共查询到20条相似文献,搜索用时 15 毫秒
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Using a 1313-?F, 3-nH, 120-kV, 9.4-MJ SHIVA Star capacitor bank, we have performed vacuum inductive store/plasma flow switch (PFS) driven implosions of low mass (200-400 ?g/cm2) cylindrical foil liners of 2-cm height and 5-cm radius. This technique employs a coaxial discharge through a plasma armature, which stores magnetic energy over 3-4 ?s and rapidly switches it to an imploding load as the plasma armature exits the coaxial gun muzzle. The current transferred to the load by the PFS has a rise time of less than 0.2 ?s. With 5-MJ stored energy, we have driven fast liner implosions with a current of over 9 MA, obtaining an isotropic equivalent 2.7-TW 0.5-MJ X-ray yield. 相似文献
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Experimental results from inductive store pulse compression experiments with plasma opening switches are presented. The experiments have been performed on the high-power pulse generators Pollux and KALIF operating at nominal powers of 0.1 and 1.5 TW, respectively. A large range of switch geometries, currents, voltages, and magnetic fields have been investigated. Diode loads with falling and rising impedance characteristics have been applied. A peak-power multiplication of 2 has been demonstrated in the Pollux experiments. The power multiplication in the present experiments was limited by the lack of magnetic insulation in the switch and adjacent feed section at higher load impedances. The limitations were much more severe than predicted by laminar flow theories of magnetic insulation. Generally, magnetic insulation was superior, with diode loads having rising impedance characteristics. 相似文献
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利用等离子体非线性系数实现超强脉冲的压缩 总被引:2,自引:0,他引:2
超短脉冲压缩技术在强场物理研究中有非常重要的作用,但由于强场电离现象在惰性气体自相位调制脉冲压缩技术中限制了脉冲的能量。Tempea等人提出可以采用等离子体非线性系数对脉冲进行压缩,本文在考虑毛细管内表面电离的情况下,讨论能量为10mJ左右,脉宽为50fs的脉冲的压缩问题,发现可以将脉冲压缩至5fs左右。计算表明频谱展宽可以在气体密度很低的情况下进行,这样半可以减小电子对脉冲传输的影响。同时,由于毛细管内表面也处于电及状态,从而使脉冲能量不会受到电离阈值的.限制。 相似文献
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The first demonstration of fully controlled high-power high-repetition-rate burst-mode operation of an inductive energy storage and transfer system with nondestructive switches was achieved with fast-recovery vacuum switches and a new repetitive transfer circuit. The system delivered a S-kHz pulse train with a peak power of 75 MW (at 8.6 kA) to a 1-? load. 相似文献
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文章介绍了用于冲击磁铁的感应叠加型脉冲发生器的实验装置.电路中采用3.3kV/800A IGBT开关,大尺寸纳米晶磁环,2.5kV/50uF储能电容.设计了基于CPLD的多路延时可调、光耦输入触发驱动电路.探讨了IGBT短路时的失效原因及保护措施.利用现有的组元电路,进行了多个单元叠加的样机实验,给出了实验波形.结果表明输出脉冲上升下降时问较快,脉宽可调,最大脉冲电流可达2kA,可以满足束流注入技术的进一步提高的要求. 相似文献
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Producing High Intense Attosecond Pulse Train by Interaction of Three-Color Pulse and Overdense Plasma 下载免费PDF全文
《中国物理快报》2017,(5)
Amplifying the attosecond pulse by the chirp pulse amplification method is impossible. Furthermore, the intensity of attosecond pulse is low in the interaction of laser pulse and underdense plasma. This motivates us to propose using a multi-color pulse to produce the high intense attosecond pulse. In the present study; the relativistic interaction of a three-color linearly-polarized laser-pulse with highly overdense plasma is studied. We show that the combination of ω_1, ω_2 and ω_3 frequencies decreases the instance full width at half maximum reflected attosecond pulse train from the overdense plasma surface. Moreover,we show that the three-color pulse increases the intensity of generated harmonics, which is explained by the relativistic oscillating mirror model. The obtained results demonstrate that if the three-color laser pulse interacts with overdense plasma, it will enhance two orders of magnitude of intensity of ultra short attosecond pulses in comparison with monochromatic pulse. 相似文献
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A near sonic nitrogen plasma jet operating at pressures between 100 Torr and 1 atm has been investigated spectroscopically. From the absolute emission coefficient of a NI spectral line, local values for the electron temperature Te have been derived. For pressures above 200 Torr, Tg was found to coincide within the limits of experimental error with the gas temperature Tg. The latter quantity has been determined via the relative emission coefficient of selected rotational line components of the N2+ molecular band at 3914 Å. The results of these measurements together with control data for the electron density derived from the continuous emission coefficient indicate that at pressures above 200 Torr the existence of a thermal equilibrium between the degrees of freedom corresponding to particle translation, electron excitation, and ionization can be accepted, at least for the inner zone of the plasma jet. To the contrary, the data for the absolute emission coefficient of N2+ molecular band lines show that the degree of dissociation in the plasma jet is much in excess of that corresponding to equilibrium. This phenomenon can be explained as a result of the rapid temperature decay in the plasma from initially 13000 K in the arc heating zone to T ≦ 9000 K in the plasma jet zone proceeding in a time interval of 10?5 s which is much shorter than the time necessary for adjustment of dissociation equilibrium. In the outer cool zone of the plasma jet, an unusual high intensity of the N2+ radiation was found thus indicating the existence of a nonequilibrium excitation mechanism typical for a decaying nitrogen plasma. From the supernormal high degree of dissociation in the high-speed subatmospheric nitrogen plasma jet, conclusions are drawn with respect to its applicability as source of reactive particles in plasma-chemical experiments. 相似文献
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Kozhevnikova A. M. Ivankov A. S. Alekseenko I. V. Sсhitz D. V. 《Russian Physics Journal》2021,64(8):1498-1504
Russian Physics Journal - A method of digital holographic interferometry and an automated laboratory unit developed to determine the parameters of a nonthermal plasma jet in a pulsed mode are... 相似文献
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Asymmetrically apodized linearly chirped fiber Bragg gratings (FBGs) are shown to have highly linearized time-delay response. In simulations of a five-stage, 5-cm grating-based dispersion compensation system, asymmetrically apodized FBGs are shown to give over 60% reduction in the energy scattered from the main pulse body, 16 ps?60 ps pulses propagated over 800 km, as compared to a symmetrically apodized grating of similar length, strength, and bandwidth. 相似文献
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Abstract A simple and stable technique of optical short pulse generation for soliton transmission based on external modulation is reviewe.By using nonlinearity of absorption characteristics of an electroabsorption modulator, ultra-short optical pulse trains having a shape close to sech2 shape can be generated just with sinusoidal modulation, without ultra-short driving pulses and ultra-broad bandwidth of the modulator. The pulse width and the repetition rate can be varied by changing the electrical driving conditions. Quasi-transform-limited optical pulseswith time-bandwidth product of 0.32 were successfully generated by the sinusoidally driven InGaAsP electroabsorption modulator with up to 20 GHz repetition rate. An application of a λ/4-shifted DFB laser-electroabsorption modulator integrated light source to a single-chip soliton source is also described. The high quality of the modulator-generator pulses has been proven by long-distance soliton transmission over 6400 km at 2.5 Gb/s using a recirculating fiber loop. 相似文献
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介绍了激光陀螺(RLG)读出信号高速采集系统的设计和实现方案。该系统包括板卡和相应的应用软件,提供两路最高60MHz采样频率、14位精度的数据采集通道,能够同时对RLG两路光强拍频信号进行高速高精度数据采集,为RLG特性分析提供重要依据。该系统通过上位机软件控制板卡的工作状态、设置和切换采样模式。板卡利用FPGA接收计算机指令并协调控制模数转换器、SDRAM和USB接口芯片,完成RLG输出拍频信号的采集、缓存和传输。FP—GA设计中结合了硬件逻辑高速灵活的优点和NIOSⅡ软核处理器在控制方面的优势。SDRAM完成海量数据缓存,USB接口芯片工作在SlaveFIFO模式下,实现板卡与计算机的通信。实验证明该系统工作稳定,在RLG测试和性能分析中具有很好的实用性。 相似文献
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介绍了一种获取高速调制电信号的新方法-基于FPGA的高速电光选通系统.此系统分为选通脉冲和高压调控两个模块.选通脉冲模块由高速信号放大、FPGA延时、可控延迟传输线三个部分组成.利用FPGA高密度、高可靠性、可反复擦写和可以现场编程、灵活调制的特点,将整个系统的主要控制部分集成在FPGA中,并将延时分为数字延时和模拟延时两部分.然后利用FPGA实现数字延时,可控延时线实现模拟延时.经试验检测,高压部分可以产生重复频率1 Hz~1 kHz,步进1 Hz,延时范围为0~1 μs,步进为1 ns,幅度为8 000 V,前沿和后沿小于10 ns,抖动小于1 ns的高压矩形电脉冲,从而满足各种电光调制系统中的需要. 相似文献
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Multistage Fiber Amplifier with Spectral Compression Elements for High-Energy Laser Pulse Generation
I. O. Zolotovskii D. A. Korobko A. A. Sysoliatin A. A. Fotiadi 《Journal of Russian Laser Research》2016,37(5):448-458
We consider general principles of spectral compression of parabolic pulses in nonlinear optical fibers. It is known that the variance analysis provides a way to describe correctly the evolution of the pulse parameters under the spectral compression. We propose a computational model of multistage amplifier with spectral compression segments incorporated. The model provides the possibility to amplify middle-power input pulses to obtain pulse energies of hundreds of nanojoules with such output spectral characteristics that provide the possibility for further effective enhancement. We also discuss a modification of the model that provides the formation of a parabolic envelope and linear frequency modulation of the output pulse. 相似文献
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Lindemuth IR Reinovsky RE Chrien RE Christian JM Ekdahl CA Goforth JH Haight RC Idzorek G King NS Kirkpatrick RC Larson RE Morgan GL Olinger BW Oona H Sheehey PT Shlachter JS Smith RC Veeser LR Warthen BJ Younger SM Chernyshev VK Mokhov VN Demin AN Dolin YN Garanin SF Ivanov VA Korchagin VP Mikhailov OD Morozov IV Pak SV Pavlovskii ES Seleznev NY Skobelev AN Volkov GI Yakubov VA 《Physical review letters》1995,75(10):1953-1956
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《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2009,37(11):2228-2233