Applied Pulsed Power Inc.

NY, United States

Applied Pulsed Power Inc.

NY, United States
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Sanders H.D.,Applied Pulsed Power Inc. | Glidden S.C.,Applied Pulsed Power Inc. | Dunham C.T.,Applied Pulsed Power Inc.
Digest of Technical Papers-IEEE International Pulsed Power Conference | Year: 2013

Applied Pulsed Power ('APP') has developed a thyristor based switch capable of replacing thyratrons in many high-frequency, high current, high-voltage, pulsed power applications. The switch can operate at frequencies up to 500 pps, voltages of 32kV or higher and maximum fault currents of 14kA, and have lifetimes of more than 1011 pulses [1]. Lower frequency models of our thyristor based thyratron replacement switches are currently in use at CERN, Argonne National Lab and SLAC National Accelerator Laboratory [2]. They offer advantages over thyratron switches in cost, lifetime, size, weight and maintenance requirements. © 2013 IEEE.


Sanders H.D.,Applied Pulsed Power Inc. | Glidden S.C.,Applied Pulsed Power Inc. | Warnow D.M.,Applied Pulsed Power Inc.
Proceedings of the 2010 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2010 | Year: 2010

There are many applications currently using spark gap switches which would like to have the long lifetime of a solid state switch such as a silicon thyristor. This was not possible till now due to the relatively long turn-on times of silicon thyristors. The turn-on time of a silicon thyristor can be improved by providing the charge carriers using a laser source rather than an electrical source. Then the limit of the turn-on time is not the rate at which the charge carriers can be generated but on how fast the device can be seeded with photo-generated charge carriers. Previous experiments have tried to create devices based on fast optical gating of high voltage silicon thyristors. However, these used thick expensive prototype devices. We examined the use of standard commercial silicon thyristors. The advantage of using commercial thyristors is their lower cost and smaller thickness. Thinner devices have a faster turn-on time with lower optical energy requirements. We previously demonstrated 50ns turn-on times using 125W laser diode pumping of 5kV commercial devices that were designed for electrical triggering and had been modified for optical triggering. These devices were tested at up to 5kA peak current. This paper will describe how 500W laser pumping of silicon thyristors achieves turn-on times of less than 40ns using commercial devices designed for laser pumping and using a compact laser diode source. © 2010 IEEE.


Sanders H.,Applied Pulsed Power Inc. | Glidden S.,Applied Pulsed Power Inc. | Warnow D.,Applied Pulsed Power Inc. | Dunham C.,Applied Pulsed Power Inc.
Proceedings of the 2012 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2012 | Year: 2012

Kicker requirements have become more complicated with each new accelerator design. This paper will talk about two designs, one for electrostatic kickers and one for electromagnetic kickers. The electrostatic kicker achieves a 20 kV transition on a 200 pF strip-line within 220 ns from trigger at a maximum transition frequency of 40 kHz using less than 8 kW at full power. The electromagnetic kicker achieves 1000 A into a 0.523 μh magnet with a 50 ns rise time operating at a maximum frequency of 20 Hz. Both systems are all solid state. The electrostatic kicker operates using a fast resonant charge circuit combined with a slow maintenance circuit in a push-pull configuration operating at ±10 kV. The rise time of the voltage change is less than 100 ns and either state can be maintained indefinitely. The magnet kicker operates using a PFN and a fast thyristor based switch followed by a small pulse compression circuit. © 2012 IEEE.


Sanders H.,Applied Pulsed Power Inc. | Glidden S.,Applied Pulsed Power Inc. | Dunham C.,Applied Pulsed Power Inc.
Proceedings of the 2012 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2012 | Year: 2012

Thyratrons and spark gap switches continue to be the predominant technologies used for high current, high voltage pulsed power applications. The offerings from thyratron manufacturers have been diminishing and prices have increased as vacuum tube manufacturing continues its decline. In addition, the maintenance requirements for thyratrons make them unsuitable for many potential main stream applications for pulsed power. High voltage IGBT based switches have become common, but current limitations have prevented them from being an attractive alternative for many thyratron replacement applications. Thyristors have the advantage of high current capacity and this paper will describe compact, high current, high voltage solid state switches for thyratron replacements, based on thyristor technology. The switches are based on series connected fast thyristors with 3cm2 die in a 20cm2 package. These switches have been tested to 50 k V, to greater than 12 kA, to greater than 50 kA/μs, to 360 Hz, and to 3×108 pulses, without failure. Thyratron replacement switches based on thyristor technology are currently in use at CERN, Argonne National Lab and SLAC National Accelerator Laboratory. They offer advantages over thyratron switches for cost, lifetime, size, weight and maintenance requirements. © 2012 IEEE.


Hegeler F.,Commonwealth Technology Inc. | McGeoch M.W.,PLEX LLC | Sethian J.D.,U.S. Navy | Sanders H.D.,Applied Pulsed Power Inc. | And 2 more authors.
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2011

A unique all solid-state pulsed power system has been tested at the Naval Research Laboratory that produced 200 kV, 4.5 kA, and 300 ns pulses, continuously for more than 11,500,000 shots into a resistive load at a repetition rate of 10 pps. The Marx has an efficiency of 80% based on calorimetric measurements. This pulser is used to evaluate components and advance solid state designs for a next generation solid-state pulsed power system to drive an electron beam pumped KrF laser system for inertial fusion energy. The solid state pulser, designed and constructed by PLEX LLC, consists of a 12 stage Marx, coupled with a 3rd harmonic stage to sharpen the Marx output waveforms, a main magnetic switch, a compact pulse forming line used as a transit time isolator, and a resistive load. Each Marx stage uses an APP Model S33A compact high voltage switch that consists of 12 series connected thyristors. A life test on individual thyristors showed operation of > 300 M shots at 20 Hz without failure. © 2011 IEEE.


Weinberg I.N.,Weinberg Medical Physics LLC | Stepanov P.Y.,Weinberg Medical Physics LLC | Fricke S.T.,Childrens National Medical Center | Probst R.,Weinberg Medical Physics LLC | And 7 more authors.
Medical Physics | Year: 2012

Purpose: A time-varying magnetic field can cause unpleasant peripheral nerve stimulation (PNS) when the maximum excursion of the magnetic field (ΔB) is above a frequency-dependent threshold level P. Mansfield and P. R. Harvey, Magn. Reson. Med. 29, 746-758 (1993). Clinical and research magnetic resonance imaging (MRI) gradient systems have been designed to avoid such bioeffects by adhering to regulations and guidelines established on the basis of clinical trials. Those trials, generally employing sinusoidal waveforms, tested human responses to magnetic fields at frequencies between 0.5 and 10 kHz W. Irnich and F. Schmitt, Magn. Reson. Med. 33, 619-623 (1995), T. F. Budinger, J. Comput. Assist. Tomogr. 15, 909-914 (1991), and D. J. Schaefer, J. Magn. Reson. Imaging 12, 20-29 (2000). PNS thresholds for frequencies higher than 10 kHz had been extrapolated, using physiological models J. P. Reilly, IEEE Trans. Biomed. Eng. BME-32(12), 1001-1011 (1985). The present study provides experimental data on human PNS thresholds to oscillating magnetic field stimulation from 2 to 183 kHz. Sinusoidal waveforms were employed for several reasons: (1) to facilitate comparison with earlier reports that used sine waves, (2) because prior designers of fast gradient hardware for generalized waveforms (e.g., including trapezoidal pulses) have employed quarter-sine-wave resonant circuits to reduce the rise- and fall-times of pulse waveforms, and (3) because sinusoids are often used in fast pulse sequences (e.g., spiral scans) S. Nowak, U.S. patent 5,245,287 (14 September 1993) and K. F. King and D. J. Schaefer, J. Magn. Reson. Imaging 12, 164-170 (2000). Methods: An IRB-approved prospective clinical trial was performed, involving 26 adults, in which one wrist was exposed to decaying sinusoidal magnetic field pulses at frequencies from 2 to 183 kHz and amplitudes up to 0.4 T. Sham exposures (i.e., with no magnetic fields) were applied to all subjects. Results: For 0.4 T pulses at 2, 25, 59, 101, and 183 kHz, stimulation was reported by 22 (84.6), 24 (92.3), 15 (57.7), 2 (7.7), and 1 (3.8) subjects, respectively. Conclusions: The probability of PNS due to brief biphasic time-varying sinusoidal magnetic fields with magnetic excursions up to 0.4 T is shown to decrease significantly at and above 101 kHz. This phenomenon may have particular uses in dynamic scenarios (e.g., cardiac imaging) and in studying processes with short decay times (e.g., electron paramagnetic resonance imaging, bone and solids imaging). The study suggests the possibility of new designs for human and preclinical MRI systems that may be useful in clinical practice and scientific research. © 2012 American Association of Physicists in Medicine.


Saethre R.,Oak Ridge National Laboratory | Morris B.,Oak Ridge National Laboratory | Sanders H.,Applied Pulsed Power Inc.
Digest of Technical Papers-IEEE International Pulsed Power Conference | Year: 2015

The Spallation Neutron Source (SNS) extraction kicker system is a high power 60 hertz pulsed power system. [1] The system consists of fourteen identical modulators, each driving a magnet to extract a proton beam from the accumulator ring through the beam transfer line to the target. Each modulator is a Blumlein Pulse Forming Network (PFN) with a fast high current switching thyratron and low inductance capacitor banks. The thyratron switches have relatively short life times, high replacement cost, long lead-Time and require routine adjustments to maintain low timing jitter and drift. [2] A solid-state thyristor based high voltage switch has been developed as a direct replacement for the thyratron. [3] This paper describes the configuration, test stand and production kicker performance of the thyristor and PFN. In addition, the development of a magnetic switch to decrease magnet current rise time is discussed. © 2015 IEEE.


Liu W.,Argonne National Laboratory | Powe J.,Argonne National Laboratory | Cond M.,Applied Pulsed Power Inc. | Ga W.,Argonne National Laboratory | Sanders H.,Argonne National Laboratory
Digest of Technical Papers-IEEE International Pulsed Power Conference | Year: 2015

The recently built 12us long pulse RF modulator at Argonne Wakefield Accelerator (AWA) facility was having many performance problems until the thyratron used in the modulators were replaced with pulsed power solid state switches. Detail of both the problems experienced with the thyratrons and the results of successful upgrade with solid state switches are presented in this paper the design of the solid state switches will also be discussed. © 2015 IEEE.


Sanders H.D.,Applied Pulsed Power Inc. | White C.,Daresbury Laboratory | Dunham C.,Applied Pulsed Power Inc. | Warnow D.,Applied Pulsed Power Inc.
Proceedings of the 2014 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2014 | Year: 2014

Fast crowbar switches are needed to protect high power amplifier tubes from potentially damaging internal arcs. Such a switch needs to have a fast turn-on to a low impedance state while also having the capability to discharge large amounts of stored energy. These switches have historically been thyratron tubes or spark gaps [1]. We will describe a new hybrid solid-state approach that combines a small fast switch with a slower large area slow switch to achieve a low cost crowbar switch for these applications up to 50 kV. © 2014 IEEE.


Patent
Applied Pulsed Power Inc. | Date: 2011-05-19

An optically triggered semiconductor switch includes an anode metallization layer; a cathode metallization layer; a semiconductor between the anode metallization layer and the cathode metallization layer and a photon source. The semiconductor includes at least four layers of alternating doping in the form P-N-P-N, in which an outer layer adjacent to the anode metallization layer forms an anode and an outer layer adjacent the cathode metallization layer forms a cathode and in which the anode metallization layer has a window pattern of optically transparent material exposing the anode layer to light. The photon source emits light having a wavelength, with the light from the photon source being configured to match the window pattern of the anode metallization layer.

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