Power Deposition Characteristics of Electrically Exploding Microscale Metallic Bridges with High-Voltage Pulse-Forming Circuit

In various forms of pyrotechnic devices for aerospace and defense systems, the safety and reliability of device functioning heavily relies on the electrical explosion of a thin metallic bridgewire in an exploding bridgewire (EBW) detonator unit for the ignition of primary explosive charges. This study presents the modeling and simulation of pulsed power deposition in a gold bridgewire of micron-sized diameter which undergoes intense joule heating followed by vaporization and bridgewire burst. The present modeling approach is based on the bulk approximation of bridgewire resistance, and it includes the circuit model of a high-voltage charging capacitor discharge unit (CDU) and the energy conservation principle with the consideration of phase changes in the bridgewire. The prediction results are well validated against the EBW firing test measurements in terms of electrical current traces and burst current for a wide range of CDU charging voltages. Threshold charging voltages for bridgewire burst and explosive ignition are investigated for the cases of varying bridgewire diameter and length, which results are found to be consistent with the EBW firing test analysis. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.