We have investigated the role of an isomeric state and its coupling to the ground state (g.s.) via photons and neutron inelastic scattering in a stellar environment by making detailed photonuclear and neutron cross-section calculations for /sup 176/Lu and /sup 210/Bi. In the case of /sup 176/Lu, the g.s. would function as an excellent galactic slow- (s-) process chronometer were it not for the 3.7-h isomer at 123 keV. Our calculations predicted much larger photon cross sections for production of the isomer, as well as a lower threshold, than had been assumed based on earlier measurements. These two factors combine to indicate that an enormous correction, a factor of 10/sup 7/, must be applied to shorten the current estimate of the half-life against photoexcitation of /sup 176/Lu as a function of temperature. This severely limits the use of /sup 176/Lu as a stellar chronometer and indicates a significantly lower temperature at which the two states reach thermal equilibrium. For /sup 210/Bi, our preliminary calculations of the production and destruction of the 3 /times/ 10/sup 6/ y isomeric state by neutrons and photons suggest that the /sup 210/Bi isomer may not be destroyed by photons as rapidly as assumed in certain …

The requirements for antenna design and phase control circuitry for a fast-wave current drive (FWCD) array operating in the ion cyclotron range of frequencies are considered. The design of a phase control system that can operate at arbitrary phasing over a wide range of plasma-loading and strap-coupling values is presented for a four-loop antenna array, prototypical of an array planned for the DIII-D tokamak (General Atomics, San Diego, California). The goal is to maximize the power launched with the proper polarization for current drive while maintaining external control of phase. Since it is desirable to demonstrate the feasibility of FWCD prior to ITER, a four-strap array has been designed for DIII-D to operate with the existing 2-MW transmitter at 60 MHz. 3 refs., 6 figs.

Initial ion cyclotron range of frequencies (ICRF) heating experiments on TFTR began in the summer of 1988. Although we were in the commissioning stage for much of the equipment, some plasma coupling measurements were made in the fall. This paper is focused on the results from the Bay L antenna. 3 refs., 3 figs., 1 tab.

The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.

The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.

This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

The history and current status of experimental and theoretical work on heliacs at the Australian National University are reviewed. 18 refs., 1 fig., 1 tab.

An electron cyclotron resonance (ECR) multicusp plasmatron has been developed by feeding a multicusp bucket arc chamber with a compact ECR plasma source. This novel source produced large (about 25-cm-diam), uniform (to within {plus minus}10%), dense (>10{sup 11}-cm{sup -3}) plasmas of argon, helium, hydrogen, and oxygen. It has been operated to produce an oxygen plasma for etching 12.7-cm (5-in.) positive photoresist-coated silicon wafers with uniformity within {plus minus}8%. Results and potential applications of this new ECR plasma source for plasma processing of thin films are discussed. 21 refs., 10 figs.

To estimate the range of seismic response at low strain of sites within Los Alamos National Laboratory, ground motion recordings were obtained at 13 sites from nuclear tests carried out in Nevada. The sites are distributed within a 10 X 10 km area. The ground motions recorded at each site were conceptually modelled as the result of source, path, and site contributions. Because almost all of the paths are in common, the variations seen for each source can be attributed to site response. The sites were monitored in various combinations with seven nuclear tests; each site recorded only a few of the tests. Because horizontal ground motion is more important for structural engineering and was larger than the vertical, we focused on horizontal site response. The range of relative site response seen is about a factor of 5 to 6 at 1.5 Hz. Topography has a strong effect on response, with sites in canyons being a factor of 3 to 4 lower than nearby sites on mesas. Increased depth to seismic basement beneath some stations also correlates with higher relative site response. Relative site response does not obviously correlate with variation of seismic velocities in the near surface (e.g. upper …

Research core hole was continuously cored to 1.762 km on the western flank of the caldera's resurgent dome in 1988. Bottom hole temperature is about 295{degree}C within Precambrian (1.5 Ga) quartz monzonite, deep within the liquid-dominated portions of the Sulphur Springs hydrothermal system. VC-2b may be the deepest, hottest, continuously cored hole in North America. Core recovery was 99.2%. The only major drilling problems encountered were when temperatures at the bit exceeded 225{degree}C below depths of about 1000 m. The result of these conditions was loss of viscosity and/or lubricity in the mud, apparently caused by breakdown of the high temperature polymers. Lithologies in caldera-fill indicate the drill site may be proximal to ignimbrite vents and that an intracaldera lake with temperatures approaching boiling formed soon after the caldera itself. Structural correlations between VC-2b and the 528-m-deep companion hole VC-2a indicate the earlier Toledo caldera (1.45 Ma; Otowi Member tuffs) and even older Lower Tuffs caldera experienced no structural resurgence similar to the 1.12 million year old Valles caldera. The hydrothermal system penetrated by these bores, consists of a shallow vapor-rich cap, which has evolved from an earlier 200{degree}C liquid-dominated system, overlying stacked, liquid-dominated zones up to about 300{degree}C. Geochemistry …

The interaction of plasma with rf fields from an ion cyclotron range of frequencies (ICRF) antenna has been studied to estimate the amount of Faraday shield erosion expected in normal ICRF heating operation. Plasma parameters and ion energies have been measured in the near field of an antenna and used in a model to estimate the erosion rate of the Faraday shield surface. Experiments were conducted on the RF Test Facility, a magnetic mirror device at Oak Ridge National Laboratory, using a single-strap resonant loop antenna with a two-tier Faraday shield. The outer tier, facing the plasma, was layered with graphite tiles. The antenna was operated at currents and voltages within 50% of those expected in tokamaks. The time-varying floating potential was measured with a capacitively coupled probe, and the time-averaged floating potential, electron temperature, and electron density were measured with Langmuir probe. Both probes were scanned in front of the antenna. Ion energies were measured with a gridded energy analyzer located below the antenna, and samples of silicon were placed on the Faraday shield surface to estimate the incident ion energy. The capacitive probe measurement show that the rf floating potential follows the magnetic field pattern of the antenna, …

The AGS Booster is being designed as a very versatile particle accelerator. Its primary function is to be a high quality injector to the currently operating Alternating Gradient Synchrotron (AGS). The Booster/AGS combination will produce proton intensities greater than 5 {times} 10{sup 13}protons per pulse (ppp), and accelerate heavy ions, with mass up to 200, to a maximum energy of 15 GeV per atomic mass unit (GeV/amu). The power supply for the Booster Main Ring (BMRPS) has to accommodate a wide range of cycles and a wide range of operating parameters. The cycles range from storage for several seconds to rapid cycling at 7.5 Hz. The peak output power is 18 MW. This paper will describe the AGS Booster machine powering requirements, the choice of power supply, the a.c. circuit tie-in and its associated problems and some of the details of the design of the BMRPS. 9 refs., 2 figs.

Since May 1986, the heavy ion transfer line (HITL) which joins the Tandem Van de Graaff facility and the AGS at Brookhaven National Laboratory has permitted the acceleration of heavy ions (up to sulfur) to 14.5 GeV/nucleon. The Tandem, operating with a pulsed ion source, supplies a fully stripped ion beam at about 7 MeV/nucleon which is transported via the HITL to the AGS. A low frequency rf system accelerates the beam in the AGS to about 200 MeV/nucleon and the high frequency rf system, normally used for proton acceleration, completes the acceleration to 14.5 GeV/nucleon. The high energy ion beams are delivered to four experimental beam lines using standard resonant extraction. Following is an update of the performance and operational characteristics associated with the production, transport, and acceleration of these ion beams. 10 refs., 2 figs., 2 tabs.

Importance sampling is essential to the timely solution of Monte Carlo nuclear-logging computer simulations. Achieving minimum variance (maximum precision) of a response in minimum computation time is one criteria for the choice of an importance function. Various methods for calculating importance functions will be presented, new methods investigated, and comparisons with porosity and density tools will be shown. 5 refs., 1 tab.

We have developed an artificial ecology in the computer core, where one is able to evolve assembler-automaton code without any predefined evolutionary path. The system, in the present version has one dimension, is updated in parallel, the instructions are only able to communicate locally, and the system is continuously subjected to noise. The system also has a notion of computational resources. Depending on the specified parameters and the level of complexity of distance from a randomized core, this electronic garden is started at, we see different evolutionary paths. For several initial conditions the system is able to develop extremely viable cooperative programs (organisms ) which totally dominates the core. This demonstrates the emergence of complex functional properties in a computational environment. 21 refs., 7 figs., 2 tabs.

Questions about the mechanism of diamond film growth by low-pressure, plasma-assisted chemical vapor deposition methods have persisted for some time now. As an attempt to explore one aspect of the problem, we examine the energetics of several adsorbed diamond (111) surfaces. The adsorbates are mixtures of methyl groups and hydrogen atoms. The model for these systems is the molecular orbital hamiltonian of Dewar and coworkers. From these calculations we find that H adsorbtion is preferred due both to bond energy and steric effects. Thus nucleation of a cluster of three or more methyl groups, as assumed in earlier work, is energetically very demanding. 6 refs., 3 figs.

The theories discussed in this paper are confined to those currently being used or considered for the calculation of activation cross sections. The theories are the same regardless of whether the activation product is long lived or short lived. However, the cross sections for the generation of long-lived radionuclides are more difficult or expensive to measure, hence there are fewer data available and the requirement on the predictive capability of the theories used is more stringent. It is clear from other papers presented in this meeting and the adjoining NEANDC specialists' meeting on activation cross sections that the nuclear theories of interest to this group are those used or needed in modern Hauser-Feshbach (H-F) codes with pre-equilibrium correction and gamma-ray cascades. The H-F formalism is indispensable due to the sensitivity of the calculated results, especially isomeric ratios, to the spins and parities of the discrete levels as well as to the spin distributions in the total and exciton level densities. Topics included in this paper are the optical model, gamma-ray strength function, total and exciton level-density theories, and the pre-compound model. In each subject, we describe the most commonly used theories first, followed by relatively new developments that are used …

Effective porosity of geologic materials is a very important parameter for estimating groundwater travel time and modeling contaminant transport in hydrologic systems. Determination of a representative effective porosity for nonideal systems is a problem still challenging hydrogeologists. In this paper, some of the conventional field geophysical and hydrological methods for estimating effective porosity of geologic materials are reviewed. The limitations and uncertainties associated with each method are discussed. 30 refs., 8 figs.

The conceptual design of a collider capable of accelerating and colliding heavy ions and to be constructed in the existing 3.8 km tunnel at Brookhaven has been developed. The collider has been designed to provide collisions of gold ions at six intersection points with a luminosity of about 2 /times/ 10/sup 26/ cm/sup /minus/2/sec/sup /minus/1/ at an energy per nucleon of 100 GeV in each beam. Collisions with different ion species, including protons, will be possible. The salient design features and the reasons for major design choices of the proposed machine are discussed in this paper. 28 refs., 2 figs., 1 tab.

An article, Art Expression, Art Skills, and Continued Artistic Development of Children by Michael Day. Literature in the field of Art Education has distinguished to three domains of art learning, critical domain which refers to the individuals response to art, the making of critical judgement and the ability to discus art with others. The cultural or historical domain, refers to the knowledge and understanding that surround a work of art within the milieu. The productive domain, refers to the making of art objects. Day's article, he'll focuses on the productive domain and the creative mediums of artwork.

This conference brought together those persons in the nuclear industry who have a vital interest in the training and licensing of nuclear reactor and nuclear fuel processing plant operators, senior operators, and support personnel for the purpose of an exchange of ideas and information related to the various aspects of training, retraining, examination, and licensing. The document contains 64 papers; each paper was abstracted for the data.

This report summarizes the results of a workshop held to receive expert advice and review existing Columbia River models that include juvenile salmonid predation components and, if warranted, recommend alternate modeling approaches. The workshop was limited to models or modeling approaches that may have practical application to the specific problems of increasing survival of juvenile salmonids in the Columbia and Snake rivers by reducing predation losses. The US Fish and Wildlife Service (FWS) and the Oregon Department of Fish and Wildlife (ODFW) under interagency agreements with the Bonneville Power Administration (BPA) conducted a multi-year study of the impact of predator populations on juvenile salmonids in the John Day Reservoir of the Columbia River. The studies were part of BPA's implementation of the Northwest Power Planning Council's (NPPC) Fish and Wildlife Program, designed to protect and enhance production of salmon as mitigation for losses caused by hydroelectric development. The FWS agreement with BPA includes provisions for refinement or development of models to understand the dynamics of predation on juvenile salmon as a basis for considering active intervention to reduce predation losses. The BPA sponsored the workshop that included a review of existing and proposed modeling approaches, identification of model development needs, …

This volume contains the written proceedings of the Symposium on High Temperature and Materials Chemistry held in Berkeley, California on October 24--25, 1989. The Symposium was sponsored by the Materials and Chemical Sciences Division of Lawrence Berkeley Laboratory and by the College of Chemistry of the University of California at Berkeley to discuss directions, trends, and accomplishments in the field of high temperature and materials chemistry. Its purpose was to provide a snapshot of high temperature and materials chemistry and, in so doing, to define status and directions.

This report contains short papers and abstracts on the following main topics: Ion-atom collision theory; laser physics; spectroscopy of atoms; spectroscopy of ions; and high velocity collisions.