【作者】 黄显宾；

【导师】 伍登学；

【作者基本信息】 四川大学 ， 核技术及应用， 2005， 硕士

【摘要】 利用Z箍缩等离子体辐射产生的软X射线驱动靶丸内爆压缩氘氚燃料是实现惯性约束聚变(ICF)的一种重要途径,目前它已经成为世界上的一个研究热点。 本论文重点对软X射线和等离子体诊断技术及其辐射特性进行了研究。主要工作包括两个部分:(1) 研制了一套Z箍缩喷气负载系统,并进行了性能测试实验及数值模拟;(2) 采用X光纳秒分幅相机、X光功率谱仪、PIN二极管阵列、X光积分针孔相机、变相管扫描相机、X射线多通道谱仪、激光差分剪切干涉仪等诊断技术在“阳”加速器上开展了喷气Z箍缩实验,测量了等离子体辐射产生软X射线能量、功率,等离子体运动过程图像。这两部分研究工作属国家自然科学基金资助课题(10035030)内容之一。 通过论文研究工作,得到了如下结论: (1) 研制的Z箍缩喷气负载系统实验结果表明:系统运行稳定、重复性好。利用流场程序对喷气负载质量线密度和气流位形进行了模拟表明:喷气负载线质量密度约13μg/cm~2,气流位形与Z箍缩实验中获得的早期等离子体图像吻合。 (2) 在喷气Z箍缩实验中,获得了能量约500J/cm、功率大于12GW,半高宽约20ns的软X射线脉冲和内爆等离子体各阶段运动发展过程的X光图像。研究表明:初始气体的空间分布极大的影响喷气Z箍缩过程。喷气负载初始击穿不均匀,导致初期负载电流主要从等离子体壳层中几个主要的通道非均匀的通过;气流“喇叭”状更多还原

【Abstract】 Considering as one of possible intense soft x-rays radiated sources from z-pinch plasma for realizing controlled thermonuclear fusion, Z-pinch plasma is being intensively studied in the world at present.This dissertation stresses the experiments studies on soft x-ray, plasma diagnostics and radiation characteristics. We have completed two items of work: (1) designing a gas-puff load system used in z-pinch and measuring the capability and flow Simulation; (2) gas-puff z-pinch experiments were carried out on the accelerator "Yang", used some diagnostic devices such as x-ray nanosecond frame-camera, x-ray power system, PIN diode array, a time-resolved x-ray pinhole camera, streak camera, x-ray multi-channel power system, differential laser interferometry for studying the soft x-ray energy and power radiated and the implosion process from z-pinch plasma. This work was supported by the National Science Foundatin of China No. 10035030.The results of experiments of gas-puff load system used in z-pinch are shown below:(1) The experimental results of the system of gas-puff load used in Z-pinch indicated: it has an advantage of stability and repetitive operations. The results of utilizing the program of flow field to simulated line mass density and flow distribution are shown below: the line mass density of gas-puff load is about 13 μg /cm~2, the flow distribution is consistent with the image of initialization plasma obtained in gas-puff z-pinch experiments.(2) In gas-puff Z-pinch experiments, the peak values of the soft Xray pulse energy and power measured with soft x-ray power system is above 800J, 12GW with pulse widths (FWHM) about 20ns and the X ray images in every phase of imploding plasma progresses are attained. And the results are shown below: the spatial distribution of initial gas has a significant influence on the course of gas-puff Z-pinch. Uniformity of the gas-puff distribution initially induces that early load electric current through the main channels of plasma layer are non-symmetrically; the flow distribution of "trumpet" shape induces "zipper" effect of plasma from cathode to anode, the flow distribution of "neck constringency" induces plasma "neck constringency" effect, early collapse and disperse of pinch plasma on anode; along z-axis, "zipper" effect of plasma is obvious and the velocity is up to 2.89xlO7 cm/s;the implode speed under "trumpet" distribution is differrent along z-axis, up to 4.4x107 cm/s at the largest radius; the instability mostly happens in mid-anaphase of pinch, and m=0 of fast increasing is dominant, m=l instability and R-T instability take second places; the cathode produces high-temperature metal plasma after plasma disperses in the anaphase of pinch, and the temperature of the cathode is always higher than that of the anode during pinch; at the same time, it is observed that when the rise time of the load driven current is shortened, pinch speeds of plasma increase enormously, the temperature of cathode and anode is consistent quickly and the influence of plasma instability is reduced.At present, the system of gas-puff load has been used in Z-pinch experiments successfully. It provides an experimental condition to study the principle of the Z-pinch physics, and establish a favorable basis for domestic researches on Z-pinch physical phenomenons and ICF.更多还原