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CPI is currently developing megawatt-class gyrotrons for fusion plasma heating and current drive across a range of frequencies in the mm-wave regime. These gyrotrons are currently at different stages of development, fabrication, and test. Design features will be compared, available test data will be presented, and future plans will be described.
Inducing apoptosis in malignant cells and controlling ES cell differentiation using sub-nanosecond high voltage pulses have been investigated. It is important to develop a high-power, high frequency electromagnetic wave focusing system for apoptosis induction in cancer. Nonlinear lumped element transmission lines (NLETL) to generate RF pulses have in recent years gained much attention. Our intention...
The A6 relativistic magnetron with diffraction output (MDO) using a single-step cavity is described in this paper. The efficiency of this device can be as high as 78% with GW output power. The UNIPIC code was used to demonstrate that when the relativistic magnetron was driven using a 400 kV applied voltage, the energetic electrons emitted from the cathode strike the relativistic magnetron's anode...
Intense pulsed active detection (IPAD, [1]; also see presentations at this conference by B.V. Weber, et al., D.P Murphy et al., S.B. Swanekamp et al. and J.C. Zier, et al.) has been proposed as a means of detecting contraband fissile material from a distance. In this approach, an intense bremsstrahlung pulse is used to induce photo fission, the products of which are detected. In this work, we report...
The vircator is a compact and robust narrow band HPM source with a simple geometry. In the most basic version of the vircator, the operating frequency depends only on the distance between the anode and cathode and the applied voltage. In a compact system the vircator is often powered by a marx generator resulting in a frequency chirp caused by the double exponential voltage pulse generated by the...
The development of the rod pinch diode [1] has led to high-resolution radiography for dynamic events such as explosive tests. Rod pinch diodes use a small diameter anode rod, which extends through the aperture of a cathode plate. Electrons borne off the aperture surface can self-insulate and pinch onto the tip of the rod, creating an intense, small x-ray source (Primary Pinch). This source has been...
The purpose of this research is to characterize and compare CREE's new N-Channel Silicon Carbide (4H-SiC) vertical power D-MOSFET with CREE's previous generation of N-Channel Silicon Carbide (4H-SiC) vertical power D-MOSFET. Changes made to the newest MOSFET design lead to a 400% increase in pulsed current handling capability over the previous generation device with the same active area.
The NIF is the world's most powerful laser facility and is used for inertial confinement fusion experiments. One hundred and ninety two laser beams are used to compress a small capsule. X-ray framing cameras are an important diagnostic used to help characterize the dynamics of the capsule. The gated x-ray framing cameras consists of several key components including a pin hole array, microstrips, microchannel...
The MILO (Magnetically Insulated Line Oscillator) is a cross-field co-axial device capable of generating high power microwaves. A MILO designed to operate at 1.1 GHz at 500 kV, with an operating current of 45 kA and a design pulse length of 100–300ns was built by the Electrical and Computer Engineering Department at the University of New Mexico, to study plasma beam interactions. High voltage and...
We observed motion of liquids (water and oils with different conductivities) under the influence of corona discharges while using wire-to-plane geometry (high voltage wire above a rectangular vessel with a metal bottom-plate and transparent plastic walls). It was possible to see the internal motion within the transparent liquid volume by suspending small (3 μm) silica particles in the liquid and illuminating...
In this work the chemistry of CF4 capacitive plasma is studied. For this, experimental measurements were made by mass spectrometry technique which allowed the analysis of neutral species generated during the fragmentation of the source gas by the electrical gas discharge. Additionally, we use global model simulations in order to complement the experimental results, allowing to discern the main chemical...
A coaxial pulse generator was designed and constructed for an experimental study on a sub-millimeter spark-gap. D-dot sensors, used to register the waveforms in both the Pulse Forming Line — PFL and Transmission Line — TL, are not located exactly on the spark-gap. To determine the effect of sensor position on voltage measurements, simulations were carried out. The PFL voltage (V1) and TL voltage (V2)...
URSA Minor is a 21 cavity linear transformer driver (LTD) at Sandia National Laboratories to evaluate LTD technology for driving radiographic diodes. Operating at ∼2.0 MV, there is substantial electron flow in the central magnetically insulated transmission line (MITL). An important concern is electron loss to the vacuum insulators, which are recessed only ∼2 cm from the MITL. Electron flow has been...
A global modeling of a He-Ne ring laser gyro (RLG) has been developed. The physical model of the positive column of the DC discharge includes a fluid description of the plasma, a collisional radiative model (1D-CRM) for the dynamics of excited atomic states and a Maxwell-Bloch calculation of laser amplification. In the present paper we use this global modeling to analyze the influence of the radial...
In this paper, we report on the existence of two electron temperature populations in the low pressure expanding dc plasma jet through the investigation of the spatial evolution of EEDF measured by a single Langmuir probe system. It was observed that for argon the plasma jet is Maxwellian type in all discharge axes. However, when an electronegative gas was inserted/replaced the EEDF turns “two-temperature”...
A magnetically insulated vacuum transmission line (MITL) is a means by which high currents can be carried from generators to loads. In addition to the current flowing in the negative conductor, the source high voltage propagating along the transmission line causes electron emission into the vacuum which forms into an electron sheath restrained by self magnetic forces to flow along the cathode surface...
Mevex is a type of X-ray machine used at AWE for flash radiography since the early 1980s. The operating principle of the machine is to switch charge, stored in a Mark bank, into a Blumlein pulse-forming line. This causes the inner Blumlein conductor to rise in voltage to about −800 kV, driving a self-magnetic pinch diode (SMP) to produce a 60-ns X-ray pulse of dose 1.4 Rad at 1 m, with an effective...
A shock wave generated by negative pulsed discharge in pressurized carbon dioxide including supercritical (SC) phase was observed by means of Schlieren method. A negative pulsed voltage with a rise time of 90 ns and half-width of 410 ns was applied to a point electrode. The resulting shock wave, seemingly a multi-layered structure, was able to be confirmed despite the single pulsed voltage. Shock...
RITS-6 is an inductive voltage adder based accelerator used for radiographic diode research and development. A recent experiment was conducted to demonstrate that a negative polarity induction voltage adder could operate in positive polarity, at reduced voltage, with minimal reconfiguration and maintenance. Circuit simulations, 2-D electrostatic field calculations, and particle-in-cell simulations...
A new set of pulsed-inductive thrusters (PITs) have been developed for the Flux-Coil-Generated, Field-Reversed Configuration Experiment (FCX) at Tri Alpha Energy, Inc. This paper details their design, simulation, and measured performance. The simulation solves coupled equations for the circuit currents and plasma parameters, including formation and acceleration. The PIT design involves: 5 pulsed-gas...
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