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The high current, fast, 100ns, Linear Transformer Driver (LTD) developmental project at Sandia Laboratories and HCEI

Mazarakis, Michael G.; Fowler, William E.; Matzen, M.K.; McDaniel, Dillon H.; McKee, George R.; Savage, Mark E.; Struve, Kenneth W.; Stygar, William A.; Woodworth, Joseph R.

Sandia National Laboratories, Albuquerque, N.M., USA, in collaboration with the High Current Electronic Institute (HCEI), Tomsk, Russia, is developing a new paradigm in pulsed power technology: the Linear Transformer Driver (LTD) technology. This technological approach can provide very compact devices that can deliver very fast high current and high voltage pulses straight out of the cavity with out any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The load may be a vacuum electron diode, a z-pinch wire array, a gas puff, a liner, an isentropic compression load (ICE) to study material behavior under very high magnetic fields, or a fusion energy (IFE) target. This is because the output pulse rise time and width can be easily tailored to the specific application needs. In this paper we briefly summarize the developmental work done in Sandia and HCEI during the last few years, and describe our new MYKONOS Sandia High Current LTD Laboratory. An extensive evaluation of the LTD technology is being performed at SNL and the High Current Electronic Institute (HCEI) in Tomsk Russia. Two types of High Current LTD cavities (LTD I-II, and 1-MA LTD) were constructed and tested individually and in a voltage adder configuration (1-MA cavity only). All cavities performed remarkably well and the experimental results are in full agreement with analytical and numerical calculation predictions. A two-cavity voltage adder is been assembled and currently undergoes evaluation. This is the first step towards the completion of the 10-cavity, 1-TW module. This MYKONOS voltage adder will be the first ever IVA built with a transmission line insulated with deionized water. The LTD II cavity renamed LTD III will serve as a test bed for evaluating a number of different types of switches, resistors, alternative capacitor configurations, cores and other cavity components. Experimental results will be presented at the Conference and in future publications.

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The high current, fast, 100ns, Linear Transformer Driver (LTD) developmental project at Sandia National Laboratories

LeChien, Keith R.; Woodworth, Joseph R.; Fowler, William E.; Long, Finis W.; Matzen, M.K.; McDaniel, Dillon H.; McKee, George R.; Struve, Kenneth W.; Stygar, William A.

Sandia National Laboratories, Albuquerque, N.M., USA, in collaboration with the High Current Electronic Institute (HCEI), Tomsk, Russia, is developing a new paradigm in pulsed power technology: the Linear Transformer Driver (LTD) technology. This technological approach can provide very compact devices that can deliver very fast high current and high voltage pulses straight out of the cavity with out any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The load may be a vacuum electron diode, a z-pinch wire array, a gas puff, a liner, an isentropic compression load (ICE) to study material behavior under very high magnetic fields, or a fusion energy (IFE) target. This is because the output pulse rise time and width can be easily tailored to the specific application needs. In this paper we briefly summarize the developmental work done in Sandia and HCEI during the last few years, and describe our new MYKONOS Sandia High Current LTD Laboratory.

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Shaping the output pulse of a linear-transformer-driver module

Proposed for publication in Physical Review Special Topics: Accelerators and Beams.

Stygar, William A.; Stoltzfus, Brian S.; Woodworth, Joseph R.; Fowler, William E.; LeChien, Keith R.; Long, Finis W.; Mazarakis, Michael G.; McKee, George R.; Mckenney, John M.; Savage, Mark E.

We demonstrate that a wide variety of current-pulse shapes can be generated using a linear-transformer-driver (LTD) module that drives an internal water-insulated transmission line. The shapes are produced by varying the timing and initial charge voltage of each of the module's cavities. The LTD-driven accelerator architecture outlined in [Phys. Rev. ST Accel. Beams 10, 030401 (2007)] provides additional pulse-shaping flexibility by allowing the modules that drive the accelerator to be triggered at different times. The module output pulses would be combined and symmetrized by water-insulated radial-transmission-line impedance transformers [Phys. Rev. ST Accel. Beams 11, 030401 (2008)].

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A 5-megavolt, 600-kiloampere laser-triggered gas switch for use on Z-R: Comparison of experiments and simulations

Digest of Technical Papers-IEEE International Pulsed Power Conference

Woodworth, Joseph R.; Rosenthal, Stephen E.; Lehr, J.M.; Maenchen, John E.; Elizondo, J.; Johnson, D.L.; Corley, J.P.; Hodge, K.C.; Drennan, S.A.; Guthrie, D.W.

The Z Refurbishment project is designed to increase the peak current to the load on Z to ∼26 MA in a 100-ns wide power pulse. This current is achieved by summing the current from 36 independent pulse-power modules. To meet these requirements, we have designed and constructed an SF6-insulated gas switch that can hold off 5.5 MV and conduct a peak current of 600 kA for over a hundred shots. The gas switch is charged by a Marx generator in ∼1 microsecond and transfers about 200-kilojoules of energy and 0.25 Coulombs of charge to a pulse-forming line in a ∼150-ns-wide power pulse peaking at 2.5 TW. The gas switch oonsists of a laser-triggered section holding off 15% of the voltage followed by 25 self-breakdown gaps. The self-breaking gaps are designed to provide multiple breakdown arcs in order to lower the overall inductance of the switch. The gas switch is submerged in transformer oil during operation. In this work, we show how simulation and experiment have worked together, first to verify proper operation of the switch, and then to solve problems with the switch design that arose during testing. © 2005 IEEE.

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Copy of An overview of pulse compression and power flow in the upgraded Z pulsed power driver

Savage, Mark E.; Maenchen, John E.; McDaniel, Dillon H.; Pasik, Michael F.; Pointon, Timothy D.; Owen, Albert C.; Seidel, David B.; Stoltzfus, Brian S.; Struve, Kenneth W.; Warne, Larry K.; Bennett, Lawrence F.; Woodworth, Joseph R.; Bliss, David E.; Clark, Waylon T.; Coats, Rebecca S.; Elizondo-Decanini, Juan M.; LeChien, Keith R.; Harjes, Henry C.; Lehr, J.M.

Abstract not provided.

Multimegavolt laser-triggered gas switching with a green laser and beam transport through water

IEEE Transactions on Plasma Science

Zameroski, Nathan D.; Lehr, J.M.; Woodworth, Joseph R.; Blickem, Jim R.; Hodge, Keith C.; Wallace, Zachariah R.; Anaya, Victor; Corley, John P.; Lott, John A.

Ultraviolet (UV) laser-triggered gas switching using laser beams at 266 nm has greatly improved the simultaneity of many large multimodule accelerators. This UV beam however cannot be transmitted significant distances through water or oil. Since the switches in these accelerators are typically submerged in water or oil, the laser beams are often conveyed to the switches through gas-filled "laser crossover tubes."These crossover tubes are difficult to field grade properly and are subject to frequent mechanical and electrical failures in the pulse-power environment. We have demonstrated that a 4.6-MV multistage gas switch insulated with SF6 can be triggered with a jitter of less than 10 ns using 110-mJ pulses of a green (532-nm) laser beam that has been transported through 67 cm of 1-MΩcm water on its way to the switch. These results may allow elimination of the laser crossover tubes in future accelerators. © 2007 IEEE.

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Results 1–25 of 39
Results 1–25 of 39