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Hydrodynamic testing constitutes a large part of the Stockpile Stewardship program. The increasingly complex modeling of hydro phenomena requires precise information on the pulsed-power mechanisms propelling the imploding driver shell. For Atlas, a large pulsed-power machine, this means accurately recording the current waveform delivered to the target. Bechtel Nevada and Los Alamos National Laboratory...
There are various plasma applications of MTF in which very high currents are delivered using modules of capacitor banks to a single load as per the load requirement. Moreover there are other applications too, in which the large number of transmission lines feed a load from a single high-energy capacitor because of their well-defined current ratings. In such type of applications, the total current...
The original Atlas upper liner cassette joint was based on the Shiva Star design and were of the cryogenic interference type. The upper joint relied exclusively on the interference of the glide plane/liner interface for electrical conductivity and structural integrity. The second-generation cassette was designed to accommodate unpredictable changes in inner power flow channel z-axis geometry by fabricating...
For approximately the past 10 years, Sandia National Laboratories (SNL) has been successfully performing high energy density physics and material studies using the Z machine. The high demand for these shots has driven the need for an upgraded driver which supplies more load current, has a higher reliability, and requires less maintenance. The next generation machine, ZR, will address these needs by...
In the seventh IEEE Pulsed Power Conference in Monterey, CA (1989), Fowler and others published the performance characteristics for the recently developed MK-IX explosive-driven magnetic flux-compression generator (FCG). Since that time we have used this generator in a variety of applications, and have published the results as one of the features of each individual experiment. In this paper, we collect...
Proper accelerator assembly is critical in maximizing the return on investment of project funds. This critical task is most often accomplished by trained technicians. Pulsed Power-driven X-ray source assembly includes project planning, system design, drawing creation, and review as vital steps toward project success. The actual assembly procedures also are critical in ensuring the accelerator performs...
Power semiconductor devices have been used in development of various pulsed power generators for industrial applications. A repetitive pulsed high-voltage modulator using power MOSFETs has been developed for accelerator applications. It is capable of high-speed switching of 2kV at repetition rate of 1 MHz. This modulator, operating in continuous mode at average power level of 30 kW, has played an...
The cumulative effect of partial discharges (PD) in solid dielectric materials can lead to insulation aging and reduction in dielectric breakdown stress levels. Partial discharge events are parasitic to power levels. This paper compares PD behaviors of four model solid dielectric materials with embedded electrodes exposed to single fast impulses. Applied impulses had a characteristic rise time of...
The authors present a conceptual approach to improve the yield, efficiency, and pulse shape characteristics from an explosively-driven magneto-cumulative generator (MCG). We propose that a Bitter coil with tailored and configurable electromagnet windings and insulation be used for the MCG stator. Several features of Bitter coil construction lend themselves as design solutions for a number of inherent...
Monopropellant hydrazine is today widely used as propellant for missiles and spacecrafts. Hydrazine is however highly toxic. ADN-based liquid monopropellants seems to be a promising alternative to hydrazine, being substantially easier to handle, giving a 10 % higher specific impulse, and up to 60 % higher density-impulse, compared to hydrazine. This paper presents the results from electrical ignition...
The PC-based program CAGEN has been described before and has since continued development. The most recent innovation implemented in CAGEN is the Kiuttu Contact Resistance Model (KCRM). This model is described elsewhere in these proceedings and represents the most important step forward for FCG modeling observed in many years. In this paper, the performance of a very large range of helical flux compression...
Isentropic compression experiments (ICE) using a high explosive pulsed power (HEPP) system have been developed to obtain isentropic equation of state data for metals at megabar pressures [1][2]. The HEPP system comprises a magnetic flux compressor, an explosively-driven opening switch and a series of closing switches; fast rising current pulses are produced, with rise times of ~500 ns at current densities...
The Hydrodynamics Department at AWE has built up an impressive suite of X-ray machines over the last four decades. The machines cover a voltage range from 800 kV to 9.5 MV which caters for a broad range of experiments. The service radiographic machines are fielded in pairs which gives the added bonus that two images can be gained from each experiment. All the machines are built on the same principles...
This paper is concerned with analyzing the ultimate velocity versus projectile mass at fixed acceleration distance for various methods of decreasing the current density at the rail-armature interface. The analysis is performed by numerical solution of the system of equations of unsteady magnetic-field diffusion and unsteady heat transfer in a two dimensional formulation. Homogeneous and multilayer...
Lawrence Livermore National Laboratory (LLNL) is evaluating design alternatives to improve the voltage regulation in our injector and accelerator cells of our Flash X-Ray (FXR) machine. The operational peak electron beam current and energy at the X-ray generating target are 3.2 kA and 17 MeV. The goal is to create a more mono-energetic electron beam with variation of less than 1%-root-mean-squared...
Continued investigations of medium-bore helical coil electric launchers (HCEL) at the University of Missouri-Columbia are presented and discussed. The HCEL under investigation has an armature diameter of 40 mm and a stator length of 750 mm. The HCEL inductance gradient is 150 muH per meter and is a factor of 300 times greater than the inductance gradient of a conventional railgun. The HCEL armature...
Rotating machinery can be used to store kinetic energy and convert it to high current electrical energy in the millisecond time frame required by pulsed loads such as electromagnetic launchers. Machines used in these applications, called pulsed alternators, often require nonstandard features, such as low impedance, more than three phases, or compensating windings inside or conductive shields outside...
PIM is a pulsed power accelerator based around the inductive voltage adder technique. Originally designed to drive high impedance (~100 Omega) electron beam diode loads at approximately 3MV it was found that the output voltage into a lower impedance (~40 Omega) load was closer to 1.5MV, the change in load impedance reflects changing requirements for PIM. Using a transmission line code to understand...
A compact low-inductance capacitors PC 200-1.5 with a 1.5-nF capacitance and with pulsed charging up to 200 kV has been designed. The PC 200-1.5 capacitor uses combined paper-film insulation with castor oil impregnation. To decrease edge effects in the capacitor, the insulation in the region of the sharp edge was divided into thin layers by means of capacitor plates displaced with respect to each...
A broad overview of long-charge inductive storage systems technology based on more than 10 years development experience at Soreq NRC is presented. Key issues are addressed: a) System architecture; b) Essential components, with an emphasis on repetitive opening switch and coil screening; c) Efficiency of coupling to various loads, such as ET and railgun, exploding wires, etc. d) Compaction issues (impact...
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