[en] The compact Marx generators, which can operate at a certain repetition frequency with small size, light weight, and high energy efficiency, are widely used in narrowband, wideband and ultra-wideband high power microwave (HPM) sources. This type of HPM source based on compact Marx generators is a worldwide research focus in recent years, and is important trend of development. The developments of this type of HPM source are described systemically in this paper. The output parameters and structural characteristics are reviewed, and the trends of development are discussed. This work provides reference and evidence for us to master the status of the HPM source based on compact Marx generators correctly and to explore its technical routes scientifically. (authors)

[en] A remote trigger-control system based on LabVIEW and PIC microcontroller is developed to control the repetitively pulsed intense-electron-beam accelerator charged by capacitive energy storage. This system employs an ordinary data-acquisition card and a microcontroller to realize complex circuit control and sequence control, with functions of signal collecting, data sheet calling, thyristor switch triggering and so on, to achieve the main purpose of controlling the charging of primary capacitance of transformer resonantly and stably. When the intense-electron-beam accelerator works repetitively with the control system, the voltage of the primary capacitance of transformer is tested to be consistent and stable, which shows that the control system can work stably and reliably with strong anti-interference ability. (authors)

[en] For the need of intense current electron accelerator, a high voltage, long-life gas spark switch was designed. Anti-pollution design is used in the switch, the outer housing of the switch is made of Cu and a metal baffle is used to prevent the top plate from pollution. These measures can prevent arc form approaching the insulated bracket as far as possible and increase the life of the switch. And the electrode structure is optimized with electromagnetic simulation software. The experimental results indicate that the operating voltage is 32-42 kV and charge transfer is about 0.38-0.48 C per pulse at 0.1-0.2 MPa pressure, and the switch works stably and reliably. (authors)

[en] The radiation generated in the process that the intense electron beam accelerator is running with pseudo load can lead to the black screen of the nearby computer and oscillograph. In this study, the research using experiment method is carried out on this problem. Three radiation periods are demonstrated in the experiment, corresponding to the time when the trigger signal arrives, the primary switch operates and the main switch operates, respectively. The radiation generated when the primary switch operates is larger than that generated when the main switch operates. The radiation in the second period reaches the largest intensity at the same height as the primary switch. The analysis of frequency spectra shows that the radiation in the experiment is mainly concentrated in low frequency range with the main frequency of 21 MHz. (authors)

[en] A new trigger program is proposed to realize the synchronization of high speed framing camera (HSFC) and intense electron-beam accelerator (IEBA). The trigger program which include light signal acquisition radiated from main switch of IEBA and signal processing circuit could provide a trigger signal with rise time of 17 ns and amplitude of about 5 V. First, the light signal was collected by an avalanche photodiode (APD) module, and the delay time between the output voltage of APD and load voltage of IEBA was tested, it was about 35 ns. Subsequently, the output voltage of APD was processed further by the signal processing circuit to obtain the trigger signal. At last, by combining the trigger program with an IEBA, the trigger program operated stably, and a delay time of 30 ns between the trigger signal of HSFC and output voltage of IEBA was obtained. Meanwhile, when surface flashover occurred at the high density polyethylene sample, the delay time between the trigger signal of HSFC and flashover current was up to 150 ns, which satisfied the need of synchronization of HSFC and IEBA. So the experiment results proved that the trigger program could compensate the time (called compensated time) of the trigger signal processing time and the inherent delay time of the HSFC.

[en] A high voltage pulse transformer (HVPT) is usually used as a charging device for the pulse forming line (PFL) of intense electron-beam accelerators (IEBAs). Insulation of the HVPT is one of the important factors that restrict the development of the HVPT. Until now, considerable effort has been focused on minimizing high field regions to avoid insulation breakdown between windings. Characteristics of the HVPT have been widely discussed to achieve these goals, but the effects of the PFL and load resistance on HVPT are usually neglected. In this paper, a HVPT is used as a charging device for the PFL of an IEBA and the effect of the change in the load resistance on the HVPT of the IEBA is presented. When the load resistance does not match the wave impedance of the PFL, a high-frequency bipolar oscillating voltage will occur, and the amplitude of the oscillating voltage will increase with the decrease in the load resistance. The load resistance approximates to zero and the amplitude of the oscillating voltage is much higher. This makes it easier for surface flashover along the insulation materials to form and decrease the lifetime of the HVPT.

[en] As a combination device for a step-up pulse transformer and a magnetic switch, the saturable pulse transformer is widely used in pulsed-power and plasma technology. A fractional-turn ratio saturable pulse transformer is constructed and analyzed in this paper. Preliminary experimental results show that if the primary energy storage capacitors are charged to 300 V, an output voltage of about 19 kV can be obtained across the capacitor connected to the secondary windings of a fractional-turn ratio saturable pulse transformer. Theoretical and experimental results reveal that this kind of pulse transformer is not only able to integrate a step-up transformer and a magnetic switch into one device, but can also lower the saturable inductance of its secondary windings, thus leading to the relatively high step-up ratio of the pulse transformer. Meanwhile, the application of the fractional-turn ratio saturable pulse transformer in a μ s range pulse modulator as a voltage step-up device and main switch is also included in this paper. The demonstrated experiments display that an output voltage with an amplitude of about 29 kV, and a 1.6 μ s pulse width can be obtained across a 3500 Ω resistive load, based on a pulse modulator, if the primary energy storage capacitors are charged to 300 V. This compact fractional-turn ratio saturable pulse transformer can be applied in many other fields such as surface treatment, corona plasma generation and dielectric barrier discharge. (paper)

[en] This paper presents the design of an all-solid state pulse generator based on a fractional-turn ratio saturable pulse transformer which, as the key component, takes the roles of magnetic switch, pulse forming device, voltage boosting device, etc. Preliminary experimental results show that a quasi-square pulse with the amplitude of 14.4 kV and the pulse width of 194 ns are obtained while the DC voltage source supply is 100 V. Hence, it is feasible to apply this technology to construct a generator outputting pulses with the pulse width of several hundred nanoseconds. This study can provide a guidance to construct a MW level solid state pulse generator module. (authors)

[en] Based on the experimental device of the water spiral pulse forming line(PFL) type electron beam accelerator, the effect of inductance between the middle and outer cylinders of PFL on diode voltage is theoretically and experimentally studied in this paper. The formulae are introduced, with which the effect of inductance on diode voltage is calculated. In addition, the diode voltage waveform is simulated through the Pspice software. The theoretical and simulated results agree well with the experimental results, which show that large inductance between middle and outer cylinders can shorten the waveform flat part of diode voltage, increase waveform rise time and reduce the diode peak voltage. When the inductance is smaller than 200 nH, a nearly square voltage waveform can be obtained in field-emission diode. (authors)