强光一号Z箍缩实验研究

Experimental research on Z-pinch at Qiangguang-Ⅰ facility

在强光一号装置驱动电流峰值1.4-2.1 MA、上升时间80-100 ns条件下,研究了喷Kr气、喷Ne气、W丝阵和Al丝阵负载Z箍缩等离子体的辐射特性和聚爆过程。实验研究中,用分压器和两个罗戈夫斯基线圈分别测量二极管的电压和流过负载的电流波形,用过滤型X射线二极管和100-1 400 eV平能谱响应闪烁探测器测量X射线时间谱,用镍薄膜量热计测量X射线总能量,用纳秒时间分辨软X射线图像诊断系统记录了Z箍缩的聚爆过程,用时空分辨的椭圆弯晶谱仪诊断了Z箍缩等离子体产生的keV级特征X射线的能谱分布。其中,喷Kr气负载的X射线辐射总能量大于60 kJ,峰值功率约1.7 TW,总能量转换效率可达23%;W丝阵负载的辐射总能量大于30 kJ,峰值功率约1.30 TW,总能量转换效率约为12.5%;喷Ne气负载的keV级辐射总能量5.6 kJ,峰值功率约256 GW,能量转换效率可达2%;Al丝阵负载的keV级辐射总能量2.3 kJ,峰值功率约94 GW,能量转换效率可达0.8%。喷气负载在Z箍缩聚爆过程中存在“拉链”现象,丝阵负载在Z箍缩聚爆过程中存在先驱现象。

Experimental research on plasma radiation characteristics and plasma implosion of Kr gas-puff, W wire array, Ne gas-puff and Al wire array Z pinches performed on Qiangguang- Ⅰpulsed power generator of 1.4-2.1 MA current with 80-100 ns rise time is reported. In the experiments, the voltage divider and two Rogowskii coils were used to measure the voltage and the current of diode respectively, a filter-XRD and a scintillator-photodiode detector with even energy respond in the energy region from 100 eV to 1 400 eV were used to measure X-ray waveforms, the Ni-film bolometer was developed for measuring the total soft X-ray energy, the time-resolved X-ray image diagnostic system was developed for recording the imploding process of Z pinches, and an elliptically-curved crystal spectrometer with temporal and spatial resolution was developed for diagnosing K-shell radiation of Z-pinch plasma. A total soft X-ray energy of 62 kJ and 32 kJ, a peak X-ray power of 1.7 TW and 1.3 TW, and a total energy transfer coefficient of 23 % and 12.5% were achieved respectively for Kr gas-puff liner and for W wire-array liner. A K-shell radiation energy of 5.6 kJ and 2.3 kJ, a peak radiation power of 256 GW and 94 GW, and an energy transfer coefficient of 2% and 0.8% were achieved respectively for Ne gas-puff liner and for Al wire-array liner. The ＂zipper-phenomenon＂ was found in the imploding process of gas puff Z pinches, and the precursor phenomenon was found in the imploding process of wire array Z pinches.