Research needs include, but are not limited to: measurement of basic thermodynamic data at elevated temperatures for species identified by modelers as potentially important; evaluation of substances which control or limit precipitation and/or nucleation kinetics; sorption studies specifically designed to provide data needed for modeling. This includes the rate of sorption, desorption, and the characterization of the solid and aqueous phases; site-mixing models and thermodynamic data for secondary minerals that form solid solutions; the development of standard techniques for measuring rate laws for precipitation and dissolution kinetics; and measurement of rate laws describing redox kinetics, dissolution, and precipitation involving aqueous species and solid phases of interest to geochemical modelers.

Gamma spectroscopy is used to determine 235U density and enrichment in U-Al fuel tubes containing recycled fuel. A collimated HPGe Y-detector views the tube surface, such that U-Al disk volumes of 6.35 mm diameter and approximately 1.0 mm thickness are examined. The Y-activities from 232U and 235U, along with the tube design parameters, are used to deduce the attenuation-corrected results. Respective density and enrichment variations of less than 1 percent and less than 0.6e percent were measurable with 2000 sec counting time per tube location. Such measurements are useful for certifying tube quality and characterizing problems associated with blending the U-Al alloy.

Described is a general approach to the development of computer programs capable of designing image-forming optical systems without human intervention and of improving their performance with repeated attempts. The approach utilizes two ideas: (1) interpretation of technical design as a mapping in the configuration space of technical characteristics and (2) development of an intelligent routine that recognizes global optima. Examples of lens systems designed and used in the development of the general approach are presented, current status of the project is summarized, and plans for the future efforts are indicated.

The use of ion beam and pulsed laser processing is reviewed for the near-surface modification of a wide range of materials. The techniques of ion implantation doping, ion beam and laser mixing, and pulsed-laser annealing are stressed with particular emphasis on the nonequilibrium aspects of these processing techniques and on new materials properties which can result. Examples are presented illustrating the utility of these techniques for fundamental materials research as well as practical surface modifications.

A three-dimensional finite-element method is used to investigate thermal convection in the earth's mantle. The equations of motion are solved implicitly by means of a fast multigrid technique. The computational mesh for the spherical problem is derived from the regular icosahedron. The calculation described use a mesh with 43,554 nodes and 81,920 elements and were run on a Cray X. The earth's mantle is modeled as a thick spherical shell with isothermal, free-slip boundaries. The infinite Prandtl number problem is formulated in terms of pressure, density, absolute temperature, and velocity and assumes an isotropic Newtonian rheology. Solutions are obtained for Rayleigh numbers up to approximately 10/sup 6/ for a variety of modes of heating. Cases initialized with a temperature distribution with warmer temperatures beneath speading ridges and cooler temperatures beneath present subduction zones yield whole-mantle convection solutions with surface velocities that correlate well with currently observed plate velocities. 8 references, 6 figures.

A crossed undulator system can produce synchrotron radiation whose polarization is arbitrary and adjustable. The polarization can be linear and modulated between two mutually perpendicular directions, or it can be circular and can be modulated between right and left circular polarizations. The system works on low emittance electron storage rings and can cover a wide spectral range. Topics discussed include the basic principle of the system, the design equations and the limitations in performance.

This paper describes health and environmental impacts of coal-fired electric power plants. Effects on man, agriculture, and natural ecosystems are considered. These effects may result from direct impacts or exposures via air, water, and food chains. The paper is organized by geographical extent of effect. Occupational health impacts and local environmental effects such as noise and solid waste leachate are treated first. Then, regional effects of air pollution, including acid rain, are analyzed. Finally, potential global impacts are examined. Occupational health concerns considered include exposure to noise, dust, asbestos, mercury, and combustion products, and resulting injury and disease. Local effects considered include noise; air and water emissions of coal storage piles, solid waste operations, and cooling systems. Air pollution, once an acute local problem, is now a regional concern. Acute and chronic direct health effects are considered. Special attention is given to potential effects of radionuclides in coal and of acid rain. Finally, potential global impacts associated with carbon dioxide emissions are considered. 88 references, 9 tables.

Recent results for charge-changing collisions of interest for cyclotrons and other particle accelerators are presented. Scaling rules, where available, are emphasized. 45 references, 11 figures.

After extensive upgrading, our radio-frequency quadrupole (RFQ) linac is again installed on the accelerator test stand (ATS). The measured parameters of the RFQ, such as the output transverse emittance, transmitted beam, average energy, and energy spread is presented.

Recent results from PEP on quark and gluon fragmentation are reviewed. Topics include: inclusive stable particle production and resonance production, particle distributions in jets, heavy quark fragmentation, flavor correlation studies and tests of fragmentation models. 37 references.

The possibilities for colliding electrons with the 20 TeV proton beams of the SSC are considered. Kinematics of ep colliding beams is reviewed. Energies that may be possible and interesting are suggested, and detector problems associated with the highly imbalanced collisions are briefly considered.

LBL has designed and tested a heavy ion RFQ linac for ions in the mass range of 1 to 40. Designed as part of a preinjector package for synchrotron applications, it is a low duty factor device, operating at 200 MHz with maximum surface fields as high as 28 MV/meter. It is a loop-driven, four vane structure employing several innovative design concepts. These include an exit matcher section, to ensure efficient capture by a following Alvarez linac; advanced mechanical design features, to ensure accurate positioning of the vane pole-tips; and vane coupling rings, to ensure field stabilization and balance. This RFQ has been used on a test bench to accelerate a variety of ions as heavy as silicon, with charge to mass ratios as low as 1/7. Results of the initial operation show that the structure meets all of the design performance criteria, and that it holds promise for a long lifetime of simple and reliable service. This RFQ linac will soon be incorporated into the Bevatron operations program as part of th 200 MHz injector upgrade. A further application of this same RFQ design is in the dedicated Heavy Ion Medical Accelerator presently under study at LBL. Details of …

Present estimates of uranium resources and reserves in the US and the non-Communist world are reviewed. The resulting implications are considered for two proposed breeder technologies: the liquid metal fast breeder reactor (LMFBR) and the fusion hybrid reactor. Using both simple arguments and detailed scenarios from the published literature, conditions are explored under which the LMFBR and fusion hybrid could respectively have the most impact, considering both fuel-supply and economic factors. The conclusions emphasize strong potential advantages of the fusion hybrid, due to its inherently large breeding rate. A discussion is presented of proposed US development strategies for the fusion hybrid, which at present is far behind the LMFBR in its practical application and maturity.

The Brookhaven National Laboratory polarized H/sup -/ injection program for the AGS utilizes a Radio Frequency Quadrupole (RFQ) for acceleration between the polarized H/sup -/ source and the Alvarez Linac. The RFQ accelerator is now in operation with low beam currents. The results of low and high power rf testing will be reported together with initial results of operation in the polarized H/sup -/ beam line.

To improve MFTF-B, one must raise the ion energy and the electrostatic confining potential. This requires higher beam energy (200 keV in this case) and, to preserve end-plug adiabaticity and hold higher plasma density in the central cell, a higher level of magnetic field. In the MFTF Upgrade we also want to incorporate the new end plug configuration first invented for the MARS reactor. This new magnet design is compared with the present MFTF-B magnet set. The differences include the addition of a pair of recircularizing coils on the ends to be used in conjunction with the end region pumping and direct converter schemes, the use of a yin-yang pair rather than a baseball-type coil in the transition, and the elimination of the axicell in favor of the simple choke coil. Also, as noted earlier, an axisymmetric mirror cell is imbedded in the central cell.

ATLAS, the Argonne Tandem-Linac Accelerator System, is a project to upgrade the existing Argonne superconducting linac heavy-ion booster which began providing beams of heavy-ions for experimental nuclear research in 1979. When completed ATLAS will provide beams of heavy ions up to approximately mass 130 at energies as high as 25 MeV/A. The construction of ATLAS is approximately 60% complete. First beam from the accelerator is expected in spring of 1985.

Calculation of absorbed dose to active marrow from photon radiation is a complex problem because electronic equilibrium may not exist in the vicinity of soft tissue-bone mineral interfaces. Snyder et al. recognized the intractable geometry of trabecular bone in their studies of photon transport in the body and formulated marrow dose estimates in a conservative manner. Other investigators have noted that this approach leads to overestimate by factors of 3 or more at low photon energy. In this paper the absorbed dose is formulated in terms of physical and anatomical parameters defining the energy deposition in the marrow space. 17 references, 2 figures, 1 table.

Effects of geothermal fluid production and injection on overlying ground-water aquifers have been studied at the Raft River Geothermal Site in southcentral Idaho. Data collected from 13 monitor wells indicate a complex fractured and porous media controlled ground-water flow system affected by natural recharge and discharge, irrigation withdrawal, and geothermal withdrawal and injection. The monitor wells are completed in aquifers and aquitards overlying the principal geothermal aquifers. Potentiometric heads and water quality are significantly affected by natural upward geothermal leakage via faults and matrix seepage. No significant change in water quality data has been observed, but potentiometric head changes resulted due to geothermal resource testing and utilization. Long-term hydrographs for the wells exhibit three distinct patterns, with superimposed responses due to geothermal pumping and injection. Well hydrographs typical of the Shallow aquifer exhibit effects of natural recharge and irrigation withdrawals. For selected wells, pressure declines due to injection and pressure buildup associated with pumping are observed. The latter effect is presumably due to the elastic deformation of geologic material overlying the stressed aquifers. A second distinct pattern occurs in two wells believed to be hydraulically connected to the underlying Intermediate aquifer via faults. These wells exhibit marked buildup effects due …

High-purity Zr has been irradiated to a dose of 2.2 x 10/sup 21/ n/m/sup 2/ (E < 0.1 MeV) using the pulsed spallation source at IPNS. Electrical resistivity was monitored continuously during irradiation. The saturation resistivity, found from a linear extrapolation of the damage-rate curve between four and five n..cap omega...m. However, comparison with data from the literature shows that the normalized damage-rate curves from five experiments at different temperatures (less than or equal to 77 K) and with different neutron spectra, all fall on the same common curve. A saturation resistivity of 100 n..cap omega...m is found from the high-dose, linear part of this curve. A spontaneous recombination volume in the range 280 to 400 atomic volumes is found using the theory of Dettmann, Leibfried and Schroeder and the saturation resistivity of 100 n..cap omega...m. Post-irradiation annealing has been done up to 300 K using stepped, isochronal anneals. The recovery spectrum is in reasonable agreement with previous work, showing a large peak near 100 K, and two smaller peaks at 160 K and 250 K.

The use of nonsymplectic procedures in particle tracing codes for relativistic electrons leads to errors that can be reduced only at the expense of using very small integration steps. More accurate results are obtained with symplectic transformations for position and momentum. A first-order symplectic integration procedure requires an iterative calculation of the new position coordinates using the old momenta, but the process usually converges in three or four steps. A first-order symplectic algorithm has been coded for cylindrical as well as Cartesian coordinates using the relativistic equations of motion with Hamiltonian variables. The procedure is applied to the steering of a beam of 80-keV electrons by a weak transverse magnetic field superposed on a strong magnetic field in the axial direction. The steering motion is shown to be parallel to the transverse field rather than perpendicular as would be the case without the strong axial field.

Recent updates on the measurements of the tau and D/sup 0/ lifetimes by the Mark II Collaboration and on measurements of the tau and B-hadron lifetimes by the MAC Collaboration are presented. A new determination of an upper limit for the tau neutrino mass by the Mark II Collaboration and a recent measurement of Cabibbo-suppressed tau decay branching ratios from the DELCO Collaboration are also presented. 18 references.

The development of reliable theoretical models for calculating the decay of quasi-stationary states of molecular systems has become an important endeavor for theoretical chemists. The understanding and analysis of a wide variety of physical and chemical phenomena depend on a knowledge of the behavior of these states in both collisional and photoionization problems. In this article we describe the theory and calculation of these cross sections using our Linear Algebraic/Optical Potential method. The theory makes optimal use of the numerical methods developed to solve large sets of coupled integral equations and the bound state techniques used by quantum chemists. Calculations are presented for a representative class of diatomic and triatomic molecules at varying levels of sophistication and for collisional and photoionization cross sections. 48 references, 11 figures.

The ideas of the two-field (6 equation model) and drift-flux (4 equation model) description of two-phase flows are presented. Several example calculations relating to reactor safety are discussed and comparisons of the numerical results and experimental data are shown to be in good agreement.

The primary application of high-current, low-energy synchrotrons and linac compressor rings is as proton drivers for pulsed-spallation neutron sources. They operate in the range of 500 to 1500 MeV with extracted beam repetition rates between 12 to 100 Hz. The time-averaged currents on target are a few tens of microamperes today, soon will be a few thousand in the future. The characteristics for the accelerators and compressor rings, their limitations, and existing and proposed major facilities are described. 22 references, 5 figures, 6 tables.