SBIR-STTR Award

We propose to develop and validate a strongly-coupled non-equilibrium plasma simulation model. Strongly coupled plasmas occur in a wide range of physical situations impacting a wide range of research and development areas connected to Air Force technology. The simulation model proposed here is based on the particle-in-cell (PIC) methodology, which has recently been validated by the proposal authors against a well-established equilibrium model of two-component, two-temperature strongly-coupled classical plasma. Non-equilibrium coupled plasmas are associated with a number of Air Force high technology developments, including the background operating environment for space-based assets, electrical energy conversion into high power electromagnetic signals, and quantum information systems such as trapped ion and cold atom systems. Schemes for including charge-particle interactions including atomic physics processes will be evaluated and implemented in the code. Modifications of the basic simulation model to include some quantum mechanical effects will also be evaluated. Once validated, the model will be used to characterize the impact of strongly coupled plasmas in high-power electromagnetic fields for counter-directed energy, explosive blast situations, and space-weather effects on electronics.

Benefit:
The new modeling capability will assist the Air Force in efforts to characterize the impact of strongly coupled plasma in high-power electromagnetic fields for counter-directed energy, explosive blast situations, and space-weather effects on electronics. The new modeling capability offers the commercial prospects of a novel chemistry based on micro-plasma technology for environmental remediation, and for quantum information systems based on trapped ions for secure business transactions. Both of these applications have long term potential for new domestic business development.

Keywords:
Coupled plasma, Non-equilibrium plasmas, Particle-in-cell methodology, Molecular dynamics

Strong coupling in ionized plasmas occurs when inter-particle interactions result in correlation energies that are comparable to the mean kinetic energy of the thermal motion of individual particles. Strongly coupled plasmas are known to be present in a number of physical systems including ultra-cold plasmas created in the laboratory and present in the ionosphere, explosive gases associated with conventional munitions, and extreme conditions associated with high-energy ultrafast laser interactions with matter. The use of the electromagnetic (EM) particle-in-cell methodology (PIC) for modeling strongly coupled plasmas is an accurate model when the inter-ion spacing is resolved. The EM PIC approach offers features that complement existing models of strongly coupled plasmas and should give computational speeds comparable to or greater than other computational methods. A framework for integrating newly developed advanced algorithms into a simulation code capable of addressing plasma physics research topics that are not treatable with currently available simulation codes. Under a Phase II award, a complete computer code deployable on conventional parallel computer systems will be developed and validated against theoretical models.

Benefit:
Non-equilibrium plasmas are playing an increasingly important role in a number of Air Force high technology situations and strongly coupled plasma conditions occur in many of these technologies. For example, creation and evolution of non-equilibrium plasmas and the management of energy flow in high energy density situations (such as directed energy weapons) is integral to Air Force programs. Large-scale numerical simulation codes are required for the laser and high power microwave analysis of non-equilibrium coupled plasmas. However, the analysis of strongly coupled classical plasmas in the electromagnetic regime is currently limited to idealized equilibrium models. The software developed under this Phase II effort represents a significant new technique to analyze coupled plasma conditions, synergistic with Air Force technology programs. Potential commercial applications for this simulation tool include university research groups, various high-technology industries supporting Air Force research and development programs, as well as DoD and DoE research institutions. Applications for this simulation tool are wide ranging and include plasma reactor modeling, extreme states of matter, ionospheric communications, and quantum computing research.

Keywords:
Strongly coupled plasmas, Particle-in-cell simulation, Electromagnetic/plasma interactions, Ultra-cold plasma modeling, Explosive gas modeling, Finite-difference time-domain, ---------- The objective of this effort is to provide next generation plasma physics modeling tools for accurate simulation of phenomenology occurring in exceptionally wide-ranging states of matter.This modeling tool will enable scientists and engineers to design robust, reliable systems operating in the harsh environments of extraordinary temperature, density, and charge-states.These designs will support directed-energy, satellite, spacecraft and other DoD programs.Presently there is no accurate physics code which provides valid design solutions. Under Air Force SBIR/STTR Phase II and enhancement support, Voss Scientific is developing a novel plasma simulation code capable of evaluating plasma evolution across unprecedented spatial, temporal, and energy scales.Evolving out of strongly coupled plasma physics simulation work for modeling transport parameters, the CHICAGO simulation code is being developed to take advantage of the latest advanced high-performance computer systems utilizing co-processor accelerators.The code developed here will be a parallel, implicit electromagnetic, finite-difference time-domain, particle-in-cell code, with a three-level domain decomposition scheme for massively parallel computer architectures.CHICAGO is an innovative approach to seamlessly transition between different plasma regimes (quasi-neutral, multi-fluid, and kinetic) using a particle-based methodology which provides multi-scale plasma modeling capabilities.Initial application will provide a detailed understanding of space-based solar cell flashover phenomena.