空气中并联金属丝阵列电爆炸等离子体自辐射特性

Plasma Self-radiation Characteristics of Electrical Wire Arrays Explosion in Air

在空气中开展了平面丝阵的电爆炸实验,对比研究了非难熔金属铜丝阵列和难熔金属钽丝阵列在电爆炸过程中的能量沉积特性,重点分析了其等离子体通道演化过程及光辐射特性。实验结果表明,随着铜丝阵列或钽丝阵列根数(质量)的增加,丝阵列在电压峰值前沉积的能量会有所增加且总体相变时间会变长。对于铜丝阵列,当其能量沉积速率较快时,电爆炸过程中的光辐射强度会随金属丝根数的增加而有所增加,但光辐射持续时间相对于单丝较短。铜丝和铜丝阵列电爆炸等离子体通道膨胀过程较快,放电中心通道内的加热和电离过程不够集中。当铜丝根数增加时,放电过程中各丝之间的相变时刻不够同步,放电等离子体通道发展极不均匀。对于钽丝阵列,在储能一定的条件下,随着钽丝阵列根数(质量)的增加,其光辐射强度会有所下降。钽丝和钽丝阵列在相变过程中的气液混合通道能够被加热到较高的温度,放电通道内热电离过程显著,等离子体通道易于发展,但放电通道膨胀速率要明显慢于铜丝。丝阵列放电过程中各丝之间相变时刻的不同步会影响电流的分布,进而导致各丝之间的能量沉积过程不同,使得丝阵列中各丝等离子体通道的建立过程不同步。

The experiment of electrical wire arrays explosion in the air was carried out.The energy deposition characteristics of the copper wire array and tantalum wire array during the electrical explosion were compared.The evolution process of the plasma channel and the characteristics of light radiation were analyzed.The results show that the deposited energy before the voltage peak and the overall phase transition time will increase when the wire array mass increases.For the copper wire array,when the energy deposition rate is high,the intensity of the light radiation will increase with the increase of the mass,whereas the light radiation duration is shorter than that of a single wire.The expansion process of its discharge channel is fast,and the heating and ionization process in the discharge center channel is not concentrated.When the number of copper wires increases,the phase transition time of each wire is not synchronous enough,and the development of the discharge plasma channel will be more non-uniform.For the tantalum wire array,the light radiation will decrease with the increase of the mass.The gas-liquid mixture channel of tantalum wire and tantalum wire array can be heated to a higher temperature in the phase transition process.The thermal electron emission process of metal particles in the discharge channel is significant,which may strengthen the ionization process of the discharge channel and enable the plasma channel to develop easily,whereas its discharge channel expansion rate is obviously slower than that of copper wire.The measurement results of copper wires with different diameters and lengths show that the energy deposition characteristics of the two wires are obviously different in the explosion process.The first phase transition wire may lead to the current redistribution and accelerate the energy deposition process of the other wires in parallel,and further affects the development process of the subsequent plasma channel.