The high volume inspection equipment currently available to support development of EUV blanks is non-actinic. The same is anticipated for patterned EUV mask inspection. Once potential defects are identified and located by such non-actinic inspection techniques, it is essential to have instrumentation to perform detailed characterization, and if repairs are performed, re-evaluation. The ultimate metric for the acceptance or rejection of a mask due to a defect, is the wafer level impact. Thus measuring the aerial image for the site under question is required. An EUV Aerial Image Microscope (''AIM'') similar to the current AIM tools for 248nm and 193nm exposure wavelength is the natural solution for this task. Due to the complicated manufacturing process of EUV blanks, AIM measurements might also be beneficial to accurately assessing the severity of a blank defect. This is an additional application for an EUV AIM as compared to today's use In recognition of the critical role of an EUV AIM for the successful implementation of EUV blank and mask supply, International SEMATECH initiated this design study with the purpose to define the technical requirements for accurately simulating EUV scanner performance, demonstrating the feasibility to meet these requirements and to explore various technical approaches …

Dimensional changes in PBX materials resulting from temperature change are of interest to engineers, designers and modelers. In this paper we present data from recent measurements made on LX17-1, as well as on the material's binder and its energetic constituent. LX17-1 is made from 7.5% KEL-F 800 binder combined with 92.5% wet aminated TATB energetic crystals. Due apparently to the anisotropic expansionary behavior of the TATB, the material exhibits irreversible growth, in addition to the usual reversible expansions and contractions associated with temperature change. In an effort understand reversible and irreversible growth behavior and to verify consistency between our measurements and those made historically, measurements were performed on billet pressed LX17-1, on die pressed TATB, and on KEL-F alone. It is important to realize that, for materials involving TATB, expansionary behavior results from the combined effects of reversible and irreversible (ratchet growth) phenomena.

This paper describes a novel methodology for the identification of mechanical systems and structures from vibration response measurements. It combines prior information, observational data and predictive finite element models to produce configurations and system parameter values that are most consistent with the available data and model. Bayesian inference and a Metropolis simulation algorithm form the basis for this approach. The resulting process enables the estimation of distributions of both individual parameters and system-wide states. Attractive features of this approach include its ability to: (1) provide quantitative measures of the uncertainty of a generated estimate; (2) function effectively when exposed to degraded conditions including: noisy data, incomplete data sets and model misspecification; (3) allow alternative estimates to be produced and compared, and (4) incrementally update initial estimates and analysis as more data becomes available. A series of test cases based on a simple fixed-free cantilever beam is presented. These results demonstrate that the algorithm is able to identify the system, based on the stiffness matrix, given applied force and resultant nodal displacements. Moreover, it effectively identifies locations on the beam where damage (represented by a change in elastic modulus) was specified.

Uncertainties in climate observations are revealed when alternate observationally based data sets are compared. General circulation model-based ''reanalyses'' of meteorological observations will yield different results from different models, even if identical sets of raw unanalyzed data form their starting points. We have examined 25 longitude-latitude fields (including selected levels for three-dimensional quantities) encompassing atmospheric climate variables for which the PCMDI observational data base contains two or more high-quality sources. For the most part we compare ECMWF with NCEP reanalysis. In some cases, we compare in situ and/or satellite-derived data with reanalysis. To obtain an overview of the differences for all 25 fields, we use a graphical technique developed for climate model diagnosis: a ''portrait diagram'' displaying root-mean-square differences between the alternate data sources. With a few exceptions (arising from the requirement that RMS differences be normalized to accommodate different units of variables) the portrait diagrams indicate areas of agreement and disagreement that can be confirmed by examining traditional graphics such as zonal mean plots. In accord with conventional wisdom, the greatest agreement between alternate data sets--hence the smallest implied observational uncertainty--occurs for upper tropospheric zonal wind. We also find fairly good agreement between reanalysis and more direct measures of precipitation, …

We have developed a small-scale safety test for initiation train components. A low-cost test was needed to assess the response of initiation components to an abnormal shock environment and to detect changes in the sensitivity of initiation components as they age. The test uses a disk of Detasheet to transmit a shock through a PMMA barrier into a the test article. A schematic drawing of the fixture is shown. The 10-cm-diameter disk of 3-mm-thick Detasheet, initiated at its center by a RISI, RP detonator, produces a shock wave that is attenuated by a variable-thickness PMMA spacer (gap). Layers of metal and plastic above the test article and the material surrounding the test article may be chosen to mock up the environment of the test article at its location in a warhead. A metal plate at the bottom serves as a witness plate to record whether or not the test article detonated. For articles containing a small amount of explosive, it can be difficult to determine whether or not a detonation has occurred. In such cases, one can use a pressure transducer or laser velocimeter to detect the shock wave from the detonation of the article. The assembly is contained in …

In this paper, we report results on exploration of two-dimensional (2D) time varying datasets. We extend the notion of multiresolution spatial data approximation of static datasets to spatio-temporal approximation of time-varying datasets. Time-varying datasets typically do not change ''uniformly,'' i.e., some spatial sub-domains can experience only little or no change for extended periods of time. In these sub-domains, we show that approximation error bounds can be met when using sub-domains from other time-steps effectively. We generate a more general approximation scheme where sub-domains may approximate congruent sub-domains from any other time steps. While this incurs an O(T2) overhead, where T is the total number of time-steps, we show significant reduction in data transmission. We also discuss ideas for improvements to reduce overhead.

We have demonstrated that a bulk absorber coupled to a TES can serve as a good gamma-ray spectrometer. Our measured energy resolution of 70 eV at 60 keV is among the best measurements in this field. We have also shown excellent agreement between the noise predictions and measured noise. Despite this good result, we noted that our detector design has shortcomings with a low count rate and vulnerabilities with the linearity of energy response. We addressed these issues by implementation of an active negative feedback bias. We demonstrated the effects of active bias such as additional pulse shortening, reduction of TES change in temperature during a pulse, and linearization of energy response at low energy. Linearization at higher energy is possible with optimized heat capacities and thermal conductivities of the microcalorimeter. However, the current fabrication process has low control and repeatability over the thermal properties. Thus, optimization of the detector performance is difficult until the fabrication process is improved. Currently, several efforts are underway to better control the fabrication of our gamma-ray spectrometers. We are developing a full-wafer process to produce TES films. We are investigating the thermal conductivity and surface roughness of thicker SiN membranes. We are exploring alternative …

Mechanical properties of FCC metals and alloys can be improved by exercising control over the population of grain boundary types in the microstructure. The existing studies also suggest that such properties tend to have percolative mechanisms that depend on the topology of the grain boundary network. With the emergence of SEM-based automated electron backscatter diffraction (EBSD), statistically significant datasets of interface crystallography can be analyzed in a routine manner, giving new insight into the topology and percolative properties of grain boundary networks. In this work, we review advanced analysis techniques for EBSD datasets to quantify microstructures in terms of grain boundary character and triple junction distributions, as well as detailed percolation-theory based cluster analysis.

Fused silica and Si-O{sub x} coatings are of interest for use under high flux conditions of laser light. Si-O{sub x} coatings are sputter deposited from silicon and fused quartz targets using planar magnetrons operated in the rf mode with a variable working-gas mixture of Argon-Oxygen. A series of coatings are prepared on optically flat, fused quartz substrates. Analysis of surface curvature reveals the deposition process conditions that minimize residual stress. Compressive stress levels that exceed 1.5 GPa can be reduced to less than 0.4 GPa for an optimum working gas pressure. Characterization using Rutherford backscattering and x-ray photoelectron spectroscopy indicates that both the fused quartz and silicon targets can be used to sputter deposit coatings with the chemical bonding features of the fused-quartz substrate material.

As the world faces growing economic and environmental challenges, the energy mix that fuels the global economy is undergoing rapid change. Yet how this change will evolve in the future is uncertain. What will be the sources of primary energy in twenty years? In fifty years? In different regions of the globe? How will this energy be utilized? Fossil energy currently supplies about ninety percent of the world's primary energy. In Japan this number is closer to eighty percent. It is clear that fossil energy will be a major supplier of global energy for some time to come, but what is not clear is the types of fossil energy and how it will be utilized. The degree to which the abundant supplies of fossil energy, especially coal, will continue to play a major role will depend on whether technology will provide safe, clean and affordable fuel for electricity and transportation. Technology will not only assist in finding more fossil energy in varying regions of the globe but, most importantly, will play a strong role in efficient utilization and in determining the cost of delivering that energy. Several important questions will have to be answered: (1) Will cost effective technologies be …

We frequently measure velocity-time histories of dynamic experiments. In some, the Doppler-shifted light is often weak compared to non-shifted light reflected from stationary surfaces and imperfections in components. With our Fabry-Perot (FP) based systems which handle multiple frequencies, data is lost where the fringes coincide; if we had used an intensity-measuring VISAR system, it would probably fail. We designed a facility for doing experiments under such conditions by selectively eliminating most of the non-shifted light. Our first filter excluded non-shifted light by a factor of 300 when manually tuned, and by 150 when run in an auto-tuning mode. It used a single 50 mm diameter FP as the filter with a spacing of 1.65 mm and reflectivities of 77%, and filters five channels prior to use in one of our 5-beam velocimeters. One use of the filter system was to embed optical fibers in long sections of explosives to make continuous detonation velocity-time histories. We have carried out many such tests with this filter, and two without. A special single-beam filter was constructed with a 40% efficiency for shifted light that rejected non-shifted light by 4 million times, with a bandpass of a few GHz.

We are working on developing an alternative technology for storage of hydrogen or natural gas on light-duty vehicles. This technology has been titled insulated pressure vessels. Insulated pressure vessels are cryogenic-capable pressure vessels that can accept either liquid fuel or ambient-temperature compressed fuel. Insulated pressure vessels offer the advantages of cryogenic liquid fuel tanks (low weight and volume), with reduced disadvantages (fuel flexibility, lower energy requirement for fuel liquefaction and reduced evaporative losses). The work described in this paper is directed at verifying that commercially available pressure vessels can be safely used to store liquid hydrogen or LNG. The use of commercially available pressure vessels significantly reduces the cost and complexity of the insulated pressure vessel development effort. This paper describes a series of tests that have been done with aluminum-lined, fiber-wrapped vessels to evaluate the damage caused by low temperature operation. All analysis and experiments to date indicate that no significant damage has resulted. Future activities include a demonstration project in which the insulated pressure vessels will be installed and tested on two vehicles. A draft standard will also be generated for obtaining insulated pressure vessel certification.

Calibration of a seismic monitoring system remains a major issue due to the lack of ground truth information and uncertainties in the regional geological parameters. Rapid and accurate identification of seismic events is currently not feasible due to the absence of a fundamental framework allowing immediate access to ground truth information for many parts of the world. Precise location and high-confidence identification of regional seismic events are the primary objectives of monitoring research in seismology. In the Department of Energy Knowledge Base (KB), ground truth information addresses these objectives and will play a critical role for event relocation and identification using advanced seismic analysis tools. Maintaining the KB with systematic compilation and analysis of comprehensive sets of geophysical data from various parts of the world is vital. The goal of this project is to identify a comprehensive database for China using digital seismic waveform data that are currently unavailable. These data may be analyzed along with ground truth information that becomes available. To date, arrival times for all regional phases are determined on all events above Mb 4.5 that occurred in China in 2000 and 2001. Travel-time models are constructed to compare with existing models. Seismic attenuation models may be …

Shock waves and high-energy particle radiation can each drive materials far from thermodynamic equilibrium and enable novel scenarios in the processing of materials. A large number of theoretical and experimental studies of shock deformation have been performed on polycrystalline materials, but shock deformation in single crystals has only recently been studied in some detail. We present Molecular Dynamics (MD) simulations of the shock response of single crystal copper, modeled using an embedded atom potential that reproduces both defect formation and high pressure behavior. Shock-induced plasticity will also be discussed. Predicting the in-service response of ferritic alloys in future fusion energy environments requires a detailed understanding of the mechanisms of defect accumulation and microstructure evolution in harsh radiation environments, which include a high level of He generation concurrent with primary damage production. The second half of this paper describes results of atomistic MD and kinetic Monte Carlo simulations to investigate the role of He on point defect cluster behavior and damage accumulation in bcc Fe. The goal of these simulations is to study the mechanisms responsible for the formation of vacancy-He clusters which serve as He bubble and void nuclei in fusion reactor materials.

OAK-B135 The Arabidopsis transcription factor LEAFY (LFY) acts upstream of homeotic genes such as AGAMOUS (AG) to confer floral identity on meristems that arise after the transition to reproductive development. Compared to the genetic circuitry regulating the establishment of floral meristem identity, little is known about its maintenance. Previous experiments with fly heterozygous plants and ag mutants grown in conditions that reduce the floral inductive stimulus have shown that both genes are required to prevent reversion of floral to inflorescence meristems. Here, we present evidence that LFY maintains floral meristem identity independently of AG, and that the primary role of LFY is either direct repression of shoot identity genes or repression of an intermediate factor that activates shoot identity genes. The latter conclusions were deduced from the phenotypes conferred by a gain-of-function transgene, LFY:VP16, that appears to act as a dominant negative, or antimorphic, allele during maintenance of floral meristem identity. These observations contrast with previous findings that LFY acts as a direct activator of floral homeotic genes, supporting the hypothesis that the transcriptional activity of LFY is dependent on specific co-regulators.

Presently the Heavy Ion Fusion Virtual National Laboratory is researching ion sources and injector concepts to understand how to optimize beam brightness over a range of currents (50-2000 mA argon equivalent). One concept initially accelerates millimeter size, milliamp beamlets to 1 MeV before merging them into centimeter size, ampere beams. Computer simulations have shown the final brightness of the merged beams is dominated by the emittance growth of the merging process, as long as the beamlets ion temperature is below a few eV. Thus, a RF multicusp source capable of high current density can produce beams with better brightness compared to ones extracted from a colder source with a large aperture and lower current density. As such, experiments have begun to develop a RF multicusp source capable of delivering one amp of extracted beam current. It is expected that it will require 10 kW of 13 MHz RF power delivered via a quartz shielded, one and half turn, four inch diameter antenna. Important considerations in the development of the source include the dependence of current density and beam ion temperature on consumed RF power and gas pressure. A fast rise time ({approx}100 ns) for the extracted beam pulse must also …

The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. An 1150 m deep gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from several gas-hydrate-bearing zones at the Mallik site. The TOUGH2 general-purpose simulator with the EOSHYDR2 module were used for the analysis. EOSHYDR2 is designed to model the non-isothermal CH{sub 4} (methane) release, phase behavior and flow under conditions typical of methane-hydrate deposits by solving the coupled equations of mass and heat balance, and can describe any combination of gas hydrate dissociation mechanisms. Numerical simulations indicated that significant gas hydrate production at the Mallik site was possible by drawing down the pressure on a thin free-gas zone at the base of the hydrate stability field. Gas hydrate zones with underlying aquifers yielded significant gas production entirely from dissociated gas hydrate, but large amounts of produced water. Lithologically isolated gas-hydrate-bearing reservoirs with no underlying free gas or water zones, and gas-hydrate saturations of at least 50% were also studied. In these cases, it was assumed that thermal stimulation by circulating hot water in the well was the …

Isoelectronic impurity states are localized states induced by stoichiometric single atom substitution in bulk semiconductor. Photoluminescence spectra indicate deep impurity levels of 0.5 to 0.9eV above the top of valence band for systems like: GaN:As, GaN:P, CdS:Te, ZnS:Te. Previous calculations based on small supercells seemingly confirmed these experimental results. However, the current ab initio calculations based on thousand atom supercells indicate that the impurity levels of the above systems are actually much shallower(0.04 to 0.23 eV), and these impurity levels should be compared with photoluminescence excitation spectra, not photoluminescence spectra.

Excess electrons can be introduced into liquids by absorption of high energy radiation, by photoionization, or by photoinjection from metal surfaces. The electron's chemical and physical properties can then be measured, but this requires that the electrons remain free. That is, the liquid must be sufficiently free of electron attaching impurities for these studies. The drift mobility as well as other transport properties of the electron are discussed here as well as electron reactions, free-ion yields and energy levels, Ionization processes typically produce electrons with excess kinetic energy. In liquids during thermalization, where this excess energy is lost to bath molecules, the electrons travel some distance from their geminate positive ions. In general the electrons at this point are still within the coulombic field of their geminate ions and a large fraction of the electrons recombine. However, some electrons escape recombination and the yield that escapes to become free electrons and ions is termed G{sub fi}. Reported values of G{sub fi} for molecular liquids range from 0.05 to 1.1 per 100 eV of energy absorbed. The reasons for this 20-fold range of yields are discussed here.

Lead-Bismuth Eutectic is under consideration as a target material with high-energy protons for generating spallation neutrons to operate actinide and fission product transmuters. An assessment has been performed to study the performance of this target material as a function of the main variables and the design selections. The assessment includes the neutron yield, the spatial energy deposition, the neutron spectrum, the beam window performance, and the target buffer requirements. Heat transfer, hydraulics, beam window material and stresses, and target engineering issues have been considered. The assessment has also considered high-energy deuteron particles to study the impact on the target performance.

Conceptual designs of 90-mm aperture high-gradient quadrupoles based on the Nb{sub 3}Sn superconductor, are being developed at Fermilab for possible 2nd generation IRs with the similar optics as in the current low-beta insertions. Magnet designs and results of magnetic, mechanical, thermal and quench protection analysis for these magnets are presented and discussed.

The purpose of this study was to determine which components of heavy-duty highway vehicles are candidates for the substitution of titanium materials for current materials if the cost of those Ti components is very significantly reduced from current levels. The processes which could be used to produce those low cost components were also investigated. Heavy-duty highway vehicles are defined as all trucks and busses included in Classes 2C through 8. These include heavy pickups and vans above 8,500 lbs. GVWR, through highway tractor trailers. Class 8 is characterized as being a very cyclic market, with ''normal'' year volume, such as in 2000, of approximately 240,000 new vehicles. Classes 3-7 are less cyclic, with ''normal'' i.e., year 2000, volume totaling approximately 325,000 new vehicles. Classes 3-8 are powered about 88.5% by diesel engines, and Class 2C at very roughly 83% diesel. The engine portion of the study therefore focused on diesels. Vehicle production volumes were used in estimates of the market size for candidate components.

Two-dimensional, steady flow of a liquid metal slender jet pouring from a nozzle in the presence of a transverse, nonuniform magnetic field is studied. The surface tension has been neglected, while gravity is shown to be not important. The main aim of the study is to evaluate the importance of the inertial effects. It has been shown that for gradually varying fields characteristic for the divertor region of a tokamak, inertial effects are negligible for N > 10, where N is the interaction parameter. Thus the inertialess flow model is expected to give good results even for relatively low magnetic fields and high jet velocity. Simple relations for the jet thickness and velocity have been derived. The results show that the jet becomes thicker if the field increases along the flow and thinner if it decreases.

The beam dynamics of superconducting (SC) heavy-ion linacs operating in the velocity range below 0.4c require a compact accelerating-focusing lattice. The use of SC solenoids together with SC RF resonators within a common cryostat can solve the real-estate problem. The solenoids must have low fringe fields to avoid magnetic flux capture in the SC RF resonators. Also, incorporating dipole steering coils together with the SC solenoids in one magnet assembly can increase the compactness of the linac lattice. R&D work has been carried out to determine the feasibility of combining the three elements of high solenoid field, low fringe field, and integral dipole field, into one compact package. A 9-Tesla magnet has been initially designed and will be prototyped, with the goal of eventually developing 14-Tesla solenoids of similar design. The most important design issues are: (1) to minimize stray field in the RF cavity region using SC bucking coils and (2) to achieve adequate mechanical stability of the transverse dipole windings in the presence of forces produced by the solenoid/bucking coil assembly. The assembly, including terminals, switches, and protection circuit, are designed to fit inside a 25-cm diameter helium reservoir. The results of the preliminary design of the solenoid, …