A 20T pulse magnet with 80% field reversal for fast hysteresis measurements

摘要

For testing of magnetic materials and for magnetizing small permanent magnets, it is desirable to have a set-up, generating fields well in excess of 10 T with a reasonable duration. Based on a 150 kJ capacitor bank, we have built a compact magnet, which allows generating fields up to 20 T. A Cu solenoid with a bore of 22.3 mm is directly put into liquid nitrogen. The magnet is engaged by discharging a 10 mF capacitor bank with a maximal voltage of 5.5 kV via an optically triggered thyristor stack. A diode stack anti-parallel to the thyristor allows for a full-sine-wave form. The self-inductance (i.e. the wire section) was chosen such that the full sine had a period of about 200 ms to reduce the generation of eddy currents in the samples. Magnetization can be measured in the temperature range 77-400 K in a 4.5-mm-diameter sample space. (C) 2001 Elsevier Science B.V. All rights reserved. [References: 1]