Study on Core-corona Suppression of Aluminum Wire Array with Megampere Current

In order to suppress the core-corona structure resulting from the initial single-wire exploding phase of wire array Z-pinch, two-stage aluminum wire array experiment was carried out on Qiangguang-Ⅰ to control the initial state of aluminum wire. Aluminum wire in top array was completely vaporized and core-corona structure was suppressed by steeping pre-pulse current and adjusting the parameter of two-stage wire array. Aluminum wire expanded to a diameter about 1.80 mm homogeneously along the axis, which reduced the initial instability caused by typical wire ablation. The switch time of inverse array mainly depends on the number of aluminum wire when wire length and diameter remain unchanged. The magneto Rayleigh-Taylor instability develops rapidly during the implosion of top array. The inward plasma stream is periodically modulated along the axis with a wavelength about 650 μm. The wire ablation as well as the precursor plasma is effectively suppressed for the change of initial wire state. The trailing mass at late implosion phase is reduced and the pinch quality is improved.