IEEE Transactions on Plasma Science

Atlas is a high-energy, pulsed-power facility under development to study materials properties and hydrodynamics under extreme conditions. Atlas will implode heavy liner loads (m /spl sim/ 45 gm) with a peak current of 27-32 MA delivered in 4 /spl mu/s, and it is energized by 96, 240-kV Marx generators storing a total of 23 MJ. The power-flow system transports current from the Marx generators to th... View full abstract»

Nuclear weapons effects simulators are large pulsed power installations for generating intense X-ray fluxes, which are used in testing the susceptibility and hardening of military systems in the radiation environment. These simulators are expensive because of the requirement for very high power pulsed output to drive radiation loads that can provide the necessary spectral and temporal characterist... View full abstract»

This paper describes an experiment and modeling in plasma immersion ion implantation using a high-voltage pulsed power system. This consists of a high-voltage pulse generator that uses a hard tube switch. The reason for using this type of circuit category in the Plasma Immersion Ion Implantation (PIII) facility rather than a previously used pulse-forming network (PFN) circuit configuration is stat... View full abstract»

A radial multichannel pseudospark switch for pulsed power applications with pulsed currents of more than 100 kA, hold-off voltages up to 30 kV, and pulse durations [full-width at half maximum (FWHM)] of several microseconds is presented. Investigations of the electrode phenomena show that the discharge current is nearly homogeneously distributed over a large electrode area of at least 10 cm2<... View full abstract»

Results are presented of an experimental study of the generation of high-voltage and high-current pulses in generators designed as open and closed ferromagnetic circuits. Experiments were carried out using a light gas gun system. The magnetic projectiles were composed of ferromagnetic disks having 1.27- and 2.54-cm diameters. It has been shown that with velocities of the magnetic projectiles of 20... View full abstract»

In a present pulsed power generator system using semiconductor switches, saturable magnetic switches are usually connected in series to compress the output pulse because the current rise-time of semiconductor switches are generally not short enough, However, the magnetic switches are heavy and they reduce the energy transfer efficiency. So we propose a pulsed power generator system using a 5500-V ... View full abstract»

The 2.0-GeV Pohang light source (PLS) is a third-generation synchrotron light source that is the first such facility in Korea and the fifth in the world. The PLS mainly consisted of a full-energy injection linac and a storage ring. Four kicker magnets are installed in the storage ring tunnel to move the stored beam orbit in the storage ring closer to the injected beam from the beam transfer line. ... View full abstract»

Science Applications International Corporation and the Air Force Research Laboratory are continuing development of a graphical design/simulation code for explosive flux compression generators (FCGs). “FCGSCA” is written in FORTRAN and Visual Basic and targets the Windows O/S (Microsoft, Chicago, IL). Basic physics principles and well-known circuit analysis techniques simulate generator... View full abstract»

The Pulsed Power Group at the Atomic Weapons Establishment (AWE) is interested in the generation of small, intense, multimegavolt X-ray sources for radiographic applications. For this paper, research has been carried out into electron beam transport and focusing studies on one of our single pulse forming line flash X-ray machines. Experiments were undertaken on E Minor to improve the radiographic ... View full abstract»

Experiments are reported to demonstrate the ability of pseudospark switches for extremely fast recovery after forward conduction at an anode voltage of up to 25 kV and peak anode currents of 1 to 2 kA. At a pulse duration of around 5 μs and at a rate of current rise of up to 1 kA/μs, the reverse current is blocked at current zero transition due to an extremely fast recovery rate. The maximum... View full abstract»

The design, construction, and testing of miniature, high-power magnetic flux compressors are presented and discussed. The magnetic flux compressors are located inside high-speed, 30-mm projectiles that are launched with a high-pressure helium gun to velocities of approximately 300 m/s. The large deceleration force created when the projectile impacts the ground is used to power the magnetic flux co... View full abstract»

Photoconductive switching of the stacked Blumlein pulsers, developed at the University of Texas at Dallas, currently produces high-power nanosecond pulses with risetimes on the order of 200 ps. The device has a compact geometry and is commutated by a single GaAs switch triggered by a low-power laser diode array. This report presents the progress toward improving the high-gain switch operation and ... View full abstract»

The physical basis for semiconductor nanosecond opening switches is a specially organized recovery process in the diode. There are two modes of this process: junction recovery (JR) mode and silicon opening switch (SOS) mode. In the JR mode, the current interruption occurs due to the recovery of pn-junction blocking capability, and in the SOS mode, due to the drastic increase in resistance of low-d... View full abstract»

A unique type of thyristor, the reverse switching dynistor (RSD), has been studied in specially designed pulsers to evaluate their performance for several high-power applications. The dynistor is an asymmetric thyristor with an alternating p+ and n+ structure in its anode. The device operates like a transistor during turn-on and generates a uniform plasma distribution enablin... View full abstract»

The emission properties of pulsed electrical discharges propagating across the surfaces of PET, PP, PTFE, UPVC, and PVDF in various gases have been investigated. The optical spectra from the discharges have been recorded over the 200-500 nm bandwidth and the effect of the interaction between the pulsed discharge and the substrate material studied. The gases used were air, argon, and SF6... View full abstract»

A new type of multipulse generator is proposed for the generation of high power pulses with an extremely short interpulse repetition interval. In this system, an air-core step-up transformer is used with a magnetic switch and a pulse forming line, which is charged in the double-resonance mode. Numerical simulations of this system have shown that 600 kV, 56 ns pulses, matched to a 20 Ω impeda... View full abstract»

Three-dimensional numerical simulations have been carried out in order to explain the experimental results with a shock-tube-driven disk magnetohydrodynamics (MHD) generator with inlet swirl for the first time. The numerical results agree well with the experimental results especially in the enthalpy extraction ratio. The isentropic efficiency obtained numerically is higher than that in the experim... View full abstract»

The use of explosively driven flux compressors as light and compact autonomous single-shot power supplies for high-power microwave applications requires special attention to be paid to the conditioning and matching elements of the overall system, due to the fast-rising high voltage output step that is needed. This paper addresses various schemes by which this may be achieved and, based on proven t... View full abstract»

In conjunction with ongoing high-current experiments on Sandia National Laboratories' Z accelerator (Albuquerque, NM) we have revisited a problem first described in detail by Heinz Knoepfel (1970). Unlike the 1-Tesla MITL's of pulsed power accelerators used to produce intense particle beams, Z's disk, transmission line (downstream of the current addition) is in a 100-1200-Tesla regime; so its cond... View full abstract»

Recent experiments have adapted existing magnetically insulated induction voltage adders (Sabre, Hermes III) to drive a 10-MV diode immersed in magnetic fields as high as 50 T. In such a diode, an electron beam of tens of kiloamperes can be confined by the magnetic field to a diameter of about 1 mm, and when it strikes a high-Z anode, it can create a bremsstrahlung X-ray source intense enough to r... View full abstract»

This paper is devoted to the study of a new triggering scheme for discharge initiation of vacuum switches. The device, which mainly comprises a carbon bridge, is characterized by its low dimension and energy consumption. Fast imaging techniques coupled to electric measurements and spectroscopic investigations have allowed us to characterize the spatiotemporal evolution of the physical processes re... View full abstract»

This research concentrates on the application of pulsed corona discharges to crack heavy tar components (hydrocarbons) of thermally generated biogas into lighter ones. The method has the advantage that it can operate at a high temperature and be retrofitted to existing installations. The corona discharge is energized by 100-150-ns-wide voltage pulses (100 kV) at a continuous repetition rate of 600... View full abstract»

The design, construction, and testing of miniature, high-power piezoelectric compression generators are presented and discussed. The piezoelectric compression generators are located inside high speed, 30-mm projectiles that are launched with a high pressure helium gun to velocities of approximately 300 m/s. The large deceleration force created when the projectile imparts the ground is used to powe... View full abstract»