Al丝物理状态调控及对芯晕演化特性的影响

The core-corona evolution of single aluminum wire was studied based on fast linear transformer driver (FLTD) with dozens of kilo-ampere current. It is found that premature breakdown of the wire can reduce the deposited energy. The rapid development of the coronal plasma can restrain further expansion of the wire core and weaken the expansion rate. By adjusting the initial voltage across the load and wire length, and inserting the flashover switch at high voltage electrode, the premature breakdown was suppressed and different physical states of wire core (partially vaporized or completely vaporized) were obtained with substantial improvement of the deposited energy. The vaporization of aluminum atoms obviously increases the expansion rate of wire core (up to 11-14 km/s) and the coronal plasma develops slowly after the ionization of vaporized atoms at the boundary, which delays the occurrence of instability and decreases the development of m=0 instability at later stage. The polarity effect of aluminum wire core along the axis is more obvious with the negative output of FLTD. The expansion rate of wire core is slower near the cathode with a higher coronal plasma density at the boundary and the development of instability is faster.