介绍了一台大型垂直极化有界波模拟装置所用中间储能电容器(简称中储电容器)的设计过程和实验结果.电容器采用基于元件和组件的模块化设计,呈锥台状结构,支撑壳体为真空工艺玻璃钢材料.电容器容值由模拟装置等效的二级脉冲压缩回路决定,取值为1.8 nF.电容器内部绝缘介质为十二烷基苯,外部绝缘介质为45#变压器油,设计耐压3?MV,其绝缘长度主要由元件的体绝缘特性决定.采用三维电磁仿真软件估算中储电容器与中储开关构成回路的电感为659?nH,接近于实测数据623?nH.电容器上脉冲电压的测量通过对电容器电流进行积分来获取,而电流的采集采用封装在SF6气体中的3个膜电阻并联后所构成测量模块实现.实际运行数据表明,中储电容器容值达到设计值,测量探头标定系数稳定,在工作电压3.1?MV条件下未发生绝缘问题.

In recent years, controllable shock wave coal seam permeability enhancement technology has been paid more and more attention as an emerging technology in the field of coal mining safety. At present, the study of coal seam permeability enhancement in densely drilled areas where the pre-drainage effect is not obvious is still a blank field. In this paper, the coal seam permeability enhancement technology based on the controllable shock wave is applied to the coal area for engineering practice. By optimizing the hole layout and without increasing the amount of drilling work, the re-increase permeability test was directly carried out in 16 original drilling holes. Observation results of 1 560 sets of data show that after adopting controllable shock wave measures to increase permeability, the drainage volume of dense drilling areas can still be increased by 3.3 times. The range of influence between the boreholes reaches 50 m, and then a flow curve of "rising-peak-decay" mode is formed. The experiment in this paper confirmed for the first time that the controllable shock wave in conventional dense boreholes still has a good effect of increasing permeability. This technology can effectively shorten the time for coal seam pre-drainage to reach the standard, and can significantly increase the speed of gas drainage.

快脉冲测量探头是大型脉冲功率装置安全稳定运行的基石,研究其标定技术对获取准确可靠的脉冲功率装置运行参数具有重要意义。为此通过分析不同快脉冲测量探头的实际应用环境,利用同轴线脉冲方波成形原理,提出了快脉冲测量探头的2种规范化标定方法:在线标定和离线标定,其中,在线标定方法适合于受分布参数影响较大的测量探头,如微分环和电容分压器等,而离线标定方法适合于受分布参数影响较小的测量探头,如Rogowski线圈和小电阻分流器等。2种标定方法均获得了响应时间为ns量级的矩形方波脉冲,且具有相同的放电回路和具有可溯源到国家标准的测量不确定度,分析了测量确定不确定度的合成方法。研究结果将对快脉冲测量探头的规范化标定具有重要参考价值。

分析了同轴薄膜电容器电参数和结构参数之间的关系,提出了以单层同轴薄膜电容器个数、两侧锥角和内芯外径等参数为变量,以实现各个单层同轴薄膜电容器薄膜介质厚度差异最小化为目标的设计方法.设计了一种耐受电压为1 MV,电容为200 pF,电容器长度不大于400 mm,外径不大于300mm的同轴薄膜电容器.其中,单层同轴薄膜电容器为13个,两侧锥角为34°,内芯外径为140 mm.最后通过模拟计算验证了上述优化设计方法的合理性.

金属丝在快脉冲电流驱动下,受到欧姆焦耳加热作用发生电爆炸现象,并呈现出复杂的物理和化学效应,已广泛应用于工农业生产、新材料制备和核聚变等方面。文中综述了金属丝电爆炸现象的研究历史和应用情况,分析了金属丝在不同电流作用下的物理现象和规律,提出了一种金属丝电爆炸现象的分类方法,即以金属丝注入能量快慢的不同,将金属丝电爆炸现象分为欠热电爆炸和过热电爆炸现象,在过热电爆炸现象中,根据产生的电爆炸等离子体温度的不同,分为高温等离子体和低温等离子体,该类低温等离子体在不同的介质环境中具有不同的应用特点;分析了金属丝电爆炸现象的研究现状,即金属丝电爆炸等离子体的参数诊断方法以及相关数值模拟方法,讨论了金属丝电爆炸现象研究的难点、热点问题和下一步发展方向。

Based on high pulsed power technology, electrical explosion is increasingly utilized to generate shock waves with high pressure. To further magnify the shock wave pressure, we have proposed a novel technique by using energetic materials ignited by the plasma of microsecond wire explosion. Organic derivatives of nitramide, termed nitroamines, are widely used as powerful and relatively insensitive explosives. In this paper, we investigated the shockwave characteristics of nitramine (RDX and HMX) powders ignited by exploding copper wire (diameter 0.3 mm and length 60 mm). With charge voltage of 24 kV and powder mass about 6.0 g, the most evident experimental results suggested that the RDX load possessed higher peak pressure of 11.38 MPa and larger areal impulse of 503.02 MPa $\cdot \mu \text{s}$ , comparing with the shock wave of HMX load (7.22 MPa and 371.28 MPa $\cdot \mu \text{s}$ ). Moreover, the RDX load also had greater ascent rate of pressure, which was nearly twofold of that of the HMX load. Finally, a simple multi-factor ignition mechanism for nitramine powder under microsecond exploding wire plasma was proposed and discussed.

In order to meet the requirements of anti EMP performance test of the difference size effect test compounds,and to generate the simulated EMP environments with more comprehensive coverage and more ideal waveform,in the paper,the basic composition and working principle of the EMP-simulator diver with one-stage pulse sharpening and based on the Marx generator are introduced.According to the actual experiences of design and debugging of this kind of devices,some problems that may be encountered when using the ideal principle to design these drivers are analyzed,and some targeted solutions are provided.In addi-tion,some drivers for the small-and-middle scale EMP simulator with rated output voltage of 100-600 kV are developed.With the development of super compact Marx generator,compact flat-form film capacitor and low inductance output switch,the optimiza-tion of the connection structure,and the selection of reasonable parameters,these drivers connected with the load of 120-180 Ωcan produce the ideal double exponential waveforms with the rise time of 1.2-2.7 ns and the half width of 32-41 ns.

Due to its low-loss and high dielectric strength, polypropylene is widely used as electrical insulation material in pulse capacitors. In order to study its breakdown characteristics for nanosecond voltage pulses, an experimental setup was designed to generate voltage pulses with a 10%-90% rise time of 38 ns and a full width at half maximum of about 90 ns. Tests of the three polypropylene films with thicknesses of 12, 15, and 18 mu m were performed. In addition, hundreds of nanoseconds pulse and de voltage were also applied for comparison. The experimental results reveal that most of the breakdown occurs during the front edge of the pulse for tens of nanoseconds pulse, and the breakdown strengths of the three kinds of polypropylene films are almost identical for different applied voltages, which show a weak correlation between the thickness of the dielectric and the breakdown field. The expected breakdown strength of tens of nanoseconds pulse defined in this paper is not significantly higher than the mean value of the hundreds of nanoseconds pulse and the dc condition, suggesting that the breakdown of a thin polypropylene film is mainly determined by the electrical field but not the voltage-time cumulative effect. All these observations strengthen the conclusion that the breakdown of a thin polypropylene film is an intrinsic phenomenon.

Based on high pulsed-power technology, electrical explosion is increasingly utilized to generate shock waves (SWs) with high pressure and short duration. To further magnify the SWs, we have proposed a novel technique by using energetic material (EM) loads. In this paper, we investigated the SW characteristics of ammonium nitrate (AN) powders ignited by the plasma of different kinds of refractory wire explosion. Evident results suggested that compared with $\Phi ~0.5$ -mm wires, $\Phi ~0.2$ -mm molybdenum and tantalum wires were able to finish vaporization, undergo the breakdown and eventually produce stronger SWs. After introducing the AN powders, the peak pressure of SW was scarcely enhanced, while the duration was significantly increased. Moreover, it was implied that various factors would affect the SW characteristics, including the EM charge density, the diameter, and material of metal wire. Finally, a simple plasma ignition mechanism based on multifactors was proposed.

A pair of W-Ni-Fe and W-Cu electrodes were tested under 100 kA level pulsed currents for 10 000 shots, respectively. Surface roughness and morphology characteristics of the two pairs of electrodes were obtained and compared. Experimental results indicated cracks divided the W-Cu electrode surface to polygons while the W-Ni-Fe electrode surface remained as a whole with pits and protrusions. Accordingly, the surface roughness of W-Ni-Fe electrodes increased to ∼3 μm while that of W-Cu electrodes reached ∼7 μm at the end of the test. The results reveal that the W-Ni-Fe alloy has a better erosion resistance and potential to be further applied in spark gaps.

In this paper,a 2 MV self-triggered switch with capacitance coupling circuit is presented under the microsecond pulse.The switch has a simple structure and a high reliabil-ity.Based on the electric field strength and circuit simulation,some key configurations and circuit parameters are obtained.The calculation results show that the voltage of designed triggered gap accounts for 1 .2 1% of the main gap,and the nonuniform factor of the main gap is 1.64,the breakdown voltage of the self-triggered gap is about 21 kV when the maxi-mum working voltage of the switch is 2.27 MV at the air pressure of 0.7 MPa.

针对化石能源开发中储层改造技术的局限性,创新性地提出了重复脉冲强冲击波增透储层新技术.分析了水中放电、金属丝电爆炸和电爆炸等离子体驱动含能混合物产生冲击波的3种机理.介绍了冲击波作用储层的机理研究和现场应用结果,从理论、实验和现场实践验证了冲击波技术增透储层的可行性.结果表明,以电爆炸等离子体驱动含能混合物产生更强的和区域可控的冲击波,可针对储层做单点多次、分段式的增透改造,在化石能源开发中的意义重大.

The output switch is a key component which connects the pulse power generator and the antenna in an intense electromagnetic pulse simulator and its turning on and off can reflect the working condition of the simulator. In order to measure the turn-on time of the output switch, the formative time of the switch is analyzed based on avalanche and streamer theory, and the optical technique which provides a method via optical fiber transmission for penetrating into high voltage cavities with the advantages of insulation and electromagnetic interference is adopted. A measuring system based on optical fiber and silicon PIN detector is developed, and an experimental platform for testing the synchronous characteristics is established. The experiments are carried out using a one-to-one scale output switch model. The experimental results show that the measuring system is excellent in electromagnetic resistance, the start point of the measured optical signal is clear to recognize; the average time delay between start points of the optical signal and the current signal is 20.42ns, the range and the jitter of the time delay are 0.78ns and 0.4ns; the designed optical system can be used to monitor the turn-on time of the output switch.

采用快开通功率MOSFET,通过优化驱动电路、磁芯参数以及耦合结构,设计了基于半导体开关和直线变压器驱动源（LTD）技术的高重频快沿高压脉冲源。该脉冲源由四级LTD串联而成,可实现单次脉冲和最高频率2 MHz脉冲串输出。脉冲最高幅值约2.3kV,上升沿约7ns,脉宽约90ns,下降沿约20ns,输出电压效率约95%。该脉冲源结构紧凑,输出脉冲稳定,实现了模块化设计,可作为重频电磁脉冲模拟源使用。

To get the better choice for achieving higher stability and reproducibility of the output voltage pulse of the generator, two pancake switches commonly used in the low energy, high peak power Marx generator have been compared. The comparison is done in several aspects including the structure, the electric field distribution, and the breakdown characteristics. Some useful conclusions are drawn. And there is a big difference between the structural capacitances of the two gas switches as a result of the different configuration of their electrodes. So a circuit simulation of the switch used in a simple, basic, two-stage Marx circuit has been done on both switches respectively.

The behavior of explosive emission cathode plasma was a fundamental physical problem in the study of high current electron beam diode. A diagnosis system was designed for getting the time-resolved and spectrum-resolved emission spectra of cathode plasma on a 1MV diode with dozens of kilo amperes in this paper. A full spectrum of direct reading spectroscopic diagnostic system which includes a high band pass spectrograph with 200-1000nm detection wavelength and an ultra high-speed intensified imaging with 2ns gate time was used in the experiment. The characteristics of emission spectra in different stages during the process of cathode plasma of several cathode materials were obtained. These results are helpful for improving the uniformity of cathode plasma emission in high current diode by choosing suitable surface treatment method of cathode.

交联聚苯乙烯具有优异的电气性能、力学性能和可加工性能,已作为高压绝缘材料得到了重要应用.随着脉冲功率技术向小型化方向发展,对交联聚苯乙烯真空沿面闪络性能提出了更高要求.以苯乙烯为单体,二乙烯基苯为交联剂,偶氮二异丁腈为引发剂,采用超声波分散技术将不同质量分数的云母均匀分散于溶液体系中,通过原位自由基聚合制备出云母/交联聚苯乙烯复合材料.采用红外光谱、电子扫描显微镜等对材料组成和形貌进行了表征,采用短脉冲高压测试平台研究了云母对交联聚苯乙烯真空沿面闪络性能的影响.结果表明,当云母质量分数低于5％时,复合材料中云母为均匀分散状态,随着掺杂量进一步提升,出现了明显的团聚现象;当云母质量分数为3.5％～5％之间时,真空沿面闪络击穿电压和耐电寿命较交联聚苯乙烯得到了明显提升.

Surface flashover properties of polymer insulator are very closely related to its surface structure and morphology. To enhance the surface flashover voltage of polymer insulator,nano-SiO2/cross-linked polystyrene (CLPS)composites with mod-ified surface structure of nano-sized cavities were developed by means of both free radical crosslinking copolymerization and surface erosion for the first time.The structures of SiO2/CLPS composites were characterized with Fourier transform infrared spectros-copy(FT-IR)and transmission electron microscopy(TEM).The results showed that nano-SiO2 particles with an average size of 20-50 nm were well dispersed in the cross-linked polystyrene matrix with excellent compatibility between the organic and inorganic components.The cavities with the same size as SiO2 particles could be formed in the surface of the polymer,and SiO2 particles in the inner layer would remain intact.The uniform cavities could be responsible for the improvement of surface flashover property of polymer insulator.The surface flashover voltages of the modified surface insulators were increased by 15%-20% by comparison with that of CLPS.It gives a novel way to develop high dielectric polymer insulator.

Ultraviolet (UV) illumination can effectively shorten the statistical lag and jitter in gas breakdown processes. The spark gap discharge can produce abundant spectrum including UV waveband. In this paper, a simple but reliable spark gap operating with N-2 at atmospheric pressure is used to test optical radiation characteristics, such as spectrum intensity, rise time, fall time, and duration of optical pulse, which are adjusted by changing the circuit or configuration parameters. Three UV-illuminated switches with different UV spark gap configurations have been tested. The experimental results approve our assumption. With a uniform electric field UV spark gap, the breakdown voltage standard deviation percentage of the switch is 0.74%.

Cathode plasma is an important factor affecting the cathode emission on high current pulsed electron beam diode. Diagnosing the cathode plasma composition by integral spectrum system is a method for studying the cathode plasma formation and development process. The aim of this paper is to study the cathode plasma composition and analyze the cathode plasma formation mechanism by integral spectroscopic diagnosis of different materials and cathode pretreatments. Experiment results show that not only cathode material itself, but also impurity material and adsorptive gas on cathode surface are found in the cathode plasma. For the same material, the cathode plasma composition remains unchanged, whereas the characteristic line intensity decreases as the experiment times increase. The composition of the cathode plasma can be controlled by adulterated treatment.