Major accomplishments during this reporting period by the Advanced Gas Turbine Systems Research (AGTSR) are: AGTSR submitted FY99 program continuation request to DOE-FETC for $4M; AGTSR submitted program and workshop Formation to the Collaborative Advanced Gas Turbine (CAGT) initiative; AGTSR distributed research accomplishment summaries to DOE-FETC in the areas of combustion, aero-heat transfer, and materials; AGTSR reviewed and cleared research papers with the IRB from Arizona State, Cornell, Wisconsin, Minnesota, Pittsburgh, Clemson, Texas and Georgia Tech; AGTSR prepared background material for DOE-FETC on three technology workshops for distribution at the DOE-ATS conference in Washington, DC; AGTSR coordinated two recommendations for reputable firms to conduct an economic impact analysis in support of new DOE gas turbine initiatives; AGTSR released letters announcing the short-list winners/non-winners from the 98RFP solicitation AGTSR updated fact sheet for 1999 and announced four upcoming workshops via the SCIES web page AGTSR distributed formation to EPRI on research successes, active university projects, and workshop offerings in 1999 AGTSR continued to conduct telephone debriefings to non-winning PI's born the 98RFP solicitation AGTSR distributed completed quarterly progress report assessments to the IRB experts in the various technology areas AGTSR provided Formation to GE-Evandale on the active combustion control research at …

In this, the second of two reports on diffractive studies at HERA, the inclusive measurements made by the two collaborations, H1 and ZEUS, are summarized.

An electrochemical molten salt alternative to the classic Kraft causticizing process has been investigated and the feasibility of the process was successfully shown. The experiments include (A) the determination of background thermal decomposition gases, (B) the electrolysis of a sodium carbonate only smelt to show that sodium oxide can be electrochemically produced, and (C) electrolysis of a synthetic smelt containing 80 mole % Na{sub 2}CO{sub 3} and 20 mole % Na{sub 2}S. The experiments show, that sodium hydroxide (NaOH) was produced by the electrochemical reduction of sodium carbonate to sodium oxide in the molten state. In the experiment containing sodium sulfide, there was formation of less than 5 mole % of polysulfide. Energy savings on the order of 500,000 BTU per ton of kraft pulp produced are estimated, based on the energy used by the mill. Operating costs are estimated to be currently similar to conventional processing. However, price increases of fossil fuels and increased co-generation of electricity in the mill will give the electrolytical process significant cost advantages.

We are analyzing erosion and tritium codeposition for ITER, DIII-D, and other devices with a focus on carbon divertor and metallic wall sputtering, for detached and semi-detached edge plasmas. Carbon chemical-sputtering hydrocarbon-transport is computed in detail using upgraded models for sputtering yields, species, and atomic and molecular processes. For the DIII-D analysis this includes proton impact and dissociative recombination for the full methane and higher hydrocarbon chains. Several mixed material (Si-C doping and Be/C) effects on erosion are examined. A semi-detached reactor plasma regime yields peak net wall erosion rates of {approximately}1.0 (Be), {approximately}0.3 (Fe), and {approximately}0.01 (W) cm/burn-yr, and {approximately}50 cm/burn-yr for a carbon divertor. Net carbon erosion is dominated by chemical sputtering in the {approximately}1-3 eV detached plasma zone. Tritium codeposition in divertor-sputtered redeposited carbon is high ({approximately}10-20 g-T/1000 s ). Silicon and beryllium mixing tends to reduce carbon erosion. Initial hydrocarbon transport calculations for the DIII-D DiMES-73 detached plasma experiment show a broad spectrum of redeposited molecules with {approximately}90% redeposition fraction.

ERRATA for PNNL-11991 [OSTI ID 1112] includes Appendix F and a revised distribution list.

When atomic photoionization is treated beyond the dipole approximation, photoelectron angular distributions are asymmetric forward and backward with respect to the direction of the photon beam. We have measured forward-backward asymmetries of Ar 1s and Kr 1s and 2s photoelectrons using 2-19 keV x-rays. The measured asymmetries compare well with calculations which include interference between electric-dipole and electric-quadrupole amplitudes within the nonrelativistic, independent-particle approximations.

This project explores the feasibility of combining geologic insight, geostatistics, and high-performance computing to analyze the capabilities of 3-D electrical resistance tomography (ERT). Geostatistical methods are used to characterize the spatial variability of geologic facies that control sub-surface variability of permeability and electrical resistivity Synthetic ERT data sets are generated from geostatistical realizations of alluvial facies architecture. The synthetic data sets enable comparison of the �truth� to inversion results, quantification of the ability to detect particular facies at particular locations, and sensitivity studies on inversion parameters

This paper presents new results obtained using the US national gamma-ray facility Gammasphere, which has been operating at the ATLAS accelerator at Argonne National Laboratory since January 1998. Gammasphere was built at Lawrence Berkeley Laboratory and used primarily as a powerful spectrometer for studying nuclei at the highest spins. For pioneering research in the high-spin regime, it was constructed with high photopeak efficiency (about 10% for 1.33 MeV gamma-rays), good energy resolution (< 2.4 keV at 1.33 meV), good photopeak-to-total response (> 55% of 1.33 MeV events are in the photopeak) and high granularity (> 100 high-purity germanium (HpGe) detector channels, of which 65 are segmented, to allow precise Doppler correction and minimize the chance of double-hits). The device has a high degree of mechanical symmetry which is ideal for angular correlation studies. The whole spectrometer, both HpGe detectors and their BGO anti-Compton shields, can be used for photon calorimetry by adding the energy deposited in the nearly 900 active elements.

In preparation for future clinical BNCT trials, neutron production via the 7Li(p,n) reaction as well as subsequent moderation to produce epithermal neutrons have been studied. Proper design of a moderator and filter assembly is crucial in producing an optimal epithermal neutron spectrum for brain tumor treatments. Based on in-phantom figures-of-merit,desirable assemblies have been identified. Experiments were performed at the Lawrence Berkeley National Laboratory's 88-inch cyclotron to characterize epithermal neutron beams created using several microampere of 2.5 MeV protons on a lithium target. The neutron moderating assembly consisted of Al/AlF3 and Teflon, with a lead reflector to produce an epithermal spectrum strongly peaked at 10-20 keV. The thermal neutron fluence was measured as a function of depth in a cubic lucite head phantom by neutron activation in gold foils. Portions of the neutron spectrum were measured by in-air activation of six cadmium-covered materials (Au, Mn, In, Cu, Co, W) with high epithermal neutron absorption resonances. The results are reasonably reproduced in Monte Carlo computational models, confirming their validity.

ERRATA for PNNL-11990. Page 2.11, and 2 pages of distribution.

In order to better understand and model the phase segregation of binary fluids we opted for a mesoscopic description that proves to be simplifying both conceptually and computationally. The system that we studied is a mixture of two kinds of particles. All particles interact with each other through strong short-range interactions modeled by hard spheres with the same mass and diameter. There is also a smooth long-range repulsion between particles of different kinds. At low overall densities and weak enough repulsion the natural dynamical description for this system is given in terms of two coupled, energy and momentum conserving Vlasov- Boltzmann equations, making it what we call a dynamical mean-field model. The computational scheme that we used is a combination of direct sim- ulation Monte Carlo (DSMC) and particle-in-the-cell (PIC) evolution, that inherits the efficiency and robustness of these two algorithms. The DSMC is a stochastic algorithm due to Bird that consistently incorporates the as- sumptions behind the Boltzmann equation into the particle dynamics. The method is essentially the following: the physical space is divided into a net- work of cells containing typically tens of particles and the free flow of the particles over a small time interval {Delta}t is …

In our IFE development plan, we have set a goal of building an Engineering Test Facility (ETF) for a total cost of $2B and a Demo for $3B. In Mike Campbell� s presentation at Madison, we included a viewgraph with an example Demo that had 80 to � 250 MWe of net power and showed a plausible argument that it could cost less than $3B. In this memo, I examine the design space for the Demo and then briefly for the ETF. Instead of attempting to estimate the costs of the drivers, I pose the question in a way to define R&D goals: As a function of key design and performance parameters, how much can the driver cost if the total facility cost is limited to the specified goal? The design parameters examined for the Demo included target gain, driver energy, driver efficiency, and net power output. For the ETF; the design parameters are target gain, driver energy, and target yield. The resulting graphs of allowable driver cost determine the goals that the driver R&D programs must seek to meet.

We study single bunch stability with respect to monopole longitudinal oscillations in electron storage rings. Our analysis is different from the standard approach based on the linearized Vlasov equation. Rather, we reduce the full nonlinear Fokker-Planck equation to a Schroedinger-like equation which is subsequently analyzed by perturbation theory. We show that the Haissinski solution [3] may become unstable with respect to monopole oscillations and derive a stability criterion in terms of the ring impedance. We then discuss this criterion and apply it to a broad band resonator impedance model.

The Savannah River Site (SRS) is in the process of removing waste (sludge and salt cake) from million gallon waste tanks. The current practice for removing waste from the tanks is adding water, agitating the tanks with long shaft vertical centrifugal pumps, and pumping the sludge/salt solution from the tank to downstream treatment processes. This practice has left sludge heels ({tilde} 30,000 gallons) in the bottom of the tanks. SRS is evaluating shrouded axial impeller mixers for removing the sludge heels in the waste tanks. The authors conducted a test program to determine mixer requirements for suspending sludge heels using the shrouded axial impeller mixers. The tests were performed with zeolite in scaled tanks which have diameters of 1.5, 6.0, and 18.75 feet. The mixer speeds required to suspend zeolite particles were measured at each scale. The data were analyzed with various scaling methods to compare their ability to describe the suspension of insoluble solids with the mixers and to apply the data to a full-scale waste tank. The impact of changes in particle properties and operating parameters was also evaluated. The conclusions of the work are: Scaling of the suspension of fast settling zeolite particles was best described by …

Two-phase flow pressure drop measurements were made during a phase-change heat transfer process with three refrigerants (R-134a, R-12, and R-113) at six different pressures ranging from 138 kPa to 856 kPa, and in two sizes of round tubes (2.46 mm and 2.92 mm inside diameters) and one rectangular channel (4.06 x 1.7 mm). State-of-the-art large-tube correlations failed to satisfactorily predict the experimental data. The data were used to develop a new correlation for two-phase pressure drop during flow boiling in small channels. The correlation was then tested against the experimental data for the three refrigerants; the error was {+-}20%.

This paper describes the design and development of the embedded control systems used to deliver and recover the National Ignition Facility (NIF) optical line replaceable units (LRUs). As part of the NIF Operations Special Equipment Control System (OSECS), the embedded control systems form a part of the front end processor (FEP) layer of the OSECS. During the start-up and operations phases of the NIF project, it is anticipated that a significant number of LRUs will be delivered to the laser beamline structure. The frequency of LRU delivery combined with the design of the facility pose severe constraints for human-only delivery and recovery operations. To reduce the risks to personnel and to allow for safe and efficient delivery of equipment, LLNL engineers are designing and developing embedded control systems for the low-level device control of NIF Transport and Handling mechanical delivery system components. The design of the embedded control system makes use of advanced PC-based motion control technology commonly found in industrial applications. The PC-based platform consists of commercial-off-the-shelf (COTS) hardware and software such as industrial computers, motion controllers, data acquisition boards, sensors technology, networking capabilities, development languages and operating system. Wireless networking technology is also being employed in the design …

A dislocation dynamics (DD) model for plastic deformation, connecting the macroscopic mechanical properties to basic physical laws governing dislocation mobility and related interaction mechanisms, has been under development. In this model there is a set of critical reactions that determine the overall results of the simulations, such as the stress-strain curve. These reactions are, annihilation, formation of jogs, junctions, and dipoles, and cross-slip. In this paper we discuss these reactions and the manner in which they influence the simulated stress- strain behavior in fcc and bcc metals. In particular, we examine the formation (zipping) and strength of dipoles and junctions, and effect of jogs, using the dislocation dynamics model. We show that the strengths (unzipping) of these reactions for various configurations can be determined by direct evaluation of the elastic interactions. Next, we investigate the phenomenon of hardening in metals subjected to cascade damage dislocations. The microstructure investigated consists of small dislocation loops decorating the mobile dislocations. Preliminary results reveal that these loops act as hardening agents, trapping the dislocations and resulting in increased hardening.

The iterative advanced mean value algorithm (AMV+), introduced nearly ten years ago, is now widely used as a cost-effective probabilistic structural analysis tool when the use of sampling methods is cost prohibitive (Wu et al., 1990). The need to establish confidence bounds on calculated probabilities arises because of the presence of uncertainties in measured means and variances of input random variables. In this paper an algorithm is proposed that makes use of the AMV+ procedure and analytically derived probability sensitivities to determine confidence bounds on calculated probabilities.

The objective of this work was to fabricate subscale candle filters using a Ce-ZTA reticulated foam material. Specifically Selee fabricated 60mm diameter cylinders with one closed end and one flanged end. Selee Corporation developed a small pore size (5-10 {micro}m) filtration membrane which was applied to the reticulated foam surface to provide a barrier filter surface. The specific tasks to be performed were as follows: (Task 1) Filter Element Development--To fabricate subscale filter elements from zirconia toughened alumina using the reticulated foam manufacturing process. The filter elements were required to meet dimensional tolerances specified by an appropriate filter system supplier. The subscale filter elements were fabricated with integral flanges and end caps, that is, with no glued joints. (Task 2) Membrane Development--To develop a small pore filtration membrane that is to be applied to the reticulated foam material. This membrane was to provide filtration characteristics that meet gas turbine requirements and pressure drop or permeability requirements specified by the filter system supplier. (Task 3) Subscale Filter Element Fabrication--To fabricate six subscale filter elements with integral flanges and closed ends, as well as fine pore size filtration membranes. Three filters were to have a central clean gas channel, while three would …

Global sensor networks could support increased activity in a number of economic sectors. Potential benefits and the predicted time scales required to realize them are estimated. Benefits are particular compelling for fundamental reasons for aviation, hotels and restaurants, natural disasters, construction, agriculture, and apparel. These benefits can be captured by simple logistic approximations.

This memo reports on the analysis of some recent measurements of solution impurity levels in the three KDP and one DKDP Pilot Production 1000 liter growth tanks (Tanks B, C, D, & F). Solution samples were taken on a weekly basis during recent crystal growth runs in each tank and were analyzed by inductively coupled plasma emission spectroscopy (ICP-ES). The solution history for five specific elements, Si, B, Al, Fe and Ca will be analyzed in detail. The first four of these elements are input into solution via slow dissolution of the glass vessel at a rate which is strongly dependent on the solution temperature. Si and B continuously accumulate in solution, since they are not incorporated into the crystal. Al and Fe by comparison are incorporated into the crystal (primarily the prismatic sectors) and present problems to inclusion-free growth (Al) and 30 damage (Fe). The level of these impurities initially increases when the crystal size is small but later decreases when the rate of incorporation into the crystal exceeds the rate of dissolution of the glass tank. The last element, Ca is of interest since it has recently been observed to be one of the elements found at the …

Sputtered thin film and multilayer x-ray mirrors are made routinely at the Advanced Photon Source (APS) for the APS users. Precise film growth control and characterization are very critical in fabricating high-quality x-ray mirrors. Film thickness calibrations are carried out using in situ and ex situ spectroscopic ellipsometry, interferometry, and x-ray scattering. To better understand the growth and optical properties of different thin film systems, we have carried out a systematic study of sputtered thin films of Au, Rh, Pg Pd, Cu, and Cr, using in situ ellipsometry. Multiple data sets were obtained in situ for each film material with incremental thicknesses and were analyzed with their correlation in mind. We found that in situ spectroscopic ellipsometry as a surface-sensitive tool can also be used to probe the growth and morphology of the thin film system. This application of in situ spectroscopic ellipsometry for metal thin film systems will be discussed.

A novel wire scanner has been developed with applications at linear accelerators where small beam spots or high intensities would otherwise destroy wires. A pattern of wires is supported on a thin membrane and remains in place even when punctured by the beam. Many scans can be made before the material needs to be replaced. Tests of the principle have been carried out at the Final Focus Test Beam at SLAC.

An overview of particle and photon beam bunch length measurements is presented in the context of free-electron laser (FEL) challenges. Particle-beam peak current is a critical factor in obtaining adequate FEL gain for both oscillators and self-amplified spontaneous emission (SASE) devices. Since measurement of charge is a standard measurement, the bunch length becomes the key issue for ultrashort bunches. Both time-domain and frequency-domain techniques are presented in the context of using electromagnetic radiation over eight orders of magnitude in wavelength. In addition, the measurement of microbunching in a micropulse is addressed.