Energetic oxetane polymers have shown promise as performance-enhancing ingredients in gun and missile propellants. In order to correctly predict the performance of energetic materials containing these polymers, it is important to have accurate, experimentally determined values for the polymer heats of formation ({Delta}H{sub f}). In support of a theoretical study on gun propellant performance, heats of combustion were experimentally determined for a series of oxetane polymers and monomers (see below) using combustion calorimetry, and from these, {Delta}H{sub f} values were calculated. Polymers included BAMO/AMMO, BAMO/NMMO (polyol and TPE), and BNMO/NMMO mixtures. In order to calculate the {Delta}H{sub f} of the polymers from heat of combustion data, a number of assumptions were made regarding the polymer structure and molecular weight. A comparison of the {Delta}H{sub f} values for the monomers and polymers were made, and these values were compared to heats of formation measured elsewhere.

The goal of this work was to determine the effects on plutonium isotopic analysis of having plutonium inside of a 0.25 inch thick stainless steel can. To do this, they analyzed plutonium samples with a U-Pu InSpector (which uses a high-resolution gamma-ray detector and the analysis code MGA (Multi Group Analysis)), to determine both the 240-Pu/239-Pu ratio and the years since the plutonium was separated from americium. They analyzed a 1.6 kg plutonium sample that was placed inside of a 0.25 inch can at varying distances (0-2 meters) and count times (10 seconds-30 minutes). In separate experiments, they analyzed 0.4g plutonium sources with stainless-steel thickness' ranging from 0.125 to 1.0 inch. This report will show three effects of having plutonium in a stainless steel can: (1) 240-Pu/240-Pu can be quickly and accurately determined for a 1.6 kg plutonium sample inside of a 0.25 inch thick stainless-steel can, as this thickness of stainless steel acts as a perfect filter to reduce the intense 59 keV gamma peak from 241-Am. (2) The accuracy of determining the plutonium-americium separation date is not effected by 0.25 inch of stainless steel. (3) Both 240-Pu/239-Pu and the americium separation date can be accurately determined for stainless-steel …

To qualify the performance of non-actinic inspection tools, a novel EUV mask inspection system has been installed at the Advanced Light Source (ALS) synchrotron facility at Lawrence Berkeley National Laboratory. Similar to the older generation actinic mask inspection tool, the new system can operate in scanning mode, when mask blanks are scanned for defects using 13.5-nm in-band radiation to identify and map all locations on the mask that scatter a significant amount of EUV light. By modifying and optimizing beamline optics (11.3.2 at ALS) and replacing K-B focusing mirrors with a high quality Schwarzschild illuminator, the new system achieves an order of magnitude improvement on in-band EUV flux density at the mask, enabling faster scanning speed and higher sensitivity to smaller defects. Moreover, the system can also operate in imaging mode, when it becomes a zone-plate-based full-field EUV microscope with spatial resolution better than 100 nm. The microscope utilizes an off-axis setup, making it possible to obtain bright field images over a field-of-view of 5 x 5 {micro}m.

Thin films of Ti-Cr-Al-O are produced for use as an electrical resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O{sub 2}. Vertical resistivity values from 10{sup 4} to 10{sup 10} Ohm-cm are measured for Ti-Cr-Al-O films. The film resistivity can be design selected through control of the target composition and the deposition parameters. The Ti-Cr-Al-O thin film resistor is found to be thermally stable unlike other metal-oxide films.

An analytical formulation of conductivity bounds by Bergman and Milton is used in a different way to obtain rigorous bounds on the real transport coefficients (electrical conductivity, thermal conductivity, and/or fluid permeability) of a fluid-saturated porous medium. These bounds do not depend explicitly on the porosity, but rather on two formation factors--one associated with the pore space and the other with the solid frame. Hashin-Shtrikman bounds for transport in random polycrystals of porous-material laminates will also be discussed.

The selling of weapons-related nuclear knowledge by Russian scientists for economic gain constitutes a threat to US national security. Some estimate that the number of Russian scientists seeking permanent employment abroad constitute five to ten percent of all researchers who have left the field of science. And, there is concern that those who have left are ''the better minds.'' Moreover, the issue of brain drain concerns not only those who move abroad permanently, but those who still reside in Russia and travel abroad to sell their knowledge. Of particular concern to the US is the potential sale of WMD knowledge by some. To ''mitigate the risk that economic difficulties...might create the temptation for individuals or institutes to sell expertise to countries of proliferation concern and terrorist organizations,'' the Department of Energy launched a Nuclear Cities Initiative (NCI) in 1998 with the goal of creating commercial jobs and economic diversification in the ten closed cities that form the core of Russia's nuclear weapons complex to accommodate the loss of employment in the nuclear weapons industry. However, unless Russia opens access to the areas of its closed cities that are, or could become, involved in commercial activities-while of course carefully controlling access …

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Adaptive mesh refinement selectively subdivides the elements of a coarse user supplied mesh to produce a fine mesh with reduced discretization error. Effective use of adaptive mesh refinement coupled with an a posteriori error estimator can produce a mesh that solves a problem to a given discretization error using far fewer elements than uniform refinement. A geometric multigrid solver uses increasingly finer discretizations of the same geometry to produce a very fast and numerically scalable solution to a set of linear equations. Adaptive mesh refinement is a natural method for creating the different meshes required by the multigrid solver. This paper describes the implementation of a scalable adaptive multigrid method on a distributed memory parallel computer. Results are presented that demonstrate the parallel performance of the methodology by solving a linear elastic rocket fuel deformation problem on an SGI Origin 3000. Two challenges must be met when implementing adaptive multigrid algorithms on massively parallel computing platforms. First, although the fine mesh for which the solution is desired may be large and scaled to the number of processors, the multigrid algorithm must also operate on much smaller fixed-size data sets on the coarse levels. Second, the mesh must be repartitioned as …

The goal of the continuous air monitor (CAM) system at the Los Alamos National Laboratory`s Plutonium Facility (PF-4) is to have a flow rate of 1 cubic feet per minute (cfm) drawn through the CAMs. However, design limitations in the house vacuum result in many CAMs having less than 1 cfm being drawn through them. Reduced flow rates through CAMs present a compromise in worker protection. Laboratory Health and Safety personnel and DOE officials established a flow rate of 0.5 cfm or less as operationally unacceptable. This report quantitatively estimated the difference in risk to workers from a reduced flow rate of 0.5 cfm relative to the risk inherent with a flow rate of 1 cfm. I calculated risk in terms of Committed Effective Dose Equivalent (CEDE) and used units of rem. Estimates for the increase in risk for 0.5 cfm compared to 1 cfm ranged from 0.32 rem to 3.3 rem. The difference in the minimum alarm concentration between 0.5 cfm and I cfm was also compared and was estimated to range from 0.4 rem to 4 rem.

A finite element method is introduced for solving the neutron transport equations. Our method falls into the category of Petrov-Galerkin solution, since the trial space differs from the test space. The close relationship between this method and the discrete ordinate method is discussed, and the methods are compared for simple test problems.

Most of the procedures and techniques described were developed over the past three years. Starting in late 1976, development began on high-accuracy computer codes for electromagnetic field and force analysis. This effort resulted in completion of a family of computer programs called MAGIC (MAGnetic Integration Calcaultion). Included in this group of programs is a post-processor called POSTMAGIC that links MAGIC to GDSAP (General Dynamics Structural Analysis Program) by automatically transferring force data. Integrating these computer programs afforded us the capability to readily analyze several different conditions that are anticipated to occur during tokamak operation. During 1977 we initiated the development of the CONVERT program that effectively links our THERMAL ANALYZER program to GDSAP by automatically transferring temperature data. The CONVERT program allowed us the capability to readily predict thermal stresses at several different time phases during the computer-simulated cooldown and warmup cycle. This feature aided us in determining the most crucial time phases and to adjust recommended operating procedure to minimize risk.

New short-pulse laser technology has made possible the production of extremely bright laser sources. The use of these new techniques on large scale Nd:Glass based laser systems would make it possible to produce 1000 TW (Petawatt) pulses. Such pulses would yield focused intensities exceeding 10{sup 21}W/cm{sup 2} corresponding to an electric field in excess of 100 e/a{sub 0}{sup 2} and an energy density equivalent to that of a 10 keV blackbody. Such a source would have important applications in x-ray laser research and lead to a fundamentally new class of experiments in atomic, nuclear, solid state, plasma and high-energy density physics. Such a facility could be constructed with existing chirped-pulse'' technology. A one-year period of research addressing outstanding technical questions can extend the technology resulting in a more compact and cost effective design. For this reason, we are seeking a Director's Initiative grant in the amount of $590,000 for FY89 to investigate these issues. An equivalent amount in personnel and facilities would be provided by Y-Division. The study will include development of a chirped-pulse'' front-end capable of producing laser pulses of 2 J at 1.053 {mu}m with a 1 psec pulsewidth laser. Upon completion, this front-end will be installed on …

A fusion breeder holds the promise of a new capability - ''dialable'' reserve capacity at little additional cost - that offers stockpile planners a new way to deal with today's uncertainties in forecasting long range needs. Though still in the research stage, fusion can be developed in time to meet future military requirements. Much of the necessary technology will be developed by the ongoing magnetic fusion energy program. However, a specific program to develop the nuclear technology required for materials production is needed if fusion is to become a viable option for a new production complex around the turn of the century.

We have been using the 3d PIC code WARP6 to model the behavior of beams in a heavy ion induction accelerator; such linacs are candidates for an ICF driver. Improvements have been added to the code to model an axially confined beam using comoving axial electric fields to simulate the confining ears'' applied to the accelerating pulses in a real system. We have also added a facility for modeling a beam in a round pipe, applying a capacity matrix to each axial Fourier mode in turn. These additions are described along with results, such as the effect of pipe shape on the beam quality degradation from quadrupole misalignments. 5 refs., 6 figs., 1 tab.

Because changes in solar activity can modify the fluxes of cosmic-ray particles in the solar system, the nature of the galactic and solar cosmic rays and their interactions with matter are described and used to study the ancient sun. The use of cosmogenic nuclides in meteorites and lunar samples as detectors of past cosmic-ray variations are discussed. Meteorite records of the history of the galactic cosmic rays are reviewed. The fluxes of solar protons over various time periods as determined from lunar radionuclide data are presented and examined. The intensities of solar protons emitted during 1954 to 1964 (11-year solar cycle number 19) were much larger than those for 1965 to 1975 (solar cycle 20). Average solar-proton fluxes determined for the last one to ten million years from lunar /sup 26/Al and /sup 53/Mn data show little variation and are similar to the fluxes for recent solar cycles. Lunar activities of /sup 14/C (and preliminary results for /sup 81/Kr) indicate that the average fluxes of solar protons over the last 10/sup 4/ (and 10/sup 5/) years are several times larger than those for the last 10/sup 6/ to 10/sup 7/ years; however, cross-section measurements and other work are needed to …

To minimize the radiological risk from the operation of a waste management system for the safe disposal of high-level waste, performance characteristics of the solidified waste form must be specified. The minimum waste form characteristics that must be specified are the radionuclide volatilization fraction, airborne particulate dispersion fraction, and the aqueous dissolution characteristics. The results indicate that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. The actual values of expected risk are sensitive to modeling assumptions and data base uncertainties. The transportation step appears to be the most limiting in determining the required performance characteristics.

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We study the structure of the moduli spaces of vacua and superpotentials of N = 2 supersymmetric gauge theories in three dimensions. By analyzing the instanton corrections, we compute the exact superpotentials and determine the quantum Coulomb and Higgs branches of the theories in the weak coupling regions. We find candidates for non-trivial N = 2 superconformal field theories at the singularities of the moduli spaces. The analysis is carried out explicitly for gauge groups U(N{sub c}) and SU(N{sub c}) with N{sub f} flavors. We show that the field theory results are in complete agreement with the intersecting branes picture. We also compute the exact superpotentials for arbitrary gauge groups and arbitrary matter content.

Solvation of small and large clusters are studied by simulation, considering a range of solvent-solute attractive energy strengths. Over a wide range of conditions, both for solvation in the Lennard-Jones liquid and in the SPC model of water, it is shown that the mean solvent density varies linearly with changes in solvent-solute adhesion or attractive energy strength. This behavior is understood from the perspective of Weeks theory of solvation [Ann. Rev. Phys. Chem. 2002, 53, 533] and supports theories based upon that perspective.

Recently Hertog, Horowitz, and Maeda (HHM) (hep-th/0310054) have proposed that cosmic censorship can be violated in the AdS/CFT context. They argue that for certain initial data there is insufficient energy available to make a black hole whose horizon is big enough to cloak the singularity that forms. We have investigated this proposal in the models HHM discuss and have thus far been unable to find initial data that provably satisfy this criterion, despite our development of an improved lower bound on the size of the singular region. This is consistent with recent numerical results (hep-th/0402109). For certain initial data, the energies of our configurations are not far above the lower bound on the requisite black hole mass, and so it is possible that in the exact time development naked singularities do form. We go on to argue that the finite radius cut-off AdS_5 situation discussed by HHM displays instabilities when the full 10D theory is considered. We propose an AdS_3 example that may well be free of this instability.

We examine a double trace deformation of SU(N) Yang-Mills theory which, for large N and large volume, is equivalent to unmodified Yang-Mills theory up to O(1/N{sup 2}) corrections. In contrast to the unmodified theory, large N volume independence is valid in the deformed theory down to arbitrarily small volumes. The double trace deformation prevents the spontaneous breaking of center symmetry which would otherwise disrupt large N volume independence in small volumes. For small values of N, if the theory is formulated on R{sup 3} x S{sup 1} with a sufficiently small compactification size L, then an analytic treatment of the non-perturbative dynamics of the deformed theory is possible. In this regime, we show that the deformed Yang-Mills theory has a mass gap and exhibits linear confinement. Increasing the circumference L or number of colors N decreases the separation of scales on which the analytic treatment relies. However, there are no order parameters which distinguish the small and large radius regimes. Consequently, for small N the deformed theory provides a novel example of a locally four-dimensional pure gauge theory in which one has analytic control over confinement, while for large N it provides a simple fully reduced model for Yang-Mills theory. …

In a fusion reactor based on the Magnetized Target Fusion approach, the permanent power supply has to deliver currents up to a few mega-amperes to the target dropped into the reaction chamber. All the structures situated around the target will be destroyed after every pulse and have to be replaced at a frequency of 1 to 10 Hz. In this paper, an approach based on the use of spherical blanket surrounding the target, and pulsed plasma electrodes connecting the target to the power supply, is discussed. A brief physic analysis of the processes associated with creation of plasma electrodes is discussed.