Computer Modeling of Plasma Flow Switches-high Current Switching on Procyon

Computer Modeling of Plasma Flow Switches-high Current Switching on Procyon

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Published: 1993

Total Pages: 13

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Procyon is a high explosive driven pulsed power system designed to drive plasma z-pinch experiments to the 1-MJ level. Details of this system are provided elsewhere in these proceedings. The final switching stage of the Procyon system is a plasma flow switch (PFS). Our most recent experiment (April 29, 1993) included a full power test of the PFS designed for the Procyon system. In this test the Mark IX explosively driven generator delivered 22 MA of current to the storage inductor. The slight flux compression that occurs in the explosively formed fuse (EFF) opening switch increased this current to 24.5 MA. The EFF then opened and switched 16.5 MA to the PFS. The PFS switched 15.5 MA to the load region (the slot that will contain an imploding foil liner in future experiments) with a 10-90 rise time of 500 ns. In this present paper we discuss the computer modeling we have done on this Procyon plasma flow switch. In the next section we discuss the design of the Procyon switch and preshot calculations. Although the April 1993 experiment was quite successful there were significant surprizes in the performance of the PFS. In the last sections of this paper we discuss the work we have done in understanding the results of this experiment and the conclusions that we have reached to date.


Modeling of Plasma Flow Switches at Low, Intermediate and High Energies

Modeling of Plasma Flow Switches at Low, Intermediate and High Energies

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Published: 1992

Total Pages: 9

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Inductively stored pulsed power technology has been used over the past thirty years to produce multi-megaamp currents to implode low inductance loads and produce x-radiation. Because of the large difference in timescales for the delivery of magnetic energy to the load and the desire for high power x-radiation output (short timescale for the implosion), most inductively stored systems require at least one opening switch. The design and understanding of fast, efficient opening switches for multi-megaamp systems represents a long standing problem in pulsed power research. The Los Alamos Foil Implosion Project uses inductively stored magnetic energy to implode thin metallic liners. A plasma flow switch (PFS) has been investigated as the final pulse shaping step for this systems. The PFS consists of a wire array and a barrier foil located upstream from the load region. Several stages can be identified in the performance of the plasma flow switch. These are: (1) the vaporization of the wire array; (2) the assembly of the initiated plasma on tie barrier foil to form the switch plasma; (3) the motion of the switch plasma down the coaxial barrel; and (4) current switching to the load (the actual switching stage). The fourth stage affects the switch's efficiency, as well as the quality of the load implosion. Instabilities may develop during any of these four stages, and their presence may seriously degrade the structure of the switch plasma. Two primary criteria may be used to characterize good switching. The first is switching efficiency. A second criterion is transferred to the load during or after switching. This paper summarizes the computational design of the PFS experiments carried out on Pegasus 1. We conclude by considering the implications of these results for the design of a PFS for the higher energy regime (Procyon) regime.


Government Reports Annual Index

Government Reports Annual Index

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Published: 1995

Total Pages: 1142

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Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.


Computational Simulations of Plasma Flow Switches and Imploding Loads

Computational Simulations of Plasma Flow Switches and Imploding Loads

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Published: 1991

Total Pages: 13

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The Procyon system in the Los Alamos Trailmaster foil implosion project is intended to produce soft x-ray radiation by delivering about 1 MJ of kinetic energy to an imploding plasma liner. The final switching stage of this system will be a Plasma Flow Switch (PFS) which delivers current to the cylindrical foil load. 1-D and 2-D simulations are now being conducted to examine: the initiation of the PFS plasma: the dynamics of the PFS and its switching efficiency; the load implosion and resulting radiation output. Considered here, for the PFS and imploding load, are the effects of electrode walls, perturbations, and radiation. Comparisons with experiments (using the 1.5 MJ Pegasus capacitor bank) are also described. 5 refs., 6 figs.