National Security Applications Research Articles

Inertial-confinement fusion with lasers

The quest for controlled fusion energy has been ongoing for over a half century. The demonstration of ignition and energy gain from thermonuclear fuels in the laboratory has been a major goal of fusion research for decades. Thermonuclear ignition is widely considered a milestone in the development of fusion energy, as well as a major scientific achievement with important applications in national security and basic sciences. The US is arguably the world leader in the inertial confinement approach to fusion and has invested in large facilities to pursue it, with the objective of establishing the science related to the safety and reliability of the stockpile of nuclear weapons. Although significant progress has been made in recent years, major challenges still remain in the quest for thermonuclear ignition via laser fusion. Here, we review the current state of the art in inertial confinement fusion research and describe the underlying physical principles. The quest for energy production from controlled nuclear fusion reactions has been ongoing for many decades. Here, the inertial confinement fusion approach, based on heating and compressing a fuel pellet with intense lasers, is reviewed.

Coordination polymers based on Mn(II) and BPNO with selective and recyclable sensing of nitroaromatics

Detection of nitroaromatic compounds as both potential explosives and environmental pollutants is important for national homeland security, environmental protection or military applications. Current detection methods are based on some sophisticated instruments including energy dispersive X-ray diffraction, gas chromatography coupled with mass spectrometry, nuclear quadrupole resonance, surface enhanced Raman spectroscopy, neutron activation analysis, electron capture detection, and cyclic voltammetry. These instruments are very expensive and not easily accessible in most conditions. As a simpler, quicker and less expensive method, the sensitive optical detection could potentially be widely employed. The coordination polymers (CPs) could be efficiently modulated by both analyte-metal and analyte-ligand interactions. Thus the CP-based fluorescent detection of nitro-explosives displays fast, sensitive and reversible compared with other methods. It is necessary to rationally design and synthesize appropriate ligands to prepare the stable and bifunctional CPs. In this work, three Mn(II) coordination polymers [Mn2(1,4-NDC)2(BPNO)2(H2O)6·(BPNO)3] n ( 1 , 1,4-H2NDC=1,4-naphthalenedicarboxylic acid, BPNO=1,2-Bis(4-pyridyl)- N , N ′-dioxide), [Mn2(BPNO)(1,4-NDC)2·

The National Ignition Facility: Transition to a User Facility

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) has been operational since March 2009 and has been transitioning to a user facility supporting ignition science, high energy density science (HEDS), national security applications, and fundamental science. The facility has achieved its design goal of 1.8 MJ and 500 TW of 3ω light on target, and has performed target experiments with 1.9 MJ at peak powers of 410 TW. The facility is on track to perform over 200 target shots this year in support of all of its user communities. The facility has nearly 60 diagnostic systems operational and has shown flexibility in laser pulse shape and performance to meet the requirements of its multiple users. Progress continues on its goal of demonstrating thermonuclear burn in the laboratory. It has performed over 40 indirect-drive experiments with cryogenic-layered capsules. New platforms are being developed for HEDS and fundamental science. Equation-of-state and material strength experiments have been done on a number of materials with pressures of over 50 MBars obtained in diamond, conditions never previously encountered in the laboratory and similar to those found in planetary interiors. Experiments are also in progress investigating radiation transport, hydrodynamic instabilities, and direct drive implosions. NIF continues to develop as an experimental facility. Advanced Radiographic Capability (ARC) is now being installed on NIF for producing high-energy radiographs of the imploded cores of ignition targets and for short pulse laser-plasma interaction experiments. One NIF beam is planned for conversion to two picosecond beams in 2014. Other new diagnostics such as x-ray Thomson scattering, low energy neutron spectrometer, and multi-layer reflecting x-ray optics are also planned. Incremental improvements in laser performance such as improved optics damage performance, beam balance, and back reflection control are being pursued.

Overview: Development of the National Ignition Facility and the Transition to a User Facility for the Ignition Campaign and High Energy Density Scientific Research

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory has been operational since March 2009 and has been transitioning to a user facility supporting ignition science, high energy density stockpile science, national security applications, and fundamental science. The facility has achieved its design goal of 1.8 MJ and 500 TW of 3ω light on target, and has performed target experiments with 1.9 MJ at peak powers of 410 TW. The National Ignition Campaign (NIC), established by the U.S. National Nuclear Security Administration in 2005, was responsible for transitioning NIF from a construction project to a national user facility. Besides the operation and optimization of the use of the NIF laser, the NIC program was responsible for developing capabilities including target fabrication facilities; cryogenic layering capabilities; over 60 optical, X-ray, and nuclear diagnostic systems; experimental platforms; and a wide range of other NIF facility infrastructure. This paper provides a summary of some of the key experimental results for NIF to date, an overview of the NIF facility capabilities, and the challenges that were met in achieving these capabilities. They are covered in more detail in the papers that follow.

A conflict-based path-generation heuristic for evacuation planning

Evacuation planning and scheduling is a critical aspect of disaster management and national security applications. This paper proposes a conflict-based path-generation approach for evacuation planning. Its key idea is to decompose the evacuation planning problem into a master and a subproblem. The subproblem generates new evacuation paths for each evacuated area, while the master problem optimizes the flow of evacuees and produce an evacuation plan. Each new path is generated to remedy conflicts in the evacuation flows and adds new columns and a new row in the master problem. The algorithm is applied to a set of large-scale evacuation scenarios ranging from the Hawkesbury-Nepean flood plain (West Sydney, Australia) which require evacuating in the order of 70,000 persons, to the New Orleans metropolitan area and its 1,000,000 residents. Experiments illustrate the scalability of the approach which is able to produce evacuation for scenarios with more than 1200 nodes, while a direct Mixed Integer Programming formulation becomes intractable for instances with more than 5 nodes. With this approach, realistic evacuations scenarios can be solved near-optimally in reasonable time, supporting both evacuation planning in strategic, tactical, and operational environments.

Alpha spectroscopy substrates based on thin polymer films

The objective of this work was to prepare a novel substrate for the simultaneous concentration of actinides and sample preparation for alpha spectroscopy. Substrate preparation involved forming ultrathin films (10–180 nm) of quaternary amine anion-exchange polymers on glass and silicon by dip-coating. Samples were loaded by submerging the polymer-coated substrates into acidified solutions of 238Pu or natural water with elevated uranium concentrations. High resolution (25–30 keV) alpha spectra were acquired from these substrates under certain loading conditions indicating that through further development they may be a useful, inexpensive, and potentially field deployable platform serving national security and environmental sampling applications.

Isotope program expands activities

To meet the growing demand for isotopes and lessen dependence on foreign sources, the Department of Energy has been realigning its capabilities and connecting with universities.

Tunstel Defining Robotic Technology Development at APL [SMC Innovators

Dr. Edward Tunstel is a senior roboticist in the Research and Exploratory Development Department of the Johns Hopkins Applied Physics Laboratory (APL), Laurel, Maryland. He also served as the space robotics and autonomous control lead in its Space Department. He leads and defines the technical direction of robotics technology development and autonomous control capabilities for national security and space applications. He joined APL in 2007 after 18 years at the NASA Jet Propulsion Laboratory (JPL) in Pasadena, California, where he was a senior robotics engineer and group leader of its Advanced Robotic Controls Group.

Germanium Detectors in Homeland Security at PNNL

Neutron and gamma-ray detection is used for non-proliferation and national security applications. While lower energy resolution detectors such as NaI(Tl) have their place, high purity germanium (HPGe) also has a role to play. A detection with HPGe is often a characterization due to the very high energy resolution. However, HPGe crystals remain small and expensive leaving arrays of smaller crystals as an excellent solution. PNNL has developed two similar HPGe arrays for two very different applications. One array, the Multisensor Aerial Radiation Survey (MARS) detector is a fieldable array that has been tested on trucks, boats, and helicopters. The CASCADES HPGe array is an array designed to assay samples in a low background environment. The history of HPGe arrays at PNNL and the development of MARS and CASCADES will be detailed in this paper along with some of the other applications of HPGe at PNNL.

Boron-10 Based Neutron Coincidence Counter for Safeguards

The shortage of 3He has triggered the search for effective alternative neutron detection technologies for national security applications, including international nuclear safeguards. Any alternative neutron detection technology must satisfy two basic criteria: it must meet a neutron detection efficiency requirement, and it must be insensitive to gamma-ray interference at a prescribed level while still meeting the neutron detection requirement. For nuclear safeguards, a system must perform measurements in the field with a prescribed precision in a specified time. This paper describes an effort to design, model and test an alternatives-based neutron coincidence counter for nuclear safeguards applications. The technology chosen for use in an alternatives-based uranium neutron coincidence collar was boron-lined proportional counters. Extensive modeling was performed of various system configurations and comparisons were made to measurements on a commercial prototype boron-10 based uranium neutron coincidence collar.

Self-powered acoustic source locator in underwater environment based on organic film triboelectric nanogenerator

Detecting/sensing targets underwater has very important applications in environmental study, civil engineering and national security. In this paper, an organic-film based triboelectric nanogenerator (TENG) has been successfully demonstrated for the first time as a self-powered and high sensitivity acoustic sensor to detect underwater targets at low frequencies around 100 Hz. This innovative, cost-effective, simple-design TENG consists of a thin-film-based Cu electrode and a polytetrafluoroethylene (PTFE) film with nanostructures on its surfaces. On the basis of the coupling effect between triboelectrification and electrostatic induction, the sensor generates electrical output signals in response to incident sound waves. Operating at a resonance frequency of 110 Hz, under an acoustic pressure of 144.2 dBSPL, the maximum open-circuit voltage and short-circuit current of the generator can respectively reach 65 V and 32 μA underwater. The directional dependence pattern has a bi-directional shape with a total response angle of 60°. Its sensitivity is higher than −185 dB in the frequency range from 30 Hz to 200 Hz. The highest sensitivity is −146 dB at resonance frequency. The three-dimensional coordinates of an acoustic source were identified by four TENGs, self-powered active sensors, and the location of the acoustic source was determined with an error about 0.2 m. This study not only expands the application fields of TENGs from the atmosphere to water, but also shows the TENG is a promising acoustic source locator in underwater environments.

Assessment of Fuzzy Logic Radioisotopic Pattern Identifier on Gamma-Ray Signals with Application to Security

Analysis of acquired nuclear detector gamma-ray signals for recognition of present radioisotopic signatures is crucial to national security and security applications. Identification algorithms must be accurate and rapid. Artificial intelligence is a scientific field with a variety of tools suitable to implement automated processing of nuclear signals. The use of low resolution portable detectors to measure gamma-ray signals has found a wide use in security and safeguards applications. In this paper, the fuzzy logic based analysis methodology that has been previously developed is applied and assessed on a variety of nuclear signals obtained with a low resolution scintillation detector, and more particularly a sodium iodide (NaI) detector. Various types of fuzzy membership functions are employed and their performance is assessed with regard to the number of positive detections, misses, and false alarms. Furthermore, recorded results from the set of low resolution gamma ray signals are used to estimate the detection sensitivity for each membership function. Results demonstrate the overall effectiveness of the fuzzy logic based identifier, and consist of the main course for the assessment of each membership function. Furthermore, comparison of results designates the triangular membership function as the best membership shape for this type of detector signals.

Macromolecular Amplification of Binding Response in Superaptamer Hydrogels

It is becoming more important to detect ultralow concentrations of analytes for biomedical, environmental, and national security applications. Equally important is that new methods should be easy to use, inexpensive, portable, and if possible allow detection by the naked eye. By and large, detection of low concentrations of analytes cannot be achieved directly but requires signal amplification by catalysts, macromolecules, metal surfaces, or supramolecular aggregates. The rapidly progressing field of macromolecular signal amplification has been advanced using conjugated polymers, chirality in polymers, solvating polymers, and polymerization/depolymerization strategies. A new type of aptamer-based hydrogel with specific response to target proteins presented in this report demonstrates an additional category of macromolecular signal amplification. This superaptamer assembly provides the first example of using protein-specific aptamers to create volume-changing hydrogels with amplified response to the target protein. A remarkable aspect of these superaptamer hydrogels is that volume shrinking is visible to the naked eye down to femtomolar concentrations of protein. This extraordinary macromolecular amplification is attributed to a complex interplay between protein-aptamer supramolecular cross-links and the consequential reduction of excluded volume in the hydrogel. Specific recognition is even maintained in biological matrices such as urine and tears. Furthermore, the gels can be dried for long-term storage and regenerated for use without loss of activity. In practice, the ease of this biomarker detection method offers an alternative to traditional analytical techniques that require sophisticated instrumentation and highly trained personnel.

Fabrication and Metrology Challenges in Making Thin, Hollow, Silver Spherical Halfraum Targets for EPEC Experiments on the National Ignition Facility

Energy partitioning, energy coupling (EPEC) is one of the new experimental platforms being investigated at the National Ignition Facility (NIF) to provide valuable data for national security applications. The EPEC target is a 7-μm-thick silver spherical halfraum driven by a single NIF quad. This paper will describe the fabrication of the hollow spherical target, starting with the selection of the mandrel, the single-point diamond turning process used to achieve the desired thickness, and the final processing to remove the mandrel. Also discussed will be the metrology technique, X-ray opacity, used to determine the wall thickness and wall uniformity and how this nondestructive technique was benchmarked by two destructive characterization techniques, dual focused ion beam and scanning electron microscope, for wall thickness determination.

Generalized Nuclear Data: A New Structure (with Supporting Infrastructure) for Handling Nuclear Data

The Evaluated Nuclear Data File (ENDF) format was designed in the 1960s to accommodate neutron reaction data to support nuclear engineering applications in power, national security and criticality safety. Over the years, the scope of the format has been extended to handle many other kinds of data including charged particle, decay, atomic, photo-nuclear and thermal neutron scattering. Although ENDF has wide acceptance and support for many data types, its limited support for correlated particle emission, limited numeric precision, and general lack of extensibility mean that the nuclear data community cannot take advantage of many emerging opportunities. More generally, the ENDF format provides an unfriendly environment that makes it difficult for new data evaluators and users to create and access nuclear data.The Cross Section Evaluation Working Group (CSEWG) has begun the design of a new Generalized Nuclear Data (or ʼGNDʼ) structure, meant to replace older formats with a hierarchy that mirrors the underlying physics, and is aligned with modern coding and database practices.In support of this new structure, Lawrence Livermore National Laboratory (LLNL) has updated its nuclear data/reactions management package Fudge to handle GND structured nuclear data. Fudge provides tools for converting both the latest ENDF format (ENDF-6) and the LLNL Evaluated Nuclear Data Library (ENDL) format to and from GND, as well as for visualizing, modifying and processing (i.e., converting evaluated nuclear data into a form more suitable to transport codes) GND structured nuclear data.GND defines the structure needed for storing nuclear data evaluations and the type of data that needs to be stored. But unlike ENDF and ENDL, GND does not define how the data are to be stored in a file. Currently, Fudge writes the structured GND data to a file using the eXtensible Markup Language (XML), as it is ASCII based and can be viewed with any text editor. XML is a meta-language, meaning that it has a primitive set of definitions for representing hierarchical data/text in a file. Other meta-languages, like HDF5 which stores the data in binary form, can also be used to store GND in a file.In this paper, we will present an overview of the new GND data structures along with associated tools in Fudge.

Graphene applications in electronics and photonics

Abstract

Materials Data for Modeling, Simulation, and Analysis

The materials science and engineering world has been focusing much attention in recent months on issues related to materials data, and the innovations and advancements needed to speed up the development of new materials and processing methods. In June 2011, the Materials Genome Initiative (MGI) was announced by the National Science and Technology Council of the Executive Office of the President. The MGI is a ‘‘new, multi-stakeholder effort to develop an infrastructure to accelerate advanced materials discovery and deployment in the United States.’’ The ultimate goal of MGI is to fast-track the development and deployment of materials for critical medical, transportation, and national security applications. Similar programs have been announced in the European Union, and it is fair to say that research and development groups across the globe are looking for ways to speed up materials innovations. In May 2012, the US National Institute of Standards and Technology (NIST) held a workshop in Washington, DC, ‘‘Building the Materials Innovation Infrastructure: Data and Standards.’’ Participants represented a broad cross section of materials research and development organizations, with experience in materials at various length scales (from nano to macro) and application areas. Some of the most pressing issues identified by participants were related to

Evaluated Nuclear Data Covariances: The Journey From ENDF/B-VII.0 to ENDF/B-VII.1

Recent interest from data users on applications that utilize the uncertainties of evaluated nuclear reaction data has stimulated the data evaluation community to focus on producing covariance data to a far greater extent than ever before. Although some uncertainty information has been available in the ENDF/B libraries since the 1970ʼs, this content has been fairly limited in scope, the quality quite variable, and the use of covariance data confined to only a few application areas. Today, covariance data are more widely and extensively utilized than ever before in neutron dosimetry, in advanced fission reactor design studies, in nuclear criticality safety assessments, in national security applications, and even in certain fusion energy applications. The main problem that now faces the ENDF/B evaluator community is that of providing covariances that are adequate both in quantity and quality to meet the requirements of contemporary nuclear data users in a timely manner. In broad terms, the approach pursued during the past several years has been to purge any legacy covariance information contained in ENDF/B-VI.8 that was judged to be subpar, to include in ENDF/B-VII.0 (released in 2006) only those covariance data deemed then to be of reasonable quality for contemporary applications, and to subsequently devote as much effort as the available time and resources allowed to producing additional covariance data of suitable scope and quality for inclusion in ENDF/B-VII.1. Considerable attention has also been devoted during the five years since the release of ENDF/B-VII.0 to examining and improving the methods used to produce covariance data from thermal energies up to the highest energies addressed in the ENDF/B library, to processing these data in a robust fashion so that they can be utilized readily in contemporary nuclear applications, and to developing convenient covariance data visualization capabilities. Other papers included in this issue discuss in considerable detail various aspects of the data producer communityʼs efforts to improve the evaluation methods and to add covariance content to the ENDF/B library. The present paper offers just a brief glimpse of these activities by drawing material from covariance papers presented at meetings, workshops and international conferences during the past five years. Highlighted are: advances in methods for producing and processing covariance data, recently developed covariance visualization capabilities, and the development and implementation of quality assurance (QA) requirements that should be satisfied for covariance data to be included in ENDF/B-VII.1.

Interference Identification for Next Generation Wireless Networks

With the huge success of cellular mobile radio communications, demand for wireless services, applications, and technologies is expected to increase further. Such an increase forces recently emerging technologies (e.g., 4G) to coexist with the old ones (e.g., 2G–3G) in next generation wireless networks (NGWNs). In order for NGWNs to support all of these services and applications with the ever-increasing demand, wireless radio interference needs to be handled in an effective manner. Interference is a phenomenon which degrades the overall system capacity, affects the quality of service, and causes call drops and unnecessary handoffs in cellular mobile systems. Interference is a very important concept from the perspective of military and of national security. Both unintentional and intentional interference, which is also known as jamming, should be cleared away as soon as possible for security reasons. Therefore, identification of interference in a reliable manner is a crucial task for all of the future wireless communications systems. In this study, identification of radio interference in NGWNs is established. The proposed method takes into account the general characteristics of wireless propagation environments. Since it is difficult to completely define a general wireless propagation environment, statistical properties of widely used propagation environment classification such as urban and suburban is analyzed. Both first- and second-order of the statistical characteristics of wireless propagation environments are considered. It is shown that the proposed method can identify the presence of interference under practical scenarios in a reliable manner. In addition, it is demonstrated that the absence of a priori knowledge about the ambient noise power does not affect the performance of the proposed method. Interference management is predicted to be an essential part of the system design for emerging NGWNs. Interference is also extremely important for military and national security applications and services. Therefore, identification of any form of interference in a reliable manner is of crucial importance. In this study, a method that can identify the presence of interference reliably under practical scenarios is proposed. The method proposed does need any a priori information to identify the interference.

Polymers for Anion Recognition and Sensing

In biological systems, the selective and high-affinity recognition of anionic species is accomplished by macromolecular hosts (anion-binding proteins) that have been "optimized" through evolution. Surprisingly, it is only recently that chemists have systematically attempted to develop anion-responsive synthetic macromolecules for potential applications in medicine, national security, or environmental monitoring. Recent results indicating that unique features of polymeric systems such as signal amplification, multivalency, and cooperative behavior may be exploited productively in the context of anion recognition and sensing are documented. The wide variety of interactions-including Lewis acid/base, ion-pairing, and hydrogen bonding-that have been employed for this purpose is reflected in the structural diversity of anion-responsive macromolecules identified to date.