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The USA faces a multitude of threats to its national security and international interests in an era of exponential technology growth and unprecedented access by anyone with a smartphone. Traditionally, the acquisition of US defense systems has relied on sequential methods of conceptual design and development. While successful in the past, these methods are time consuming and in danger of creating vulnerability gaps that could limit or constrain US response options. The challenge is clear. Either the US Department of Defense (DoD) evolves the way it plans, develops, buys, and manufactures new weapons systems, or it cedes the high ground to a rapidly changing global environment. Adapting and expanding advances in high performance computing (HPC), developing and employing complex physics-based software tools for high fidelity modeling and simulation, and implementing a vision that combines these elements with other processes are critical enablers the DoD is pursuing. This paper describes the synergy of three major DoD efforts designed to address needs in the areas of acquisition program development and execution: the DoD High Performance Computing Modernization Program (HPCMP) (the DoD HPCMP began as an Office of the Secretary of Defense program in 1992; in October 2011, leadership transferred to the Assistant Secretary of the Army for Acquisition, Logistics and Technology; the US Army Corps of Engineers Engineer Research and Development Center manages the program, https://www.hpc.mil/index.php ) Computational Research and Engineering Acquisition Tools and Environments program; the Engineered Resilient Systems program; and the DoD Digital Engineering vision.

The goal of the CREATE program is to develop and deploy physics-based computational engineering tools that can be used to develop virtual prototypes of ships, air vehicles, ground vehicles, and radio frequency antennas to accurately predict their performance in support of the US Department of Defense acquisition process, DoD 5000. The purpose of this article is to describe the approach taken to address the verification and validation of the CREATE software products. The approach is based on the adoption of a set of practices aligned with the recommendations of the National Academy of Sciences to promote a test-driven development culture.

With an annual budget of nearly US600 billion, the US Department of Defense (DoD) is tasked with protecting the US and its allies and interests abroad against potential adversaries. It must accomplish these tasks in a globalized and highly interconnected world where the pace of technology is moving faster than the current time-consuming DoD acquisition systems can keep up with. Moving forward, the DoD must change these time-consuming paradigms and accelerate the pace of innovation. One way to do this is to shift to a virtual prototyping environment where the benefits of high-performance supercomputing and complex physics-based engineering software can expand the decision space and enable the DoD to field better systems faster, cheaper, and at less risk than previous methods. This is the goal of the Computational Research and Engineering Acquisition Tools and Environments (CREATE) program. This issue of CiSE provides the third installment of articles relating to the history, formation, and ongoing work of the High Performance Computing Modernization Program (HPCMP) CREATE program.

Today, rapid product innovation is essential to remain competitive. To help spur innovation in the acquisition of major defense systems and reduce their cost, time, and risks, the US Department of Defense launched the Computational Research and Engineering Acquisition Tools and Environments (CREATE) program in 2006 to develop and deploy physics-based, high-performance computing software applications for the design and analysis of military aircraft, ships, and radio frequency antenna systems (and more recently, ground vehicles) through the construction and analysis of virtual prototypes. Code development began in 2008, and eight years later, CREATE is already beginning to accomplish these goals.

The Department of Defense's High Performance Computing Modernization Program Computational Research and Engineering Acquisition Tools and Environments Computational Research and Engineering Acquisition Tools and Environments (CREATE) program is developing and deploying multiphysics high-performance computing software applications for engineers to design and make accurate performance predictions for military aircraft, ships, ground vehicles, and radio frequency antennas. When CREATE started (2007), no commonly recognized set of successful software project management practices existed for developing multiphysics, HPC engineering software. Based on lessons learned from the HPC and computational engineering communities, CREATE leadership developed and implemented a risk-based, practice-centered strategy to organize and manage the highly distributed program. This approach led to a good balance between ensuring a sufficiently structured workflow and accountability and providing the flexibility and agility necessary to create new sets of engineering tools with the capabilities needed to design next-generation weapon systems.

Silicon Valley is the home of many of the most innovative high-technology industries that have ever existed. Their level of innovation gives them a competitive economic advantage that sustains a significant portion of the US economy. While there have been dozens of attempts in the US and abroad to replicate this success, few have been very successful. A relatively new approach to product development is emerging, computational engineering. It is based on the use of computing, especially high-performance computing, to design, construct, and analyze virtual prototypes of new products.

The high level of technological innovation required for a strong national economy and defense is only achievable with a highly productive engineering workforce. AEIC Douglass Post and consultant Richard Kendall discuss how virtual tools and processes can help.

The Department of Defense (DoD) High Performance Computing Modernization Program (HPCMP) Computational Research and Engineering Acquisition Tools and Environments (CREATE) Program is developing and deploying a suite of multi-physicsbased high performance computing tools for the design and analysis of DoD ships, air vehicles, ground vehicles, and radio frequency antennas that enable DoD acquisition engineers to make accurate predictions of the physical performance of complex weapons systems (entire airplanes or ships) quickly enough to provide timely design decision data. These tools will enable acquisition engineers to identify and eliminate design defects and integration problems much earlier in the acquisition process, before manufacturing has begun, significantly decreasing acquisition time, costs, and risks while improving weapon system performance.

The field has reached a threshold at which better organization becomes crucial. New methods of verifying and validating complex codes are mandatory if computational science is to fulfill its promise for science and society.

Features incorporated in the design of the International Thermonuclear Experimental Reactor (ITER) tokamak and its ancillary and plasma diagnostic systems that facilitate operation and control of ignited and/or high?Q DT plasmas are presented. Control methods based upon straightforward extrapolation of techniques employed in the present generation of tokamaks are found to be adequate and effective for ITER plasma control with fusion powers of up to 1.5?GW and burn durations of ? 1000?s. Examples of simulations of key plasma control functions, including plasma magnetic configuration control and fusion burn (power) control, are given. The prospects for the creation and control of steady state plasmas sustained by non-inductive current drive and bootstrap current are also discussed.

Physics knowledge (theory and experiment) in energetic particles relevant to design of a reactor scale tokamak is reviewed, and projections for ITER are provided in this Chapter of the ITER Physics Basis. The review includes single particle effects such as classical alpha particle heating and toroidal field ripple loss, as well as collective instabilities that might be generated in ITER plasmas by energetic alpha particles. The overall conclusion is that fusion alpha particles are expected to provide an efficient plasma heating for ignition and sustained burn in the next step device. The major concern is localized heat loads on the plasma facing components produced by alpha particle loss, which might affect their lifetime in a tokamak reactor.

A dynamical model has been developed which solves a time-dependent coupled system of equations for the (1) plasma density and (2) hydrogenic concentrations in the implantation layer of several representative plasma facing/limiting walls in tokamaks in order to examine the density behaviour during the transient phase of discharges as well as long pulse discharges, which are dominated by the wall pumping/fuelling characteristics. A 1-D plasma particle transport code including a model for the SOL and an analytical neutral transport model has been used to describe the plasma particle transport processes. The Local Mixing Model with some adaptations has been used to describe the behaviour of the hydrogenic concentrations in the walls. The new model significantly improves the simulation of a Tore Supra experiment with a transition from limiting the plasma on the outer limiter to limiting the plasma on the inner wall compared our previous, more simple model. Long pulse discharges in Tore Supra are examined by the more simplified model to identify the dominant mechanisms for the constant particle absorption mechanisms.

This is the May 1996 report of a subpanel of the US Department of Energy Fusion Energy Sciences Advisory Committee (FESAC), charged with conducting a review of the progress, priorities and potential near-term contributions of TFTR, DIII-D and Alcator C-MOD (and other facilities as appropriate) as part of the transition to a Fusion Energy Sciences Program and produce an optimum plan for obtaining the most scientific benefit from them.

This paper describes models that address both power and particle control with the ITER divertor. For power control, the characteristics of the transition from attached to detached divertor operation are studied with an extension of our previous simple model [Y. Igitkhanov et al., 22nd EPS, Bournemouth (1995) p. IV-317]. This new model has been applied to JET experiments to show that the model can reproduce global features of the transition. The model has been applied to ITER to identify the range for detached operation in terms of the heating power, upstream density, and impurity level, and the relation between divertor control and core plasma conditions. For particle control, we use the PRETOR transport code together with a two point divertor model [K. Borrass and G. Janeschitz, Nucl. Fusion 34 (1994) 1203] for the edge boundary conditions to study the sensitivity of the central helium concentration to the pumping speed and helium enrichment in the divertor.

This paper reviews the status of the design of the divertor and first-wall/shield, the main in-vessel components for ITER. Under nominal ignited conditions, 300 MW of alpha power will be produced and must be removed from the divertor and first-wall. Additional power from auxiliary sources up to the level of 100 MW must also be removed in the case of driven burns. In the ignited case, about 100 MW will be radiated to the first wall as bremsstrahlung. Allowing the remaining power to be conducted to the divertor target plates would result in excessive heat fluxes. The power handling strategy is to radiate an additional 100–150 MW in the SOL and the divertor channel via a combination of radiation from hydrogen, and intrinsic and seeded impurities. Vertical targets have been adopted for the baseline divertor configuration. This geometry promotes partial detachment, as found in present experiments and in the results of modelling runs for ITER conditions, and power densities on the target plates can be ≤ 5 MW / m 2 . Such regimes promote relatively high pressure (> 1 Pa ) in the divertor and even with a low helium enrichment factor of 0.2, the required pumping speed to pump helium is ≤ 50 m 3 / s . An important physics question is the quality of core confinement in these attractive divertor regimes. In addition to power and particle handling issues, the effects of disruptions play a major role in the design and performance of in-vessel components. Both centered disruptions and VDE's produce stresses in the first-wall/shield modules, backplate and the divertor wings and cassettes that are near or even somewhat in excess of allowables for normal operation. Also plasma-wall contact from disruptions, including at the divertor target, together with material properties are major factors determining component lifetime. Considering the potential for impurity contamination and minimizing tritium inventory as well as thermomechanical performance, the present material selection calls for carbon divertor targets near the strike point, tungsten on the rest of the target and on the baffle where the charge-exchange flux could be high, and beryllium elsewhere. All three materials and relevant joining techniques are being developed in the R&D program and the final selection for the first assembly will be made at the end of the EDA.

This article is a response to the Office of Energy Research of the US DOE from the Fusion Energy Advisory Committee on a review of major US magnetic confinement facilities. This response was solicited in response to one of the suggestions made as part of the advisory report `A Restructured Fusion Energy Sciences Program` submitted to the US DOE in early 1996.

Plasma operation conditions and physics requirements to be used as a basis for safety analysis studies are developed and physics results motivated by safety considerations are presented for the ITER design. Physics guidelines and specifications for enveloping plasma dynamic events for Category I (operational event), Category II (likely event), and Category III (unlikely event) are characterized. Safety related physics areas that are considered are: (i) effect of plasma on machined and safety (disruptions, runaway electrons, fast plasma shutdown) and (ii) plasma response to ex-vessel LOCA from first wall providing a potential passive plasma shutdown due to Be evaporation. Physics models and expressions developed are implemented in safety analysis code (SAFALY, couples 0-D dynamic plasma model to thermal response of the in-vessel components). Results from SAFALY are presented.

Reduction of the peak heat loads on the plasma facing components is essential for the success of the next generation of high fusion power tokamaks such as the International Thermonuclear Experimental Reactor (ITER) 1 . Many present concepts for accomplishing this involve the use of atomic processes to transfer the heat from the plasma to the main chamber and divertor chamber walls and much of the experimental and theoretical physics research in the fusion program is directed toward this issue. The results of these experiments and calculations are the result of a complex interplay of many processes. In order to identify the key features of these experiments and calculations and the relative role of the primary atomic processes, simple quasi-analytic models and the latest atomic physics rate coefficients and cross sections have been used to assess the relative roles of central radiation losses through bremsstrahlung, impurity radiation losses from the plasma edge, charge exchange and hydrogen radiation losses from the scrape-off layer and divertor plasma and impurity radiation losses from the divertor plasma. This anaysis indicates that bremsstrahlung from the plasma center and impurity radiation from the plasma edge and divertor plasma can each play a significant role in reducing the power to the divertor plates, and identifies many of the factors which determine the relative role of each process. For instance, for radiation losses in the divertor to be large enough to radiate the power in the divertor for high power experiments, a neutral fraction of 10-3 to 10-2 and an impurity recycling rate of netrecycle of ~ 10^16 s m^-3 will be required in the divertor.

The ITER-EDA(93) design has been analyzed to evaluate the physics basis for: (i) size and design trade-off issues, (ii) confinement capability, (iii) power levels, and (iv) burn control.

The Computational Research and Engineering Acquisition Tools and Environments (CREATE) Program was established as a new 12-year program in FY 2008 by the Department of Defense (DoD). The CREATE goal is to enable major improvements in DoD's acquisition engineering design and analysis processes by developing and deploying scalable, multi-disciplinary, physics-based computational engineering software products for the design and analysis of DoD Ships, Air Vehicles, and Radio Frequency Antennas. Meshing and Geometry (MG) generation is being provided by a fourth project, MG. CREATE is a multi-institutional, multi-service, multi-agency and multi-disciplinary program with participation by the Navy, Air Force, Army, the Office of the Secretary of Defense, industry, and academia. The CREATE products are being developed and released on an annual cycle. In 2010, the program released five new products: SENTRI 1.0 -- RF antenna design; NESM 0.1 -- Ship Shock Analysis; IHDE 1.0 -- Ship Hydrodynamic Design and Analysis; Kestrel 1.0 -- Fixed-wing air vehicle analysis; and Helios 1.0 -- Rotorcraft analysis. Enhanced versions of these products will be released every year starting in 2011. In 2011, five additional products will begin annual releases: DaVinci -- a tool for the rapid physics-based design of air vehicles; RDI -- an integrated suite of tools to enable rapid physics-based design of naval ships; Firebolt -- components to provide models for gas turbine propulsion systems for Kestrel and Helios; NavyFoam -- a high- fidelity hydrodynamics analysis tool for predicting drag and resistance, sea-keeping and seaway loads; and Capstone -- components to enable the generation of geometries and meshes for all of the other products. The CREATE products are designed to be modular, maintainable, extensible, and scalable. To accomplish this, the CREATE team1 has developed a set of software engineering and software project management practices and processes that strike the appropriate balance between the agility and flexibility, and organizational structures and planning that are appropriate for developing complex physics-based, scalable and sustainable engineering software.

The Computational Research and Engineering Acquisition Tools and Environments (CREATE) Program is charged with positively impacting the US Department of Defense (DoD) Acquisition Process via Computational Engineering for capability gaps identified by the CREATE Boards of Directors. These prioritized requirements have been characterized and are annually reconciled in terms of gaps associated with required analysis cycle-times, physical accuracy, and necessary analysis capabilities. Furthermore, the Office of the Secretary of Defense(OSD) Overarching Integrated Product Team (OIPT) has provided goals which drive the usage of CREATE software by DoD Acquisition Programs. In order to achieve these usage targets, the CREATE Program has established a governance model and thence a hosted set of services to enhance collaboration among the developer teams and the targeted Acquisition Program (AP) subject matter experts. The goals of these collaboration services are to: 1) scale and speed the feedback amongst the CREATE and AP teams, while 2) minimizing interruption to developer and user workflows. Towards these goals, the community services have been architected as discussion forums, issue tracking, and documentation. Such services are now common place in the enterprise and open-source software projects, and efficiently scale with the user community by enabling a searchable knowledge base. In addition, owing to the key capabilities of this DoD software, CREATE requires authenticated and authorized access for each member of the community. This paper summarizes the governance model and process by which the services were selected, the architecture implemented, and the challenges going forward.

The divertor and SOL plasma parameters predicted for the ITER double-null reference configuration are reviewed with emphasis on model uncertainties and peaking factors. Predicted divertor performance is reported for two alternate ITER magnetic configurations, a high-aspect-ratio and a single-null design, both proposed to remedy divertor heat load and erosion problems. Physical processes and fluid-plasma numerical simulations of a divertor plasma operating near the gaseous neutralization phase transition are described.