A compact low jitter high power repetitive long-pulse relativistic electron beam source with novel circuit structure and mechanical structure is presented. Based on Marx type circuit and direct-drive idea, the key technologies such as high energy density pulse forming network, repetitive high voltage pulse generator and low jitter electrical trigger technology are developed. The volume and weight of the pulsed electron beam source are reduced remarkably by using two-capacitor pulse forming modules, alternating superposition structure on both sides and high electric field shielding technology. The key technical parameters of the electron beam source design include a peak output voltage 1 MV with peak current 20 kA. The impulse is 180 ns and has a repetition frequency 1 ∼ 50 Hz, however, the output power and repetition frequency are able to be adjusted within a certain operating range. The machine has a total volume of 2.5 m3 and weighs 2.2 tons, making it much more compact than conventional electron beam sources. The experimental results show that when the e-beam source is operated under a single pulse condition, the output voltage, current, and power are 0.98 MV, 19.6 kA, and 19.2 GW, respectively. When the e-beam source has a continuous operating time of 10 s at a repetition frequency of 30 Hz and an output power of 16.7 GW, the voltage fluctuation range is limited to within ± 1.5%, and the current fluctuation range is limited to within ± 2%. The delay time jitter between the trigger pulse and the output pulse is limited less than 6.5 ns standard mean deviation. Statistical distributions of the delay time jitter and current amplitude variation of the 300 pulses are approximately Gaussian. When the cooling system is working, the electron beam source can work continuously for 100 s under the conditions of an output power of 16.7 GW and repetition frequency of 30 Hz, and the system operation is stable and reliable.

A compact low jitter high power repetitive long-pulse relativistic electron beam source

Biaxially oriented polypropylene (BOPP) films are currently an indispensable material for pulse capacitor production. Research on the structure-activity relationship of BOPP films is an important way to optimize its manufacturing process and achieve high energy density. In this article, the influences of three key structural characteristic parameters (thickness, crystallinity, and tensile strength) on the electrical properties were investigated by testing and analyzing BOPP films manufactured by designed processes. The results show that when the thickness of films obtained with the same manufacturing process increases from 5.8 to $11.8~\mu \text{m}$ , the corresponding breakdown strength increases from 681 to 803 V/ $\mu \text{m}$ ; when the crystallinity of films increases from 71.66% to 75.93%, the corresponding breakdown strength increases from 728 to 756 V/ $\mu \text{m}$ ; and when the tensile strength of films increases from 22.3 to 29.1 MPa, the corresponding breakdown strength increases from 726 to 746 V/ $\mu \text{m}$ . It can be concluded further that increasing the thickness, crystallinity, and tensile strength of the BOPP film through a reasonable process will effectively increase its energy density.

Dielectric Strength Structure-Activity Relationship of BOPP Film for High Energy Density Pulse Capacitor

The [x BaO, (1 − x) SrO]-Na2O (x = 00, 02, 05, 08) niobate-based glass–ceramics were prepared through the controlled crystallization method Crystallization mechanism, phase structure, dielectric properties, and energy-storage properties were studied by adjusting Ba/Sr ratio It was found that the surface and internal crystallization occurred simultaneously at first crystallization peak, while surface crystallization occurred at second crystallization peak With Ba/Sr ratio increasing, dielectric constant increased firstly and then decreased, while dielectric loss firstly decreased and then increased When x = 02, optimal dielectric constant of 88 and dielectric loss of 00055 were obtained, which is related to the solid solution phase Sr05Ba05Nb2O6 Breakdown strength (BDS) showed a behavior of increase before decrease The highest BDS reaches 1975 kV/cm for x = 02, which is attributed to uniform and dense microstructure Correspondingly, the theoretical energy-storage density was increased up to 154 J/cm3 Also, discharged efficiency reaches a high value of 91% Discharged power density of 065 MV/cm3 was obtained for x = 02 in the RLC pulsed circuit

Crystallization Mechanisms and Energy-Storage Performances in BaO-SrO-Na 2 O-Nb 2 O 5 Based Glass–Ceramics

The invention relates to a microsecond pulse generator, particularly relates to an all-solid-state high-voltage microsecond pulse generator based on a FRSPT (Fractional-turn Ratio Saturable Pulse Transformer) and an anti-resonance network, and belongs to the field of pulse power. The pulse generator consists of a charging module, a pulse boosting module, a pulse forming module and a load. The charging module is mainly used for charging the pulse generator, and charges the pulse forming module by the pulse boosting module; the pulse boosting module is the FRSPT; in one aspect, the FRSPT is used as a transformer of the pulse boosting module, and in the other aspect, the FRSPT is used as a switch of the pulse forming module; and the pulse forming module is used for forming a quasi-square wave pulse which is reasonable in leading and lagging edge time and good in flat top degree. The pulse generator is long in service life and stable to operate; all-solid-state compact integration of the pulse generator is implemented; an output square wave is high in quality; and the all-solid-state high-voltage microsecond pulse generator can be used for the fields of a high-power microwave source, foods, sterilization and disinfection, wastewater treatment and the like.

All-solid-state high-voltage microsecond pulse generator based on FRSPT (Fractional-turn Ratio Saturable Pulse Transformer) and anti-resonance network

A compact PFN (pulse forming network)-Marx generator, which is based on mica capacitors, is constructed to generate intense electron beams for the purpose of high-power microwave generation. The key components of the generator, including a PFN-Marx, a trigger source, a multi-stage gas switch, and a load, are introduced in this paper. The PFN-Marx is composed of 19 PFN modules, which are formed by four mica capacitors in parallel. The temperature characteristics and pulse characteristics are tested in this study. The mica capacitor is insensitive to the temperature, and its lifetime is tens of thousands. Considering the influence of the ultraviolet light pre-ionization, gas gap switches are assembled in a nylon house. The trigger source, which is a mini-Marx generator based on the integration into the magnetic transformer and the magnetic switch, is used for increasing the stability of the switches. The generator has been tested on a water load and a relative magnetron. The experimental results show that this generator can deliver electrical pulses with the pulse width of 120 ns and the amplitude of 400 kV on a 40-Ω water load at a repetition rate of 50 Hz. In addition, utilizing the generator to drive a Ku band magnetron at a voltage level of 330 kV, a 500 MW microwave pulse with the pulse width of 50 ns at the frequency of 14.4 GHz is obtained.

A compact 4 GW pulse generator based on pulse forming network-Marx for high-power microwave application.

Compact pulsed power system based on compact Marx generator is widely used in terms of drive resistance and capacitive loads. This system usually adopts high performance components such as high energy density capacitors, compact switches, and integrated structure. Traditional compact Marx generator can only output double-exponential pulse profile. In this paper a compact, low-impedance Marx module which can output rectangular pulse profile is design and tested. This module has multiple circuits of different discharge frequencies in parallel to generate quasi-rectangular pulse. Discharge characteristic of an ideal module with infinite branches is calculated theoretically. A module with two branches has been designed and tested. Test results show that the impedance of the module is 1.2 Ω. When charging voltage is 100.6 kV and load resistance is 1 Ω, the peak output pulse is 45.2 kV voltage, the peak power is about 2 GW, the pulse width is about 130 ns, and the rise time is about 35 ns. The energy density and power density of the module are 15 kJ/m3 and 140 GW/m3, respectively.

Design of compact Marx module with square pulse output

Breakdown characteristics of ferroelectric glass-ceramic capacitors in the PbO-SrO-Na2O-Nb2O5-SiO2 system were studied, including under dc charging and pulse charging. Results revealed that capacitance before and after charging was with no significant alternation. Relationship between dielectric constant and electric field was also explored. Meanwhile, a peculiar phenomenon was found that the breakdown strength of glass-ceramic dielectric under pulse charging was much lower than that under dc charging, which is of considerable discrepancy to common theory. Possible explanations were summarized afterward.

Breakdown Characteristics of Ferroelectric Glass-Ceramic Dielectric for Pulsed Power Applications

The invention discloses a unipolarity low-temperature plasma power supply which comprises an AC (Alternate Current) conversion unit, a waveform shaping unit and a material surface processing unit which are sequentially connected. The unipolarity low-temperature plasma power supply has the beneficial effects that the waveform shaping unit of the unipolarity low-temperature plasma power supply adopts a multi-primary transformer, various front edge pulse outputs can be output and by pulse width modulation of an output square wave of a square-wave generator, a unipolarity pulse with an adjustable frequency in the range of 0 to 50kHZ, an adjustable voltage in the range of 0 to 50kV, an adjustable pulse width in the range of 1 to 100mus and an adjustable rising edge in the range of 300ns to 15mus is implemented; and an output voltage of the unipolarity low-temperature plasma power supply has unipolarity, so that discharge between two electrode plates is very uniform, a workpiece and the electrode plates are basically not damaged, the integrity of the workpiece or a material is ensured and the service lives of the electrode plates are prolonged.

Unipolarity low-temperature plasma power supply

The invention discloses a multi-circuit high-voltage isolation power supply for series connection of semiconductor switches. The multi-circuit high-voltage isolation power supply comprises a preceding-stage inverter, a cascading transformer bank, multiple distributed transformers and multiple local transformers. The cascading transformer bank is formed by cascading multiple cascading transformers. The primary side of the first cascading transformer is connected with the output stage of the preceding-stage inverter, and the auxiliary side of each cascading transformer is composed of an output side and an energy feeding side, wherein the energy feeding side is connected with the primary side of the corresponding distributed transformer, and the output side is connected with the primary side of the next cascading transformer. Output-stage windings of the distributed transformers are connected with the primary sides of the local transformers. The local transformers further comprise rectification and voltage stabilizing circuits which are connected with the output-stage windings of the local transformers. The multi-circuit high-voltage isolation power supply can provide multiple circuits of power supply for a pulse power device, a power electronic device, a converter valve and the like in a high-voltage isolation mode. The multi-circuit high-voltage isolation power supply has the advantages of being high in isolation voltage, multiple in number of output circuits, high in stability and anti-interference performance, high in efficiency and the like and is particularly suitable for isolation power supply of suspension voltage devices or multiple devices which have the voltage of at least 200 kV.

Multi-circuit high-voltage isolation power supply for series connection of semiconductor switches

A high-power gas switch trigger system comprises a high voltage arm resistor and a low voltage arm resistor which are connected between a high voltage electrode and a low voltage electrode in series and further comprises a light emitting device capable of making laser illumination act on a photoconductor switch, wherein the common end of the high voltage arm resistor and the low voltage arm resistor is connected with a trigger electrode through a first pulse device, and a second pulse device is connected with the two ends of the low voltage arm resistor in parallel; a circuit current limiting resistor is connected between the first pulse device and the trigger electrode; the first pulse device and the second pulse device are respectively one of an energy storage capacitor and the photoconductor switch. The high-power gas switch trigger system has the advantages that the trigger system of a high-power pulse power device is simpler; multiple high-power gas switches can synchronously work easily; the laser for triggering the photoconductor switch is led in through an optical fiber, and high voltage isolation between the pulse power device and an external system can be achieved; the output waveform of the pulse power device can be controlled more flexibly.

Jiang Ping

Papers

Design of compact Marx module with square pulse output

Breakdown Characteristics of Ferroelectric Glass-Ceramic Dielectric for Pulsed Power Applications

Unipolarity low-temperature plasma power supply

Multi-circuit high-voltage isolation power supply for series connection of semiconductor switches

High-power gas switch trigger system