We present new results in axiomatic group theory obtained by using automated deduction programs. The results include single axioms, some with the identity and others without, for groups of exponents 3, 4, 5 and 7, and a general form for single axioms for groups of odd exponent. The results were obtained by using the programs in three separate ways: as a symbolic calculator, to search for proofs,and to search for couterexamples. We also touch on relations between logic programming and automated reasoning.

Interest in reducing the labor-intensive requirements for calibrating HPGe detectors has resulted in various efficiency models. The present study examines a method for predicting the efficiencies over ranges of sample geometries, whereby only a few measurements are required. The method has been appraised against extensive HPGe calibrations, and has been used for a nondestructive'' calibration for samples from a NASA satellite.

In a short review of recent work, we discuss the general problem of constructing the actions of new conformal field theories from old conformal field theories. Such a construction follows when the old conformal field theory admits new conformal stress tensors in its chiral algebra, and it turns out that the new conformal field theory is generically a new spin-two gauge theory. As an example we discuss the new spin-two gauged sigma models which arise in this fashion from the general conformal non-linear sigma model.

In model calculation, population inversions for 2s{sup 2}2p{sup 2}3s-2s{sup 2}2p{sup 2}3p and for 2s{sup 2}2p{sup 2}d3p-2s{sup 2}2p{sup 2}3d are predicted for ions of the N-like isoelectronic sequence (Kr{sup 29+}, Zr{sup 33+}, Mo{sup 35+}, Pd{sup 39+}, Sn{sup 43+} and Xe{sup 47+}), at electron densities higher than 10{sup 22} cm{sup {minus}3}. Maximum gains of 46 cm{sup {minus}1} for Kr{sup 29+} at 245{angstrom}, and 231 cm{sup {minus}1} at 126{angstrom} for Xe{sup 47+} are obtained. The electron temperature T{sub e} is fixed at half the ionization potential for all ions. A detailed analysis shows that the mechanisms responsible for the population inversion enhancement are collisional de-excitation and radiation trapping. 16 refs., 6 figs.

Recent improvements in the Super Transition Array (STA) method for calculating Bound-Bound (BB) and Bound-Free (BF) emission and absorption spectra for LTE plasma are described and illustrated. The method accounts for all possible BB and BF radiative transitions in the plasma. Full detailed first order quantum relativistic treatment is used for calculating transition energies and probabilities. The enormous number of configurations are divided into sets of superconfigurations comprised of a collection of energetically grouped configurations. The contribution of the transition array between two superconfigurations to a specific one-electron transition is then represented by a Gaussian whose moments are calculated accurately using a technique that bypasses the necessity of direct summation over all the levels involved. The calculation of these moments involves the populations of the configurations given by their statistical weights and the Boltzmann factor. For each configuration within the super configuration we use zeroeth order energies in the Boltzmann factor corrected by a super configuration averaged first order term. The structure of the spectrum is increasingly revealed by splitting each STA into a number of smaller STAs. When the spectrum converges it describes the detailed UTA' structure, where each configuration-to-configuration array is represented by a separate Gaussian with first …

The gauge hierarchy problem is reviewed and a class of effective field theories obtained from superstrings is described. These are characterized by a classical symmetry, related to the space-time duality of string theory, that is responsible for the suppression of observable supersymmetry breaking effects. At the quantum level, the symmetry is broken by anomalies that provide the seed of observable supersymmetry breaking, and an acceptably large gauge hierarchy may be generated. 39 refs.

A seismic analysis of the P-reactor buildings that were built in the early 1950's has been performed using current criteria and analysis techniques. The seismic input is based on the RG 1.60 free field response spectra anchored at 0.2g ZPA. The SSI analysis applied deconvolution techniques to establish soil parameters based on strain dependent damping and shear modulus relationships. The analysis used 2-dimensional soil structure interaction techniques to generate floor response spectra. The spectra were adjusted to account for torsional amplifications resulting from differences between the locations of the center of mass of the floors and the center of rigidity of the connecting vertical column elements. The resulting floor response spectra were smoothed and broadened in accordance with NRC criteria. In addition to developing floor response spectra, building shears and moments were obtained and an assessment of the structural capacity of the buildings to withstand the seismic loads was made.

Two-dimensional fluid simulations of ITER double-null divertor scrape-off-layer plasma conditions have been restricted to examining a single outboard divertor plate with up/down symmetry assumed. The present work evaluates the effect of pumping at only one plate on particle flow patterns and other parameters of interest. Pumping only at one plate results in reduced sheath temperatures at both plates but an increased heat flux at the pumped plate. The physics assumptions for separatrix density (n{sub SEP}={l angle}n{r angle}/3.5) and for radial particle diffusivity (D=0.66m{sup 2}/s) used in the simulation of ITER edge plasma result in particle throughputs two orders of magnitude greater than that required for acceptable fusion-product ash removal rates. The particle confinement time, however, is an order of magnitude shorter than the transport energy confinement time, {tau}{sub E}. Plasmas (D=0.04m{sup 2}/s) which would have {tau}{sub p} {approximately} {tau}{sub E} are evaluated and found to have unacceptably high plasma temperatures and heat flux at the plate. Ash removal rates are still acceptable. A plasma recycle coefficient of R=0.965 reduces the particle throughput by a factor of 2.8 below the no-recycle case.

Addition of vertex detectors to CDF and D0 will facilitate a rich program of beauty physics at the Tevatron, and may enable tags of B and {tau} which facilitate searches for top and other heavy objects. We also address the operational considerations of triggering and radiation protection, and speculate on possible directions for upgrades. 9 refs., 7 figs.

The power of the detectors and the datasets at hadronic colliders begins to allow measurement of the electroweak parameters with a precision that confronts the perturbative corrections to the theory. Recent measurements of M{sub z}, M{sub w}, and sin {theta}{sub w} by CDF and UA2 are reviewed, with some emphasis on how experimental precision is achieved, and some discussion of the import for the specifications of the Standard Model. 14 refs., 10 figs., 4 tabs.

In this note, we consider multilevel preconditioning of the reduced boundary systems which arise in non-overlapping domain decomposition methods. It will be shown that the resulting preconditioned systems have condition numbers which be bounded in the case of multilevel spaces on the whole domain and grow at most proportional to the number of levels in the case of multilevel boundary spaces without multilevel extensions into the interior.

A systematic variation in the line intensity ratios of GaI-like and ZnI-like ions of rare earth elements has been recently observed in spectra emitted in a low density, high temperature tokamak plasma. This variation is shown to be correlated with the gradual opening of autoionizing channels through inner-shell excited configurations of the GaI-like charge-state. These channels enhance the indirect ionization rate of GaI-like ions through excitation-autoionization (EA), effecting the ionization balance and temperatures of greatest abundance. We present a systematic investigation of EA and direct impact ionization (DI) in the GaI-like isoelectronic sequence from Mo (Z = 42) to Dy (Z = 66). As Z decreases from Dy to Pr (Z = 59) the levels of the configuration 3d{sup 9}4p4f, which are excited from the ground state by strong dipole collisional transitions, gradually cross the first ionization limit of the ion and are responsible for this ionization enhancement. When Z decreases further an additional channel is opened through the configuration 3d{sup 9}4p4d. 9 refs., 3 figs., 1 tab.

This report contains lecture notes on beam dynamics and acceleration concepts in particle accelerators. (LSP)

Nonrelativistic models of nuclear systems have provided important insight into nuclear physics. In future experiments, nuclear systems will be examined under extreme conditions of density and temperature, and their response will be probed at momentum and energy transfers larger than the nucleon mass. It is therefore essential to develop reliable models that go beyond the traditional nonrelativistic many-body framework. General properties of physics, such as quantum mechanics, Lorentz covariance, and microscopic causality, motivate the use of quantum field theories to describe the interacting, relativistic, nuclear many-body system. Renormalizable models based on hadronic degrees of freedom (quantum hadrodynamics) are presented, and the assumptions underlying this framework are discussed. Some applications and successes of quantum hadrodynamics are described, with an emphasis on the new features arising from relativity. Examples include the nuclear equation of state, the shell model, nucleon-nucleus scattering, and the inclusion of zero-point vacuum corrections. Current issues and problems are also considered, such as the construction of improved approximations, the full role of the quantum vacuum, and the relationship between quantum hadrodynamics and quantum chromodynamics. We also speculate on future developments. 103 refs., 18 figs.

Ammonia assimilation has been implicated as participating in regulation of nitrogen fixation in free-living bacteria. In fact, these simple organisms utilize an integrated regulation of carbon and nitrogen metabolism; we except to observe an integration of nitrogen and carbon fixation in plants; how could these complex systems grow efficiently and compete in the ecosystem without coordinating these two crucial activities We have been investigating the role of ammonia assimilation regulating the complex symbiotic nitrogen fixation of legumes. Just as is observed in the simple bacterial systems, perturbation of ammonia assimilation in legumes results in increased overall nitrogen fixation. The perturbed plants have increased growth and total nitrogen fixation capability. Because we have targeted the first enyzme in ammonia assimilation, glutamine synthetase, this provides a marker that could be used to assist selection or screening for increased biomass yield. 45 refs., 4 tabs.

This paper is a status report on the ADVANCED LIGHT SOURCE (ALS) control system. The current status, performance data, and future plans will be discussed. Manpower, scheduling, and costs issues are addressed.

The x-ray holography program at the Lawrence Livermore National Laboratory has two principal goals: (1) the development of x-ray diffraction techniques for DNA sequence analysis and (2) the development of x-ray laser holography for structural analysis of intact biological cells and organelles. DNA sequence analysis will be accomplished by applying x-ray diffraction techniques to determine the ensemble average of the sequence of labels along the individual elements of crystalline DNA. X-ray laser holographic imaging will be accomplished by applying three dimensional x-ray holography to elucidate the structure of few hundred angstrom objects such as 300 {Angstrom} chromatin fibers, nuclear pores and nucleic acid replication complexes in living cells. Existing laboratory x-ray lasers will be utilized to produce flash x-ray holograms of the biological structures.

We investigate the effects of secondary interactions in nucleus- nucleus and proton-nucleus collisions using a modified HIJET Monte Carlo generator. The effects of N[sup *] production is explored and it is found that the numbers of kaons can almost be explained by their inclusion. However the transverse momentum spectrum of the kaons is not explained, since their production in HIJET is a soft secondary scattering process and not a hot thermal process like the data.

We present the results of [Lambda] and K[sub s[sup o]] production from Si and Pb targets with 14.6[times][Lambda] Gev/c Si beams. The measured rapidity distributions and the transverse mass exponential slopes are presented and compared with models.

Two-dimensional fluid simulations of ITER double-null divertor scrape-off-layer plasma conditions have been restricted to examining a single outboard divertor plate with up/down symmetry assumed. The present work evaluates the effect of pumping at only one plate on particle flow patterns and other parameters of interest. Pumping only at one plate results in reduced sheath temperatures at both plates but an increased heat flux at the pumped plate. The physics assumptions for separatrix density (n{sub SEP}={l_angle}n{r_angle}/3.5) and for radial particle diffusivity (D=0.66m{sup 2}/s) used in the simulation of ITER edge plasma result in particle throughputs two orders of magnitude greater than that required for acceptable fusion-product ash removal rates. The particle confinement time, however, is an order of magnitude shorter than the transport energy confinement time, {tau}{sub E}. Plasmas (D=0.04m{sup 2}/s) which would have {tau}{sub p} {approximately} {tau}{sub E} are evaluated and found to have unacceptably high plasma temperatures and heat flux at the plate. Ash removal rates are still acceptable. A plasma recycle coefficient of R=0.965 reduces the particle throughput by a factor of 2.8 below the no-recycle case.

The utility of the arbitrary-Lagrangian-Eulerian (ALE) code format is evaluated in the context of use in simulating metal forming processes. Emphasis is on large deformation processes such as casting, forging and extrusion. The basic point at issue is whether the continual remapping capability inherent in the ALE approach can provide advantages relative to the more standard approach of using a Lagrangian mesh but allowing for isolated remeshing as required. A particular ALE implementation, ALE3D, is used as the basis for the discussion. Pros and cons for this approach are presented along with illustrations of its application to actual forming problems.

This paper is a status report on the ADVANCED LIGHT SOURCE (ALS) control system. The current status, performance data, and future plans will be discussed. Manpower, scheduling, and costs issues are addressed.

Tritium behavior in ceramic breeder blankets is a key design issue for this class of blanket because of its impact on safety and fuel self-sufficiency. Over the past 10-15 years, substantial theoretical and experimental efforts have been dedicated world-wide to develop a better understanding of tritium transport in ceramic breeders. Models that are available today seem to cover reasonably well all the key physical transport and trapping mechanisms. They have allowed for reasonable interpretation and reproduction of experimental data and have helped in pointing out deficiencies in material property data base, in providing guidance for future experiments, and in analyzing blanket tritium behavior. This paper highlights the progress in tritium modeling over the last decade. Key tritium transport mechanisms are briefly described along with the more recent and sophisticated models developed to help understand them. Recent experimental data are highlighted and model calibration and validation discussed. Finally, example applications to blanket cases are shown as illustration of progress in the prediction of ceramic breeder blanket tritium inventory.

A seismic analysis of the P-reactor buildings that were built in the early 1950`s has been performed using current criteria and analysis techniques. The seismic input is based on the RG 1.60 free field response spectra anchored at 0.2g ZPA. The SSI analysis applied deconvolution techniques to establish soil parameters based on strain dependent damping and shear modulus relationships. The analysis used 2-dimensional soil structure interaction techniques to generate floor response spectra. The spectra were adjusted to account for torsional amplifications resulting from differences between the locations of the center of mass of the floors and the center of rigidity of the connecting vertical column elements. The resulting floor response spectra were smoothed and broadened in accordance with NRC criteria. In addition to developing floor response spectra, building shears and moments were obtained and an assessment of the structural capacity of the buildings to withstand the seismic loads was made.