Implicit time integration methods have been used extensively in numerical modelling of slowly varying phenomena in systems that also support rapid variation. Examples include diffusion, hydrodynamics and reaction kinetics. This article discussed implementation of implicit time integration in plasma codes of the ''particle-in-cell'' family, and the benefits to be gained.

Plasma physics and engineering models of tandem mirror devices operated with a high-field technology test-cell insert in the central cell, which have been incorporated recently in the TMRBAR tandem mirror reactor physics code, are described. The models include particle and energy balance in the test-cell region as well as the interactions between the test-cell particles and those flowing through the entire device. The code calculations yield consistent operating parameters for the test-cell, central cell, and end cell systems. A benchmark case for the MFTF-..cap alpha..+T configuration is presented which shows good agreement between the code results and previous calculations.

A staff paper by the Office of Technology Assessment (OTA) assessing the workplace reproductive health hazards regulations.

The TS-1 and TS-2 TREAT transient experiments subjected a low burnup (2 MWd/kg) and a medium burnup (58 MWd/kg), respectively, FFTF irradiated fuel pin to unprotected 5 cents/s overpower transient conditions. The fuel pin failure response was similar in the two tests, which demonstrated a large margin to failure (P/P/sub 0/ > 3) and a favorable upper level failure location. Thus, for these transient conditions, burnup effects on transient performance appeared to be minimal in the range tested. Pin disruption in the medium burnup TS-2 test was more severe due to the higher fission gas pressurization, but failure occurred at only a 5% lower power level than for the low burnup TS-1 fuel pin. Both tests exhibited axial extrusion of molten fuel to the region above the fuel column several seconds before pin failure, demonstrating a potentially beneficial inherent safety mechanism to delay failure and mitigate accident consequences.

Models of the plasma particle and power balances in a tandem mirror with a high-field test-cell insert in the central cell have been used to calculate operating points for test-cell upgrades of the MFTF-B configuration. The code results have been benchmarked against the proposal plasma parameters for the MFTF-..cap alpha..+T configuration operating in the high neutron wall loading mode. Some parametric studies have been done. Using the results from these parametrics an optimized set of operating parameters for an MFTF-..cap alpha..+T-like configuration with a test-cell which will accommodate two 1.5 m long blanket test modules has been generated. This operating point has the same test-cell neutron wall loading as the original configuration and lower input powers to other systems in the device. The neutral beam power per unit blanket module length is also somewhat reduced in the optimized case.

Models of tandem mirror devices operated with a test-cell insert have been used to calculate operating parameters for FPD-II+T, an upgrade of the Fusion Power Demonstration-II device. Two test-cell configurations were considered, one accommodating two 1.5 m blanket test modules and the other having four. To minimize the cost of the upgrade, FPD-II+T utilizes the same coil arrangement and machine dimensions outside of the test cell as FPD-II, and the requirements on the end cell systems have been held near or below those for FPD-II. The maximum achievable test cell wall loading found for the short test-cell was 3.5 MW/m/sup 2/ while 6.0 MW/m/sup 2/ was obtainable in the long test-cell configuration. The most severe limitation on the achievable wall loading is the upper limit on test-cell beta set by MHD stability calculations. Modification of the shape of the magnetic field in the test-cell by improving the magnet design could raise this beta limit and lead to improved test-cell performance.

Use of atmospheric dispersion models to assess pollutant impacts in complex terrain is increasing. However, the temporally and spatially varying wind and turbulence fields in mountainous areas often invalidate the assumptions of straight-line flow and horizontal homogeneity inherent in standard plume models. A dispersion model was recently developed at the Rocky Flats Plant to realistically simulate dispersion processes in complex terrain. The new model treats pollutant releases as a series of overlapping ellipsoidal puffs. The ends of each puff axis are defined by ''tracer'' particles, which are independently advected through the modeled windfield. The puff axes are not, in general, orthogonal. Thus, a puff can develop an arbitrary shape in response to differential diffusion rates, horizontal convergence and divergence, vertical shear, surface reflection, and gravitational settling. The model includes modules for puff transport, diffusion, wet and dry deposition, resuspension, surface roughness effects, ingrowth, decay, and external and internal dosimetry. This report focuses on the simulation of puff growth and shape.

The studies reported here include conductor current level optimizations at 0.15 T, 2.0 T, 3.0 T, and 3.25 T, maximum conductor fields at 3.25 T, sensitivity of field quality to variations in the magnetic shunt, and effects of up-down asymmetries. This design is characterized by a magnetic shunt which separates the aperture from the primary coils. The current in the three coils, labeled I/sub c'/ I/sub in'/ and I/sub out'/ may be individually controlled. Two configurations of the trim coil, labeled I/sub c'/ were investigated. The three currents are to be used as parameters to control the dipole field value, and to zero the first two allowed harmonic components, the sextupole and decapole.

Hybrid codes in which part of the plasma is represented as particles and the rest as fluid are discussed. In the past few years such codes with particle ions and massless, fluid electrons have been applied to space plasmas, especially to collisionless shocks. All of these simulation codes are one-dimensional and similar in structure, except for how the field equation are solved. We describe in detail the various approaches that are used (resistive Ohm's law, predictor-corrector, Hamiltonian) and compare results from the various codes with examples taken from collisionless shocks and low frequency wave phenomena upstream of shocks.

We have conducted parametric economic studies for heavy-ion-beam fusion electric power plants. We examined the effects on the cost of electricity of several design parameters: maximum achievable chamber pulse rate, driver cost, target gain, and electric conversion efficiency, and net electric power. We found with reasonable assumptions on driver cost, target gain, and electric conversion efficiency, a 2 to 3 GWe heavy-ion-beam fusion power plant, with a chamber pulse rate of 5 to 10 Hz, can be competitive with nuclear and coal power plants.

The High Resolution Spectrometer is a general-purpose spectrometer which measures both charged particles and electromagnetic energy over 90% of the solid angle. The detection elements are in a 1.62-T magnetic field. The detector elements consist of a central drift chamber, an outer drift-chamber system, a barrel shower counter, and an end-cap shower-counter system. The goals of the program of research with the High Resolution Spectrometer include measurements of the electroweak coupling of the quarks and leptons, studies of the strong interactions of the quarks, and search for qualitatively new phenomena. 20 refs., 35 figs. (LEW)

With the employment of a novel octopole end plug scheme, we examine the plasma engineering design of MINIMARS, a small compact fusion reactor based on the tandem mirror principle. With a net electric output of 600 MW/sub e/, MINIMARS is expressly designed for short construction times, factory built modules, and a passively safe blanket system. We show that the compact octopole/mantle provides several distinct improvements over the more conventional quadrupole (yin-yang) end plugs and enables ignition to be obtained with much shorter central cell length. In this way we can design economic small reactors which will minimize utility financial risk and provide attractive alternatives to the conventional larger fusion plants encountered to date.

Conventional spherical shell model calculations have been undertaken to describe /sup 90,88/Zr and /sup 90,88/Y. In these large scale calculations valence orbitals included 1f/sub 5/2/,2p/sub 3/2/,2p/sub 1/2/, and 1g/sub 9/2/. The d/sub 5/2/ orbital was included for /sup 90/Y and for high-spin calculations in /sup 90/Zr. Restrictions were placed on orbital occupancy so that the basis set amounted to less than 25,000 Slater determinants. Calculations were done with a local, state independent, two-body interaction with single Yukawa form factor. Predicted excitation energies and electromagnetic transition rates are compared with recent experimental results. 6 refs., 2 figs.

The beam quality or brightness of an electron beam produced with field immersed emission is studied with two models. First, an envelope formulation is used to determine the scaling of brightness with current, magnetic field and cathode radius, and examine the equilibrium beam radius. Second, the DPC computer code is used to calculate the brightness of two electron beam sources.

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Whether a commissioners court may expend county travel funds to oppose issuance by the Alcoholic Beverage Commission of a private club permit

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Whether a commissioners court may bar video cameras from a public meeting held under article 6252-17, V.T.C.S.

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We present the arrival directions of 117 upward-going muon events collected with the IMB proton lifetime detector during 317 days of live detector operation. The rate of upward-going muons observed in our detector was found to be consistent with the rate expected from atmospheric neutrino production. The upper limit on the total flux of extraterrestrial neutrinos >1 GeV is <0.06 neutrinos/cm/sup 2/-sec. Using our data and a Monte Carlo simulation of high energy muon production in the earth surrounding the detector, we place limits on the flux of neutrinos from a point source in the Vela X-2 system of <0.009 neutrinos/cm/sup 2/-sec with E > 1 GeV. 6 refs., 5 figs.

The main thrust of this experiment will be to measure the asymmetry parameter for the electroweak decay {Sigma}{sup +} {yields} p{gamma} and verify its branching ratio. As a secondary goal they will measure, or set new upper limits for, the branching ratio of the electroweak decay {Xi}{sup -} {yields} {Sigma}{sup -}{gamma}. Since the {Xi}{sup -} are expected to be polarized, information on the asymmetry parameter may also be available.

Weekly report of the Texas Crop and Livestock Reporting Service on broiler chick numbers in Texas and compared with other states. It includes compiled statistics across six consecutive weeks, from the week ending November 24 to the week ending December 29, during 1983 and 1984 for broiler eggs set, chicks hatched, and chicks placed.

Weekly report of the Texas Crop and Livestock Reporting Service on broiler chick numbers in Texas and compared with other states. It includes compiled statistics across six consecutive weeks, from the week ending May 25 to the week ending June 29, during 1984 and 1985 for broiler eggs set, chicks hatched, and chicks placed.

Weekly report of the Texas Crop and Livestock Reporting Service on broiler chick numbers in Texas and compared with other states. It includes compiled statistics across six consecutive weeks, from the week ending February 23 to the week ending March 30, during 1984 and 1985 for broiler eggs set, chicks hatched, and chicks placed.

Samples of Topopah Spring tuff selected from vertical drill holes USW G-1, GU-3, and G-4, and from the horizontal air-drilled hole at Fran Ridge were reacted with J-13 water at 150{sup 0}C. The primary purpose of these experiments was to compare the resulting solution chemistries to estimate the degree of homogeneity that might be expected in thermally affected ground water in a potential nuclear waste repository at Yucca Mountain. The second purpose was to relate data obtained from welded devitrified Topopah Spring tuff collected from the potential repository depth to that previously obtained using outcrop samples. The results show very similar aqueous phase chemistries for all samples after reaction for times up to 70 days. The largest difference in final solution concentrations was for silica in one of the samples from Fran Ridge. All vertical drill core samples gave results for silica that were in agreement to within +-6 ppM and indicated solubility controlled by cristobalite. The results for reaction at 150{sup 0}C are in agreement with those obtained in previous experiments using surface outcrop samples from Fran Ridge. The major difference between the drill core results and the outcrop samples is found in the data for room-temperature rinse solutions. …