- Robert E. Terry received the B.S. degree in physics from the Massachusetts Institute of Technology, Cambridge, MA, fo... moreRobert E. Terry received the B.S. degree in physics from the Massachusetts Institute of Technology, Cambridge, MA, followed by the M.A. and Ph.D. degrees from Johns Hopkins University, Baltimore, MD, in 1968, 1975, and 1978, respectively. He is currently an independent research scientist and was a senior research physicist affiliated with Enig Associates of Bethesda, MD from 2007 to 2014. From 1985 to 2007, Dr. Terry worked with the Radiation Hydrodynamics Branch of the Plasma Physics Division, Naval Research Laboratory (NRL). From 1979 to 1984 he worked with the theoretical physics division of Jaycor, Inc in Alexandria, VA. Joining NRL in 1985, he has worked on plasma radiation source (PRS) dynamics, power flow, plasma flow and reflex triode switches, magnetic interlayer pinches, gyrokinetic flows and microturbulence, RF discharge theory, plasma chemistry, and specialized wire z-pinch models. His current research interests include novel fluid particle models, climate physics, polywell fusion schemes, in-situ fuel production for Mars, Mars sample return missions, EDL at Mars, as well as novel schemes for electric propulsion. At Enig, he served as the Principal Investigator on a DARPA sponsored research effort in high altitude heat rejection. A founding lifetime member of the Mars Society, he works as the Director of Aerospace Education for the Maryland Wing of the Civil Air Patrol. Dr. Terry maintains a local web discussion list focused on Mars exploration.edit
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The goal of this analysis was not to create the most complex and definitive hydrogen breakdown model, but rather to gain enough insight from the substantial existing literature to winnow down the chemistry set to the point that it is... more
The goal of this analysis was not to create the most complex and definitive hydrogen breakdown model, but rather to gain enough insight from the substantial existing literature to winnow down the chemistry set to the point that it is easily manageable within a more complex 1D or 2D transport code that can really assess the prompt breakdown process in a typical pulse power machine.
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The prospects for achieving net energy production with pB11 fuel have recently considerably brightened. Studies have shown that the multi-GG field potentially obtainable with modest dense plasma focus devices have the effect of reducing... more
The prospects for achieving net energy production with pB11 fuel have recently considerably brightened. Studies have shown that the multi-GG field potentially obtainable with modest dense plasma focus devices have the effect of reducing the flow of energy from the ions to the electrons and thus suppressing bremsstrahlung radiation that cools the plasma. We report here on new simulations that indicate that net energy production may be achievable in high-magnetic-field devices at peak currents as low as 2.3 MA. While these simulations only model the dense plasmoid formed in the focus, new simulation techniques can allow a full particle-in-cell simulation of DPF functioning over the wide range of time and space scales needed. Such simulations will be of great value in the next round of experiments that will use pB11 fuel.
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With restrictive Courant criteria, the time integration of a radiation diffusion equation is generally done by a fully or partially implicit method. Relaxation methods are often effective and cooperative relaxation refers to a technique... more
With restrictive Courant criteria, the time integration of a radiation diffusion equation is generally done by a fully or partially implicit method. Relaxation methods are often effective and cooperative relaxation refers to a technique that will diffuse each spectral radiation group as a separate operation and combine the changes to a full spectrum. Successive passes over the groups provide convergence, as well as conserving energy over time, space and spectrum. Linearized and fully nonlinear variations on the method are discussed.
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Summary form only given. Plasma radiation source (PRS) loads of a few larger diameter wires offer a relatively unexplored path to energetic implosions. Such loads with larger initial wire diameters and load radii will provide lower... more
Summary form only given. Plasma radiation source (PRS) loads of a few larger diameter wires offer a relatively unexplored path to energetic implosions. Such loads with larger initial wire diameters and load radii will provide lower inductance at the expense of more precursor plasma involvement. In contrast to closed arrays with hundreds of fine wires, this relatively unexplored path to energetic implosions would use two or three load wires of appropriately heavier mass and aims to create a focused axial stagnation of dense wire cores amidst the assembled precursor plasma. Initial studies of low wire count loads show promising results with respect to initial inductance and available stagnation energy. Here we examine the trade space of stagnation energy, machine current, implosion time, and delivered mass for several drivers in common use. In contrast to earlier WDM formulations with inductance matrix elements good only in the thin wire limit, the present work makes full use of a new analytic result that accounts for proximity effects among the wire cores and a direct Lorentz gauge field solver to treat the TM mode set at the midplane in the pinch region. The current elements associated with the coronal plasma are then axial filaments constrained by the local conductivity, thermal gradients, and fluid velocity. A fluid particle representation enables the resolution of precursor plasma flows and wire core stagnation. Radiation yields are estimated with tabular CRE methods.
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The original nested array geometry due to Davis et al set the inner and outer wire arrays at equal length. Lebedev et al modify that arrangement by installing axially offset anchors for the inner array, increasing the initial inductance.... more
The original nested array geometry due to Davis et al set the inner and outer wire arrays at equal length. Lebedev et al modify that arrangement by installing axially offset anchors for the inner array, increasing the initial inductance. Terry et al have proposed counter twisting the arrays as an alternate means of adjusting the initial inductance as well as forming a magnetic interlayer. Here we use the wire dynamic model (WDM) to compare the variations in implosion dynamics arising from these alternatives. As observed experimentally, the WDM can show three modes of nested array interaction: sticky, mass exchanging, and magnetically buffered. The expected range of variation in implosion times and current partition histories is large enough to be observed in experiments
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Research Interests: Electromagnetic Fields, Wave Equations, Mathematical Models, Electromagnetic Field, Electric Fields, and 10 moreWave Equation, Mathematical Model, Radiative Transfer, Diodes, Lagrange Multiplier, Electric Field, Electron Temperature, Frequency Domain, Chemical Potential, and Probability Distribution Function
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The recent development of the computationally efficient tabulated collisional radiative equilibrium (TCRE) radiation transport model(J.W. Thornhill, J.P. Apruzese, J. Davis, R.W. Clark, A.L. Velikovich, J.L. Giuliani, Jr., Y.K. Chong,... more
The recent development of the computationally efficient tabulated collisional radiative equilibrium (TCRE) radiation transport model(J.W. Thornhill, J.P. Apruzese, J. Davis, R.W. Clark, A.L. Velikovich, J.L. Giuliani, Jr., Y.K. Chong, K.G. Whitney, C. Deeney, C.A. Coverdale and F.L. Cochran, Phys. Plasmas 7, 3480 (2001).) has made possible full multidimensional radiation MHD simulations of hot dense Z-pinch plasmas with a realistic description
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Summary form only given. A practical wire dynamical model (WDM) treats the individual wire segments of an array load as a self-consistent electrical and mechanical ensemble. From a mechanical viewpoint the segments are mutually... more
Summary form only given. A practical wire dynamical model (WDM) treats the individual wire segments of an array load as a self-consistent electrical and mechanical ensemble. From a mechanical viewpoint the segments are mutually interacting particles driven by Biot-Savart force to attract or repel one another according to the currents each carries. Electrically, the segments are viewed as mutually inductive
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Summary form only given. Argon gas puff Z-pinches are used as sources of pulses of K shell X radiation. The density and velocity distributions of these gas puffs determine the quality of their subsequent implosions. These distributions... more
Summary form only given. Argon gas puff Z-pinches are used as sources of pulses of K shell X radiation. The density and velocity distributions of these gas puffs determine the quality of their subsequent implosions. These distributions are controlled by carefully designed annular nozzles. The effect of changes in the nozzle design on the quality of the gas puff can
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E. Nolting, L. Miles, J. Miller, J. Draper, V. Kenyon, IIP, W. Spicer, Jr.b, C. Parsons;, and F. Warnock Carderock Division, Naval Surface Warfare Center, White Oak Laboratory, Silver Spring , MI> 20903-5640 ... A. Fisher, G.... more
E. Nolting, L. Miles, J. Miller, J. Draper, V. Kenyon, IIP, W. Spicer, Jr.b, C. Parsons;, and F. Warnock Carderock Division, Naval Surface Warfare Center, White Oak Laboratory, Silver Spring , MI> 20903-5640 ... A. Fisher, G. PetersonC, and R. Terry Naval Research Laboratory, ...
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A plasma kinetic theory is developed which provides a statistical description of plasma turbulence by rigorously incorporating the initial distribution functions into an extended statistical mechanics. With the hypothesis that strong... more
A plasma kinetic theory is developed which provides a statistical description of plasma turbulence by rigorously incorporating the initial distribution functions into an extended statistical mechanics. With the hypothesis that strong particle interaction is a necessary condition for turbulent plasma evolution and upon specializing the subdynamics to select phase space domains implying either strong interaction or its absence, the extended statistical mechanics becomes a statistics of the detailed space-time structure of a turbulent plasma. Hastened thermalization was observed in theta-pinch plasma, and its characteristics support, qualitatively, the hypothesis of strong interaction as a necessary condition for turbulent evolution. Observed dispersion curves for electrostatic waves in a turbulent magnetoplasma support this new ensemble averaging concept more than the conventional notion of stochastic fields.
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Experimental results on a 1MA pulser suggest that axial magnetic fields can stabilize z-pinch implosions and enhance the compression ratio(S. Sorokin and S. Chaikovsky, Dense Z-Pinches, AIP Conf. Proc. 299, p.83 (1993).). The present... more
Experimental results on a 1MA pulser suggest that axial magnetic fields can stabilize z-pinch implosions and enhance the compression ratio(S. Sorokin and S. Chaikovsky, Dense Z-Pinches, AIP Conf. Proc. 299, p.83 (1993).). The present theoretical work calculates the effects of an axial magnetic field on the plasma and field profiles in an imploding z-pinch. The initial mass configuration is an annular shell of krypton. The 1-D simulation model includes: resistive diffusion (skin effect) for both the azimuthal and axial fields, ionization dynamics, and non-LTE radiation transport. Unlike the constant pulser current of self-similar models for the screw-pinch, a transmission line is used to model the circuit of a realistic ~10MA pulser. The implosion dynamics resulting from an axial field generated by a twisted return current cage will be compared with results due to an initial field from external Helmholtz coils. The dependence of the radiative performance on compression ratio, which i...
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