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The impulsive acceleration of active protection elements can preferably be realized by single-stage electromagnetic launcher systems using pancake coils1. In order to produce time varying magnetic field, during the year 2004, a pulsed power system with two modular structured energy packs (300 kJ) has been built up as a basic facility for testing pancake coils systems. Each power supply module comprises...
Spectroscopic investigations in the visible and near UV are underway to study plasmas present in X-ray radiography diodes during the time of the electron beam propagation. These studies are being performed on the RITS-3 accelerator (5.25 MV and 120 kA) at Sandia National Laboratories using several diode configurations. The proper characterization of the plasmas occurring during the time of the X-ray...
Pulsed power technology has been used in many applications such as control of NOx and SOx from exhaust gases, treatment of dioxins, removal of volatile organic compounds, and generation of ozone. Since the pulse width of the applied voltage has a strong influence on the energy efficiency of the removal of pollutants, the development of a short pulse generator is of paramount importance for practical...
A new version of a very fast impulse current generator based on the use a floating electrode was designed and constructed. The "Roman generator" is an electrostatic generator able to produce lightning-like current derivatives, with amplitude in the order of kA. The design of a new prototype of the Roman generator, called here "fast impulse current generator", took in consideration...
A 1 MV linear transformer driver (LTD), capable of driving a radiographic diode load, has been built and tested. A circuit model of this accelerator has been developed using the BERTHA circuit simulation code. Simulations are compared to data from power-flow experiments utilizing a large area electron-beam diode load. Results show that the simulation model performs well in modeling the baseline operation...
In the PIM pulsed power machine a 1.5 MV, 100 ns duration pulse is generated by a 10 Ohm water Blumlein A prepulse reduction system based on a gas switch has been designed and built by Titan PSD. This has been fitted and reduced the prepulse to less than 3 kV. Prepulse of this order is necessary to drive the focused e-beam diodes used for flash radiography. Details of the prepulse reduction system,...
It is expected that, just as the proximity of a wall stabilizes a Z-pinch in a capillary, the proximity of a wall (solid or liquid) can also stabilize an exploding wire placed in a capillary or in liquid (water), the density of which can be further increased by a suitably focused shock wave. A wire explosion will be used in our new apparatus CAPEX-U (current amplitude 100 kA, quarter period 70 ns)...
The control of systems used in pulsed power applications, such as electromagnetic launchers, is difficult due to factors such as short timescales and complex system dynamics. Open loop controllers are often used in such applications, and the control inputs are designed offline, often using empirical techniques based on system simulations. We present a technique for computing optimal open loop controllers...
The COBRA accelerator at Cornell University has been reconfigured for use with wire arrays. Design goals included 1 MA peak current with a variable zero to peak current rise-time of as little as 100 ns. COBRA is now driven by two Marx generators, each of which feeds a parallel-plate water capacitor. These capacitors are switched into four parallel pulse-forming lines via self-breaking gas switches...
Efficiency and scaling relationships for DC (i.e., non- induction) electromagnetic launchers (EML's) are presented and discussed. Efficiency and scaling relationships for these types of launchers are easily generalized since their principle of operation is the same, namely the production of an electromagnetic force via a spatial change in inductance. Electromagnetic force, efficiency, back-voltage,...
In the fields of electronic warfare airborne applications, the High Voltage Power Supply (HVPS) of phased array transmitters must have the characteristics of high power density and stable dc output voltage for driving mini TWTs. The high voltage stability of HVPS is known critical to keep the directivity of phased array transmitters which is easily affected by the phase noise of RF output. This paper...
This paper presents the results of an experiment in which the effect of generation of picosecond superradiation pulses was first observed during the induced backward scattering of a high-power pump microwave by a short high-density relativistic electron beam. These investigations became feasible due to an experimental setup built around two high-current electron accelerators of the Radan series that...
The ZR refurbishment project [1] at Sandia National Laboratories (SNL) required a set of diverter switches to protect the Marx generators and intermediate storage (IS) capacitors from Marx pre-fire and/or laser triggered output switch (LTS) no-fire. Thirty-six such diverters, one for each Marx-IS set, will need to operate reliably over the full range of Marx charge voltages and LTS anticipated closure...
TRIUMF's Ion Trap for Atomic and Nuclear Science (TITAN) Radio Frequency Quadrupole (RFQ) Beam Cooler is a device that cools and collects short-lived isotopes, with half-lives as short as 10 ms, created by an Isotope Separator and Accelerator (ISAC). An RF square wave driver (RFSWD), that must have rise and fall times of less than 125 ns (10% to 90%), performs 2-dimensional focusing of the ion beam...
The Refurbished Z machine, ZR, has 3 distinct missions. The first is to increase the capability for the user community by providing higher peak currents. The second is to increase the precision by increasing pulse repeatability and pulse shape flexibility. The third is to increase the capacity by providing operational turnaround time consistent with conducting a shot per shift. The pursuit of the...
Sandia national laboratories (SNL) and lockheed martin MS2 are designing an electromagnetic missile launcher (EMML) for naval applications. Lhe EMML uses an induction coilgun topology with the requirement of launching a 3600 lb. missile up to a velocity of 40 m/s. Lo demonstrate the feasibility of the electromagnetic propulsion design, a demonstrator launcher was built that consists of approximately...
As pulsed-power systems used to drive EM launchers evolve from laboratory to operational environments, high- power solid-state devices are emerging as the leading switch technology for these systems. These devices, specifically high-power thyristors and diodes, offer the advantages of improved energy efficiency, reduced volume, and reduced auxiliaries over spark-gaps and ignitrons. Proper application...
We are developing an inexpensive compact accelerator system primarily intended for pulsed radiography. Design characteristics are an 8 MeV endpoint energy, 2 kA beam current, a cell gradient of approximately 3 MV/m (for an overall accelerator length is 2-3 m), and <$1/Volt capital costs. Such designs have been made possible with the development of high specific energy dielectrics (>10J/cm3),...
The application of pulsed power to transient RF/microwave generation for warhead/projectile payloads is currently a significant research area. In this application, traditional fixed antenna designs have two major drawbacks: the size required for efficient radiation can be prohibitive for frequencies much less than 1 GHz, and the fixed antenna can make the device vulnerable to electromagnetic counterattack...
Lawrence Livermore National Laboratory (LLNL) is evaluating design alternatives to improve the voltage regulation in our Flash X-Ray (FXR) accelerator cell and pulse-power system. The goal is to create a more mono-energetic electron beam. When an electron beam crosses the energized gap of an accelerator cell, the electron energy is increased. However, the beam with the associated electromagnetic wave...
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