The author have studied by means of numerical simulations the dynamical evolution of a network of cosmic strings, both in the radiation and matter era. Our basic conclusion is that a scaling solution exists, i.e., the string energy density evolves as t/sup -2/. This means that the process by which long strings dump their energy into closed loops (which can gravitationally radiate away) is efficient enough to prevent the string domination over other forms of energy. This conclusion does not depend on the initial string energy density, nor on the various numerical parameters. On the other hand, the generated spectrum of loop sizes does depend on the value of our numerical lower cutoff (i.e., the minimum length of loop we allow to be chopped off the network). Furthermore, the network evolution is very different from what was assumed before), namely the creation of a few horizon sized loops per horizon volume and per hubble time, which subsequently fragment into about 10 smaller daughter loops. Rather, many tiny loops are directly cut from the network of infinite strings, and it appears that the only fundamental scale (the horizon) has been lost. This is probably because a fundamental ingredient had been overlooked, …

Candidate heat exchanger materials tested in the Low Mass Flow train at the Coal-Fired Flow Facility (CFFF) at Tullahoma, TN. were analyzed to evaluate their corrosion performance. Tube specimens obtained at each foot of the 14-ft-long Unbend tubes were analyzed for corrosion-scale morphologies, scale thicknesses, and internal penetration depths. Results developed on 1500- and 2000- h exposed specimens were correlated with exposure temperature. In addition, deposit materials collected at several locations in the CFFF were analyzed in detail to characterize the chemical and physical properties of the deposits and their influence on corrosion performance of tube materials.

The splitting of interstitial loops formed by irradiation is considered in detail. It is shown that they may split to form obtuse--angled single shear faults on the intersecting (111) planes. A detailed description of the splitting is given in which the interstitial Frank loop is viewed as being made up of perfect dislocation loop and two shears. The detailed description is then considered in the context of the formation of complex loops as are observed in quenching and irradiation studies. Experimentally observed geometries are explained viz, triangular loops within hexagonal ones etc. The nucleation of a DC' loop in complex interstitial loop formation is shown to be feasible. DC' has the magnitude of a perfect dislocation loop and encloses an intrinsic shear. (auth)

A thin boron film has been applied to the DIII-D tokamak plasma facing surfaces to reduce impurity influx, particularly oxygen and carbon. A direct result of this surface modification was the observation of a regime of very high energy confinement, VH-mode, with confinement times from 1.5 to 2 times greater than predicted by H-mode scaling relation for the same set of parameters. VH-mode discharges are characterized by low ohmic target densities, low edge neutral pressure, and reduced cycling. These conditions have reduced the collisionality, {nu}*, in the edge region producing a higher edge pressure gradient and a significant bootstrap current, up to 30% of the total current. We will describe the edge plasma properties after boronization including reductions in recycling inferred from measurements of {tau}{sup p}*. In particular we will discuss the edge plasma conditions necessary for access to VH-mode including the boronization process and properties of the deposited film.

Construction of the Shiva laser system is nearing completion. This laser will be operating in fall 1977 and will produce over 20 terawatts of focusable power in a subnanosecond pulse. Fusion experiments will begin early in 1978. It is anticipated that thermonuclear energy release equal to one percent that of the incident light energy will be achieved with sub-millimeter deuterium-tritium targets. From other experiments densities in excess of a thousand times that of liquid are also expected.

It was shown that by the use of ion beam probing system with the proper detectors experimental expressions can be obtained for v/sub o/ = v/sub o/ (x,y,z) and v/sub d/ = v/sub d (x,y,z). It was also shown that by taking the curl of the difference between the equations, the magnetic field and consequently the plasma current density distribution can be evaluated.

Transport processes in large measure determine the rate at which electrolytic metal deposition and dissolution can be conducted. Unusually high rates, often accompanied by the formation of solid reaction products, are achieved in electrochemical machining by the use of high electrolyte flow velocities between closely-spaced electrodes. Geometrical shape and surface finish resulting from deposition or dissolution reactions are determined by the current distribution on a macroscopic and microscopic scale. Macroscopic current distributions have been determined experimentally by different electrical and optical means and are compared to theoretical expectations based on transport correlations and numerical models.

Introduction. A regime of very high confinement (VH-mode) has been observed in divertor discharges in DIII-D. The VH-mode, first seen following the initial boronization of the DIII-D vessel in 1991, exhibits total energy confinement a factor of 2.5 to 3.5 greater than that predicted by the ITER89-P L-mode scaling relation. Also, confinement of thermal energy alone is greater than 1.6 times that of the JET/DIII-D H-mode scaling and in many cases has exceeded twice that amount. VH-mode is observed during a long ({le}0.8 sec) ELM-free phase of the discharges. At the beginning of the ELM-free period, the plasma appears to be in H-mode, with confinement near that predicted by the JET/DIII-D scaling. In the usual H-mode, confinement is observed to decrease or remain constant over time. In the present discharges, confinement has been observed to remain nearly constant for up to hundreds of milliseconds, after which the behavior sharply deviates from H-mode as the confinement begins to increase over time. This increase in confinement continues until the occurrence of a beta- related ({beta}>2.8I/aB) global MHD event, which rapidly decreases the plasma stored energy with a temperature reduction across the entire profile. Magnetic measurements indicate that at least in some cases, …

The suggestion of S. van der Meer for stochastic cooling or feedback damping of a circulating charged particle beam offers promise of increasing the luminosity of a storage ring and may be a particularly attractive technique if antiprotons are to be employed as one of the beams in such a device. The original report of van der Meer considered the repeated use of a kicker to suppress the transverse phase-space displacement of the centroid of a group of particles detected at a pick-up station situated up-stream, and the report estimated the expected rate of damping of the mean-square oscillation amplitude. This analysis is extended so as to provide information on the manner in which the character of the amplitude distribution function may be affected by the damping procedure mentioned above. It is believed that information concerning the evolution of the form of the distribution function may be of particular interest in cases in which a ''halo'' is imposed on the distribution by injection of a group of particles to supplement those in a beam that has already been subjected to appreciable feedback damping. Results of the analytic work is illustrated, and compared with the results of simulation computations.

The observed decomposition of the lowest (N = 3,4) N-point correlation functions in symmetrized (N - 1) products of two-point correlation functions suggest the possibility that the Universe may obey a specific scale invariance, at least in some range. Assuming that this scale invariance is strictly verified for all N, some specific predictions concerning the void probability function P(sub O), and more generally the count probabilities P(sub N), as well as the fractal dimensions of the system can be made. In this report, the authors investigate the possibility that the non-linear evolution in a CDM Universe indeed to such a scale invariance.

A brief summary of the activities of the traveler, information derived, and impressions gained while participating in the Japanese Science and Technology Agency's Forum for Multi-Disciplinary Research is given. A visit to the construction site of SPring 8, the new Japanese synchrotron radiation facility, also is described.

A code, CACECO, has been written to assist in the analysis of containment situations peculiar to sodium cooled reactors. Typically, these situations involve relatively slow energy release processes and chemical reaction heat. Two examples are given to illustrate some of the code's features. These particular cases illustrate the potential for hydrogen formation in the containment building, but show that time is available to take corrective action. The code is suitable for other problems involving passive heat absorption in massive structures over long periods of time.

Separate abstracts were prepared for the 51 papers presented. (JFP)

Previously reported Monte Carlo code calculations of the electron energy distributions and the consequent reflex triode characteristics will be presented for two different anode designs. In addition, a generalized formulation of Poisson's equation will be used to examine the virtual cathode side of a reflex diode. The familiar ''resonance'' solution for the reflex triode is again found, but with a different physical interpretation. In the former case the current diverges, but in the virtual cathode space the linear dimension diverges as one approaches the ''resonance.''

It is assumed that objects exist, and the consequences and possible tests of these assumptions are examined. Various experiments on particle interactions are considered. (JFP)

An analysis of the scheme to heat magnetically confined plasma columns to kilovolt temperatures with a laser beam requires consideration of two propagation problems. The first question to be answered is whether stable beam trapping is possible. Since the laser beam creates its own density profile by heating the plasma, the propagation of the beam becomes a nonlinear phenomenon, but not necessarily a stable one. In addition, the electron density at a given time depends on the preceding history of both the medium and the laser pulse. A self-consistent time dependent treatment of the beam propagation and the medium hydrodynamics is consequently required to predict the behavior of the laser beam. Such calculations have been carried out and indicate that propagation of a laser beam in an initially uniform plasma can form a stable filament which alternately focuses and defocuses. An additional question that is discussed is whether diffractive losses associated with long propagation paths are significant.

The CHSH inequality is demonstrated from locality alone without using either determinism or the concept of hidden variables. Then a comment is made about the violation of this inequality by quantum theory. (JFP)

The successful operation of an optoelectronic analog link for transfer of particle detector signals in high radiation area requires a detailed radiation damage study. We present at this conference the study of Ti: LiNbO[sub 3] optical modulators with gamma-rays and neutrons.

Three different but related problems are discussed in this contribution, all related to the so-called Anderson, Hubbard, and t-J Hamiltonians -- the prototype Hamiltonians for systems with highly correlated electrons: the relationship -- based on the well known canonical (Schrieffer-Wolff) transformation -- between the Anderson model (in the small-hybridization and large-Coulomb-interaction regime) and the local moment, the Kondo, the Hubbard and the t-J models, in particular the phenomena of rare-earth magnetism, intermediate valence, and heavy fermions; the exact solution of these Hamiltonians in the periodic small-cluster approximation and the conditions for the existence of the heavy-fermion phenomenon; the metamagnetic transition in heavy-fermion systems.

The study of Rydberg spectra and ionization thresholds of ten lanthanides using several variations of time-resolved resonant multistep techniques is reported. The ionization limits for the lanthanides determined in this way show a systematic dependence on atomic number. A physical model explaining these results is presented. 16 references. (JFP)

Three-dimensional hydrodynamic models for gas-solids flow are developed and used to compute bubble and solids motion in rectangular fluidized beds. Our computed results demonstrate the significance and necessity for three-dimensional models of hydrodynamics and erosion in fluidized-bed combustors. A kinetic theory model for erosion using Finnie's single-particle ductile erosion model was used to compute erosion in a rectangular fluidized bed containing a single tube. Comparison of two-dimensional and three-dimensional computed hydrodynamics, erosion rates, and patterns clearly show the superiority of three-dimensional modeling.

The problem of understanding the branching fractions of the 1-charged particle decay modes of the /tau/ lepton is reviewed. The emphasis is on a recent study by K.G. Hayes and M.L. Perl of the statistical validity of the branching fraction measurements. Unconventional explanations of the problem, none of them satisfactory, are also discussed. 25 refs., 4 tabs.

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The treatment of nucleon-antinucleon systems physics includes the relation between NN and anti NN forces, evidence for narrow anti NN resonances and bound states near threshold and their interpretation as quasimolecular anti NN states, constraints on NN potentials from anti NN scattering, and the important experiments. (JFP)