An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

A report is given on progress made during the second year of a three year contract studying the feasibility of nuclear pumping the atomic iodine laser. Experimental results are presented showing efficiencies of 25--38% at converting neutron-induced nuclear reaction energy in the excimer XeBr into UV photons which can be used to pump the laser. Parametric studies were done utilizing the {sup 10}B(n,{alpha}){sup 7}Li reaction, with three bromine donor chemicals, over a range of pressures and mix ratios, to optimize the fluorescence efficiency.

The objective of this project is to demonstrate on a commercial scale several innovative applications of cost-reducing technology to the Chiyoda Thoroughbred-121 (CT-121) process. CT-121 is a second generation flue gas desulfurization (FGD) process which is considered by the Electric Power Research Institute (EPRI) and Southern Company Services (SCS) to be one of the most reliable and lowest cost FGD options for high-sulfur coal-fired utility boiler applications. Demonstrations of the innovative design approaches will further reduce the cost and provide a clear advantage to CT121 relative to competing technology.

An improvement over prior compositions wherein the ductility of Ni-Si alloys are improved with minor alloying additions of hafnium or zirconium.

Effective supergravity theories suggested by superstrings can be explored to determine their potential for successfully describing both observed physics at zero temperature and an inflationary cosmology. An important ingredient in this study is the dynamics of gaugino condensation, which has been the subject of recent activity. 33 refs., 2 figs.

The Refuge Revenue Sharing Fund (RRSF) was enacted in response to the concern of local governments regarding losses to their tax base due to the presence of federally owned land under the jurisdiction of the Fish and Wildlife Service. This report outlines recent history of RRSF payment levels. It examines the RRSF and describes how the fund differs in its treatment of reserved and acquired lands under the jurisdiction of FWS. The report also examines the Payment in Lieu of Taxes (PILT) program in detail.

The drought of 1988 caused the operations group to become concerned about the rate of evaporation from the Main Ring cooling ponds. They needed a way to data-log windspeed and direction. They had an old broken Heathkit weather station. The anemometer and windvane were salvaged and repaired. An interface to two MADC channels on the PBAR CAMAC link was built on an old piece of CAMAC card with salvaged parts. The project cost nothing. It has been in service since January 1989.

Development of the All Particle Method, a project to simulate the transport of particles via the Monte Carlo method, has proceeded on two fronts: data collection and algorithm development. In this paper we report on the status of the data libraries. The data collection is nearly complete with the addition of electron, photon, and atomic data libraries to the existing neutron, gamma ray, and charged particle libraries. The contents of these libraries are summarized.

A new optical technique for quantitatively measuring the spectral density of passive scalar fluctuations in a turbulent flow has been developed. The technique exploits the photorefractive properties of BaTiO{sub 3} to separate the optical signal of the turbulent field from the coherent illumination background. It is a major improvement over existing techniques in that it is non-intrusive, has excellent frequency response and spatial resolution, and is capable of simultaneously measuring two components of the three-dimensional spectral density, {Phi}{theta}({kappa}). The technique is thus especially well suited to the directly study of anisotropic flows. We have applied this technique to study the spectrum of temperature fluctuations in a fully developed turbulent channel flow with heat addition. The flow is highly anisotropic, yet the spectrum in directions transverse to the flow is seen to exhibit an inertial--convective subrange behavior which is characteristic of isotropic flows. The spectral behavior in the flow direction, due to the direct influence of the mean strain rate, is observed to be markedly different. 17 refs., 7 figs.

We have answered the PAC question ( Demonstrate the jet energy resolution of your proposed detector by studying decays Z {yields} jet + jet and Z{prime} {yields} jet + jet, M{sub Z{prime}} = 1 TeV.'') using a general program called SSCSIM. This program is a tool for investigating simple questions involving the relations between detector parameters and physics capabilities of a detector. A different package called ANLSIM developed by our colleagues at Argonne has also been used to answer this question. The results as expected are very similar. In this note we will try to document our procedures. Our tentative conclusion from this study is that physics induced effects, out-of-cone fluctuations and underlying event fluctuations, dominate the resolution. Pushing the detector performance to the limits of technology improves the effective resolution by at most 20%. 20 refs., 6 figs., 5 tabs.

A microscopic mechanism of optical nonlinearity in {pi}-conjugated polymers is presented. It is shown that the bulk of the nonlinearity is determined by only two well defined channels, even though an infinite number of channels are possible in principle. The above conclusion is true for both short and long range Coulomb interactions. The complete frequency dependence of the third harmonic generation in both trans-polyacetylene and polydiacetylene are explained within the same theoretical picture. 19 refs., 4 figs.

The explosion of a supernova forms because of the collapse to a neutron star. In addition an explosion requires that a region of relatively high entropy be in contact with the neutron star and persisting for a relatively protracted period of time. The high entropy region ensures that the maximum temperature in contact with the neutron star and in hydrostatic equilibrium is less than some maximum. This temperature must be low enough such that neutrino emission cooling is small, otherwise the equilibrium atmosphere will collapse adding a large accretion mass to the neutron star. A so-called normal explosion shock that must reverse the accretion flow corresponding to a typical stellar collapse must have sufficient strength or pressure to reverse this flow and eject the matter with 10{sup 51} ergs for a typical type II supernova. Surprisingly the matter behind such a shock wave has a relatively low entropy low enough such that neutrino cooling would be orders of magnitude faster than the expansion rate. The resulting accretion low would be inside the Bondi radius and result in free-fall accretion inside the expanding rarefaction wave. The accreted mass or reimplosion mass unless stopped by a high entropy bubble could than exceed …

The escape rates and evolution of a distribution of particles are considered for a 2-D model of transverse motion of particles in hadronic storage rings, when nonlinear resonances and external diffusion are present. Dynamic enhancement of diffusion inside separatrices can develop under a certain geometry of resonance oscillations and relatively wide resonances, leading to the fast growth of distribution tails and escape rates. The phenomenon is absent in 1-D. 10 refs., 4 figs.

A laser works by amplified spontaneous emission (ASE) of inverted atomic ions confined in an amplifier of rod-like geometry, such that ASE radiation is directed out of both ends of the rod. The forward and backward ASE waves are coupled through the population-rate equations and cause the saturation of the lasing transition (gain saturation). Diffraction of the waves in the transverse direction is responsible for the radiation pattern (angular distribution) observed on a distant screen and for the degree of spatial coherence of the radiation. Refraction of the light also occurs due to spatial gradients in the electron density. In order to describe this situation a code has been developed which numerically solves paraxial Maxwell's equations in the time and two spatial dimensions. The code uses the Peaceman-Rachford Alternating-Direction-Implicit algorithm and is benchmarked against laboratory DYE-LASER experiments. 4 refs., 1 fig.

This talk is dealing with the nuclear low energy collective motion as described in the context of microscopic versions of the Bohr Hamiltonian. Two different ways of building microscopically Bohr collective Hamiltonians will be sketched; one within the framework of the Generator Coordinate Method, the other using the Adiabatic Time-Dependent Hartree-Fock-Boholyubov approximation. A sample of recent results will be presented which pertains to the description of transitional even nuclei and to the newly revisited phenomenon of superdeformation at low spin.

Complete linearization is a very powerful technique for solving multi-line transfer problems that can be used efficiently with a variety of transfer formalisms. The linearization algorithm we describe is computationally very similar to ETLA, but allows an effective treatment of strongly-interacting lines. This algorithm has been implemented (in several codes) with two different transfer formalisms in all three one-dimensional geometries. We also describe a variation of the algorithm that handles saturable laser transport. Finally, we present a combination of linearization with a local approximate operator formalism, which has been implemented in two dimensions and is being developed in three dimensions. 11 refs.

The traveler collaborated with Drs. J. L. Sarmiento and J. C. Orr of the Program in Atmospheric Sciences at Princeton University to finish the article A Perturbation Simulation of CO{sub 2} Uptake in an Ocean Circulation Model,'' which has been submitted to the Journal of Geophysical Research for publication. With F. Joos, a graduate student from the University of Bern, the traveler started writing a journal article describing a box model of the global carbon cycle that is an extension of the one-dimensional box-diffusion model. The traveler further collaborated with F. Joos and Dr. J. L. Sarmiento on modeling the potential enhancement of oceanic CO{sub 2} uptake by fertilizing the southern ocean with iron. A letter describing the results is currently being written for the journal Nature.

A high resolution capacitive image sensing technique for measuring edge and surface profiles during manufacturing processes has been invented. A prototype device utilizing this technique consists of two 0.020 in. (500 {mu}m) diameter electrodes fabricated on a printed circuit board with a 0.010 in. (250 {mu}m) gap between them. As the device is mechanically scanned over the workpiece, the spatial variations in the edge or surface to be measured interfere with an electric field imposed between the electrodes, altering the mutual capacitance. The sensor functions as a near field proximity sensor producing range images of surface imperfections. This sensor has been used in applications requiring a preview image of burrs on the edge of a machined part and other processes requiring an inspection image after automated deburring operations. 10 refs., 8 figs.

This paper specifies the usage of structural bolts in terms of their design, selection and application, in accordance with the American Institute of Steel Construction (AISC) Ninth Edition. Manual of Steel Construction.''

A self-consistent design strategy for induction linacs is presented which addresses the issues of brightness preservation against space charge induced emittance growth, minimization of the beam breakup instability and the suppression of beam centroid motion due to chromatic effects (corkscrew) and misaligned focusing elements. A simple steering algorithm is described that widens the effective energy bandwidth of the transport system.

The traveler participated in an International Symposium on Trends in Biological Dosimetry and presented an invited paper entitled, Adducts in sperm protamine and DNA vs mutation frequency.'' The purpose of the Symposium was to examine the applicability of new methods to study quantitatively the effects of xenobiotic agents (radiation and chemicals) on molecular, cellular and organ systems, with special emphasis on human biological dosimetry. The general areas covered at the meeting included studies on parent compounds and metabolites; protein adducts; DNA adducts; gene mutations; cytogenetic end-points and reproductive methods.

Research continued on coal combustion. The project objectives are (1) to measure the effect of devolatilization temperature and time on the properties of the char and (2) characterize and quantify the effect of thermal annealing on char reactivity during char burnout under conditions of pulverized combustion. Work done during this reporting period includes: coal devolatilization/char generation; char oxidation in the thermogravimetric analyzer (TGA). Oxidation was conducted at 500{degree}C in a 5% O{sub 2}-N{sub 2} mixture at 150 cm{sup 3}/min flowrate. Under these conditions external and intraparticle diffusional limitations were negligible. Three chars obtained from the Pittsburgh No. 8 coal were used in the experiments; oxidation of single char particles in the electrodynamic balance. Experiments were carried out with particles from the Pittsburgh No. 8 char and a spherocarb'' synthetic char obtained from a vendor. The spherocarb char was used because the particles are nearly spherical thus avoiding the complications of irregular particle shape. 15 figs., 1 tab.

To forecast the ecological impact of global change, research initiatives are needed on the explicit role of humans in ecological systems, and on how ecological processes functioning at different spatial and temporal scales are coupled. Furthermore, to synthesize the results of ecological research for Congress, policymakers, and the general public, a new agency, called the United States Ecological Survey (USES) is urgently required. Also, a national commitment to environmental health, as exemplified by establishing a National Institutes of the Environment (NIE), should be a goal.

We have recently been trying to accumulate all of the information necessary to decide on the layout of the regular curved arcs of the Low Energy Ring (LER) and there have been several ABC Notes published on different aspects of the problem. This note will describe the layout that has been derived from these considerations.