permeability measurements at a high constant magnetization rate and test results for nanocrystalline and ferrite materials

Abstract

A test stand was developed to measure the energy losses and unsaturated permeability of toroidal magnetic cores, relevant to applications of magnetic switching requiring a constant magnetization rate of the order of 1-10 T/micros. These applications in pulsed power include linear induction accelerators, pulse transformers, and discharge switches. The test stand consists of a coaxial transmission line pulse charged up to 100 kV that is discharged into a magnetic core load. Suitable diagnostics measure the voltage across and the current through a winding on the magnetic core load, from which the energy losses and unsaturated permeability are calculated. The development of the test stand is discussed, and test results for ferrite CN20 and the nanocrystalline material Finemet FT-1HS are compared to demonstrate the unique properties of a nanocrystalline material. The experimental data are compared with published data in a similar parameter space to demonstrate the efficacy of the experimental methods.