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Middle cross section of the X generator: 1, capacitors; 2, HV central plate; 3, body case; 4, switch electrodes; 5 and 6, shielding electrodes on the cap terminals; 7 ∕ 8 , front/rear acryl insulators; 9, inductive load; 10, inductive groove; 11, ground side flange; 12, triggering cable input; 13, acrylic body of the switch block; and 14, front cover.
Source publication
AX-1 generator was designed for small scale experiments with imploding liners, es-pecially X-pinches. Main parts of the generator are capacitor bank and multichannel multi-gap spark switch. The capacitor bank consists of 12 Sorrento type capacitors (20 nF, 25 nH, 0.2 Ohm, 100 kV). It stores ~ 0.9 kJ at 85 kV charging voltage. The 24-channel, 7-gap...
Contexts in source publication
Context 1
... and each module can be re- moved separately. Switch blocks are connected between high voltage output of the cap and the generator body. The switch block is connected in parallel to each group of three capaci- tors. Each of four switch blocks consists of 64 ball electrodes steel, 22 mm in diameter, placed on the acrylic plate po- sition 13 on Fig. 2 in eight rows with eight electrodes in a row. The voltage between rows 6 mm gap between rows, 42 mm total gap between HV and ground electrodes is dis- tributed by the resistive voltage divider. Electrodes in a row are connected by conductive rubber cord with high specific resistance in order to be held under equal potential. Switch ...Context 2
... voltage divider. Electrodes in a row are connected by conductive rubber cord with high specific resistance in order to be held under equal potential. Switch triggering is provided by distortion of the homogeneous volt- age distribution on switch gaps at the arrival of the triggering pulse on the third row of switch electrodes position 12 on Fig. 2 through capacitive coupling between triggering cable and electrodes. Principles of multigap switches operation are well described in Refs. 13 and 14. Figure 2 shows a middle cross section of the generator. Central HV plate 2, capacitors 1, and switch blocks 4 are insulated from the front side of the generator body, serving as a current ...Context 3
... of multigap switches operation are well described in Refs. 13 and 14. Figure 2 shows a middle cross section of the generator. Central HV plate 2, capacitors 1, and switch blocks 4 are insulated from the front side of the generator body, serving as a current return electrode, by acrylic insulator 7 10 mm thickness. ...Context 4
... current is measured by the voltage drop on annular inductive groove 10, machined in the body of the current return electrode as shown on Fig. 2 inner and outer diameters are 246 and 286 mm, respectively, inductance L gr 154 pH, active resistance of the skin laye r R gr = 2.15 10 −5 . Signal is picked up at four points at centers of blocks 3 capacitor-switch, which allows one to make conclusions also about current distribution and syn- chronization. The voltage drop on the ...Similar publications
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Citations
... In the stage, one IK-50-3 capacitor (3-μF capacitance) is switched on by a multichannel SG 4 on two inductors 6 that are connected in parallel. A multichannel multigap SG of linear geometry is used, which is similar to that described in [56,57]. The design of the inductor was described in detail [58,59]. ...
High-voltage (HV) pulsed technology is one of the most effective methods for disintegrating and grinding rocks, separating ores and synthesized materials, and processing of construction and elastic–plastic materials. Since 2007, the Department of Pulse Technology of the Institute of High-Current Electronics, Siberian Branch, Russian Academy of Sciences, has been conducting research on the development of instruments for electric-pulse crushing. Instruments with energies from 100 J to 8 kJ that operate in the pulse-packet mode with fully automated control were developed and investigated. A HV pulse generator can be created using a Marx circuit or an HV transformer. Both options are discussed in this review. The results of the design and testing of compact generators designed for crushing materials are presented, although other technological applications are possible for them.
... Two types of SWs were used in a small current generator [69]: a linear SW (Fig. 15a) and a disk SW (Fig. 15b). The ball electrodes of the SWs (steel, 22-mm diameter) are fixed on acrylic insulators. ...
... Two types of switches were tested for a compact X-pinch generator: 74 flat switch [ Fig. 14(a)] and disk switch [ Fig. 14(b)]. Both switches are formed by ball electrodes (steel, 22 mm in diameter) placed on the acrylic plates. ...
High action, high voltage closing switches are the key components of pulsed power systems based on high energy capacitor banks, primarily used for high power lasers, electromagnetic accelerators, high pulsed magnetic field facilities, crushing materials, and electromagnetic compatibility tests. There are several options for closing switches, including ignitrons, vacuum switches, pseudo-spark switches, solid-state switches, and high pressure gas switches (spark gaps). Spark switches are currently the most used due to their relatively simple design, reliability, and ease of maintenance and repair. The main disadvantage of spark gaps is a limited lifetime, which is directly or indirectly related to the erosion of the electrodes. To prevent erosion of the electrodes, multichannel switches and switches with movement of the discharge channel were proposed. In this Review, both types of switches are considered. Published under license by AIP Publishing. https://doi.
... of ICE is important in avoiding any shock wave propagating during ramp loading and raising the peak pressure as high as possible [12,13]. Such generators are also convenient for compact X-pinch [14] and Zpinch [15] devices. The high energy density of pulsed lasers can be used also to generate shockless loading in solids to high pressures [16], but this equipment is definitely more sophisticated. ...
This paper presents the design and test of a 0.5 MA generator with a tunable pulse shape. The main parts are: the storage capacitor (3.95 μF ∼ 12.6 kJ at 80 kV), multi-channel coaxial switch, strip transmission line, load, pulse forming block (two versions are considered here, namely with peaking capacitor and wire opening switch). A set of inductances in parallel with the peaking switch as well as using various gases into this switch allow us to modify the current wave shape. Jitter from shot to shot did not exceed 10 ns in the experiments. This paper describes the design of main module elements and the results of experiments for two schemes at operation on load equivalent. In combination of the two pulse forming blocks, the generator proves the possibility of pulse shape tuning in a very wide range, namely delivering between 400 and 600 kA with a 200–800 ns rise time. The generator weight was ∼ 200 kg and the dimensions are 1x0.6x0.8 1 m³ with a pumping system. The generator design allowed for an easy increase in the number of modules in the arbitrary series–parallel combination in order to get the required current amplitude and pulse shape. Operation and handling are very simple, because no oil, water, nor SF6 are required for the generator.
... The harder X-ray source can also be used for imaging imploding inertial confinement fusion targets, for example, on the NIF. 24 Because suitable modern pulsed power generators have small size, simple design, 36,37 and are relatively inexpensive, they could be used with HXP loads as sources of X-rays for many different applications. ...
X pinches are well known to produce very small, dense plasma pinches (“hot spots”) that emit sub-nanosecond bursts of 1–8 keV radiation. Hard X-ray radiation in the range from 8 to 300 keV or more is also emitted, and only a small portion of which is associated with the X-pinch hot spot. In hybrid X-pinches (HXP), the 10 ns hard X-ray pulse is terminated by fast closure of the gap between the two conical electrodes of the HXP by rapidly expanding electrode plasmas. The temporal, spectral, and spatial properties of this higher energy radiation have been studied. This radiation was used for point-projection imaging with magnification between 1.5 and 6, and spatial resolution of 20–100 μm was demonstrated.
... The Lorentz force drives the implosion of the ablated wires, due to the interaction of the large currents and the generated magnetic field. However, to obtain the X-ray source for the X-pinch plasma, a rate of current rise of the pulsed-power generator is required to be 1 kA/ns, i.e. 100 kA of current and 100 ns of current rising time [9,10,11,12]. To achieve the required high rate of current rise for generating X-pinch plasma, the pulsed-power generators have the pulse compression system and/or the relatively high voltage system [9,13,14]. ...
A pulsed-power generator with a high rate of current rise was studied toward generating intense X-ray source from an X-pinch plasmas. The pulsed-power generator consists of 48 pulse-forming-network (PFN) modules with a three-stage of LC ladder circuit. To evaluate the rate of current rise for the pulsed-power generator, we demonstrated the short circuit experiments with low operation voltage. The rate of current rise depends on the number of PFN modules due to the decrease of inductance of PFN. The rate of current rise for 48 PFN modules at 10 kV of an operation voltage is estimated to be 0.1 kA/ns. To predict the rate of current rise for the requirement to obtain the intense X-ray from the X-pinch, the circuit simulation was demonstrated. The results indicated that the operation voltage requires over 70 kV for the rate of current rise of 1 kA/ns.
... A Linear Transformer Driver (LTD) technology was pioneered by the Institute of High Current Electronics in Russia more than a decade ago. 1 This technology is being examined for use in high current high voltage (HV) pulsed accelerators, including high current Z-pinch drivers, 2 medium current drivers for Isentropic Compression Experiments, 3 and relatively low current accelerators for radiography and X-pinches. 4 The LTD driver is an induction generator similar to a linear induction accelerator (LIA), an inductive voltage adder (IVA), and a linear pulsed transformer (LPT). Detailed review on the induction generators is given by Smith. ...
... The module design is shown in Fig. 15. Blocks (1) are placed between basement (2) from the # 12 -shaped channel (base 120, leg 52) and angle profile (3) and fixed through the polyamide bolts (4). Grooves are made in the channel (2) and angle profile (3) opposite to each block. ...
In the Linear Transformer Driver (LTD) technology, the low inductance energy storage components and switches are directly incorporated into the individual cavities (named stages) to generate a fast output voltage pulse, which is added along a vacuum coaxial line like in an inductive voltage adder. LTD stages with air insulation were recently developed, where air is used both as insulation in a primary side of the stages and as working gas in the LTD spark gap switches. A custom designed unit, referred to as a capacitor block, was developed for use as a main structural element of the transformer stages. The capacitor block incorporates two capacitors GA 35426 (40 nF, 100 kV) and multichannel multigap gas switch. Several modifications of the capacitor blocks were developed and tested on the life time and self breakdown probability. Blocks were tested both as separate units and in an assembly of capacitive module, consisting of five capacitor blocks. This paper presents detailed design of capacitor blocks, description of operation regimes, numerical simulation of electric field in the switches, and test results.
... Recently, compact X-pinch devices have been developed in different institutions such as the Institute of High Current Electronics in Russia [12], [13], the University of California at San Diego in the U.S. [14], Imperial College in the U.K. [15], Ecole Polytechnique at Palaiseau in France [16], and Nanyang Technological University in Singapore [17]. The compact Xpinch devices were usually driven by three types of pulsedcurrent generator. ...
... The compact Xpinch devices were usually driven by three types of pulsedcurrent generator. The first type is based on a compact Marx bank-driven pulse forming line (PFL) that delivers a short rise (∼50 ns) and a relatively low current (< 100 kA) to the Xpinch load [14], [15], [17], the second one is based on a compact linear transformer driver [12], and the last one is based on a low-inductance (LC) generator in which paralleled capacitors directly discharge to a load [13], [16]. The current for the last two types of pulsed-current generator is 200-300 kA in amplitude and 100-200 ns in rise time. ...
Based on a compact (2m×1m×1.5m) pulsed current generator (~ 100 kA, 60ns), a table-top X-pinch device was constructed and tested. The load current was almost unchanged for X-pinches made using different wires (5μm, 8μm, 10μm and 13μm Wu wire> 13μm and 25μm Mo wire), which means that the impedance of the wires is much lower than the total impedance of the load section. When the above mentioned wires were used as two-wire load, X-ray pulses from X-pinch were always observed. As the mass of the two-wire load increases, the time delay of the x-ray emission relative to the beginning of the load current increases. As was expected, the X-ray pulse consists of single peak or two overlapping peaks of subnanosecond pulsewidth. The x-ray source is usually one point or two partly overlapping points, which is consistent with the measurement of x-ray pulse. The size of x-ray point source is ranging from 5 Dm to 50 Dm. Two X-ray pulses with a time interval on the order of 10 ns were often observed for a small mass load when the load current is high enough. The appearance of the second X-ray pulse is attributed to the second pinch of the plasma.
... A typical current waveform is shown in Fig. 4. The second machine, GenASIS, is an LTD design—a full description can be found in [27]. The LTD cavity is a square design developed by the Institute for High Current Electronics, Tomsk, Russia [28], in collaboration with the SNL. The driver uses 12 × 20-nF double-ended capacitors arranged around the central discharge plate in blocks of three. ...
... Linear-transformer-driver (LTD) technology was pioneered by the Institute of High Current Electronics in Russia more than a decade ago [1]. LTD based drivers are currently considered for many applications, including high-current Z-pinch drivers [2], medium current drivers for isentropic compression experiments [3], and relatively low current accelerators for radiography and X pinches [4]. The LTD driver is an induction generator similar to a linear induction accelerator (LIA), an inductive voltage adder (IVA), and a linear pulsed transformer (LPT). ...
In this report we present state of work under development of LTD stages with air insulation in a primary circuit and vacuum insulation in a secondary turn. Special unit, named capacitor block, was developed for use as a main structural element of the transformer stages. It incorporates two capacitors GA 35426 (40 nF, 100 kV) and multichannel multigap gas switch. Two types of stages were developed: 1) Stage LTD-20 with 4 modules in parallel and 5 capacitor blocks in each module. In tests of this stage current amplitude up to 850 kA with ~ 140 ns rise time was obtained on a 0.05 Ω load at 100 kV charging voltage. 2) Stage LTD-4 with 2 modules in parallel and 2 capacitor blocks in each module. Several installations were built on base of these stages, including linear transformer, consisting of two identical LTD-20 stages in series, and high power electron accelerator on base of LTD-4 stages. Design of installations and tests results are presented and discussed in this report.
