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介绍了基于聚龙一号装置的Z箍缩诊断和实验布局, 分析了丝数132~300、丝直径5~10 m、丝阵直径13~30 mm的单/双层钨丝阵Z箍缩内爆动力学过程和软X射线辐射特性规律。研究表明, 钨丝阵等离子体的停滞时间与零维薄壳模型计算的停滞时间一致, 内爆轨迹存在偏离, 丝阵等离子体内爆开始前以丝烧蚀为主, 内爆开始时间约为总内爆时间的67%;随着负载质量和半径的增大, 负载电流、内爆停滞时间和X射线辐射脉冲半高宽也相应增加, X射线辐射峰值功率减小。双层钨丝阵的内爆均匀性和一致性优于单层丝阵, 其辐射峰值功率明显高于单层钨丝阵, 但单/双层钨丝阵辐射产额基本相当, 能量转换效率约为15%。此外, 还初步讨论了单层钨丝阵驱动的低密度泡沫动态黑腔辐射功率波形特征及其与纯钨丝阵内爆辐射的差异。 相似文献
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在“阳”加速器(电流峰值为500—850 kA,上升时间约为85 ns)上利用单壳层喷气负载开展了Z箍缩等离子体内爆实验,获得了等离子体的辐射产额、X光辐射图像等诊断结果.利用相应的诊断结果,定义了内爆时间,对内爆过程的主要阶段进行了划分,研究了等离子体位形、辐射强度分布等实验现象,同时对等离子体的内爆轨迹、内爆质量、径向收缩比、磁流体不稳定性等进行了初步分析.
关键词:
Z箍缩')" href="#">喷气负载Z箍缩
等离子体内爆
X光辐射功率
“阳”加速器 相似文献
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研究了丝阵Z箍缩等离子体内爆过程中单丝行为、物理参数匹配、X射线发射情况。根据丝阵Z箍缩等离子体动力学一维模型研制了相关的计算程序,对单丝的内爆过程进行了数值模拟,对丝阵箍缩匹配关系进行了计算,给出了丝阵初始半径、电流脉冲宽度和峰值电流的匹配关系,同时对丝阵内的最小丝间距、材料的选择等问题进行优化研究。 相似文献
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在一台毛细管快放电软x射线激光实验装置上,在相同主脉冲条件下(电流峰值18—30kA,半周期80ns),通过观测放电产生的软x射线辐射,研究了该装置固有的高幅值(2—5kA)和外加的低幅值(10—20A)两种预脉冲,对聚乙烯毛细管和高纯度陶瓷毛细管(99.9%)放电的管壁烧蚀及等离子体状态的影响.采用装置固有的几kA预脉冲和聚乙烯毛细管,放电 过程中产生了大量的管壁烧蚀,并且这种情况下的等离子体均匀性差,没有可能获得激光输 出.而采用20A的预脉冲和高纯度陶瓷毛细管,管壁烧蚀量大大减少,预电离等离子体的均匀 性好,在这种情况下,实验上利用x射线二极管观测到了激光尖峰信号.
关键词:
预脉冲
毛细管放电
软x射线激光 相似文献
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在分析了喷气Z箍缩内爆等离子体物理过程的基础上,作了必要的假定和简化,给出了物理模型和相应的数学方程组.研制了一维三温辐射磁流体动力学的数值模拟程序,对氖喷气Z箍缩内爆产生高温高密度等离子体过程进行了总体数值模拟,得到了等离子体各参量在内爆过程中的时空分布,再现了该内爆动力学整体过程,并与GAMBLE-Ⅱ装置的实验结果进行了比较.计算结果表明,在对热传导系数和等离子体电阻率作适当调整后,得到的计算结果是自洽的,其中内爆到心时刻、x射线辐射脉冲的脉宽和总能量等宏观量与实验结果比较接近.同时对喷气Z箍缩内爆过
关键词:
喷气Z箍缩
x射线辐射
辐射磁流体动力学 相似文献
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袁光伟 《工程物理研究院科技年报》2009,(1):53-54
描述多维内爆动力学过程的非平衡辐射流体力学问题包括电子、离子、光子(三温)热传导或辐射多群扩散等,它们具有多介质、大变形、高温、高压与强非均匀性等特点,其方程组具有强间断、强耦合和强非线性等特征。现有的九点格式和多点通量逼近方法(MPFA)在任意四边形网格上物理量计算出负,且九点格式中节点值计算不准确。全隐Picard迭代方法仅具有一阶收敛速度; 相似文献
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固体套筒内爆是采用实验方法研究高能量密度状态下的材料力学性能的重要加载手段之一,国内已经建立起若干开展电磁内爆研究的驱动器。从电流脉冲前沿对固体套筒内爆性能影响的角度进行分析,为如何选择现有的实验装置开展固体套筒内爆实验研究提供依据。采用不可压缩零维模型进行计算,获得了套筒内爆速度受套筒尺寸、电流幅值以及电流脉冲前沿的影响情况。计算结果表明,开展固体套筒内爆的实验研究应选择电流脉冲前沿大于2 s的装置,这也为未来设计驱动能力更强的固体套筒内爆实验装置奠定了基础。 相似文献
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E. Demler G. Gerstein A. Dalinger F. Nürnberger A. Epishin D. A. Molodov 《Bulletin of the Russian Academy of Sciences: Physics》2018,82(9):1079-1085
The electroplastic effect is studied on mechanically loaded single crystals of nickel-based CMSX-4 superalloy and pure aluminum bicrystals. Both objects of study exhibit elevated plasticity under electrical pulses. Traces of the electroplastic deformation that occurs in CMSX-4 single crystals at current densities J higher than 3 kA mm?2 and aluminum bicrystals at J exceeding 1.6 kA mm?2 are analyzed using a scanning electron microscope. 相似文献
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为了研究碳纳米管薄膜的强流脉冲发射特性, 采用酞菁铁高温热解方法在机械抛光铜基底上直接生长了碳纳米管薄膜 (Cu-CNTs), Cu-CNTs生长方向各异. 在20 GW脉冲功率源系统中采用二极结构对Cu-CNTs的强流脉冲发射特性进行研究, 研究结果表明: 在单脉冲发射条件下, 随脉冲电场峰值的增大, Cu-CNTs薄膜的发射电流峰值呈线性增加, 当宏观场强为15.5 V/μ时, 发射脉冲电流的峰值可达到5.56 kA, 对应的发射电流密度0.283 kA/cm2, 当宏观场强达到32.0 V/μ时, 发射脉冲电流的峰值可达到18.19 kA, 对应的发射电流密度0.927 kA/cm2, 发射电流能力明显优于已有报道. 在相同峰值, 连续多脉冲情况下, 碳纳米管薄膜具有良好的发射可重复性, 且发射性能稳定.
关键词:
强流脉冲发射
碳纳米管
铜基底
稳定性 相似文献
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Lutz Michael A. Harvey Robin J. Alting-Mees Hemmo 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1976,4(2):118-128
Results of an experimentalprogram to determine the feasibility of using a crossed field device as a high average power triggered closing switch are reported. The tube contained coaxial, cylindrical electrodes and was triggered by pulsing a magnetic field (<0.1 T) to a value sufficiently high to trap electrons and initiate conduction. Holdoff voltages up to 60 kV were achieved, with peak (circuit limited) currents as high as 20 kA and pulse durations in the range of 1 to 100 ?s. Ignition jitter was ~0.1 ?s, and the voltage recovery rate was 2 kV/?s after 20 kA conduction and a 50 ?s deionization time. These single and double shot data indicate that it should be possible to build such a device to operate at high average power levels for use in high power (MW) modulators. 相似文献
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Nakayama Y. Kimura T. Koyama K. Sasao H. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(4):906-910
We have clarified the relation between the decay of tungsten ion density in the vicinity of current zero and vacuum arc mode in high current period by using a laser induced fluorescence method in tungsten vacuum arcs of 60 Hz sinusoidal current with the peak value of 3.3, 6.7, and 9.8 kA. In the case of 6.7 kA, the arc mode was the anode spot mode. Because of the generation of the anode spot, the tungsten ion density near the anode was higher than near the cathode and the density near the anode was about ten times as high as the case of 3.3 kA which was the diffuse mode. In the case of 9.8 kA, which was the intense arc mode, the density near the anode was not significantly different from the case of 6.7 kA. The density near the cathode was higher than near the anode and tungsten ions were observed till about 30 μs after current zero while they disappeared at current zero in the other cases 相似文献
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Spectroscopic observations were carried out on transient free-burning arcs drawn by separating copper/tungsten electrodes in SF6 gas. The peak value of the arc current was varied up to 60 kA. A new optical method was developed to measure temperature and pressure profiles of the arc taking the magnetic pinch force into account. The arc voltage calculated from the obtained temperature and pressure profiles agreed well with electrical measurements. The results made it clear that the composition of the arc changes significantly at the critical instantaneous current of 10 kA. Above 10 kA the arc is composed of the electrode vapor, while it contains SF6 gas below 10 kA. 相似文献
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Boxman Raymond L. Harris Jeffrey H. Bless Adam 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1978,6(3):233-237
The variation of threshold current for the transition between the low current quiescent vacuum arc mode, and the high voltage noisy mode associated with anode spot formation, was measured as a function of peak current, current waveform frequency, and electrode separation on fixed diameter (25 mm) Cu and Ni electrodes. At current waveform frequencies of about 60 Hz on Cu electrodes, the threshold current depends mainly on electrode spacing, as has been observed by other investigators. However, at higher waveform frequencies, the threshold current becomes a strong function of peak current as well. At 347 Hz on 25 mm. diam. Cu electrodes separated by 10 mm, the threshold current rose from approximately 2 kA to 5.5 kA, as the peak current rose from 2 kA to 6 kA. At 543 Hz on 25 mm diam Ni electrodes separated by 9 mm, a saturation in threshold current at about 7.5 kA was observed for peak currents greater than 9 kA. Simultaneous anode temperature measurements indicated that the Ni anode surface temperature immediately prior to transition rose from about 1550° K to 2250° K with variations of peak current from 5 kA to 13 kA. Predictions of the variation of threshold current based on random transitions, and on cathode spot migration over the edge of the cathode, are compared with the experimental data. 相似文献
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Do Bang Nguyen Huy DanNguyen Anh Tuan Nguyen Xuan Phuc 《Journal of magnetism and magnetic materials》2007
The Cu2MnAl alloy was prepared by rapidly quenched (suction-casting and melt-spinning) methods with various thicknesses of 20, 40 and 1000 μm. The X-ray diffraction (XRD) patterns of the fabricated samples show a single phase of Cu2MnAl. All the samples reveal soft magnetic behavior with coercivity below 1.6 kA/m and Curie temperature of about 600 K. Resistance of the alloy behaves as a linear function of applied magnetic field. Magnetoresistance (MR) ratio depends on the thickness of the samples and achieves ∼0.8% at the field of 240 kA/m for the sample with thickness of 20 μm. The variation of the properties of the alloy can be interpreted by the difference of energy band structure caused by defects in the alloy. 相似文献