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The IEEE International Conference on Plasma Science (ICOPS) is held annually, sponsored by the Plasma Science and Applications Committee (PSAC) of the IEEE Nuclear and Plasma Science Society (NPSS). The 45th IEEE NPSS ICOPS was held on June 24–28, 2018, in Denver, CO, USA. The conference's technical program included a wide range of topics, which ranged from basic and fundamental research to traditional and emerging technology applications. Over 530 accepted abstracts, representing scientists from over 30 countries. The program also included a minicourse on “New Directions in Plasma Diagnostics for High Energy Density and Burning Plasmas.” This year, the ICOPS sessions were enhanced by several exceptional plenary talks and two IEEE Birdsall award talks. John Cary from the University of Colorado (the 2016 Birdsall Award Winner) gave a talk entitled “The Evolution of Computational Physics,” and Alex Friedman from the Lawrence Livermore National Laboratory (the 2017 Birdsall Award Winner) spoke on “Computer Simulations of Plasmas and Beams: A View From Multiple Angles.” Other plenary talks covered areas that included: particle accelerator technology; challenges of high-energy density physics and inertial fusion; the physics, chemistry, and interactions of plasma with liquids; radiation belt remediation; and electron beams, plasmas, and EM fields and waves. [ABSTRACT FROM AUTHOR]

This paper deals with the challenges of railgun electromagnetic compatibility. After some general remarks on integration issues, the current regulations, norms, and standards of a high-power railgun are discussed. Different standards for ordnance or staff are considered. Also, preliminary results from the French-German Research Institute of Saint-Louis are presented. Since these laboratory data are not yet representative for future weapon systems, scaling calculations were carried out concerning energy levels, electrical sources, and cabling architecture. The obtained signal profiles are compared to the values defined by U.S., EU, or NATO standards. [ABSTRACT FROM AUTHOR]

Energetic electrons can be trapped in Earth’s magnetic field, forming the radiation belts (also known as the Van Allen Belts). These electrons, which can originate from the solar wind or a high-altitude nuclear explosion (HANE), have the potential to damage satellites in low-Earth orbit (LEO). For example, in 1962, the U.S. detonated a nuclear device at an altitude of about 400 km in the Starfish experiment. The resulting enhancement of the radiation belts disabled several satellites within a few months and energetic electrons remained in the radiation belts for up to several years. In order to address this potential vulnerability, schemes have been proposed to drain electrons from the radiation belts, with the most promising approaches based on using high-power very-low-frequency (VLF) waves to scatter the electrons into more field-aligned trajectories, forcing them to precipitate into Earth’s atmosphere. This paper will provide an overview of enhanced electron distributions in the radiation belts as well as approaches to VLF wave belt remediation including the use of either antennas or relativistic electrons beams in space to generate the VLF waves. [ABSTRACT FROM AUTHOR]

A magnetohydrodynamic model of irradiating Z-pinch is the basis of a 2-D (in Euler cylindrical coordinates r–z) computer code FLUX-rz developed in VNIIEF (Russia). Earlier, the code considered the thermal radiation transfer in one-group (gray) diffusion approximation. This paper presents a modification of the FLUX-rz code in which we realized a multigroup diffusion model of the radiation transfer. Efficiency of an improved algorithm has been demonstrated by sample calculations of Shot 52 and Shot 567 on Z-machine at Sandia National Laboratories (U.S.). [ABSTRACT FROM PUBLISHER]

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). NIF construction was certified by the Department of Energy as complete on March 27, 2009. NIF, a 192-beam Nd:glass laser facility, will ultimately produce 1.8 MJ 500 TW of 351-nm third-harmonic ultraviolet light. On March 10, 2009, a total of 192-beam energy of 1.1 MJ was demonstrated; this is approximately 30 times more energy than ever produced in an ICF laser system. The principal goal of NIF is to achieve ignition of a deuterium--tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy, and broader frontier scientific exploration. NIF experiments in support of indirect-drive ignition began in August 2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a national effort to achieve fusion ignition and is coordinated through a detailed execution plan that includes science, technology, and equipment. The equipment required for ignition experiments includes diagnostics, a cryogenic target manipulator, and user optics. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory, and the University of Rochester Laboratory for Energetics. The primary goal for NIC is to have all of the equipment operational, integrated into the facility, and ready to begin a credible ignition campaign in 2010. With NIF now operational, the long-sought goal of achieving self-sustained nuclear fusion and energy gain in the laboratory is much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step toward demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus the world's attention on the possibility of an ICF energy option. NIF experiments to demonstrate ignition and gain will use central-hot-spot (CHS) ignition, where a spherical fuel capsule is simultaneously compressed and ignited. The scientific basis for CHS has been intensively developed. Achieving ignition with CHS will open the door for other advanced concepts, such as the use of high-yield pulses of visible wavelength rather than ultraviolet and fast-ignition concepts. Moreover, NIF will have important scientific applications in such diverse fields as astrophysics, nuclear physics, and materials science. The NIC will develop the full set of capabilities required to operate NIF as a major national and international user facility. A solicitation for NIF frontier science experiments is planned for summer 2009. This paper summarizes the design, performance, and status of NIF and plans for the NIF ignition experimental program. A brief summary of the overall NIF experimental program is also presented. [ABSTRACT FROM AUTHOR]

Tests of up to three simultaneously firing 40-cm NASA's Evolutionary Xenon Thrusters took place at NASA Glenn Research Center. In addition to numerous engineering tests, the experiment was instrumented to measure plasma properties in the interacting plumes, charge exchange return current to the active and dormant thrusters, and current and plasma properties at various locations. This paper describes the use of Nascap-2k to calculate plume potentials and charge exchange ion return currents to active and dormant ion optics and to diagnostic probes. Calculations were performed varying the numbers of active thrusters, thruster power levels, and gimbaling. The results were extrapolated to space conditions. Despite several simplifying assumptions, we obtained good agreement with experimental results. No major problems associated with multiple thruster operation were found. [ABSTRACT FROM AUTHOR]

Jet Propulsion Laboratory (JPL) is currently assessing the applicability of the 25-cm Xenon Ion Propulsion System (XIPS) as part of an effort to infuse low-cost technically mature commercial ion thruster systems into NASA deep space missions. Since these mission require extremely long thruster lifetimes to attain the required mission ΔV, this paper is focused on understanding the dominate wear mechanisms that effect the life of the XIPS three-grid system. Analysis of the XIPS three-grid configuration with JPL's CEX3D grid erosion model shows that the third "decel" grid effectively protects the accel grid from pits and grooves erosion that is commonly seen with two-grid ion thruster grid systems. For a three-grid system, many of the charge-exchange ions created downstream of the grid plane will impact the decel grid at relatively low energies (~25 V), instead of impacting the accel grid at high energies (~200 V), thus reducing overall erosion. JPL's CEX3D accurately predicts the erosion patterns for the accel grid, although it appears to overpredict the pits and grooves erosion rates due, mainly, to uncertainties in incident energies and angles for sputtering ions and since it does not account for local redeposition of sputtered material. Since the model accurately simulates the erosion pattern but tends to overpredict the erosion rates for both the two- and three-grid sets, this comparative analysis clearly shows how the decel grid significantly suppresses the erosion of the downstream surface of the accel grid as observed in experimental tests. The results also show that the decel grid has a relatively small effect on barrel erosion (erosion of the aperture wall) and erosion of the upstream surface of the accel grid. Decreasing the accel grid voltage of the XIPS can reduce barrel (and total) erosion of the accel grid and should be considered for high-ΔV missions. [ABSTRACT FROM AUTHOR]

Tests of arcing and current collection in simulated-space-plasma conditions have been performed at the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) in Cleveland, OH, for over 30 years and at the Marshall Space Flight Center (MSFC) in Huntsville, AL, for almost as long. During this period, proper test conditions for an accurate and meaningful space simulation have been worked out, comparisons with actual space performance in spaceflight tests and with real operational satellites have been made, and NASA has achieved the authors' own internal standards for test protocols. It is the purpose of this paper to communicate the test conditions, test procedures, and types of analysis used at the NASA GRC and MSFC to the space environmental testing community at large, to help with international space-plasma arcing-testing standardization. Discussed herein are the neutral gas conditions, plasma densities and uniformity, vacuum chamber sizes, sample sizes and Debye lengths, biasing samples versus self-generated voltages, floating samples versus grounded samples, test electrical conditions, arc detection, preventing sustained discharges during testing, real samples versus idealized samples, validity of low Earth orbit tests for geosynchronous Earth orbit samples, extracting arc threshold information from an arc rate versus voltage tests, snapover, current collection and glows at the positive sample bias, Kapton pyrolysis, thresholds for trigger arcs, sustained arcs, dielectric breakdown and Paschen discharge, tether arcing and testing in very dense plasmas (i.e., thruster plumes), arc mitigation strategies, charging mitigation strategies, models, and analysis of test results. Finally, the necessity of testing will be emphasized, not to the exclusion of modeling, but as part of a complete strategy for determining when and if arcs will occur, and preventing them from occurring in space. [ABSTRACT FROM AUTHOR]

This paper is an observation of the Aurora Borealis, commonly known as the "northern lights" in Southern USA. This is only the second time in a century has this rare spectacular event occurred in the observed location. [ABSTRACT FROM AUTHOR]