The role of particle identification (PID) in both fixed-target and colliding-beam studies of ultrarelativistic nuclear (URN) collisions is examined. The demands placed on the PID systems by peculiarities of URN collisions, such as large multiplicities and the need for simultaneous measurement of a number of observables, are discussed. A variety of PID techniques are reviewed, with emphasis on their applicability and efficiency in the environment of such collisions. Two examples of PID as incorporated into existing fixed-target nuclear-beam experiments are presented. 18 refs., 5 figs.

The observation of substantial current drive from neutral beam injection (NBI) in TFTR, JET and DIII-D has led to renewed interest in a steady state, non-inductively driven tokamak. The discovery of apparently considerable neoclassical (bootstrap) current in TFTR, makes a steady state device even more attractive since the bootstrap portion of the current could be obtained without additional power input. Motivated by these results, we have developed a code, ACCOME, which self-consistently computes the 2-D MHD equilibrium with the current driven by neutral beams, bootstrap and the electric field. In this paper we first describe some details of the code in the next section and in the subsequent section show some applications to DIII-D and to a possible ITER design.

Light microscopy, bare-film radiography, secondary ion mass spectroscopy, electron microprobe and physical testing were used to examine beryllium specimens exhibiting a stratified, pitted, pattern after chemical milling. The objective was to find the cause of this pattern. Specimens were found to have voids in excess of density specification allowances. These voids are attributed, at least in part, to the sublimation of beryllium fluoride during the vacuum hot pressing operation. The origin of the pattern is attributed to these voids and etching out of fines and associated impurities. Hot isostatic pressing with a subsequent heat treatment close residual porosity and dispersed impurities enough to correct the problem.

A summary is given of the activities of those in the Media Accelerator Group. Attention was focused on the Inverse Cherenkov Accelerator, the Laser Focus Accelerator, and the Beat Wave Accelerator. For each of these the ultimate capability of the concept was examined as well as the next series of experiments which needs to be performed in order to advance the concept.

The high-grade sensible heat rejection characteristic of the high-temperature gas-cooled reactor-gas turbine (HTGR-GT) plant is ideally suited to cogeneration. Cogeneration in this nuclear closed-cycle plant could include (1) bottoming Rankine cycle, (2) hot water or process steam production, (3) desalination, and (4) urban and industrial district heating. This paper discusses the HTGR-GT plant thermodynamic cycles, design features, and potential applications for the cogeneration operation modes. This paper concludes that the HTGR-GT plant, which can potentially approach a 50% overall efficiency in a combined cycle mode, can significantly aid national energy goals, particularly resource conservation.

Interactive computer graphic displays can be extremely useful in augmenting understandability of data structures. In complexly interrelated domains such as bibliographic thesauri and energy information systems, node and link displays represent one such tool. This paper presents examples of data structure representations found useful in these domains and discusses some of their generalizable components. 2 figures.

Formation damage studies using artificially fractured, low-permeability sandstone cores indicate that viscosified fracturing fluids can severely restrict gas flow through these types of narrow fractures. These studies were performed in support of the Department of Energy's Multiwell Experiment (MWX). Extensive geological and production evaluations at the MWX site indicate that the presence of a natural fracture system is largely responsible for unstimulated gas production. The laboratory formation damage studies were designed to examine changes in cracked core permeability to gas caused by fracturing fluid residues introduced into such narrow fractures during fluid leakoff. Polysaccharide polymers caused significant reduction (up to 95%) to gas flow through cracked cores. Polymer fracturing fluid gels used in this study included hydroxypropyl guar, hydroxyethyl cellulose, and xanthan gum. In contrast, polyacrylamide gels caused little or no reduction in gas flow through cracked cores after liquid cleanup. Other components of fracturing fluids (surfactants, breakers, etc.) caused less damage to gas flows. Other factors affecting gas flow through cracked cores were investigated, including the effects of net confining stress and non-Darcy flow parameters. Results are related to some of the problems observed during the stimulation program conducted for the MWX. 24 refs., 4 figs., 7 tabs.

A highly sophisticated and accurate approach is described to compute on an hourly or daily basis the energy consumption for space heating by individual buildings, urban sectors, and whole cities. The need for models and specifically weather-sensitive models, composite models, and space-heating models are discussed. Development of the Colorado State University Model, based on heat-transfer equations and on a heuristic, adaptive, self-organizing computation learning approach, is described. Results of modeling energy consumption by the city of Minneapolis and Cheyenne are given. Some data on energy consumption in individual buildings are included.

The components of geothermal brines that cause corrosion and scaling problems are reviewed, especially brine pH, CO/sub 2/, H/sub 2/S, oxygen (from air), silicia, calcium, sulfides, and suspended particulates. Instrumental methods for on-line measurement are discussed to show how to keep costs low by operating a geothermal plant from a position of knowledge of what is occurring to the plant materials. The US Department of Energy research and development program in brine chemistry and on-line instrument development at Pacific Northwest Laboratory is discussed along with the strategy for commercial availability of new instruments to the geothermal industry.

The purpose of this note is to describe the electrical and mechanical properites of particle accelerator rf cavities in a manner which will be useful to physics and engineering graduates entering the accelerator field. The discussion will be limited to proton (or antiproton) synchrotron accelerators or storage rings operating roughly in the range of 20 to 200 MHz. The very high gradient, fixed frequency UHF or microwave devices appropriate for electron machines and the somewhat lower frequency and broader bandwidth devices required for heavy ion accelerators are discussed extensively in other papers in this series. While it is common pratice to employ field calculation programs such as SUPERFISH, URMEL, or MAFIA as design aids in the development of rf cavities, we attempt here to elucidate various of the design parameters commonly dealt with in proton machines through the use of simple standing wave coaxial resonator expressions. In so doing, we treat only standing wave structures. Although low-impedance, moderately broad pass-band travelling wave accelerating systems are used in the CERN SPS, such systems are more commonly found in linacs, and they have not been used widely in large cyclic accelerators. Two appendices providing useful supporting material regarding relativistic particle dynamics and …

The author here reviews what is presently known about factors affecting indoor concentrations of radon 222 and its daughters. In US single-family homes, radon concentrations are found to average about 1.5 pCi/1, but substantially higher concentrations occur frequently: perhaps a million US homes have concentrations exceeding 8 pCi/1 (from which occupants receive radiation doses comparable to those now experienced by uranium miners). The major contributor to indoor radon is ordinary soil underlying homes, with this radon being transported indoors primarily by the slight depressurization that occurs toward the bottom of a house interior (due to indoor-outdoor temperature differences and winds). Water from underground sources contributes significantly in a minority of cases, primarily residences with private wells, with public water supplies contributing only a few percent of indoor radon, even when drawn from wells. The strong variability in indoor concentrations is associated primarily with variability in the amount of radon entering homes from these various sources, and secondarily with differences in ventilation rates. However, for a given entry rate, the ventilation rate is the key determinant of indoor concentrations. Human doses are also influenced strongly by the chemical behavior of the daughters (i.e., decay products of radon), and considerable progress has …

Imaging diagnostics are used for spatially/emdash/and temporally/emdash/resolved quantitative measurements of plasma properties such as the ionization particle source, particle and energy loss, and impurity radiation in magnetically confined fusion plasmas. Diagnostics equipped with multi-element solid-state detectors (often with image intensifiers) are well suited to the environment of large fusion machines with high magnetic field and x-ray and neutron fluxes. We have both conventional (16msframe) and highspeed video cameras to measure neutral deuterium H/sub ..cap alpha../ (6563 /angstrom/) emissions from fusion plasmas. Continuous high-speed measurements are made with video cameras operating at 0.1 to 0.5 msframe; gated cameras provide snapshots of 10 to 100 ..mu..s during each 16-ms video frame. Digital data acquisition and absolute intensity calibrations of the cameras enable detailed quantitative source measurements: these are extremely important in determining the particle balance of the plasma. In a liner confinement device, radial transport can be determined from the total particle balance. In a toroidal confinement device, the details of particle recycling can be determined. Optical imaging in other regions of the spectrum are also important, particularly for the diverter region of large tokamaks. Absolutely calibrated infrared cameras have been used to image to temperature changes in the wall and thereby …

Electrical heater experiments have been conducted underground in granite at Stripa, Sweden, to investigate the effects of heating associated with nuclear waste storage. Temperature data from these experiments are compared with closed-form and finite-element solutions. Good agreement is found between measured temperatures and both types of models, but especially for a nonlinear finite-element heat conduction model incorporating convective boundary conditions, measured nonuniform initial rock temperature distribution, and temperature-dependent thermal conductivity. In situ thermal properties, determined by least-squares regression, are very close to laboratory values. A limited amount of sensitivity analysis is undertaken.

Reservoir performance is one of the key issues that have to be addressed before going ahead with the development of a geothermal field. In order to select the type and size of the power plant and design other surface installations, it is necessary to know the characteristics of the production wells and of the produced fluids, and to predict the changes over a 10--30 year period. This is not a straightforward task, as in most cases the calculations have to be made on the basis of data collected before significant fluid volumes have been extracted from the reservoir. The paper describes the methodology used in predicting the long-term performance of hydrothermal systems, as well as DOE/GTD-sponsored research aimed at reducing the uncertainties associated with these predictions. 27 refs., 1 fig.

Two-photon transitions have been examined in molecular hydrogen using coherent vacuum ultraviolet (VUV) photons at a fixed wavelength of 118 nm and a tunable photon from a dye laser. Though the VUV intensity is very weak (/approximately/100 nJ per pulse) it was utilized very efficiently since most VUV photons in the ionoization region were absorbed. This is the first time that coherent VUV light has been employed with tunable visible light for the production of two-photon spectra and the measurement of two-photon rates. A new parameter is proposed for direct comparison of the data from various two-photon experiments. 4 refs., 2 figs., 1 tab.

Time-series analysis techniques are applied to nuclear reactor thermocouple data to investigate coolant temperatures measured within the fueled test assembly. The coolant temperature distribution within a fuel assembly affects the length of time a fuel assembly may be operated in a power reactor and, therefore, is an important economic consideration in the design of reactor fuel systems. Frequency-domain signal conditioning techniques were used to reveal the smoothly varying thermocouple signals from the noisy digital data. Examination of the cross-correlation function for thermocouple pairs suggested an alternate surging and ebbing of coolant flow within certain zones of the fuel assembly. These zones corresponded to thermocouples which experienced higher or lower than predicted coolant temperatures. This time series analysis contributed greatly toward the understanding of fuel assembly thermal hydraulics.

This paper presents recent detector developments and perspectives for positron emission tomography (PET) instrumentation used for medical research, as well as the physical processes in positron annihilation, photon scattering and detection, tomograph design considerations, and the potentials for new advances in detectors. 117 refs., 4 figs., 4 tabs.

The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs.

Using the results of large scale multivent tests conducted by GKSS, a physical model of chugging is developed. The unique combination of accurate digital data and cinematic data has provided the derivation of a detailed, quantified correlation between the dynamic physical variables and the associated two-phase thermo-hydraulic phenomena occurring during lean suppression (chugging) phases of the loss-of-coolant accident in a boiling water reactor pressure suppression system.

Both gas pressure in bubbles and lateral stress have been suggested as primary causes of blistering. An analysis of both mechanisms is presented, and the conditions for blistering are examined. To realistically predict the gas pressure in bubbles, a recently derived high-density equation of state for helium is utilized.

Defect structures in YBa/sub 2/Cu/sub 3/O/sub 7/minus/delta/ produced by electron irradiation at 300/degree/K, were investigated by transmission electron microscopy. Threshold energies for the production of visible defects were determined to b 152 keV and 131 keV (+- 7 keV) in directions near the a- and b-axes, respectively (b > a, both perpendicular to c, the long axis in the orthorhombic structure). During above-threshold irradiations in an electron flux of 3 x 10 /sup 18/ cm/sup /minus/2/s/sup /minus/1/, extended defects were observed to form and grow to sizes of 10--50 nm over 15 minutes, in material thicknesses varying between 20 and 200 nm. Upon irradiation between the a- and b-thresholds, movement of twin plane boundaries and shrinkage of twinned volume were observed. All these findings suggest oxygen atom displacements in the basal plane with recoil energies near 20 eV. Above-threshold irradiations also show the collapse of c-axis long-range order into a planar faulted defect structure with short range order peaks at 1.2 c and 1.07 c, depending on the irradiation direction. 9 refs., 4 figs.

The flow behavior of unirradiated 20% cold worked AISI 316 tubing during constant pressure, increasing temperature tests was modeled with a constitutive relation approach; strain below approximately 0.2% came predominantly from an anelastic portion of the model while higher strains were predominantly plastic. The flow of cladding sections from irradiated fuel pins was largely restricted to the strain region attributed to anelastic deformation due to reduced ductility compared to unirradiated tubing. Another major effect of irradiation exposure on cladding flow was softening, or increased strain, found with increasing irradiation temperature. This was noted only when test pressures were high enough to cause flow below 950/sup 0/K.

The basic objective of the DOE Central Power Systems group is the development of technology for increasing the use of coal in central station electric power generation in an economical and environmentally acceptable manner. The two major research and development areas of this program are the Open Cycle Gas Turbine System and the Closed Cycle Gas Turbine System. Recognizing that the ultimate success of the DOE program is measured by end-user acceptance of the technology developed, the workshop was held to obtain utility industry comments and suggestions on the development of these systems and their potential use by electric power utilities. Representatives of equipment manufacturers, architect and engineering firms, and universities were also invited as participants to provide a comprehensive review of the technology development and implementation process. The 65 participants and observers examined the following topics: technical considerations of the Open Cycle and of the Closed Cycle Gas Turbine program; commercialization of both systems; and regulatory impacts on the development of both systems. Each group evaluated the existing program, indicating R and D objectives that they supported and cited recommendations for modifications and expansion of future R and D work.

Increasing numbers of designers are choosing beryllium for fusion reactor blankets because it, among all nonfissile materials, produces the highest number (2.5 neutron in an infinite media) of neutrons per 14-MeV incident neutron. In amounts of about 20 cm of equivalent solid density, it can be used to produce fissile material, to breed all the tritium consumed in ITER from outboard blankets only, and in designs to produce Co-60. The problem is that predictions of neutron multiplication in beryllium are off by some 10 to 20% and appear to be on the high side, which means that better multiplication measurements and numerical methods are needed. The n,2n reactions result in two helium atoms, which cause radiation damage in the form of hardening at low temperatures (<300/degree/C) and swelling at high temperatures (>300/degree/C). The usual way beryllium parts are made is by hot pressing the powder. A lower cost method is to cold press and then sinter. There is no radiation damage data on this form of beryllium. The issues of corrosion, safety relative to the release of the tritium built-up inside beryllium, and recycle of used beryllium are also discussed. 10 figs.