A novel compact low impedance Marx generator with quasi-rectangular pulse output

2018 ◽  
Vol 89 (4) ◽  
pp. 044703 ◽  
Author(s):  
Hongwei Liu ◽  
Ping Jiang ◽  
Jianqiang Yuan ◽  
Lingyun Wang ◽  
Xun Ma ◽  
...  
1997 ◽  
Vol 15 (2) ◽  
pp. 241-248 ◽  
Author(s):  
H. Chuaqui ◽  
E. Wyndham ◽  
C. Friedli ◽  
M. Favre

The design and constructional aspects of a novel pulse power generator for use in dense plasma research presently under construction are presented. The generator consists of two Marx capacitor banks, each of 0.25 μF, 480 kV, and 28.8 kJ. Each Marx generator drives a water transmission line, in which the live electrode is the central conductor. The transmission lines consist of a constant impedance section followed by a multielectrode gas linegap followed by an exponential taper to the load section. The novel feature is the use of an auxiliary exponential line coupled at the load. This line controls both the voltage and the effective impedance at the load section. In addition, by leaving this line circuit open, energy not coupled to the plasma in the initial high-impedance phase may be reflected back and deposited into the discharge, increasing the peak current by 50%. Circuit simulations using a real-time-varying load impedance show that the current pulse rises in an approximately linear way to a maximum of 1.2 MA at 250 ns. The current falls to zero in the following 250 ns. The current waveform may be flattened simply by disconnecting the auxiliary line, giving a rectangular pulse of 350 ns with a maximum value of 950 kA. The overall impedance of the entire system may be adjusted by varying the separation between the conductors. The equivalent source impedance at the load is 0.8 Ω. This low value is by virtue of the auxiliary line, which limits the voltage at the load section and reduces the insulator constraints. We present simulations of the generator under real load conditions. The model also is checked against analytical solutions of exponential line behavior and against other published models of pulse power generators.


2019 ◽  
Vol 9 (2) ◽  
pp. 192-197
Author(s):  
Somrita Ghosh ◽  
Aritra Acharyya

Background: The time and frequency responses of Multiple Quantum Barrier (MQB) nano-scale Avalanche Photodiodes (APDs) based on Si~3C-SiC material system have been investigated in this final part. Methods: A very narrow rectangular pulse of pulse-width of 0.4 ps has been used as the input optical pulse having 850 nm wavelength incidents on the p+-side of the MQB APD structures and corresponding current responses have been calculated by using a simulation method developed by the authors. Results: Finally the frequency responses of the devices are obtained via the Fourier transform of the corresponding pulse current responses in time domain. Conclusion: Simulation results show that MQB nano-APDs possess significantly faster time response and wider frequency response as compared to the flat Si nano-APDs under similar operating conditions.


Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 313
Author(s):  
Jacek Rąbkowski ◽  
Andrzej Łasica ◽  
Mariusz Zdanowski ◽  
Grzegorz Wrona ◽  
Jacek Starzyński

The paper describes major issues related to the design of a portable SiC-based DC supply developed for evaluation of a high-voltage Marx generator. This generator is developed to be a part of an electromagnetic cannon providing very high voltage and current pulses aiming at the destruction of electronics equipment in a specific area. The portable DC supply offers a very high voltage gain: input voltage is 24 V, while the generator requires supply voltages up to 50 kV. Thus, the system contains two stages designed on the basis of SiC power devices operating with frequencies up to 100 kHz. At first, the input voltage is boosted up to 400 V by a non-isolated double-boost converter, and then a resonant DC-DC converter with a special transformer elevates the voltage to the required level. In the paper, the main components of the laboratory setup are presented, and experimental results of the DC supply and whole system are also shown.


2009 ◽  
Vol 45 (1) ◽  
pp. 237-240 ◽  
Author(s):  
Y. Aso ◽  
T. Hashimoto ◽  
T. Abe ◽  
S. Yamada

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3492
Author(s):  
Yahia Achour ◽  
Jacek Starzyński ◽  
Jacek Rąbkowski

The paper introduces a new design of Marx generator based on modular stages using Silicon Carbide MOSFETs (SiC-MOSFET) aimed to be used in biomedical applications. In this process, living cells are treated with intense nanosecond Pulsed Electrical Field (nsPEF). The electric field dose should be controlled by adjusting the pulse parameters such as amplitude, repetition rate and pulse-width. For this purpose, the structure of the proposed generator enables negative pulses with a quasi-rectangular shape, controllable amplitude, pulse-width and repetition-rate. A complete simulation study was conducted in ANSYS-Simplorer to verify the overall performance. A compact, modular prototype of Marx generator was designed with 1.7 kV rated SiC-MOSFETs and, finally, a set of experiments confirmed all expected features.


1975 ◽  
Vol 30 (5) ◽  
pp. 571-582 ◽  
Author(s):  
C. J. Winscom

Abstract The behaviour of spin sublevel populations with time following periodic photo-excitation is ex-amined. The treatment is limited to conditions of magnetic field strength and temperature for which the spin lattice relaxation rates dominate the individual spin sublevel decay rates. The response of the system to three modes of excitation is considered: (i) continuous excitation using a time-independent intensity (ii) periodic rectangular pulse excitation and (iii) periodic waveform excitation. A convenient correspondence between the various forms of solutions is pointed out. The requirements of an experiment to determine spin-lattice relaxation rates in organic triplets at 77 K are discussed.


2016 ◽  
Vol 34 (4) ◽  
pp. 675-686 ◽  
Author(s):  
Z.-L. Pan ◽  
J.-H. Yang ◽  
X.-B. Cheng

AbstractAn anti-resonance pulse forming network (PFN) has been designed, analyzed, and tested for its application in generating quasi-square pulses. According to the circuit simulations, a compact generator based on two/three-section network was constructed. Two-section network is applied in the generator due to its compact structure, while three-section network is employed for generating pulses with higher quality. When two-section network is applied in the generator, the full-width at half-maximum of the load pulse is 400 ns, at the same time, its rise time, flat top and fall time are 90, 180 and 217 ns, respectively. When the three-section network is applied with the same pulse width of the load pulse, the rise time of the output decreases to 60 ns, while the flat top increases to 240 ns and the fall time reduces to 109 ns. Meanwhile, this kind of network could be used to shape the output pulses of generators whose equivalent circuit is LC series discharge network, such as MARX generator, into quasi-square pulses. And the preliminary experiment demonstrates that anti-resonance network could work well on four-stage Marx generators. A sine pulse generated by the four-stage Marx generator is shaped into a quasi-square pulse with voltage of 11.8 kV and pulse width about 110 ns based on two-section anti-resonance network.


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