短脉冲电流作用下铜微桥箔的电热分析

摘要

Plasma initiation is an advanced initiating technique that ensures intrinsic safety and high reliability of the initiator,small-scale bridge foils is a promising energy exchange element for future low energy plasma initiating device. The thermal-electrical performance of small-scale copper bridge foils was simulated using finite element method. Results show that higher temperature acceleration occurs at the corners of the bridge,and then the generated ohmic heat will diffuse all over the bridge. While the energy excitation is identical,the time to melt temperature at the center of the bridge will decrease as the bridge width decreases. Furthermore,when the period of the pulse current remains constant,time to melt temperature will increase as the charge voltage decreases till the bridge cannot reach melt temperature.%等离子体换能起爆技术是一种具有高安全性和高可靠性的先进起爆技术，微桥箔是高能等离子体换能元的重要组成部分。本研究采用有限元方法对短脉冲电流作用下铜微桥的电热过程进行了模拟，模拟结果表明在桥区的四个拐点处升温速率最高，热量从这四个区域向整个桥区扩散；在同一脉冲刺激下，桥区尺寸越小，达到融化温度所需时间越短。当输入脉冲电流周期不变时，随着充电电压的降低，桥区中心处温度达到融化温度所需的时间逐渐增加，当电压降低至一定值后（临界电压），桥区将不能完全融化；在临界电压附近，达到融化温度所需的时间随电压变化的趋势越明显。