For {sup 238}U targets and the five elements considered here, the best yields of neutron-rich isotopes are obtained from neutrons in the 2-20 MeV range. High energy beams of neutrons, protons, and deuterons have comparable integral yields per element to neutrons below 20 MeV, but the distributions are peaked at lower neutron numbers. This is presumably due to a higher neutron multiplicity in the pre-equilibrium stage and/or the compound nucleus/fission stage. For {sup 235}U targets there are high yields predicted especially for thermal neutrons, and also for the fast neutron spectrum. For the high energy neutrons, protons, and deuterons {sup 235}U has no advantage over {sup 238}U. A detailed comparison of the relative advantages of {sup 235}U and {sup 238}U for radioactive beam applications is beyond the scope of this study and will be addressed in the future. The present work is the first step of a more detailed analysis of various possible one- and two-step target geometry calculated with the LAHET code system. It is intended to serve as a guide in choosing geometry and beams for future studies. It is desirable to extend this study to higher beam energies, e.g. 200 to 1000 MeV, but at this time …

The phase transformation of {beta}-HMX (< 0.5% RDX) to the {delta} phase has been studied for over twenty years and more recently with an optically sensitive second harmonic generation technique. Shock studies of the plastic binder composites of HMX have indicated that the transition is perhaps irreversible, a result that concurs with the static pressure results published by F. Goetz et al. [l] in 1978. However the stability field favors the {beta} polymorph over {delta} as pressure is increased (up to 5.4 GPa) along any sensible isotherm. In this experiment strict control of pressure and temperature is maintained while x-ray and optical diagnostics are applied to monitor the conformational dynamics of HMX. Unlike the temperature induced {beta} -> {delta} transition, the pressure induced is heterogeneous in nature. The room pressure and temperature {delta} -> {beta} transition is not immediate although it seems to occur over tens of hours. Transition points and kinetics are path dependent and so this paper describes our work in progress.

The US DOE, with technical assistance from Sandia National Laboratories, has successfully received EPA certification and opened the Waste Isolation Pilot Plant (WIPP), a nuclear waste disposal facility located approximately 42 km east of Carlsbad, New Mexico. Performance assessment analyses indicate that human intrusions by inadvertent, intermittent drilling for resources provide the only credible mechanisms for releases of radionuclides from the disposal system. In modeling long-term brine releases, subsequent to a drilling event, potential migration pathways through the permeable layers of rock above the Salado formation were analyzed. Major emphasis is placed on the Culebra Member of the Rustler Formation because this is the most transmissive geologic layer overlying the WIPP site. In order to help quantify parameters for the calculated releases, radionuclide transport experiments have been earned out using intact-core columns obtained from the Culebra dolomite member of the Rustler Formation within the WIPP site. This paper deals primarily with results of analyses for {sup 241}Pu and {sup 241}Am distributions developed during transport experiments in one of these cores. Transport experiments were done using a synthetic brine that simulates Culebra brine at the core recovery location (the WIPP air-intake shaft--AIS). Hydraulic characteristics (i.e., apparent porosity and apparent dispersion coefficient) …

Recent experience showed that bunch rotations are needed in the AGS for gold as well as proton operations before the beams are injected into RHIC. The longitudinal bunch area is increased for gold operation from 0.3 up to 0.5 eV {center_dot}s/u at design intensity. This paper reviews the revised longitudinal parameters in RHIC during injection, acceleration, transition crossing, rebucketing, and storage for gold and proton beams, accommodating for the change in injection conditions at the AGS.

Minimum-time trajectory tracking of an under-actuated mechanical system called the Acrobot is presented. The success of the controller is demonstrated by the fact that the tracking error is reduced by more than an order of magnitude when compared to the open-loop system response. The control law is obtained by linearizing the system about the nominal trajectory and applying differential dynamic programming to the resulting linear time-varying system, while using a weighted sum of the state-deviation and input-deviation as the cost function.

Beam echos have been measured at FNAL [3] and CERN [5] in coasting beams. A coherent oscillation introduced by a short RF burst decoheres quickly, but a coherent echo of this oscillation can be observed if the decohered oscillation is ''bounced off'' a second RF burst. In this report we describe first longitudinal echo measurements of bunched beam in the AGS accelerator. We applied a method proposed by Stupakov [1] for transverse beam echos, where the initial oscillation is produced by a dipole kick and is bounced off a quadrupole kick. In the longitudinal case the dipole and quadrupole kicks are produced by a cavities operating at a 90{degree} and 0{degree} phase shift, respectively.

Bent solenoids can be used to transport low energy beams as they provide both confinement and dispersion of particle orbits. Solenoids are being considered both as emittance exchange sections and spectrometers in the muon cooling system as part of the study of the muon collider. They present the results of a study of bent solenoids which considers the design of coupling sections between bent solenoids to straight solenoids, drift compensation fields, aberrations, and factors relating to the construction, such as field ripple, stored energy, coil forces and field errors.

A preliminary demonstration of free-space electric power transmission has been conducted using non-coherent laser diode arrays as the transmitter and standard silicon photovoltaic cell arrays as the receiver. The transmitter assembly used a high-power-density array of infrared laser diode bars, water cooled via integrated microchannel heat sinks and focused by cylindrical microlenses. The diode array composite beam was refocused by a parabolic mirror over a 10 meter path, and received on a {approximately}15 x 25 cm panel of thinned single crystal high efficiency silicon solar cells. The maximum cell output obtained was several watts, and the cell output was used to drive a small motor. Due to operating constraints and unexpected effects, particularly the high nonuniformity of the output beam, both the distance and total received power in this demonstration were modest. However, the existing transmitter is capable of supplying several hundred watts of light output, with a projected received electric power in excess of 200 watts. The source radiance is approximately 5 x 10{sup 9} W/m{sup 2}-steradian. With the existing 20 cm aperture, useful power transmission over ranges to {approximately}100 meters should be achievable with a DC to DC efficiency of greater than 10%. Non-coherent sources of this type …

Radiation damage production and accumulation in solids can be divided into two stages. In the production stage, the impinging particle gradually gives off its kinetic energy to lattice atoms in the form of energetic recoils. These deposit their energy by generating secondary and higher order recoils that result in a displacement collision cascade. The outcome of this stage, of the time scale of a few to 100 picoseconds, is a population of point or clustered defects known as the primary state of damage. In the second stage, which can extend over seconds, defects that survive recombination within their nascent cascade migrate over long distances, interacting with the microstructure. These freely migrating defects (FMD) are responsible for the changes in the macroscopic properties of metals under irradiation, such as void swelling, embrittlement, radiation enhanced diffusion, etc. Such changes in mechanical properties are most often detrimental and severely limit the flexibility in materials choice and operating temperature when designing a fusion power plant. Under most conditions, such as those that would be present in a magnetic fusion energy plant, or when bombarding with fission or spallation neutrons, irradiation takes place at a certain dose rate and temperature, but in a continuous manner. …

The design of the National Ignition Facility (NIF) is based on conversion of 1.05 {mu}m wavelength light (1{omega}) into third harmonic light (3{omega}) by passage through KDP frequency conversion crystals. It is important for proper coupling of radiation into the targets that the final beam impinging upon the target should have little 1{omega} or 2{omega} light. It is also desirable to avoid direct line-of sight for neutrons between the target and the KDP crystals, in order to prevent damage. These issues can be overcome by employing diffraction gratings immediately before the final NIF focusing lens to direct the 3{omega} beam to the target. A single grating design is highly dispersive, and may introduce intolerable divergence into the beam. In order to overcome this limitation, we propose to use a grating pair. This will provide transverse offset of the beam and eliminate the dispersion while offering several other advantages.

The long-term success of the Experimental Breeder Reactor-II (EBR-II) provides several insights into fundamental characteristics and design features of a nuclear generating station that enhance safety, operability, and maintainability. Some of these same characteristics, together with other features, offer the potential for operational lifetimes well beyond the current licensing time frame, and improved reliability that could potentially reduce amortized capital costs as well as overall operation and maintenance costs if incorporated into advanced plant designs. These features and characteristics are described and the associated benefits are discussed.

The US Department of Energy and its national laboratories are a major employer of scientists and engineers and consequently have a strong interest in the development and training of a qualified pool of employment candidates. For many years the DOE and its national laboratories have supported education activities devoted to increasing the number and quality of science and engineering graduates. This is part of the DOE mission because of the critical national need for scientists and engineers and the recognized deficiencies in the education system for science and mathematics training. Though funding support for such activities has waxed and waned, strong education programs have survived in spite of budget pressures. This paper reviews a few of the education programs presently supported at Sandia by the Science and Technology Outreach Department. The US DOE Defense Programs Office and Sandia National Laboratories provide financial support for these education activities.

The D0 and CDF proton-antiproton collider experiments at the Tevatron accumulated large samples of high energy jet production data during Run I (1992- 1996). Presented here are measurements of the central inclusive jet cross section at center-of-mass energies of 1800 and 630 GeV (by the D0 and CDF experiments) and a forward ( |{eta}| < 1.5) inclusive cross section measurement by the D0 experiment at 1800 GeV. Cross sections are compared to next-to-leading order QCD predictions with recent parton distribution functions. Also included is a measure of subjet multiplicity in jets produced at 1800 GeV using a successive combination type of jet algorithm.

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Efforts to more effectively monitor the Comprehensive Nuclear-Test-Ban Treaty (commonly referred to as the CTBT) include research into methods of seismic discrimination. The most common seismic discriminants exploit differences in seismic amplitude for differing source types. Amplitude discriminants are quite effective when wave-propagation (a.k.a. path) effects are properly accounted for. However, because path effects can be exceedingly complex, path calibration is often accomplished empirically by spatially interpolating amplitude characteristics for a set of calibration earthquakes with techniques like Bayesian kriging. As a result, amplitude discriminants can be highly effective when natural seismicity provides sufficient event coverage to characterize a region. However, amplitude discrimination can become less effective for events that are far from historical (path-calibration) events. It is intuitive that events occurring at a distance from historical seismicity patterns are inherently suspect. However, quantifying the degree to which a particular event is unexpected could be of great utility in CTBT monitoring. Epicenter location is commonly used as a qualitative discriminant. For instance, if a seismic event is located in the deep ocean, then the event is generally considered to be an earthquake. Such qualitative uses of seismic location have great utility; however, a quantitative method to differentiate events from the …

The purpose of this test was to characterize the conductance of different configurations of vent paths put into weapons assemblies through application of Halthane 88-3 precoats onto the parts. Conductance is a measure of the ease of gas flow in an assembly. It is the inverse of resistance which may be more familiar to most readers. It is defined as the resultant of the gas flow (torr-1/sec) divided by the pressure drop (torr) in the assembly. Its dimensions are thus liters per second. The conductance paths are put into the precoats to allow pumpdown of weapon assemblies and communication during stockpile life. They are put into the precoats by applying tape of the desired width onto the part prior to coating. The Halthane 88-3 is then rolled onto the part and when the tape is removed the vent paths are left. To keep this report unclassified some of the description of the situation has been abbreviated. For a more complete description of the device configuration and conductance issue, see the final report on WDW 9009-A and -B (CODT 98-0809).

The ferroelectric and piezoelectric properties of 2000 {angstrom} thick chemical solution deposited Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT) thin films were investigated. Several Zr/Ti ratios were studied: 30/70, 50/50 and 65/35, which correspond to tetragonal, near-morphotropic, and rhombohedral symmetries. In all samples, a {l_brace}111{r_brace}-texture is predominant. Longitudinal piezoelectric coefficients and their dc field dependence were measured using the contact AFM method. The expected trend of a maximum piezoelectric coefficient at or near to the MPB was not observed. The composition dependence was small, with the maximum d{sub 33} occurring in the tetragonal material. To explain the results, crystallographic texture and film thickness effects are suggested. Using a modified phenomenological approach, derived electrostrictive coefficients, and experimental data, d{sub 33} values were calculated. Qualitative agreement was observed between the measured and calculated coefficients. Justifications of modifications to the calculations are discussed.

Successful operation of large-scale high-power lasers, such as those in use and planned at LLNL and elsewhere, require optical elements that can withstand extremely high fluences without suffering damage. Of particular concern are gratings used for pulse compression. Laser induced damage to bulk dielectric material originates with coupling of the electric field of the radiation to bound electrons, proceeding through a succession of mechanisms that couple the electron kinetic energy to lattice energy and ultimately to macroscopic structural changes (e.g. fracture, melting, ablation, etc.). The constructive interference that is responsible for the diffractive behavior of a grating or the reflective properties of a multilayer dielectric stack can enhance the electric field above values that would occur in unstructured homogeneous material. The presence of nonuniform electric fields, resulting from diffractive coherence, has the potential to affect damage thresholds We describe aspects of LLNL work directed towards understanding the influence of dielectric structures upon damage, with particular emphasis on electric fields within multilayer dielectric stacks.

The Sextant Test of the Relativistic Heavy Ion Collider (RHIC) was an important step towards its completion. One sixth of the two RHIC accelerators was fully commissioned. Gold ion beam was injected and transported through one sextant of one of the two rings. The betatron phase advance per cell was measured by recording differences in the horizontal and vertical positions of the beam at the end of the sextant due to a sequence of correction dipole kicks along the beam line. Measurement results show excellent agreement with predicted values, confirming that production measurements of the integral functions of the quadrupoles were very accurate, and that the polarity of all elements (correction dipoles, quadrupoles, dipoles etc.) was correct.

This paper describes the design process of physical security as applied to a U.S. Border Port of Entry (PoE). Included in this paper are descriptions of the elements that compose U.S. border security. The physical security design will describe the various elements that make up the process as well as the considerations that must be taken into account when dealing with system integration of those elements. The distinctions between preventing unlawful entry and exit of illegal contraband will be emphasized.

Successful operation of large-scale high-power lasers, such as those in use and planned at LLNL and elsewhere, require optical elements that can withstand extremely high fluences without suffering damage. Of particular concern are dielectric diffraction gratings used for beam sampling and pulse compression. Laser induced damage to bulk dielectric material originates with coupling of the electric field of the radiation to bound electrons, proceeding through a succession of mechanisms that couple the electron kinetic energy to lattice energy and ultimately to macroscopic structural changes (e.g. melting). The constructive interference that is responsible for the diffractive behavior of a grating or the reflective properties of a multilayer dielectric stack can enhance the electric field above values that would occur in unstructured homogeneous material. Much work has been done to model damage to bulk matter. The presence of nonuniform electric fields, resulting from diffractive coherence, has the potential to affect damage thresholds and requires more elaborate theory. We shall discuss aspects of work directed towards understanding the influence of dielectric structures upon damage, with particular emphasis on computations and interpretation of electric fields within dielectric gratings and multilayer dielectric stacks, noting particularly the interference effects that occur in these structures.

Novel chemically bonded phosphate ceramics have been investigated for stabilization and solidification of chloride and nitrate salt wastes. Using low-temperature processing, we stabilized and solidified chloride and nitrate surrogate salts (with hazardous metals) in magnesium potassium phosphate ceramics up to waste loadings of 70-80 wt.%. A variety of characterizations, including strength, microstructure, and leaching, were then conducted on the waste forms. Leaching tests show that all heavy metals in the leachant are well below the EPAs universal treatment standard limits. Long-term leaching tests, per ANS 16. 1 procedure, yields leachability index for nitrate ions &gt; 12. Chloride ions are expected to have an even higher (i.e., better) leachability index. Structural performance of these final waste forms, as indicated by compression strength and durability in aqueous environments, satisfies the regulatory criteria. Thus, based on the results of this study, it seems that phosphate ceramics are viable option for containment of salt wastes.

The Relativistic Heavy Ion Collider (RHIC) consists of two rings with six fold symmetry. The six interaction regions (IR)s are connected with twelve FODO cells. RHIC quadrupoles in the interaction regions have independent tuning capability. The betatron functions will be measured by a three methods. First, tunable IR quadrupoles will be adjusted to measure betatron functions at those locations through the change in tune. Second, sinusoidal coherent dipole oscillations will be used to measure the betatron phases and functions (as performed in LEP). Third, a correction dipole kick technique will be used (as at Fermilab). Special attention will be given to the ''betatron squeeze'' procedure by which the two large experiments PHENIX and STAR will achieve minimum betatron functions between 1 and 2 m.

Alumina (94 and 99.8% grade compositions) was brazed directly to itself with gold-based active brazing alloys (ABA's) containing vanadium additions of 1,2 and 3 weight percent. The effects of brazing conditions on the joint properties were investigated. Wetting behavior, interfacial reactions, microstructure, hermeticity and tensile strength were determined. Wetting was fair to good for the ABA and base material combinations. Microanalysis identified a discontinuous Al-V-O spinel reaction product at the alumina-braze interface. Tensile strength results for 94% alumina were uniformly good and generally not sensitive to the vanadium concentration, with tensile values of 85-105 MPa. There was more variability in the 99.8% alumina strength results, with values ranging from 25-95 MPa. The highest vanadium concentration (3 wt. %) yielded the highest joint strength for the brazed 99.8% alumina. Failures in the 99.8% alumina samples occurred at the braze-alumina interface, while the 94% alumina specimens exhibited fracture of the ceramic substrate.