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Plasma immersion ion implantation (PIII) was conducted in a large volume chamber with a current-controlled high-voltage pulser, to test the vacuum, plasma, and PIII conditions, in a preparation for the treatments of large workpieces or the batch-processing mode. For that purpose, a rugged high-power pulser (10 kW average) based on solid-state moderate voltage pulse system (1 kV) was coupled to a high-voltage transformer (1:22) to feed different loaded sample supports placed in different positions inside the chamber. It was found that the plasma, when produced by a hot filament enhanced glow discharge source, is not uniformly distributed in the chamber but despite that, implantation doses are locally uniform within 10% for 10–15-cm distances, along with the supports. Stainless steel 304 (SS304) -type samples were successfully treated with nitrogen PIII and different tests showed improvements on their mechanical and tribological properties.

In this paper the authors present the analysis and interpretation of the results of the immunity tests on a LEDs luminaire with an apparent or suspended mounting FIPAD-08 type, subject to a series of typical simulated disturbances, namely: electrostatic discharges, rapid voltage pulse trains, shock waves, drops, short interruptions and voltage variations. The luminaire for which the photometric curves were reconstructed can also be analyzed from a photometric point of view according to the calculation algorithms proposed in the studies previously conducted by the authors.

The high-voltage pulse modulator based on the modern semiconductor elements is described. The modulator is intended for use in the power supply system of LINAC helium ions injector and has the ability to smoothly adjust the amplitude (110…150 kV) and the pulse duration (0.5…1 ms). The use of a pulse-to-peak stabilization scheme, made on the basis of a parametric stabilizer with parallel switching of the load, made it possible to increase the accelerated current at the accelerator output by 2 times.

Carbon nanotubes (CNT) resistance-change memory devices were assessed for neuromorphic applications under high frequency use conditions by employing the ultra-short (100 ps -10 ns) voltage pulse technique. Under properly selected operation conditions, CNTs demonstrate switching characteristics promising for various NN implementations.

This paper mainly concentrates on the analysis of different charging techniques adopted in the solid-state Marx generator. The unipolar Marx topology has been simulated using resistance, inductive and input switch charging methods. Results obtained by simulations are validated from experimental set-up for a two-stage Marx generator circuit. The characteristics (traits) of each charging method are investigated based upon the parameters such as current drawn by source during charging and discharging instant of capacitors, voltage across the input charging elements, output voltage, load current, degree of isolation provided by each method. Finally, a comparison between all charging methods is carried out for all above-mentioned parameters. Resistance charging is simple and less complex method. Boosting phenomenon of the output voltage pulse is obtained from the RL charging method. This method also limits the source current too few milliamperes as compared to the other two methods. Switch charging method provides complete isolation from the high-voltage source during the erection of Marx generator.

The cavitation is directly related to the safety of many large water conservancy projects. There are two types of cavitation bubbles, one is generated by the gas nucleus, called the non gas-bearing cavitation bubble, and another is generated by the gas bubble, called the gas-bearing cavitation bubble. They have significantly different collapsing characteristics. This paper studies the cavitation bubbles, generated by a high voltage pulse bubble generation system, and discusses the gas-bearing cavitation bubble’s characteristics a from the aspects of the collapse process, the cycle, the size and the collapse strength. It is shown that: (1) the collapse of the gas-bearing cavitation bubbles can be divided into two types: the centripetal collapse and the bisected collapse, (2) the cycle period and the size of the gas-bearing cavitation bubble increase significantly, and the increase norm has a certain relationship with the bubble diameter ratio, (3) the collapse strength of the gas-bearing cavitation bubble decreases significantly. The larger the bubble diameter ratio, the greater the effect will be.

In this paper, GeTe and Sb4Te layers were alternately deposited to form superlattice-like structure (SLL) for multilevel phase change memory (PCM). It is shown that SLL GeTe/Sb4Te film can realize a multilevel storage with various appropriate thickness ratios between GeTe and Sb4Te layers. The crystallization behavior of SLL GeTe/Sb4Te film can be tuned by the thickness ratios which is associated closely with the thermal stability. GeTe(4 nm)/Sb4Te(6 nm)-based device demonstrated the minimum voltage pulse for the RESET operation of 3.2 V-5 ns, suggesting the low power consumption in comparison with that of Ge2Sb2Te5 (4.1 V). An electric pulse as short as 5 ns can trigger different operations among three stable resistance states for GeTe(4 nm)/Sb4Te(6 nm)-based device, which can be explained by the asynchronous crystallization of GeTe and Sb4Te. These results demonstrate that SLL GeTe/Sb4Te films are promising candidate for multilevel phase-change memory.

This paper dealt with the application of transient earth voltage (TEV) sensors for the online measurement and analysis of partial discharge (PD) in medium-voltage switchboards. To simulate the typical insulation defects in the switchboards, four types of artificial electrode systems, including high-voltage protrusion, low-voltage protrusion, particle-on-conductor, and void inside cast-resin potential transformer were fabricated. A TEV sensor with a frequency range of 1–150 MHz and a non-inductive resistor were used to detect the PD-induced TEV signal and the PD voltage pulse, respectively. The frequency spectrums of TEV signals were analyzed, and it was found that they had a mutual frequency range of 5–50 MHz. However, the amplitude of TEV signal was not proportional to the apparent charge specified in IEC 60270, resulting the difficulty of quantification of PD. The phase-resolved partial discharge patterns were acquired using the TEV sensor and the developed measuring algorithm, by which distinguishable patterns were obtained from different defects.

Herein, we present the details of the design and performance of a compact low-trigger-threshold multigap gas switch used for linear transformer drivers. By integrating a resistor-capacitor network in parallel with switch gaps, the trigger threshold voltage of the switch is reduced; meanwhile, the switch has a compact structure of 117 mm in diameter and 156 mm in height. The self-breakdown and triggering characteristics of the switch are theoretically and experimentally investigated. The experimental results show that at a charging voltage of ±80 kV and operating at 60% of self-breakdown voltage, the switch has a jitter of less than 3 ns when triggered by a pulse of 50 kV. It can be reliably triggered by a high voltage pulse with polarity opposite to that of the charging voltage on the capacitor-mounted side of the switch.

The FAIR accelerator chain comprises a 68 MeV proton injector (pLINAC). Seven identical high power RF systems can supply the RFQ, CCH and CH accelerating structures with up to 2.5 MWRF. The klystrons require a cathode voltage pulse of -115 kV, -54 A with a flat-top droop of less than 1% over 360 µs. A klystron modulator has been developed at GSI to meet this demand and two prototype systems are currently under construction in-house.

A novel type of variable resistor micro system based on electro-explosion is described and its performance test results are presented. The variable resistor consists of four metallic leads in parallel with different width and length thus different resistances and four one-time shot MEMS solid on-off switches. By killing off the metallic lines, the variable resistor varies its resistance. Switching is accomplished by a voltage pulse. The resistor can be driven by external signal and its predicted lifetime is very long. Besides, the resistor has no movable parts, therefore the resistor can be used for long term store systems and harsh environments.

We describe recent developments towards a laser-based vector network analyzer, where a femtosecond laser is used for the generation and detection of ultrashort voltage pulses on a coplanar waveguide. We show that the device allows us to obtain scattering parameters over a broad frequency range and facilitates the development of an ultrashort voltage pulse standard whose shape is exactly known.

Single Co adatoms adsorbed on a double-layer NaCl film supported by Cu(111) were negatively charged after applying a positive voltage pulse to the sample in a scanning tunnelling microscope. Density functional calculations showed that the magnetic moment of Co changed from 3μB to 2.2μB after charge state manipulation.

Aiming at the burst point time measuring device cannot timely show the burst point time measurement situation, a new measuring system was designed. The pulse signal when the ammo was outing of the muzzle and exploding was detected by APD, the light pulse was converted to voltage pulse through an amplifying circuit. The timing display module was designed, the timing circuit got the voltage pulse and timing, and then the burst point time would show on LCD. All the photoelectric detector module was fixed with the special mechanical properties. The system could increase the maximum detection distance effectively, improve its detecting precision, and display the burst point time immediately. With the simulation experiment, the system had no failing to get the burst point time, and owned a stable performance. This design can provide a reference for the optimization and improvement of the burst point time measuring device.

Slow deformation seriously restrains application development of IPMC actuator, especially for thick and ionic liquid-based IPMC. Inspired by the action potential of muscle cell, this letter proposes a concept of high electrical pulse stimulus to accelerate IPMC deformation. By analyzing the dynamic process of voltage drop at the electrode-polymer interface, high voltage pulse is proved theoretically to be safe for IPMC in a short time. After charging the electrical double layer at the interface, the voltage pulse should be reduced to a safe level before electrochemical reactions. In our experiments, applying various high voltage pulses to a thick IPMC, the deformation can be sped up a few hundred times at most without any electrolysis damage. The results strongly support the practicability of the impulsive driving method.

A study was carried out into the mechanisms of formation of an SSVD in CO2–N2–He gas mixtures initiated by an auxiliary barrier discharge distributed on the surface of a cathode. The volume discharge was initiated when the discharge gap was filled by an electron flux formed from the barrier discharge plasma in the course of a smooth rise of the voltage across the electrodes. Measurements were made of the small-signal gain, confirming the model of formation of an SSVD and demonstrating that a discharge of this kind could be used to amplify nanosecond light pulses.

The dynamics of breakup of the compressed state of an electron beam with a virtual cathode (VC) transported in a two-section drift tube of a high-current electron accelerator has been studied. Based on the results of numerical simulations, the method of partial capture of the injected beam current during the applied voltage pulse is proposed and implemented, which can ensure the conditions necessary for the breakup of the electron beam compressed state. The VC velocity during the breakup of the electron beam compressed state amounts to 6–8% of the velocity of light in vacuum. The experimental data qualitatively agree with the results of analytical estimations and numerical simulations.

An improved dynamic driving scheme is proposed to eliminate data-pattern-dependent defects in cholesteric LCD images by inserting a framing voltage pulse between each successive selected pixel voltage pulse, such that the effective selection time is independent of the preceding and following non-selected pixel voltages.

A 15[inch] diagonal mercury-free flat discharge lamp with insulated electrode has been developed as backlight for a LCD backlighting. When the drive voltage pulse conditions were set properly, a uniform and stable discharge extends over the entire volume. It was obtained luminance of without prism sheet in uniform and stable discharge.

International audience; We propose in this paper novel approach for improving mass resolution in atom probe tomography. Using conventional counter-electrode or microelectrode design, improved mass resolution at half, tenth and 1% of the mass peak maximum is predicted when shaping properly the voltage evaporation pulse. Using a numerical approach, it is shown that a flat top voltage pulse used to trigger the field evaporation with sharp front and leading edges associated with a short tip to counter electrode distance(≈10 μm) strongly minimizes the energy deficits of evaporated ions from the sample, so that energy compensation devices are not necessary to obtain high mass resolution.

A novel trigger method based on an internal brick and azimuthal line in cavities is presented for Linear Transformer Drivers (LTD). The triggered brick is similar as the other normal bricks in cavities, which has the same charge voltage and the switch gas pressure. When the switch in triggered brick is closed by an external pulse, a high voltage pulse is produced and transmitted to other bricks along an azimuthal line installed in the middle insulator of cavities. Therefore, one external trigger pulse is enough for a 1 MA LTD cavity. This novel trigger manner has been applied successfully in 800 kA cavity with 36 bricks. Based on this novel trigger manner, a trigger method is proposed for a LTD module with multi-stage cavities stacked in series. Only several upstream cavities are triggered by external trigger pulses, and the residual cavities are triggered by the high pulses produced from the particular-location of upstream cavities. This trigger method will greatly simplify the requirements of trigger system, which has a promising application for future 60-MA LTD accelerator.

A thermochemical hole burning (THB) effect was observed on two organic charge transfer complexes, when applying a suitable voltage pulse using a scanning tunneling microscope (STM), which is closely related to a STM current-induced localized thermochemical decomposition of the charge-transfer complex. The decomposition reaction evolves the low boiling point decomposition components of the charge-transfer complex, leaving a nanometer-sized hole on the crystal surface. This effect demonstrates the possibility of creating an ultrahigh-density THB memory, in which information bit is recorded as a hole.

We reconsider the mode of operation of a Marx bank circuit and analyze the secondary breakdown of transistors with shorted emitter-base. The mechanism of breakdown of the transistor when a fast rising voltage pulse is applied across is investigated. The device exhibits chaotic behavior at the breakdown point where it can go into two possible modes of breakdown. A new explanation for the working of the circuit consistent with the experimental observations is proposed.

The STM is used as a tool for nanostructure formation by applying a high voltage pulse. Usually these nanostructures are explained in terms of field ion evaporation, which is shown to be questionable. For the Au-Au system a new model is suggested on the basis of local melting of the tip by the Nottingham effect.

On an Au(111) surface, Au atomic diffusion induced by a voltage pulse was demonstrated using a scanning tunneling microscope (STM) with an Au tip in air. Applying a voltage pulse as a trigger, we observed local diffusion of Au atoms around the position where the voltage pulse was applied. Upon repeating tip scanning, fingerlike stripes grew gradually from a step; the direction of the stripes was affected by the structure of the Au(111) surface and the tip-scan direction. In our experiments, movable Au atoms on the local area were swept by tip scanning via the field gradient effect. Local atomic Au diffusion could be induced since activation energy was reduced by applying the voltage pulse.

A nano-scale bonding process using a multi-wall carbon nanotube (CNT) has been successfully applied in a scanning electron microscope (SEM)/scanning tunneling microscope (STM) combined system. Under the SEM observation, a Ti-coated STM tip was approached onto a CNT bridging Ti pads, which is patterned with a 4 µm gap on a SiO2 surface, to investigate the conduction property of the CNT. A voltage pulse of 12 V peak and 50 µs duration was applied in order to deposit Ti clusters onto the CNT, which is well known as a field evaporation process in the STM regime. The two-terminal current-voltage characteristics of the CNT have been improved from a nonlinear behavior at 2.5 V of 208 kΩ to a linear one of 1.8 kΩ.

We describe the development of a voltage pulse standard on a coplanar waveguide using laser-based optoelectronic techniques. The pulse standard, whose temporal shape (or complex frequency spectrum) is exactly known, has frequency components exceeding 500 GHz and a 500 MHz frequency spacing.

A novel prototype suitable for electronic ballast based on class Φ 2 inverter with the parallel resonant tank is proposed for fluorescent lamp driver. Compared with traditional ballast based in class E, class Φ 2 can effectively improve the dynamic response and reduce switching voltage stress and thus is another competitively alternative prototype used in electronic ballast. In addition, a parallel resonant tank should be connected to the class Φ 2 inverter so as to obtain a high voltage pulse during ignition of the lamp. This paper implements a prototype electronic ballast based on class Φ 2 inverter with the parallel resonant tank operating at 13.56MHz, which is for fluorescent lamp(F6W T5 SYLVANIA).

The charge pumping current results from recombination associated with the SiO2-Si interface traps under the gate of a MISFET when a voltage pulse is applied to the gate. The modified Kaw's model is proposed which predicts this current as a function of frequency, amplitude and average voltage of pulses with peak-to-peak amplitudes larger than the difference between the flatband and inversion voltages and with pulse transitions fast enough so that negligible capture or emission occurs during the transition. The presented modification of Kaw's model of the charge pumping effect enables to compute the dependences of the charge pumping current for various types of MIS transistors with different dimensions manufactured by different technologies.

A study of the aging behavior of atomic layer epitaxy (ALE) ZnS:Mn alternating‐current thin‐film electroluminescent (ACTFEL) devices is undertaken by monitoring the internal charge‐phosphor field (Q‐Fp) and capacitance‐voltage (C‐V) characteristics as a function of aging time. The electrical properties of ALE ZnS:Mn ACTFEL devices are asymmetrical with respect to the applied voltage pulse polarity; the aging characteristics of such devices are also asymmetric. The electrical asymmetries are attributed to differences in the interface state densities at the top and bottom phosphor/insulator interfaces. The presence of Cl at the indium tin oxide interface and its tendency to migrate into the ZnS during aging is believed to be the major cause of the observed asymmetrical aging characteristics.

Methods to manipulate single Si atoms on the Si(111)7 × 7 surface at room temperature, using a scanning tunneling microscope (STM) operated in ultrahigh vacuum, are reported. The extraction and redeposition of single Si atoms and the displacement of the redeposited Si atoms can be done with a W tip, if the tip is carefully cleaned, by applying a voltage pulse between tip and sample with its polarity, magnitude and duration being selected appropriately.

A high-voltage nanosecond-pulse shaper based on microcircuits and high-power MOS transistors is described. The output pulse amplitude is 5 to 300 V; at a 50-Ω load, pulse duration is 100 ns; pulse rise time is 5 ns; pulse-repetition period in a packet is 100 μs; packet duration is 10 ms, and packet-repetition period is 100 ms.

A new method to increase the operational frequency of electromechanical memory cells based on the telescoping motion of multi-walled carbon nanotubes through the selection of the form of the switching voltage pulse is proposed. The relative motion of the walls of carbon nanotubes can be controlled through the shape of the interwall interaction energy surface. This allows the use of the memory cells in nonvolatile or volatile regime, depending on the structure of carbon nanotube. Simulations based on ab initio and semi-empirical calculations of the interwall interaction energies are used to estimate the switching voltage and the operational frequency of volatile cells with the electrodes made of carbon nanotubes. The lifetime of nonvolatile memory cells is also predicted.

Voltage pulse dependent resistive switching behavior during SET process in HfO 2 -based RRAM device is investigated. When a resistor is connected in series to RRAM during the SET process, the resistance uniformity can be improved. Voltage pulse controlled resistance states were observed. This behavior may provide the new application with the new function circuits.

The remanent polarization (2Pr) of thin-film PZT capacitors was examined using a voltage pulse method. The amount of polarization remaining after a “write” pulse was found to be a function of both the time between the write and read pulses and the duration of the write pulse. The 2Pr was found to decrease significantly from 3 μs to 100 ms after the initial write. In some cases the remanent polarization decayed by almost 70 percent in this time regime. The fast decay component of 2Pr was also observed to be dependent on the duration of the write pulse (the write, pulse width). The longer the write pulse was applied the smaller the fast decay component became, leaving more measurable charge retained after 100 ms.

The method of applying two consecutive voltage pulses is presented as a method to study the dynamics of injected charges in the “off-state,” i.e., after the removal of the applied voltage pulse. Pulses of different widths are used to selectively probe the dynamics of holes and electrons. The use of multiple (>2) pulses is also described as an additional carrier monitoring technique.

In order to determine possible causes of resistance and noise index changes in thick-film resistors during high- voltage pulse stressing, deterministic model was used. Irreversible micro- and macro-structural changes observed during high- voltage pulse stressing of thick film resistors based on 1, 10 and 100 kOmega/sq compositions were analyzed and performed analysis resulted in determination of primary technological, geometrical and physical parameters responsible for observed changes.

A force microscope has been used to deposit and image localized charge on insulating surfaces. The charge is deposited either by applying a voltage pulse to the microscope tip or by contact charging the insulator surface with the tip. An improved mode of charge imaging is presented, which distinguishes between charge and topography and allows the sign of the charge to be determined in a single scan.

In this work, we will present a strategy for the evaluation of depth and thickness of defects like holes and cracks in metallic plates via the analysis of the response in frequency of a suitable eddy-current detection system. In order to obtain the data for the inversion in real time, the analysis in frequency domain is deduced by the analysis of the response of the system to an exciting rectangular voltage pulse of suitable length, according to the size of defect to detect. By finite element method numerical simulations in time domain of the detection system applied to known defect configurations, we have found some interesting information for the inverse problem solution. In this paper, we present the theory of the detection technique above mentioned and results about numerical and experimental analysis.

We report the electroluminescent characteristics of organic multilayer light‐emitting diodes (LEDs) with a benzophenone (BP) dispersed poly(methylmethacrylate) (PMMA) film as an emitting layer. The electroluminescence (EL) intensity of these LEDs increases with decreasing temperature from 273 to 100 K when they are operated at the same voltages or the same current densities. The EL spectrum of the LEDs, which peaks at around 450 nm, is identical to the phosphorescence spectrum of BP in PMMA. In addition, the EL decay time was determined as 46.8 μs at 100 K by applying a rectangular voltage pulse. These results indicate that the EL of the LED originates from the triplet excited states of BP.

We propose a method for NO/sub x/ decomposition using a reciprocal pulse generator. The pulse generator consists of only a few components; a coaxial cable, a grounding switch and a DC voltage source. When the cable was charged and then grounded at one end of the cable without any resistance, a traveling voltage pulse reciprocated in the cable with a change in its polarity, so that the voltage pulse was repeatedly applied to a barrier-type reactor at the open end. In tests of NO removal, the pulse generator gave a better performance compared with a self-matched pulse generator. Results of an optical study showed that gas molecules in the reactor were repeatedly exposed to intense pulsed discharges with a very high frequency because the voltage oscillation caused by one switching induced alternate propagation of positive and negative streamers from a wire electrode in the reactor.

The question to what extent particle induced transients in combinational parts of a circuit propagate into memory elements is addressed in this paper An experimental method is presented in which the proportion of bit flips originating from heavy-ion hits in combinational logic is determined. It is proposed that a voltage pulse may only propagate through a limited number of transistor stages and still be latched. The proportion of all transients in combinational logic that were latched into registers was experimentally, estimated to be between 0.7/spl middot/10/sup -3/ and 2/spl middot/10/sup -3/ for a custom designed CMOS circuit. Very few multiple bit flips were observed during the experiments which indicates that the single bit flip model used in many high-level simulations is reasonable accurate. >

The energy in magnetocumulative generators is stored in low value inductances, of the order of 10 nH, but the currents involved may reach tens and even hundreds of megaamperes. Transferring the corresponding large amount of energy into different types of loads poses a major problem, because the inductance of the MCG is smaller than that of the load. When the load is series connected to the MCG, efficient operation is only possible when the load parameters are matched to those of the generator. If pulse sharpening or matching devices are not used on the output of the MCG, it may still operate satisfactorily with an inductive load, provided that the inductance of the load is of the same order of magnitude as that of the MCG, i.e., several nanohenrys, or with an active resistance provided that its resistance is of the order of milliohms. To match the MCG to loads that do not meet these criteria, several methods have been developed to couple the energy from the MCG into the load. These methods include: • disconnecting the MCG from a circuit branch using an opening switch, followed by its connection to the load in a parallel circuit branch (Fig. 4.1). When the switch opens, a voltage pulse is delivered to the load, • using a transformer connected through an opening switch to the MCG and a closing switch to the load (Fig.4.2). When the opening switch is activated, energy is stored in the transformer. When the closing switch is activated, energy is delivered from the transformer to the load, • using an opening switch to shunt the current. When the switch opens, a closing switch simultaneously connects the load to the output of the MCG (Fig. 4.3).