Tech-X Corporation Federal Contracts
Tech-X Corporation uniquely combines object-oriented software, grid-based middleware, simulation and modeling, and massively parallel computing expertise to assist customers in solving the most difficult scientific problems.
Projects
Active Federal Contract Projects are listed alphabetically by title.
Accelerating Large-Scale Beam Dynamics Simulations with GPUs (DE-SC0004585) |
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The Advanced Photon Source (APS) at Argonne National Laboratory (ANL) is a third-generation, high-brightness, 7 GeV storage-ring-based x-ray light source that has been in operation since 1996. Several possible long-term upgrades to the APS are investigated at Argonne, including an ERL- based upgrade and an Ultimate Storage Ring (USR), both of which could provide more than two orders of magnitude improvement in brightness over the existing APS. In the near term, Argonne is pursuing an APS upgrade project known as the APS Renewal, aiming at improvements through upgrades of beamline optics, detectors, and end-station equipment. Intensive computation is a pivotal aspect of this accelerator modeling and optimization effort, and significant acceleration of already existing computational tools used for this work will allow to explore a wider range of parameters and produce optimal designs in less time and at lower cost. Particle accelerator code ELEGANT has been used extensively for the APS upgrade work, as well as for numerous other light source design and optimization projects in the United States and abroad. We propose to develop an optimized, benchmarked set of CUDA kernels and drivers for GPU-accelerated simulation of beam dynamics with ELEGANT. We expect that this will translate into roughly an order of magnitude speedup of the most time consuming simulations such as tracking-based dynamic and momentum aperture optimization. We will closely collaborate with the ELEGANT code developers to ensure the optimal usage of the new capabilities. |
PI: Ilya Pogorelov |
Accelerating PETSc through Next-Generation, Heterogeneous Supercomputing (DE-SC0004439) |
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It is often found that seemingly distinct computational codes in fields such as biology, engineering, and physics confront the same issues and bottlenecks. Indeed, one of the more typical computations found across these distinct fields is the solution of sparse-linear systems such as those arising in the discretization of elliptic and/or parabolic partial differential equations. However, this computation can severely hinder the scientists' ability to solve bigger and harder problems if not properly implemented. Moreover, this problem becomes all the more pernicious as the computing facilities evolve from the traditional homogenous super-computers composed of tens to hundreds of thousands of processors of the same type to heterogenous systems composed of massively parallel processors (MPPs), i.e. accelerators such as Cell, GPU, Larrabee, and FPGA, coupled to traditional CPU nodes. Currently though, many commonly-used libraries for tackling this computation and of importance to the DOE cannot make use of these emerging heterogeneous petascale architectures. We propose to develop implementations/interfaces of Krylov algorithms associated with solving sparse linear systems on the most ubiquitous and easy-to-use, heterogenous computing architectures: multi-GPU machines. Our main goal is to develop an interface between the core algorithms that reside on the accelerator with the PETSc (Portable, Extensible Toolkit for Scientific Computation) library so that this new capability can be used transparently by a scientist. In particular, we will develop parallel-GPU sparse matrix-vector products and triangular matrix inversions based on the most recent developments in the literature. Moreover we will port the techniques to run on the most recent GPU architectures. In addition, we will attempt to optimize other bottlenecks in the algorithms and also hide the data transfer costs using kernel splitting techniques. |
PI: Paul J Mullowney |
ACCESS: ACCelerator of Electromagnetic Scattering Simulations (N68335-10-C-0394) |
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Determining the scattering properties of small boats on a rough sea surface is a problem of high importance to the Navy. Due to the conducting nature of the surrounding water, the scattering signature of the boat cannot be determined just from a geometrical model in vacuum, but requires the simulation of its environment as well. The resulting simulations require large amounts of memory and computing time and innovation is required to accelerate these simulations. During Phase I, we demonstrated that graphics processing units (GPUs) can be used to accelerate a key algorithm for electromagnetic scattering simulations, a parallel out-of-core dense solver, by at least an order of magnitude. Based on inferred scaling laws, we expect this speedup to be maintained for systems beyond 1,000,000 unknowns. The Phase II project will be split into a base and an option period. The goal of the Phase II base period is to incorporate the GPU accelerated solver into the widely used electromagnetic modeling code WIPL-D. In addition, we will investigate GPU acceleration of the matrix-fill part. In the Phase II Option period we will then investigate the suitability of GPUs to accelerate a more approximate method, the fast multipole method. This project will result in a hardware accelerator for electromagnetic scattering simulations based on off-the-shelf components. This accelerator will enable researchers to perform simulations that took moths within a few days. Electromagnetic scattering simulations, antenna simulations or microwave circuit simulations are widely used within DOD and other government agencies, as well as in industry. The resulting accelerator is therefore expected to be of interest to a broad customer base. |
PI: Travis Austin |
Analysis of RF Heating of Fusion Plasmas Using the Delta-f Particle-in-Cell (DFPIC) Method (DE-FG02-07ER84722) |
Critical to the US fusion program is the ability to assess the efficacy of radiofrequency heating and current drive in fusion plasmas. At present, the primary means of assessment is through use of full wave codes that assume linearity and quasi-local plasma response. Needed are computational methods for addressing the effects caused by the fact that the curvature of particle orbits can be large. The proposed project includes the development and application of delta-f particle-in-cell methods to toroidal plasmas, with the goal of developing analysis methods that apply to low-frequency (ion time scale) phenomena. The project will implement linear delta-f for the ions along with a reduced model for the electrons in R-Z geometry that will eliminate the fast time scales from the problem. This new simulation tool will be used to study physics at the ion time scale and to examine the effect of heating in such tokamaks as NSTX and ITER. |
PI: Travis Austin |
Analyzing and Visualizing Next Generation Climate Data (DE-FG02-08ER85153) |
The continuous effort to improve global warming predictions has led numerous computer climate models to abandon longitude-latitude grids in favor of assemblies of structured meshes. These novel “Mosaic” grids exhibit complex folding patterns, which are posing severe problems to postprocessing and visualization applications (e.g. CDAT). We are developing the Mosaic Data Analysis and Visualization Extension (MoDAVE) software package in order to allow postprocessing applications to correctly interpret data on large Mosaic grids. We use the Gridspec format developed at the Geophysical Fluid Dynamics Laboratory to encode the connectivity between equi-resolution sub-grids (tiles), and flux conserving expressions for other cases. |
PI: Alex Pletzer |
Capillary discharge modeling to improve high gradient advanced accelerators (DE-SC0004433) |
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A main priority for the Office of High Energy Physics is the development of advanced accelerator concepts, such as laser-driven, plasma-based accelerators. Illustrating this priority is the recent funding of the BELLA project. An important part of the BELLA project will be the capillary discharges that form the meter-scale plasma source, and understanding these discharges in detail will be critical to the success of BELLA. Researchers have used computer modeling to help understand the capillary plasma properties, however, current modeling tools are not adequate. In particular, no tool exists that can handle important physics effects such as diffusion and Ohm's law, can handle general magnetic field geometries, including applied solenoidal fields, and can perform calculations in multi-dimensions. The goal of this work is to help researchers improve their understanding of the properties of capillary plasma sources by providing a new, state-of-the-art modeling tool. This new tool will expand on previously successful models to include important new physics effects, such as diffusion and a detailed Ohm's law. Further, this tool will be flexible enough to model multiple geometries in multiple dimensions, and including the effects of general magnetic field geometries, including the effects of externally imposed axial magnetic field, which is under consideration as an approach to regulate heat transport in the capillaries and hence provide greater flexibility in the guiding properties to tune BELLA stages. |
PI: Peter Stoltz |
Center for Extended Magnetohydrodynamic Modeling (DE-FC02-08ER54972) |
The proposed work aims at further developing the world’s most powerful simulation codes for studying the macroscopic dynamics of MHD-like phenomena in fusion plasmas, and using them on the most advanced computers to address critical issues facing burning plasma experiments such as ITER. Our 8-institution Center has existed since June 2001. It has already pioneered simulations that have shed new insight in many different application areas and has demonstrated that the algorithms in its major codes can scale to 1000s of processors. We have developed excellent working relationships with the SciDAC applied math and computer science centers TOPS, ITAPS, and APDEC; these collaborations have substantially improved the algorithms and efficiency of our leading tokamak global codes, NIMROD and M3D, and have facilitated the development of a new code, AMRMHD, utilizing adaptive mesh refinement. The physical problems we propose to focus on are: sawteeth, sawteeth in the presence of energetic particles, excitation and control of neoclassical tearing modes, resistive wall modes, disruptions, edge localized modes, error field studies, and pellet fueling. |
PI: Scott Kruger |
Center for Simulation of Wave-Plasma Interactions with Magnetohydrodynamics (DE-FC02-06ER54864) |
The proposed work will build upon the successes of the DOE SciDAC programs by taking several of the most advanced fusion computer codes, combining these to provide a unique tool in the worldwide fusion program, and implementing them on the Leadership-Class and other computing facilities. This will be done in concert with the computer science and math communities in such a way that the software framework we form will lay a foundation for even more powerful and comprehensive simulations in the future. Intense radio-frequency waves provide an essential control technique for fusion grade tokamak plasmas. The frequency and phasing of these waves can be adjusted using precision control so as to keep the plasma in a quiescent state, significantly improving its quality as a confinement device and greatly reducing the likelihood of a catastrophic disruption. The work described here is aimed at providing an essential design tool for such a control system. The framework will allow for the treatment of two regimes of potential plasma global instabilities: fast phenomena and slow phenomena. In the first, the wave fields act only indirectly on the instabilities by modifying the background equilibrium, while in the second they act directly by competing with the instability drive terms. We will work with the community to develop standards and documented APIs for fusion application modules which will allow the incorporation of many of today’s fusion application codes into this framework. |
PI: Scott Kruger |
ClimateXplorer: Serving climate data to industry end-users |
Global temperatures are predicted to rise by 2 to 5 °C over the next hundred years. Thus, climate change represents a formidable challenge for multiple sectors of the US economy, including health, agriculture, transport, energy, real estate, water resources management, and tourism. In order for these sectors to adjust, each economic player will need to make informed decisions based on predictions for global warming. The best climate prediction data available today are the result of running multiple coupled atmosphere-ocean computer models under various greenhouse gas emission scenarios. These data are stored at web portals (e.g. http://www-pcmdi.llnl.gov). However, climate prediction data have found little use so far beyond climatology due to access restriction and the difficulty of translating raw climate data to data that are meaningful to industries. Given that restrictions to the access of climate prediction data will be removed, the challenge of reducing terabytes of stored data to a small set that can be transformed to meet commercial customers' needs remains. We propose to develop software (ClimateXplorer) that consumes raw climate data and produces derived data relevant to to specific industries and agencies, such as solar insolation for solar power, snow cover for water management and precipitation for agriculture. Data will be accessed using a web protocol and combined with Google Maps and other web services to provide regional predictions. Visualization techniques capable of representing the uncertainties associated with multi-model and multi-scenario datasets will be explored. |
PI: David Filllmore |
Common Component Architecture for Electron Cloud Accelerator Simulations (DE-FG02-08ER85152) |
Electron cloud generation is one of the most scientifically important effects relating to the dynamics of particle beams. The build up of an electron cloud is a potentially limiting factor in the performance of both high-intensity electron and proton machines. Electron cloud simulation presents computational challenges in that the number of particles required in simulation is large and because efficient code coupling of beam physics with electron cloud generation code is required. The modeling of electron cloud effects is important for high energy accelerators and the Fermilab main injector. In the case of the Fermilab main injector, electron cloud effects are expected to play a significant role when the main injector operates in the regime of a high-intensity proton source for the neutrino program. Computational accelerator physicists would like to be able model electron cloud generation and beam dynamics in a single self-consistent simulation. We will provide accelerator components that can be used to compose electron cloud simulations on leadership-class supercomputing hardware. Our approach of applying performance analysis and modeling will enable the most efficient use of available resources while addressing portability and usability will ensuring a broad use of the developed accelerator components. |
PI: Nanbor Wang |
Computational and Data Analysis System for Multi-Technique Rapid Tomography Reconstruction and Quantification Processing (DE-SC0004586) |
Software for rapid image processing and 3D tomography reconstruction is needed for large-scale neutron and x-ray facilities such as the Spallation Neutron Source (SNS) and High Flux Isotope Reactor (HFIR) located at Oak Ridge National Laboratory (ORNL) and the Advanced Photon Source (APS) located at Argonne National Laboratory (ANL). The SNS can offer novel imaging methods as well as significant improvements on existing methods by using its high peak flux capabilities as well as neutron time-of-flight techniques can offer easy and cost-efficient access to energy-selective imaging. But these techniques are not available or beyond the scope of available tools. Furthermore, the planned advancements provided by the application of Graphics Processing Units (GPUs) for neutron scattering are also applicable for x-ray scattering. We propose the open-source Rapid Image Processing and Quantification (RIP+Q) Toolkit project to provide a solution for Neutron Computed Tomography, rapid image processing, and hybrid neutron and x-ray imaging system for neutron imaging at the ORNL and ANL. The goal is to use the SNS and HFIR for development and testing of the RIP+Q Toolkit, which will leverage existing software and tools in conjunction with state-of-the-art GPU processor technologies for fast image analysis and 3D tomography reconstruction. In achieving the project goals, not only will the scientists have the ability to visualize their data more rapidly, but they will also be able to quantify contrast optimizations made possible by time-of-flight information from the pulsed neutron source. |
PI: Mark L. Green |
Customizable Web Service for Efficient Access to Distributed Nuclear Physics Relational Databases (DE-FG02-07ER84757) |
An increasing fraction of the data generated in Nuclear and High-Energy Physics (HENP) is managed in distributed and relational databases. As the size of this data grows and the collaborative nature of HENP experiments increases, the ability to access differently organized relational databases remotely, efficiently and yet in a user-friendly and interoperable manner is becoming very important. HENP community lack tools addressing this need and accommodating related challenges. Tech-X proposes to develop a customizable Web Service for efficient access to distributed Nuclear Physics (NP) databases. The proposed system will consist of a generic Web Service for accessing arbitrary distributed relational databases, a reference client implemented for the Solenoidal Tracker at the RHIC (STAR) experiment at Brookhaven National Laboratory (BNL), and a tool for creation of the high-level and domain-specific clients required by particular applications. |
PI: Mark L. Green |
Data Filtering and Assimilation of Satellite Derived Aerosol Optical Depth (NNX10CB46C) |
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Satellite observations of the Earth often contain excessive noise and extensive data voids. Aerosol measurements, for instance, are obscured and contaminated by clouds, possible only on the sunlit side of the globe, and difficult over bright land areas. We propose to extend filtering and data assimilation techniques for satellite derived aerosol optical depth based on the wavelet transform. The assimilation system is based on the Model for Atmospheric Transport and Chemistry (MATCH) and include improvements such as the incorporation of satellite observed aerosol size modes and column water vapor. Initially we will focus specifically on aerosol measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments flying on the Terra and Aqua satellites. The assimilated fields will be tested against surface network observations of aerosol optical depth. We will employ the assimilation assimilation system to produce aerosol datasets for application in Earth radiation budget observations and atmospheric correction methods. Phase II will produce an enhanced daily global aerosol dataset that will be provided to the Clouds and the Earth's Radiant Energy System (CERES) project as an input to the the Surface and Atmosphere Radiation Budget (SARB) subsystem. This dataset will be based on the assimilation of the MODIS Collection 5 Level 2 Aerosol Product, and span the time period starting with the launch of Terra. This work will be continued for the next generation instruments that will replace MODIS and CERES; respectively, the Visible-Infrared Imager Radiometer Suite (VIIRS) and the Earth Radiation Budget Sensor (ERBS), which will fly on the tri-agency National Polar Operational Environmental Satellite System (NPOESS) and the NPOESS Preparatory Project (NPP) satellite. |
PI: David W. Fillmore |
Designing a Coherent Electron Cooling System for High-Energy Hadron Colliders (DE-FG02-08ER85182) |
The orders-of-magnitude higher ion luminosity required for a future electron-ion collider (EIC) requires cooling of the ion beam. For polarized protons, the only known approach that could work is electron cooling. An exciting concept known as “coherent” electron cooling (CEC) combines the best features of electron cooling and stochastic cooling, via free-electron laser (FEL) technology, to enable the cooling of >250 GeV proton bunches and other high-energy hadron beams with order-of-magnitude shorter cooling times. The CEC concept is unproven and requires detailed simulation of its key components. |
PI: David Bruhwiler |
Examination and Significance of Sparse Preconditioners for High-Order Finite Element Systems (DE-FG02-08ER85154) |
Hundreds of millions of dollars have been committed towards the study of complex natural phenomena on today's massively parallel computers. Access to such computing power is enabling scientists to employ highly-accurate high-order finite element methods to solve previously intractable problems. However high-order finite element methods present new challenges to existing solution methods since the corresponding matrices have fundamental differences and also yield higher memory consumption. A common approach to solving large matrix problems is to use an algebraic mulltigrid preconditioner to improve the effectiveness of the iterative method. Using algebraic multigrid preconditioners for high-order finite element problems yields a preconditioner that requires a large amount of memory. In this work, algebraic multigrid preconditioners generated from sparser matrices than the dense matrices generated from high-order finite elements will be considered as cheaper alternatives to the algebraic multigrid preconditioners generated from high-order finite element matrices. The sparser matrices will have sparsity patterns equivalent to trilinear finite elements on a mesh constructed from the Gauss nodes of the high-order finite element basis functions and yield preconditioners with robust performance for many problems. |
PI: Travis Austin |
Extending Chombo with PETSc (DE-SC0000837) |
Among the most challenging problems in computational physics are elliptic equations with vastly different spatial and temporal scales. The block structured Adaptive Mesh Refinement (AMR) technique is particularly amenable to such problems, combining the benefits of “classical” finite difference/finite volume discretization in terms of efficiency, with the advantage of locally increased resolution where needed. The Chombo software infrastructure has been developed for users in need to apply AMR to problems ranging from magnetohydrodynamics to combustion, and has proven to be 1-2 orders of magnitude more efficient than standard finite differences. However, there are problems where Chombo’s built-in linear solvers encounter convergence difficulties, particularly in regimes where time steps are large and heat conductivity, electric resistivity, and/or viscosity have strong spatial variation, as in fusion devices. We propose to extend Chombo so as to allow users to invoke linear matrix solves implemented by the Portable, Extensible Toolkit for Scientific (PETSc) library. PETSc is the leading library for sparse matrix solves, offering a large choice of direct and iterative solver algorithms. In Phase I, we demonstrated a multi-grid interface to solvers that is more robust than the native Chombo geometric multi-grid solver (without line relaxation or semi-coarsening), and have shown that PETSc/Hypre-BoomerAMG solves can produce high performance without sacrificing robustness. In Phase II we will implement high performance C++, multi-grid/multi-block matrix assembly code for Poisson type operators. This will allow Chombo to interface with all available PETSc solvers and preconditioners. |
PI: Alex Pletzer |
Framework Application for Core-Edge Transport Simulations (DE-FC02-07ER54907) |
This project will provide a multiphysics, parallel framework application, FACETS, that will enable whole-device modeling for the U.S. fusion program, and provide the modeling infrastructure needed for ITER, the next step fusion confinement device. FACETS will be highly flexible, through use of modern computational methods, including component technology and object oriented design, to facilitate switching from one model to another for a given aspect of the physics. This will enable use of simplified models for rapid turnaround or high-fidelity models that will take advantage of the largest supercomputer hardware. FACETS will do so in a heterogeneous parallel context, where different parts of the application will take advantage through parallelism based on task farming, domain decomposition, and/or pipelining as needed and applicable. An integral part of the FACETS development will be the coupling of existing core and edge simulations, with the transport and wall interactions described by reduced models. Adding more detailed wall interactions will follow. In the out years, we will bring in greater coupling complexity, including the addition of near-first-principles computations of turbulent transport in the core and the edge. This development plan was created to provide early delivery of capability, with continual delivery of new capability throughout the project. A strong, interdisciplinary team of computational physicists, applied mathematicians, and computer scientists has been assembled for this project in order to address the issues of physics model construction, dynamical systems coupling and solving, and software methodologies and application performance. |
PI: John Cary |
GPU Acceleration of Spin Tracking in Colliding Beam Accelerators (DE-SC0004432) |
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To elucidate the mysterious origins of nuclear spin, the Nuclear Science Advisory Committee (NSAC) has identified the science of electron-ion colliders, and, specifically, the proposed polarized electron and ion collider, as “absolutely central to U.S. science.” These machines, estimated to cost as much as 500M – 1B, will require highly polarized particle beams. To reduce the risk associated with building these machines, scientists need accurate simulations of spin dynamics in colliding beam accelerators. However current spin tracking technology takes many hours to track an ensemble of particles across a single resonance in RHIC. We have demonstrated an eighty-fold speed-up in simple spin dynamics simulations just by using Tech-X's high-level library of GPU algorithms (GPUlib). Previous work by Tech-X has revealed the importance of handling thick element spin tracking correctly for accurate RHIC simulations. We plan to develop these algorithms further and use them to enhance the speed and capabilities of a code that is currently used to model spin dynamics. This will put into the hands of DoE scientists an essential tool they need for performing fast and accurate simulations of spin-polarized particle beams. We will develop algorithms and code that take advantage of the highly-parallel and relatively inexpensive computing power of modern graphics processing units (GPUs). In particular, we will prototype GPU kernels for the simultaneous tracking of both orbital and spin degrees of freedom, as well as higher-order symplectic tracking through thick spin elements. |
PI: Vahid Ranjbar |
Gyrotron Design and Evaluation using New Particle-in-Cell Capability (DE-SC0004436) |
ITER will depend on high power CW gyrotrons to deliver power to the plasma at ECR frequencies. However, gyrotrons can suffer from undesirable low frequency oscillations (LFOs), which are known to interfere with the gun-region diagnostics and data collection, and are also expected to produce undesirable energy and velocity spread in the beam. The origins and processes leading to these oscillations are poorly understood, and existing gyrotron R&D tools, such as static gun solvers and interaction region models, are not designed to look at time-dependant oscillatory behavior. We are proposing the application of a time-domain particle-in-cell method to address the LFO problem. Our company is at the forefront of smooth-curved-boundary treatment of the electromagnetic fields and particle emission surfaces, and such methods are necessary to simulate the adiabatically trapped and reflected electrons thought to be driving the oscillations. This approach provides the means for understanding in microscopic detail the underlying physical processes driving the low-frequency oscillations. In order to establish the feasibility of simulating LFO physics with this tool on office-scale and larger, parallel cluster computers, an electron gun region from an existing gyrotron, known to observe LFOs, will be selected as a proof-of-principle geometry. The tool will be used to investigate the trapped and reflected electron population behind the LFO phenomenon, both in terms of its origins, and in terms of the particle life cycle within the population. Several candidates for the origin of the electron population will be evaluated in turn, including non-uniform emission with temperature spread, both physical, and geometrically induced, and space charge effects. The goal is to be able to reproduce observed experimental variations with gun voltage, current, and LFO mitigation schemes, and predict LFO behavior in future gyrotrons. |
PI: Ming-Chieh Lin |
High Fidelity Simulation of Low-Energy Ion Beam Chopping for the Spallation Neutron Source (DE-SC0000844) |
The parallel simulation framework VORPAL will be used to simulate H- ion beam transport experiments being planned as part of the long-term SNS power upgrade project at Oak Ridge National Lab (ORNL). The Phase I project will use data from the planned experiments to validate the utility of the simulations, including complicated electrode geometries and impact ionization physics, and perhaps provide useful insights to the experimental program at ORNL. In Phase I, it was demonstrated that the parallel VORPAL framework can model all key aspects of chopping in the ORNL LEBT design: 3D electrostatic particle-in-cell (PIC), complex 4-quadrant chopper geometry and radio frequency quadrupole (RFQ) entrance, gradual build-up of background ion plasma, converging ion beam with initial phase space taken from ORNL specifications, and external solenoidal magnetic field. The design potentials were applied to the chopper quadrants with specified rise and fall times and the beam steering angle was verified, while strong plasma dynamics were observed. In Phase II, all possible avenues for beam-plasma instabilities will be explored over multiple time scales: electron plasma frequency (very fast), ion plasma frequency (fast) and rf chopper frequency (slow). Previous experiments and present intuition suggest that problems are occurring on the slow time scale, for which a fast Boltzmann electron model will be used. Code validation and experimental support during LEBT design and commissioning are planned. |
PI: David Bruhwiler |
High-Fidelity Modulator Simulations of Coherent Electron Cooling Systems (DE-SC0000835) |
The modulator of a CEC system is similar to a conventional electron cooling system, with copropagating ion and electron beams. The key physics to be simulated is the coherent aspect of the electron density and velocity wake created by each ion. This is an extremely subtle and difficult problem to solve – previous simulation efforts have proved only marginally successful. The parallel VORPAL framework, which has successfully simulated the underlying physics of conventional electron coolers, will be used to test the utility of novel algorithms, such as full 3D Vlasov-Poisson and delta-f particle-in-cell. In Phase I, prototype 1D1V and 2D2V Vlasov-Poisson models were implemented in VORPAL. Vlasov and f-PIC simulations of Debye shielding were shown to agree with each other and, for Lorentzian electron velocity distributions, with theory. A low-order Vlasov update enables future hybrid use with other algorithms and efficient parallelization. In Phase II, a general multidimensional (1D1V, 1D2V, 1D3V, 2D2V, 2D3V) Vlasov algorithm will be implemented in the parallel VORPAL framework, designed to work in hybrid mode with other VORPAL algorithms, such as PIC and fluid. The f PIC algorithm and Poisson solver will be further improved. The integrated GUI that is being developed for ease of use and state-of-the-art 3D visualization, known as VORPAL Composer, will be generalized to work with the higher-dimensional Vlasov grids. VORPAL Composer will also be generalized to work with GENESIS 3.1 and to manage code coupling and processing that is required for the very specialized modeling of coherent electron cooling systems. Parametric models for the effective velocity drag will be developed or generalized to account for various real-world effects. We will provide computational support for design and commissioning of the CeC experiment at BNL. |
PI: David Bruhwiler |
Integrated Multiple Effects Software for Nuclear Physics Applications (DE-FG02-08ER85184) |
Design, analysis, and computer modeling of hardware for nuclear physics accelerators is a complex process, usually involving different software for different physical aspects of the same hardware. In one of the most important examples of this, electromagnetic modeling of RF sources, waveguides, couplers, and cavities is handled by one piece of software, while heat load analysis of the same components is handled by completely different software. The modeling and analysis of this hardware is a critical task since cooling requirements are a main driver of the overall cost of a superconducting rf cavity system. Using separate software tools for modeling of the same hardware has several disadvantages, including: a) duplicative efforts in terms of specifying the same hardware in different software packages, b) difficulties in moving data from one package to another, c) the complexity of the design and analysis iteration cycle, d) and the overall speed of the design cycle. Furthermore, there is strong desire to have the design cycle functioning on modern parallel computing architectures, which can be difficult if using legacy software. Tech-X has been developing multiple effects software, VORPAL, which is designed for modern parallel computing platforms. It is a leading electromagnetic particle simulation code, with demonstrated capabilities in accelerator component modeling, charge-particle simulation, fluid simulation, and plasma modeling. However, missing from its capabilities is thermal and temperature analysis. New multi-purpose field analysis techniques recently introduced into the software permits rapid development and deployment of the desired thermal modeling capability. |
PI: David Smithe |
Integrating Scientific, Grid, and Cloud Computing Infrastructures (DE-SC0004583) |
Although powerful, the Grid has not provided the level of service needed for their efficient use by a majority of scientists. One of the problems of the Grid is an uncertain execution environment where a significant investment of labor is required up front to verify and validate complicated applications only to reap disproportionate and minimal rewards at execution time. Scientists and Virtual Organizations, specifically Compact Muon Solenoid (CMS), working to scale-up usage of their Grid-enabled applications on national Grids, need a means to identify and understand the reasons for the workflow failures that occur while executing their application on the Grid. This project provides an alternative approach such that application managers can work in a local known environment that can be managed efficiently; this will significantly reduce the amount of time and effort required to Grid-enable complex scientific applications. We seek to combine the “best” aspects of both Grid and Cloud computing paradigms into a Grid Cloud Computing Service (GCCS). Since the communities have already built substantial Grids (i.e. Open Science Grid (OSG), Worldwide LHC Computing Grid (WLCG), cancer Biomedical Informatics Grid (caBIG), Geosciences Network (GEON), Earth System Grid (ESG), New York State Grid (NYSGrid), TeraGrid, etc.) the GCCS will be of immediate benefit to these Grids by providing a homogeneous execution environment completely under the control of the scientific application developer. In collaboration with the Open Science Grid, CMS experiment, and Condor project, we will provide a general solution for more effectively utilizing the Grid. |
PI: Mark L. Green |
Inverse Cyclotrons for Intense Muon Beams (DE-FG02-08ER85044) |
Statement of the problem or situation that is being addressed: Intense muon beams are sought for their role in the future of both the high-energy and medium-energy physics programs at national labs, such as BNL and Fermilab. Inverse cyclotrons are a promising alternative to more expensive methods of cooling muon beams, but their ability to cool intense muon beams is untested. We will provide to the muon beams community a software suite capable of providing a complete, end-to-end simulation of an inverse cyclotron. It is uncertain what the acceptance of such a device is for intense muon beams or what kind of losses can be expected. We will develop the particle-in-cell (PIC) code VORPAL to perform detailed simulations of the entire inverse cyclotron, from injection to extraction and initial re-acceleration. |
PI: Kevin Paul |
Modeling and Optimization of Electron Emission from Diamond Amplifiers (DE-SC0004431) |
The Relativistic Heavy Ion Collider (RHIC) in the Brookhaven National Lab (BNL) contributes fundamental advances to nuclear physics by colliding a wide range of ions. A novel electron cooling section, which is a key component of the proposed luminosity upgrade for RHIC, requires the acceleration of high-charge electron bunches with low emittance and energy spread. Experimental measurements in BNL have recently demonstrated the emission of amplified electron beams from diamond. However, there is no available code to accurately model the emission process for investigation of diamond photocathodes via computer simulations. Generation of secondary electrons and charge transport in bulk diamond can now be simulated with the three dimensional, particle-in-cell (PIC) code VORPAL. However, it lacks algorithms for modeling surface effects and electron emission from diamond-amplified photocathodes. We will develop and implement software code for modeling of electron emission from diamond surfaces with negative electron affinities within the VORPAL Computational Framework to enable end-to-end simulations of diamond-amplified photocathodes coupled to electron guns. |
PI: Dimitre A. Dimitrov |
Modeling of Diamond Based Devices for Beam Diagnostics |
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Beamlines at new light sources, such as the National Synchrotron Light Source II (NSLS II) will operate at ux levels beyond the saturation level of existing diagnostics, necessitating the development of new devices. Currently, there is no detector which can span the entire ux range that is possible even in a second generation light source and will become crucial for next generation light sources. One new approach is a diamond-based detector, that will be able to monitor beam position, ux and timing, at ux levels at least two orders of magnitude greater than a conventional detector, however, the successful development of the detector requires thorough understanding and optimization of the physical processes involved. The VOPRAL particle-in-cell (PIC) code can already be used to model charge transport in bulk diamond at a range of electric fields but requires the development of new models to simulate high-photon ux phenomena for investigation of diamond beam monitors. We will implement algorithms, within the VORPAL PIC code to enable integrated simulation capabilities for generation of electron-hole pairs due to absorption of photons, charge transport at high photon uxes, collection efficiency, charge trapping, injection, and time response in diamond. |
PI: Dimitre A. Dimitrov |
Modeling of Signal Generation in Gamma-Ray Detectors (DE-FG02-07ER84758) |
Gamma ray detectors are widely used devices in nuclear physics research. The GRETINA gamma ray detector significantly improves upon existing technologies like Gammasphere due to its novel segmentation design, however much work is needed in order to maximize its full capabilities. In particular, there are problematic regions on the detector that could strongly benefit from high fidelity computational modeling. We will develop accurate bulk- and surface-transport models of charged carriers as well as codes for computing the electric fields in the GRETINA crystals. Moreover, we will focus our efforts on poorly understood regions of the devices such as the passivated surface where the measured signals are highly pathological. These developments will yield a more accurate set of basis signals from which one can efficiently determine the location of gamma ray events. Ultimately, this will vastly improve the performance of these detectors. During Phase I, Monte Carlo models of charged carrier bulk-transport were developed. In addition, we identified several refinements which can significantly improve our bulk- and surfacemobilities in the GRETINA crystal. We also developed prototype codes for computing the electric field in the entire crystal. Our codes reproduce results from commercially available software. During Phase II, we will extend our Monte Carlo transport code to more accurately model transport in the crystal bulk. Then, we will implement methods for computing surface carrier transport on problematic passivated surfaces. Simultaneously, we will extend our field calculation code to incorporate more realistic boundary conditions. The new computational infrastructure will then be used to understand the surface physics of the GRETINA detectors. In particular, we will use hypothetical surface charge distributions to create a new set of basis signals to which we will compare the experimental measurements. We will develop a procedure for inferring unknown surface characteristics from the quality of the matches between simulated signal basis sets and the experimental signals. |
PI: Paul Mullowney |
Multipaction Mitigation Simulator for Satellite Applications (N66001-11-M-5101) |
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Multipaction is known issue with radio frequency components used in satellite systems like diplexers. The mitigation of this multipaction is an important step in the design and development process for these components. Numerical simulation can play an important role in testing current mitigation techniques such as magnetic insulation and surface treatments, as well as assist in the development of new mitigation techniques. We propose to develop a new multipaction mitigation simulation tool based on the electromagnetic plasma code VORPAL. By mitigating multipaction in radio frequency devices, our software will improve the overall efficiency and performance of these devices. These benefits could be applied across many other Navy programs as well as programs in other branches of the DoD. The addition of multipaction mitigation creates opportunities for VORPAL in other areas as well, including civilian radio frequency devices. |
PI: Chet Nieter |
Next-Generation Ion Thruster Design Tool to Support Future Space Missions (NNX10CF60P) |
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Computational tools that accurately predict the performance of electric propulsion devices are highly desirable by NASA and the broader electric propulsion community. Large investments in running the long duration test programs (> 20 kHrs) at NASA GRC can be> reduced with computer models and allow more focus on exploring the NEXT ion thruster design for future space missions. The current state of electric propulsion modeling relies heavily on empirical data – frequently taken directly from the device of interest – and relies on numerous computational “knobs.” A self-consistent particle model that minimizes the number of free parameters used in thruster modeling, and allows accurate electric thruster simulations is desired. We propose a kinetic model that simulates the dynamic electric fields inside the NEXT ion thruster discharge chamber plasma. This will be the first time that this has been done. In addition kinetic erosion models will be used for modeling the ionimpingement effects on thruster components. We envision one seamless model of the plasma from emission within the hollow cathode to ejection to outer space in the exhaust plume. This model will help NASA GRC to predict the lifetime operation of the high power ion propulsion options for earth-orbital applications. The off-the-shelf ion thruster discharge chamber computational tools should reduce the time spent by NASA employees developing these tools for electric propulsion systems such as the 40-cm diameter NEXT thruster. The easy-to-use and user-friendly graphical user interface plasma software from Tech-X are viable high performance modeling tools for NASA to study the current and future electric thruster concepts which will help their planning for future space missions. Also these tools can be applied to modeling Hall thrusters such as the HiVHAC thruster, which is currently being developed at NASA GRC. The fully electromagnetic capabilities in these codes make them an ideal tool for modeling cathodeless RF ionization schemes as well. |
PI: Sudhakar Mahalingam |
NIMROD Development and Application for Advanced Simulations of Tokamak Plasmas (DE-FC02-04ER54875) |
Low-frequency, long-wavelength instabilities in tokamak plasmas remain a challenge for theoretical understanding. The most challenging problems; for example, plasma shaping effects; are difficult to study analytically and require a numerical treatment. Because of the temporal and spatial scales, fluid models remain the most effect approach for computational modeling of these instabilities. The efficacy of the fluid model for modeling these nearly collisionless plasmas depends on how one closes the plasmas. This work plans on improving heuristic “local closures” for computational efficiency. With improved closures, the NIMROD code will be able to improve the understanding of several problems of importance to ITER: disruptions, neoclassical tearing modes, and ELMs. With this improved understanding, numerical scans will be able to explore the extent to which shaping and profile modifications can ameliorate these problems. During Phase I of the project, NIMROD's algorithms were generalized to have more robust gridding algorithms applicable for H-mode plasmas, to allow for more flexible boundary conditions, and to allow for more flexible source specification. Phase II will take advantage of these developments and apply them to the study of the application of Resonant Magnetic Perturbations (RMP) stabilization of Edge Localized Modes (ELMs). With the goal of accurately addressing the time scales involved and verifying the experimental observations, we propose to study the evolution of the ELMs as they become unstable as the RMP is applied. This requires an understanding of extended MHD stability limits below the ideal stability limit, the behavior of field-error penetration in an H-mode plasma, and transport in the presence of a stochastic field. During Phase II, a plan for studying these physics effects individually and in integrated simulations is will be implemented. As an added benefit, the application of the NIMROD code to these difficult will improve the code's capability for additional tokamak simulations. |
PI: Scott Kruger |
Non-Axisymmetric Modeling of RF in Tokamaks (DE-FG02-09ER55006) |
This project will perform highly detailed, fully 3-D investigation of the ITER RF coupling scenarios, including non-axisymmetric equilibrium and vessel wall. These investigations will use the nascent capability of the software recently developed in the CSWPI SciDAC project, and provide a means of evaluating the performance of these tools on a challenging and important topic to magnetic fusion energy. Specifically, these studies will use: a) integrated time-domain, general geometry, plasma simulation capability, and b) the multi-scale-basis methodology to handle non-axi-symmetric modeling with an accuracy unavailable in frequency-domain methods. The ITER experiment is planning to use resonant magnetic perturbation (RMP) to help suppress edge-localized modes (ELMs). Such perturbation creates an apparent toroidal asymmetry in the plasma equilibrium, when viewed at the time-scale of RF (ICRH, LHCD, ECRH). Yet, in the case of the state-of-the-art RF full-wave modeling tools, such as TORIC and AORSA-2D for example, toroidal symmetry is the well-worn approximation which permits practical solution of the wave fields, by virtue of superposition of independent toroidal modes. ITER presents an additional toroidal asymmetry in its recessed antenna structure, such that the asymmetry of the vacuum vessel wall, and its effect on the implied long distance coupling is also more of a concern than in previous tokamak configurations. Again, existing full-wave modeling tools are not readily capable of treating walls with asymmetry. Finally, the possibility of magnetic islands, even at nominal volume and small field variation, generate a non-axisymmetric plasma volume comparable to that of today’s large tokamaks. Analysis of power deposition into such volumes is not presently modeled, nor is it widely known how it should be characterized, as the usual assignment of power to axi-symmetric flux surfaces is no longer valid. |
PI: David Smithe |
OrbBilder FACETS Orbiter Pilot Dashboard System ORNL Consultant Contract (4000100830) |
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We propose the development and integration of a web-based build dashboard into the FACETS build process. The FACETS project is a DOE sponsored fusion and computing project designed to develop, debug, and deploy coupled core and edge simulation codes for use by the Fusion community. The fusion community has a history of large codes with complex software infrastructure and decades of person years of experience in terms of software expertise and specific physics insight and development, all embedded into different code bases. Re-engineering these scientific edifices from the ground up is an unworkable proposition considering the valuable sunk cost in these codes. Instead, FACETS seeks to integrate codes that have specific applicability to different parts of the multi-sclae , multi-physics aspects of controlled fusion included the fully ionized plasma dynamics in the core region as well as the cooler edge region and even wall interactions. Coupling these codes creates significant software engineering challenges such as simply managing successful builds. This scope of work will look to establish a production build dashboard for FACETS and FACETS-related software components. The specific FACETS tool-chain builds will not only build the requested packages, but will also have the option to report the build results to a dashboard information service in order to be displayable via a RESTful web-service build dashboard that can report build success and failure. The primary consumer of this service will be the FACETS collaboration site, but it also could be used for other uses such as dynamic workflow decision-making on target execution platform, etc. |
PI: Mark L. Green |
Parallel Validation Tools for Fusion Simulations (DE-SC0000832) |
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Numerical simulations play a critical role in exploration of new experimental regimes needed for design and operation of new fusion devices such as ITER. Hence, simulations must be carefully validated against existing experiments. Synthetic diagnostics, the generation of data that can be directly compared to experimental diagnostics, is an excellent test for simulations. The development and use of synthetic diagnostics is often problematic due to incompatibilities of data representation used in simulations and experiments. There is a need for tools to standardize and streamline generation of synthetic diagnostics and a means to run them in a scalable manner. In this project we intend to develop a standard to describe diagnostics data, implement a set of synthetic diagnostics modules, and facilitate the workflow related to running diagnostics and sensitivity analysis in high-performance environment as a post-processing step or concurrently, as a co-process, thus making efficient use of high-performance resources and without degrading the performance of the main simulation. The synthetic diagnostics modules will apply transformations to simulation data and produce data directly comparable with experiments. |
PI: Sveta Shasharina |
Plasma Jet Modeling for MIF (DE-SC0000833) |
Los Alamos National Lab is currently developing an experiment to investigate the use of plasma jets to implode magnetized targets in what is called magneto-inertial fusion (MIF). In a typical MIF scheme a solid liner is imploded around a magnetized target, however this poses the problem of placing the liner for each shot and rebuilding mechanical connections - this is know as the stando problem. Plasma jets, on the other hand, can be located far from the target and do no require mechanical connections, therefore a high rep rate reactor becomes much more feasible. Theoretical analysis of implosion using plasma jets suggests that this may be an economical approach to a commercial fusion reactor however a number of issues need to be resolved. These issues will be resolved through experiment in combination with device modeling. We propose to validate and enhance Tech-X's plasma fluids code, TxFluids, for the particular application of plasma jets for MIF. The code is based on shock capturing finite volume and discontinuous Galerkin techniques for MHD, Hall MHD, Two-Fluid plasma models as well as neutral fluids. These fluid models will be used to analyze the effect of instabilities during jet merging and magnetized target implosion in order to learn of potential issues with the concept and approaches to mitigating those issues. During phase I, it was shown that TxFluids could be used to model plasma jet merging with and without magnetized targets. In order to get good results in the presence of vacuum an Euler/MHD algorithm was implemented. Simulations were performed with argon jets and an argon target. When radiation was included huge fields on the order ˜300 Tesla were observed though with low peak pressure as a result of radiative losses in the target. When radiation was not included, significant compression of the target was observed, before Rayleigh Taylor instabilities set in. A paper was submitted to the Journal of Fusion Energy outlining the results. During Phase II, 3D simulations of the plasma jet merging experiment and accretion disk experiment will be performed. Radiation models will be improved by adding a gray approximation, and later, multigroup approximation. Atomic physics capability will be improved with assistance from University of Alabama through the use/development of LTE, and non-LTE atomic physics libraries. Comparisons of TxFluids with smooth particle hydrodynamics results will be performed to determine any algorithm dependent problems that might arise and to gain confidence with the numerical results. |
PI: John Loverich |
QuAI: A Quality Assurance Infrastructure for Data-Centric Applications (DE-SC0000842) |
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Data processing is becoming an integral part of modern experiments and should operate with the timeliness and quality necessary to each project. There is a need for a customizable, resource-aware and dynamic mechanism allowing for automatic dissemination of the quality assurance data to the right parties at the right time. The Data Distribution Service (DDS) is a promising new technology that is expected to deliver these features but is not readily available for the quality assurance applications. In this project we are developing a Quality Assurance Infrastructure for timely distribution of quality assurance data between concurrent data processing applications. The infrastructure will consist of reusable core DDS entities and application-specific extensions. In particular, we will target quality assurance for data processing in the upcoming Join Dark Energy Mission (JDEM) cosponsored by HEP/DOE and NASA. QuAI then will be available to the DOE teams implementing the production data processing system of JDEM. |
PI: Sveta Shasharina |
Rapid Low-Noise Simulation of Ultra-bright 10 GeV Electron Bunches in Laser Plasma Accelerators (DE-SC0004441) |
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The BELLA project at LBNL seeks to develop ~10 GeV laser-plasma accelerator stages that will produce ultra-short, low-divergence ~1 nC electron bunches, total energy spread of ~1% and slice energy spread of ~0.1%. A beam of sufficient brightness for collider applications can be used to drive a free electron laser and so this is an experimental goal for 2012. Simulation support is required to reduce technical risk and increase the chances of experimental success. However, traditional particle-in-cell (PIC) simulations suffer from high-frequency particle noise, which artificially increases the emittance and energy spread of the simulated electron bunch. Fundamentally new techniques are required to adequately suppress numerical noise. Our Phase II objective is to develop software that will reduce technical risk and help to improve the performance of next-generation laser-plasma accelerator (LPA) experiments. In Phase I, we will determine the best approach to accurate low-noise simulation of high charge, ultra-bright relativistic electron beams. Such extreme beams must be simulated as part of production LPA modeling, so we consider only finite-difference time domain electromagnetic techniques. We will consider an approach analogous to what is done in many particle tracking codes, in which self-fields (aka space charge forces) are calculated in the beam frame by solving Poisson's equation and then Lorentz-transformed back to the laboratory frame, where the particle dynamics is evolved. Second, we will attempt to completely eliminate the high-frequency macro-particle noise by representing the beam as a warm relativistic fluid. New algorithms will be implemented in the parallel VORPAL framework and tested rigorously, including use in a full-scale 2D simulation of a 10 GeV stage with parameters relevant to the BELLA project at LBNL. |
PI: David Bruhwiler |
Remote Data Exploration with the Interactive Data Language (NNX09CA72C) |
We propose to develop a tool for NASA researchers based on IDL (Interactive Data Language) and DAP (Data Access Protocol) for user-friendly remote data access. IDL is a popular data analysis tool in the NASA research community. For instance, two examples of important NASA missions that rely on IDL are the Solar and Heliospheric Observatory (SOHO) and the Solar TErrestrial RElations Observatory (STEREO). However, a difficulty for many NASA researchers using IDL is that often the data to analyze is located remotely from the scientist and the data is too large to transfer for local analysis (the recent report1 on data standards in the Space and Solar Physics community exemplifies how data access needs are a main concern currently). Researchers have developed a protocol for accessing remote data, DAP, which is used for both SOHO and STEREO datasets. Presently one can use DAP from within IDL, but the DAP-IDL interface is both limited and cumbersome. We propose to develop a more powerful, user friendly interface to DAP for IDL. A final main goal of the Phase II will be to enable user-friendly interaction with multiprocessor and multi-core resources, allowing users to seamlessly retrieve remote data with DAP and take advantage of parallel computing resources for analyzing that data. Where possible, we plan to make these features available in the open-source GDL (Gnu Data Language) version of IDL. Figure 1 shows the prototype GUI interface developed in Phase I. This figure shows the DAP browser with an open NASA data set, including the list of data available for retrieval and meta-information about that data. The Phase II tasks listed above will build on this successful work. We indicate the tremendous potential for this project by including letters of support from the research community (Princeton Plasma Physics Lab and NCAR), the commercial community (Tokyo Electron), and the company that develops IDL (ITT Visual Information Solutions). |
PI: Michael Galloy |
Schema-Based Environment for Configuring, Analyzing and Documenting Integrated Fusion Simulations (DE-FG02-08ER85155) |
The FACETS and SWIM SciDAC efforts, with the upcoming Fusion Simulation Project, form a foundation for a comprehensive, full-device modeling needed for successful operations of ITER and designing the steps beyond. For the software developed in these projects to become a productive tool for a wide range of users, there is a need for a user-friendly interface to facilitate configuring components, setting up integrated simulations and performing simulation analysis such as sensitivity studies, parameter scans and optimization – all efficiently working on a variety of platforms, in particular on the Leadership Computing Facilities (LCFs). Tech-X therefore proposes to develop SECAD - a user-friendly environment for setting up integrated fusion simulations and their analysis, and performing visualization and performance improvement. In Phase I we have developed a prototype of SECAD capable of editing partial configuration files for the SWIM framework and running DAKOTA parameter studies for the IPS simulations using IPS model components. In Phase II we will fully develop SECAD consisting of: (1) infrastructure for integrating FACETS and SWIM with the DAKOTA analysis tool, (2) a Graphical User Interface (GUI) allowing users to edit and validate FACETS and SWIM inputs, visualize their simulation data via VisIt, and set up DAKOTA runs for parameter studies and optimization runs and visualize the output, and (3) performance instrumentation enhancements for all the components developed for a variety of platforms including the LCFs. To promote adoption and foster the scientific goals of FACETS and SWIM, we will develop several DAKOTA scenarios for particular optimization and parameter studies relevant for ITER modeling. This project will be performed in collaboration with the FACETS, SWIM and ParaTools teams and strongly leveraged by their synergistic activities and several ongoing Tech-X efforts. |
PI: Sveta Shasharina |
SciDAC Center for Simulation of Wave-Plasma Interactions (DE-FG02-08ER54953) |
The Massachusetts Institute of Technology (MIT) is submitting this grant application as part of a combined proposal for the SciDAC Center for Simulation of Wave – Plasma Interactions (CSWPI). The principal investigator for MIT is Paul T. Bonoli who is also the principal investigator for the combined project. The world community has joined together to construct ITER, the next scientific and engineering step on the path towards the development of a safe and economically attractive controlled fusion energy source. This device is designed to produce burning plasma conditions for the first time ever in a man-made laboratory plasma. The power to drive the ITER plasma to the burning regime will be supplied primarily with a combination of externally supplied power from radio frequency waves in the ion cyclotron range of frequencies (ICRF) and the injection of energetic ions from either negative ion or neutral beam injection (NINB/NBI) sources, in addition to internally-generated Ohmic heating from the induced plasma current that also serves to create the magnetic equilibrium for the discharge. Since the success of the ITER project depends critically on the ability to create and maintain burning plasma conditions, it is absolutely necessary to have physics-based models that can accurately simulate the RF processes that affect the dynamical evolution of the ITER discharge. In this new proposal MIT will work with other collaborating institutions to take advantage of high performance, massively parallel computing platforms to develop a predictive simulation capability in three distinct areas: First for ICRF antenna-edge coupling processes in order to understand the linear coupling between a 3D antenna structure and plasma, nonlinear parasitic loss mechanisms such as RF sheath formation and parametric decay instability (PDI), and the excitation of surface waves and coaxial modes and their interaction with the 3D geometry and structure of the SOL and vacuum vessel. Second we will work on the development of a predictive simulation capability for core heating and current drive processes in burning plasma, including a complete microscopic description of the interaction of ICRF and lower hybrid (LH) waves with energetic particles produced by the RF itself and with energetic ions produced by fusion reactions and neutral beam injection. Third, we will work on combing the antenna – edge and the core heating / current drive simulation capabilities into a fully integrated model. This activity will require an extensive program of code verification and validation (V&V) and code algorithm refinement and improvement. This core to edge RF description will be ideal for providing macroscopic and microscopic source information needed by MHD and transport codes in fully integrated modeling activities such as the Fusion Simulation Project (FSP) and Focused Integration Initiatives (FIIs). The work proposed here, dealing with multi-physics issues, strong non-linearity, and involving much more intense verification and validation will require even greater use of both capacity and capability high performance computing. The work proposed here, dealing with multi-physics issues, strong non-linearity, and involving much more intense verification and validation will require even greater use of both capacity and capability high performance computing. |
PI: David Smithe |
Self-consistent numerical design and modeling of radio frequency power sources (DE-SC0004438) |
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In development of next generation accelerator facility, it is in high demand to accurately and conveniently design and model radio frequency (RF) power sources of complex shape and multi-physics effects with advanced numerical simulations. It is also desired that physical parameters of interest to the designers at national labs can be obtained easily by performing integration of the simulation results. The particle in cell code VORPAL has all the capabilities in self-consistent multi-physics effect simulations of complex geometry RF power source. With proper extension of its existing capability, VORPAL can yield more accurate results in design and modeling. Current VORPAL requires an advanced user to set up a complicated power source simulation properly. A user-friendly interface for RF power source simulations is desired to minimize input and reduce work flow. We propose to extend current VORPAL capability, making it a more accurate and convenient self-consistent multi-physics simulation package for RF power source design. We will implement an accurate method to interpolate electric and magnetic field values to curved boundaries, implement surface and volume integration capability in VORPAL, and develop a macro library for user-friendly interface of RF power source specific simulations. In the end, these improved capabilities will benefit the researchers on RF power source design and optimization. |
PI: Chuandong Zhou |
Service-Oriented Architecture for Next Generation, Large-Scale Accelerator Control Systems (DE-FG02-08ER85043) |
Traditional frameworks for accelerator control system development do not scale for control systems of next-generation large- scale accelerators that consist of many sub-accelerators and operation teams. A new development paradigm is needed to encourage the robust integration of heterogeneous control subsystems. Most importantly, we need to be able to manage the inherent and accidental complexity of developing and running such large-scale control systems. Tech-X proposes to develop a reference Service-Oriented Architecture (SOA) that promotes multiple levels of loose coupling to increase the robustness and adaptability of overall control applications. Various control subsystems and activities can be implemented separately and packaged into “services” with well-defined “interfaces” for to enable composition of applications. |
PI: Nanbor Wang |
Simulation Tool for Weakly Ionized Plasma (FA9550-010-C-0115) |
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We propose to develop a commercial weakly ionized plasma modeling capability based off of Tech-X=92s high energy density plasma fluid code TxFluids. The new additions will be able to be used to model hypersonic vehicle physics including shock waves, plasma chemistry, and innovative techniques for blackout mitigation and hypersonic vehicle control through the application of electric and/or magnetic fields. A small part of the project will be spent on the development of a new experiment at George Washington University for validating the code. Currently there is no commercially available weakly ionized plasma modeling tool that is immediately applicable to hypersonics. Through this project a commercial weakly ionized modeling tool will be developed and will be available to the air force, industry, and academia. Air force applications include modeling hypersonic flow control, blackout mitigation, hall thrusters, ionizing shock waves, dielectric barrier discharge, and in the highly ionized regime, applications include modeling pulsed power devices and other plasma devices used in generating neutrons for detecting IED=92s or nuclear materials. Non Air Force applications include modeling biological plasmas used in sterilization, industrial plasma arcs, and lighting. |
PI: John Loverich |
SVOPME: A Scalable Virtual Organization Privilege Management Environment (DE-FG02-07ER84733) |
Although modern Grid middleware is beginning to support role-based authorization, there is an information disconnect in existing mechanisms between VO and site authorization control. This disconnect prevents privilege policies defined by VOs from propagating to Grid sites automatically. As more Virtual Organizations (VO)s are joining the Grid, manually maintaining and administrating VOs and grid sites becomes very costly. Tech-X Corporation is proposing to develop SVOPME for automating the propagating of VO privileges to Grid sites. We utilize the eXtensible Access Control Markup Language (XACML) for specifying VO privilege policies will develop tools and services to facilitate the functionality. |
PI: Nanbor Wang |
Virtual Instrumentation Experiment Optimization for High Throughput Scientific Analysis (DE-FG02-08ER85000) |
Large-scale neutron facilities such as the Spallation Neutron Source (SNS) located at Oak Ridge National Laboratory need easy-to-use Portal access to the Department of Energy Leadership Computing Facilities. Demand for neutron beams at the SNS have exceeded expectations resulting in a strong incentive to rapidly proceed with a planned facility expansion. Neutron scientists are very serious about maximizing the usage of these neutron beams and want to be prepared when they arrive at the facility but the virtual experiment capabilities are not sufficient for proper planning. General statement of how this problem is being addressed. Tech-X proposes to extend the Orbiter Virtual File System, developed in collaboration with the Spallation Neutron Source, for providing virtual instrumentation experiment optimization capabilities to neutron scientists. In achieving the project goals not only will the neutron scientist have the ability to perform extensive pre-experiment virtual simulations, thus arriving at the facility better prepared, but during experiment the Orbiter software and tools will provide a high Quality of Service yielding more efficient use of the facility. |
PI: Mark L. Green |