We report macroparticle simulations for comparison withmeasured results from a proton beam-halo experiment in a 52-quadrupoleperiodic-focusing channel. An important issue is that the inputphase-space distribution is not experimentally known. Three differentinitial distributions with different shapes predict different beamprofiles in the transport system. Simulations have been fairly successfulin reproducing the core of the measured matched-beam profiles and thetrend of emittance growth as a function of mismatch factor, butunderestimate the growth rate of halo and emittance for mismatched beams.In this study, we find that knowledge of the Courant-Snyder parametersand emittances of the input beam is not sufficient for reliableprediction of the halo. Input distributions iwth greater population inthe tails produce larger rates of emittance growth, a result that isqualitatively consistent with the particle-core model of halo formationin mismatched beams.

When waste glass is poured into metal canisters, it fractures, primarily due to temperature gradients induced during cooling. A technique to quantitatively determine the additional glass surface area due to fracture was developed based on this study.

The Yucca Mountain Site Characterization Project is currently evaluating the future performance of the proposed U.S. high-level nuclear waste repository. Using the Total System Performance Assessment (TSPA) model, a stylized analysis was conducted to evaluate the relative importance of natural and engineered barriers to movement of radionuclides from the proposed repository. These stylized ''one-on'' analyses consist of sequentially adding features, components, and processes, associated with the natural and engineered barriers, incorporated within the TSPA model and evaluating the effect of these elements on repository performance, as measured by the total mean annual dose to a reasonably maximally exposed individual. The analyses are ''stylized'' in the sense that they are performed to gain insight only. They are not meant to represent a real physical system in most cases, and in some cases allow the TSPA model to simulate results using parameter ranges outside the normal bounds of the TSPA model. In particular, the analyses provide insight into the relative contributions of repository features and processes in a way that is not possible using the full TSPA performance-assessment model. For example, in the nominal scenario of the TSPA model, the contribution of the natural system is masked by the contribution of the …

This document describes a laboratory tracer facility which was used to show Duolite CS-100 resin's capability for removing cesium from supernate.

The Linac Coherent Light Source (LCLS) Project includes the undulator subsystem that has 33 undulator magnetic structures each 3.4 m long. Positioning of the LCLS undulators along the undulator line with an accuracy of 50 {micro}m in the vertical transverse direction is required. A prototype of the LCLS undulator has been built with a positioning system based on three stages with cam shafts. Each cam shaft produces reciprocating motion with a range of {+-}3 mm. A servomotor with integrated brake, incremental rotary encoder, servo amplifier, and controller is used with a 100:1 ratio gear box to drive each cam shaft. Resolution of the motion control is about 0.05 {micro}m. SmartMotors are connected in parallel through an RS-485 interface to the serial port of the computer. With this approach, the control system is easily expandable; up to 120 motors can be controlled with one serial port. Positioning accuracy of about 10 {micro}m for the LCLS undulator prototype is demonstrated.

Conventional annular Hall thrusters become inefficient when scaled to low power. An alternative approach, a 2.6-cm miniaturized cylindrical Hall thruster with a cusp-type magnetic field distribution, was developed and studied. Its performance was compared to that of a conventional annular thruster of the same dimensions. The cylindrical thruster exhibits discharge characteristics similar to those of the annular thruster, but it has a much higher propellant ionization efficiency. Significantly, a large fraction of multi-charged xenon ions might be present in the outgoing ion flux generated by the cylindrical thruster. The operation of the cylindrical thruster is quieter than that of the annular thruster. The characteristic peak in the discharge current fluctuation spectrum at 50-60 kHz appears to be due to ionization instabilities. In the power range 50-300 W, the cylindrical and annular thrusters have comparable efficiencies (15-32%) and thrusts (2.5-12 mN). For the annular configuration, a voltage less than 200 V was not sufficient to sustain the discharge at low propellant flow rates. The cylindrical thruster can operate at voltages lower than 200 V, which suggests that a cylindrical thruster can be designed to operate at even smaller power.

The purpose of this report is to describe the methodology and results obtained from a continuing DOE Office of Transportation Technologies (OTT) activity to estimate future effects of OTT projects on national energy use, petroleum consumption, criteria emissions, greenhouse gas emissions, and various measures of national income and employment. Assumptions are made about the future costs and characteristics of alternative vehicles and fuels. Models that take into account the value that vehicle buyers place on various vehicle characteristics are used to estimate the market penetration of new vehicle technologies. A different set of assumptions would yield results that are different from what is presented here. Analysis results quantify various benefits including: energy and petroleum reductions, carbon equivalent greenhouse gas emissions, criteria pollutant emissions reductions, and the associated economic impacts on the Gross Domestic Product (GDP) and jobs. The scope of this report addresses light vehicles including passenger automobiles, Class 1 and 2 trucks, and heavy trucks (Classes 3 through 8). The time period spans the present through the year 2030. All energy savings start from baseline projections of transportation sector energy use obtained from the ''Annual Energy Outlook,'' issued annually by the US Department of Energy, Energy Information Administration (Ref. …

The history and recent progress of atmospheric neutrinos are reviewed. An emphasis is placed on results from experiments other than Super-Kamiokande.

The objective of this study was to develop further understanding of the effects of waste loading on glass leaching. Specifically, waste loadings up to 60 wt per cent oxides were investigated by leaching glasses in buffered and unbuffered solutions.

This paper presents the radiological effect on the offsite population from technetium-99 (Tc-99) releases associated with the disposal of the Savannah River Plant high-level waste.

We have acquired spatial-spectral datacubes of astronomical objects using the Livermore visible-band imaging Fourier transform spectrometer at Apache Point Observatory. Each raw datacube contains hundreds of thousands of spectral interferograms. We present in-progress demonstrations of these observations.

In the second phase of a program to develop a compact accelerator based on a dielectric-loaded accelerating structure, we have conducted high power tests on a traveling-wave and a standing-wave prototype. Indications are that the traveling-wave structure achieved an accelerating gradient of 3-5 MV/m before the input coupling window failed, while the standing wave structure was poorly matched at high power due to contamination of copper residue on its coupling window. To solve both of these problems, a new method for coupling RF into the structures has been developed. The new couplers and the rest of the modular structure are currently under construction and will be tested at the Naval Research Laboratory shortly.

The next major frontier in magnetic fusion physics is to explore and understand the strong nonlinear coupling among confinement, MHD stability, self-heating, edge physics, and wave-particle interactions that is fundamental to fusion plasma behavior. The Fusion Ignition Research Experiment (FIRE) Design Study has been undertaken to define the lowest cost facility to attain, explore, understand, and optimize magnetically confined fusion-dominated plasmas. The FIRE is envisioned as an extension of the existing Advanced Tokamak Program that could lead to an attractive magnetic fusion reactor. The FIRE activities have focused on the physics and engineering assessment of a compact, high-field tokamak with the capability of achieving Q approximately equal to 10 in the ELMy H-mode for a duration of about 1.5 plasma current redistribution times (skin times) during an initial burning-plasma science phase, and the flexibility to add Advanced Tokamak hardware (e.g., lower-hybrid current drive) later. The configuration chosen for FIRE is similar to that of ARIES-RS, the U.S. Fusion Power Plant study utilizing an Advanced Tokamak reactor. The key ''Advanced Tokamak'' features are: strong plasma shaping, double-null pumping divertors, low toroidal field ripple (<0.3%), internal control coils, and space for wall stabilization capabilities. The reference design point is R subscript ''o'' …

Stitching interferometry, using small-aperture, high-resolution, phase-measuring interferometry, has been proposed for quite some time now as a metrology technique to obtain 3-dimensional profiles of surfaces of oversized optical components and substrates. The aim of this work is to apply this method to the specific case of long grazing-incidence x-ray mirrors, such as those used in beamlines at synchrotron radiation facilities around the world. Both fabrication and characterization of these mirrors would greatly benefit from this technique because it offers the potential for providing measurements with accuracy and resolution better than those obtained using existing noncontact laser profilers, such as the long trace profiler (LTP). Measurement data can be used as feedback for computer-controlled fabrication processes to correct for possible topography errors. The data can also be used for simulating and predicting mirror performance under realistic conditions. A semiautomated stitching system was built and tested at the X-ray Optics Metrology Laboratory of the Advanced Photon Source at Argonne National Laboratory. The initial objective was to achieve a measurement sensitivity on the order of 1 {micro}rad rms. Preliminary tests on a 1 m-long x-ray mirror showed system repeatability of less than 0.6 {micro}rad rms. This value is comparable to that of a …

Grain-boundary (GB) properties in a polycrystalline system are generally anisotropic; in particular, both the GB energy and mobility depend on the GB misorientation. Moreover, in nanocrystalline materials, in which the grain size is less than 100 nm, grain rotations leading to the coalescence of neighboring grains via elimination of the common GB between them may provide a new mechanism for grain growth. Here they investigate the combined effect of curvature-driven GB migration and grain-rotation grain-coalescence on the kinetics, topology and morphology of grain growth. A stochastic velocity-Monte-Carlo algorithm based on a variational formulation for the dissipated power is implemented. The presence of both growth mechanisms introduces a physical length scale R{sub c} into the system, enabling the growth process to be characterized by two regimes. If the average grain size is smaller than R{sub c}, grain growth is dominated by the grain-rotation-coalescence mechanism. By contrast, if the average grain size is greater than R{sub c}, growth is dominated by curvature-driven GB migration. The values of the growth exponents, different for the two growth regimes and different from a system with isotropic GB properties, are rationalized in terms of the detailed growth mechanism and the continuous change of the fraction of …

Metallic uranium fuel from the Hanford N Reactor was corroded in aqueous solutions and the resulting colloidal suspensions were analyzed to determine particle size, morphology, population, and radionuclide association. The experiments used a range of solution chemistry conditions including deionized water, single salt solutions, and modified groundwater from Yucca Mountain. Colloids were analyzed by inductively coupled plasma mass spectrometry, transmission electron microscopy, photon correlation spectroscopy, and synchrotron small-angle x-ray scattering. The results of these analyses indicate that stable suspensions of small (1-10 nm diameter), spherical uranium oxides are generated and aggregate to approximately 100-200 nm colloids. There is no indication that these colloids continue to aggregate to larger size. In silicate solutions, large acicular uranium silicate colloids are formed in small quantities as are large uranium-bearing smectite clay colloids. Plutonium clearly associates with colloidal particles. Large particles contain the same Pu/U ratio as the uncorroded fuel, possibly indicating that the Pu is incorporated in the particle matrix. Smaller particles are highly enriched in Pu relative to the uncorroded fuel.

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