共查询到20条相似文献,搜索用时 15 毫秒
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基于开口谐振环结构设计了多频带太赫兹波调制器,并在谐振环的开口处及两侧均填充温敏介质锑化铟(InSb),研究了锑化铟的电磁性质随温度的变化、等效电感的组数对共振频带数目的影响以及锑化铟不同的填充方式对太赫兹波调制特性随温度的变化规律。研究结果表明,当环境温度从160 K上升到350 K时,锑化铟的载流子浓度和等离子体频率逐渐增大,然而等效介电常数却不断减小;每增加一组等效电感,太赫兹波调制器都会相应的增加一个共振频带;在调制器开口处和两侧均填充锑化铟时,当环境温度在160~350 K变化时,温度对太赫兹波的共振频率和共振幅度的调制效果比仅在开口处或者两侧填充锑化铟时更明显,且随着温度的升高,每个共振频带所对应的共振频率均明显增大。 相似文献
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In the Isar I linear theta pinchm=0 instabilities were observed and experimentally investigated. The variation of the plasma parameters over a wide range (τ ii =10?2... 102μsec) showed that them=0 instabilities only occurred in sufficiently hot and thin plasmas, and so they are most probably due to the anisotropic pressure of the ions and should be mirror instabilities. Perturbations of the plasma limited in space and time were observed by measuring the continuum radiation, by 90 ° laser scattering measurements and by measuring the magnetic field and the local neutron rate. All measurements showed distinct, correlated, local perturbations of the plasma cylinder. These perturbations were accompanied by bulging of the plasma cylinder and increasing density. The extent in the axial direction was of the order of the plasma diameter. It may be assumed that the observed instabilities contribute appreciably to relaxation of the anisotropic ion pressure and increase the end losses. 相似文献
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It is found that an anomalous resistivity exists even before the implosion phase, that is, it exists already at the so-called plasma formation stage of the theta pinch in the low-pressure regime. 相似文献
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为方便描述聚龙一号装置与Z箍缩负载的电磁耦合过程,基于大量电参数实验数据和全电路模拟分析,建立了一个简化的集总电路模型,获得了等效电压波形和等效电阻、电感等集总参量。采用水介质三板输出线出口位置的开路电压作为等效电压,进一步拟合为正弦平方函数,峰值为3.3 MV(当前驱动器充压为65 kV),零到峰值的时间长度为102.5ns。采用简化的流阻抗模型描述磁绝缘传输线内部空间电子流的电流损失效应。将电路程序与零维负载动力学程序耦合模拟,得到了与实验结果符合的负载电流波形,尤其电流波形的前沿和峰值符合较好,分析了电磁能转化为负载动能的过程。 相似文献
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Abstract The pulse-echo-overlap method was used to measure the longitudinal and transverse wave velocities in single-crystal (100) and (111) samples of InSb up to 3 GPa at room temperature. The peculiar variations of the elastic constants were observed near the covalent-metallic transition. 相似文献
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由于Z箍缩动态黑腔负载中的低密度聚合物泡沫柱具有多孔结构和极低的力学强度,在装配过程中对胶粘剂有一定的特殊要求。实验以聚氨酯丙烯酸酯为主体树脂,丙烯酸异冰片酯为活性单体,配以光引发剂和偶联剂制得了适用于低密度泡沫粘接用的紫外光固化胶粘剂。测试表明,所研制的胶粘剂的体积收缩率仅为2.25%,且具有较高的固化速率和适当的粘接强度,能够满足稳固、快速装配的要求。通过对粘接界面的观测发现,胶粘剂在诊断孔内没有明显的扩散,且在低密度致密结构泡沫中的扩散厚度较小,均匀性好。 相似文献
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Gerhard Becker 《Zeitschrift für Physik A Hadrons and Nuclei》1970,234(1):6-16
The ion flux parallel to the axis of a linear theta pinch (p 0=10–30 μ D2) is analyzed by a new 10-channel energy spectrometer (E=1–10keV). Time resolved energy spectra were measured in each single discharge. It can be shown experimentally that neutral gas, electrons and magnetic fields considerably influence the flux distribution. The measured energy spectra (E≦15 keV) are broad and have no ion groups. At 10 μ D2 dn/dE is proportional to exp {?E/ē} forE≧3 keV, whereē≈1 keV. For 10, 20 and 30 μ D2 ē is about equal to thekT deduced from the neutron flux. The time developments of the neutron and ion fluxes (in the range 1–10 keV) are correlated. For the initial phase of the discharge the measuring results are incompatible with relaxation by Coulomb collisions. It seems rather, that there is anomalously fast relaxation due to a microinstability. After the anomalous relaxation the end losses, particularly of the slower ions, continue as a result of Coulomb collisions. This produces increasing distortion of theE-distribution with smallE, which leads to a second microinstability with loss of energetic ions in particular (probably a loss-cone type). 相似文献
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Two dynamics modes,named short ablation mode and long ablation mode,are observed in implosion experiments of planar wire array Z pinch on ’QiangGuang-I’ facility utilizing an optical streak camera.The long ablation mode has a lagged trajectory compared with the short ablation mode.For shot 10035 in a short ablation mode,the initial time of K-shell radiation is consistent with the interaction time for ablation plasma arriving at the centre of wire array,while for shot 10038 in long ablation mode,the initial time of K-shell radiation is about 10 ns earlier.In the two modes,the partial ablation plasma could traverse the wire array plane and then collide in the centre to form a dense plasma column with a diameter of 2.2 mm for shot 10035 and 1.5 mm for shot 10038. 相似文献
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丝阵负载内爆动力学行为基本可以分为以下四个过程:1)丝的烧蚀;2)壳层的形成;3)内爆;4)滞止.利用所研制的可见光分幅相机和X射线分幅相机在"强光一号"加速器上对多种型号的丝阵负载Z箍缩内爆动力学行为进行了实验研究,获得了从早期单丝烧蚀到等离子体柱崩毁全过程图像,并对实验结果进行了分析,主要研究成果如下:1)发现存在较长时间的丝烧蚀过程,且单丝烧蚀在轴向上并不均匀;实验得到的内爆轨迹与唯像模型计算结果较为一致.2)不论早期的可见光图像还是中后期的软X射线图像都存在明显的阴极发射,内爆后期在阴极附近存在明
关键词:
丝阵
内爆动力学
Z箍缩
脉冲功率技术 相似文献
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Line profiles from impurity ions in a small theta pinch have been analyzed. Isotropization of the distribution function is fast compared to binary collision times and occurs preferentiallly perpendicular to the magnetic field in the beginning. 相似文献
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E.E. Farias M. Raineri J. Reyna Almandos F.O. Borges 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(15):2463-2468
The spectrum of five-time ionized krypton, Kr VI, was recorded in the 240-2600 Å wavelength range, resulting in 61 new classified lines as transitions between levels of configurations 4p3, 4s25p, 4s4p4d, 4s4p5s and 4s4p5p. All the 18 energy levels belonging to 4s4p5p configuration except one were determined. Eight new energy level values corresponding to configurations 4s4p4f and 4p24d, supported by 26 new classified lines were also determined and used in the interpretation of the observed 4s4p5p configuration. The experimental data were obtained from a capillary-discharge tube and theta pinch light sources. Multiconfiguration Hartree-Fock calculations with relativistic corrections and a least-squares fitted parametric calculation has been carried out. 相似文献
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The ionization rates of Kr(IX), (X), (XI), and (XII) have been measured using a fast 60-kV-60kJ theta pinch as a plasma source. The line emission from each ion stage has been identified and the time evolution observed. A coupled set of rate equations was used along with time- and space-resolved measurements of the electron density and temperature to model the plasma light emission. The ionization rates of Kunze were adjusted by multiplying the rate for each ion stage with a constant until the peak intensity of the calculated emission agreed with the time of the observed peak intensity. The constants required for best fit were 2.5, 0.15, 3.0, and 2.0 for Kr(IX), (X), (XI), and (XII), respectively. Two successive ionization stages, Kr(X) and Kr(XI), have shown the same time dependence and possible reasons for this observation are discussed. During the course of modeling the light emission, we have also found that the rate for the excitation from the 3dn to the 3p53dn+1 level in Kr(X) (n=9) and Kr(XI) (n=8) is a factor of 5 lower than predicted by the van Regemorter excitation rate equation. 相似文献
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阳极杆箍缩二极管(RPD)具有小焦斑、高亮度的特点,是闪光X光机领域的研究热点。基于Marx发生器和脉冲形成线技术路线产生1 MV高电压脉冲驱动RPD,开展了不同结构参数二极管实验研究。基于RPD物理过程的数值模型,分析了结构参数对箍缩物理过程的影响。研究表明在1 MV电压下,RPD阴极等离子体平均扩散速度、阳极等离子体平均扩散速度分别为2,0.6 cm/μs时,该模型可以较好地描述实验结果。在阳极杆直径一定的情况下,二极管数值模型表明减小阴极孔径可以使二极管更快进入强箍缩状态,但过小的阴极孔径会导致二极管间隙过早闭合。 相似文献