Marx generator

About: Marx generator is a research topic. Over the lifetime, 1276 publications have been published within this topic receiving 8970 citations.

Design and preliminary experimental results of wave erection Marx generator

Abstract: A 10-stage wave erection Marx generator with coaxial structure is designed,which realizes the miniaturization of pulse power modulator with capacitance energy storageLow-inductance capacitors of 3 nF are chosen as energy storage capacitors,and solid resistors are utilized as charging resistorsBy means of rapid discharge of each short gas spark gap and ultraviolet coupling between stages,wave erection can be realized on the output loadUnder the consideration of stray capacitance of electrodes to ground,equivalent eccentric transmission line effect and circuit inductance,equivalent circuit model is constructed for PSpice software to simulate the operation processUnder low charging voltage of 7 kV and 11 kV,preliminary experimental results are achievedThe output voltage waveforms are close to square wave,which are much improved compared to the traditional Marx generators' triangle wave form with large rise timeFor both situations of 7 kV and 11 kV charged,the full width half maximum of output voltage is 40~50 ns,and the rise time is more than 10 ns,while the amplitudes are 41 kV and 575 kV,respectivelyExperimental results and calculated results agree basically

Factors affecting the pulse width of capillary discharge soft X-ray laser

Abstract: Summary form only given, as follows. There are two ways to realize the population inversion in capillary discharge soft X-ray lasers: electron-collisional recombination pumping and electron-collisional excitation pumping schemes. It is possible to enhance the output of laser energy by increasing the gain-length product and the laser pulse width. While the former scheme can extract laser pulses of several tens of ns, the latter scheme can extract only several ns. Pulse widths are determined by the preservation time of optimal plasma condition and the growth time of plasma instability. The object of our study is to reveal the cause which restricts the duration of lasing in the collisional excitation scheme. The device consists of a Marx generator, a pulse transformer, a speed-up capacitor, a gap switch, a capillary and a pre-discharge circuit. The capillary is made of Pyrex glass and is 60 mm in length and 3 mm in inner diameter and is filled with an argon gas of 100-1000 mTorr. Uniformly pre-ionized argon gas in the capillary is excited with the current pulse having an amplitude of 15-60 kA and a first half cycle duration of 100 ns. The plasma photographs were taken from the side and axial directions using a high-speed camera in order to confirm its pinch and the growth of instability. The temporal evolution of the laser energy was measured with a vacuum X-ray diode. The duration of lasing is discussed based on the results of these experiments and MHD simulations of the imploding plasma.

Pulsed microsecond high‐energy electron beam accelerator

Abstract: Electron beams delivering up to 60 kA at 1.5 MV with pulse durations of 0.5–1.5 μsec were obtained by connecting a low‐inductance Marx generator directly across a vacuum diode. Beams with up to 44 kJ and conversion efficiencies up to 51% from Marx energy into electron beam energy were obtained.

Soft x-ray output from a pinch plasma using laser-induced Au plasma

Abstract: An experimental investigation of the characteristics of soft x-ray output emitted from a pinch plasma using a laser-induced Au plasma has been performed. The Au plasma is produced by focusing a laser pulse with a focal spot diameter of 100 μm on the tip of an Au pin anode electrode. A pulsed pinch discharge driven by a Marx generator utilizes the plasma as a discharge medium. Soft x-ray output with a pulse duration of ∼120 ns, an energy of ∼1 μJ mm−2, and an effective photon energy of ∼1 keV, has been obtained with the discharge. It is shown that the output characteristics depend strongly on the Marx charging voltage, laser pulse energy, and delay time of the discharge from the laser irradiation.

ZR Marx capacitor lifetime test results

Abstract: The ZR upgrade to the Z machine at Sandia National Labs (SNL) has a total output current requirement of at least 26 MA for a 100-ns standard z-pinch load. To accomplish this with minimal impact on the surrounding hardware, the existing Marx generator capacitors must be replaced with identical size units with twice the capacitance. Before the 2005 six-month shut down and transition from Z to ZR occurs, 2500 of these capacitors will be delivered. This paper summarizes the results of our lifetime testing of the selected General Atomics P/N 32896. 11/spl times/14/spl times/25-inch, Scyllac-style insulator bushing, 2.65-/spl mu/F, 100-kV, 30-nH, 35% reversal capacitor. We have completed lifetime tests with twelve capacitors at 100 kV and with fourteen capacitors at 110-kV charge voltage. The means of the fitted Weibull distributions for these two cases are about 17,000 and 10,000 shots, respectively. As a result of this effort plus the rigorous vendor testing prior to shipping, we are confident in the high reliability of these capacitors and have acquired information pertaining to their lifetime dependence on the operating voltage. One result of the analysis is that for these capacitors lifetime scales inversely with voltage to the 6.28/spl plusmn/0.9 power, over this 100 to 110-kV voltage range. Accepting the assumptions leading to this outcome allows us to predict the overall ZR system Marx generator reliability at the expected lower operating voltages of about 85 to 90 kV.