The fission cross sections of /sup 238/Pu have been measured from 0.1 eV to 80 keV energy range using the Rensselaer Intense Neutron Spectrometer. The cross sections were normalized to the /sup 235/U ENDF/B-V data broadened to the resolution of the Rensselaer Intense Neutron Spectrometer system. The fission areas and widths were determined for the resolved low-energy resonances. The ENDF/B-V fission cross sections for the /sup 238/Pu isotope are, in general, not in good agreement with the measured cross sections and a new evaluation is recommended. The observations of structure in the unresolved fission cross sections is suggestive of the existence of intermediate structure. 18 refs., 1 fig., 1 tab.

A brief review is given of selected topics in the electromagnetic structure of nucleons and nuclei, including nucleon form factors from both quantum chromodynamics and electron scattering data, measurements of the deuteron and triton form factors, quasi-elastic scattering, and the EMC effect. 47 refs., 13 figs. (LEW)

The injection/extraction systems of the 1.21 GeV Stanford Linear Collider (SLC) damping rings uses four pairs of water cooled septum magnets. Each pair consists of a thin-septum, low-field (3 mm, 3 kilogauss) magnet plus a thick-septum, high-field (12 mm, 8 kilogauss) model. In the latest design cooling reliability was improved by using stainless-steel tubing imbedded in the copper. The operating current in each is 2600 amperes, at a density of up to 120 amperes per mmS. Plasma-sprayed alumina is used to provide electrical insulation. The magnet system is compatible with 10 Z torr ultra-high vacuum. The magnet design, fabrication, and measurements are described.

This paper addresses specific and unique chemical engineering aspects of the Defense Waste Processing Facility (DWPF) at the Savannah River Plant. This paper also addresses the glass melter and those processes that are directly coupled to it. A somewhat disproportionate emphasis is given to sludge pretreatment, for the sake of completeness in this session. We have attempted to focus on those features of the DWPF that may be of general interest or even useful to the practicing chemical engineer.

QCD predictions for ..gamma gamma.. annihilation into single mesons, meson pairs, and baryon pairs are reviewed. Two-photon exclusive processes provide the most sensitive and practical measure of the distribution amplitudes, and thus a critical confrontation between QCD and experiment. Both the angular distribution and virtual photon mass dependence of these amplitudes are sensitive to the shapes of the phi (chi, Q). Novel effects involving the production of qq anti q anti q states at threshold are also discussed, and a new method is presented for systematically incorporating higher-order QCD corrections in ..gamma gamma.. reactions.

The MEVVA (Metal Vapor Vacuum Arc) ion source is a new kind of source which can produce high current beams of metal ions. Beams of a wide range of elements have been produced, spanning the periodic table from lithium up to and including uranium. The source extraction voltage is up to 60 kV, and we are increasing this up to 120 kV. A total ion beam current of over 1 Ampere has been extracted from the present embodiment of the concept, and this is not an inherent limit. The ion charge state distribution varies with cathode material and arc current, and beams like Li/sup +/, Co/sup +,2+,3+/ and U/sup 3+,4+,5+,6+/ for example, are typical; thus the implantation energy can be up to several hundred kilovolts without additional acceleration. The ion source has potential applications for ion implantation and ion beam mixing for achievement of improved corrosion resistance or wear resistance in metals or surface modification of ceramic materials and semiconductors. Here we outline the source and its performance, and describe some very preliminary implantation work using this source.

Monte Carlo calculations with the Lund string fragmentation model are compared to experimental results on the reactions ..gamma gamma -->..2..pi../sup +/2..pi../sup -/, ..gamma gamma -->..K/sup +/K/sup -/..pi../sup +/..pi../sup -/ and ..gamma gamma -->..p anti p..pi../sup +/..pi../sup -/. It is found, that when the parameters of the Lund model are tuned to low energy, inclusive multi hadron production in photon-photon collisions, the cross sections of exclusive processes near threshold are qualitatively reproduced. 14 refs., 3 figs.

The Advent of laser-ion-guiding in the Advanced test Accelerator along with the development of accelerator cavities optimized with respect to beam breakup coupling impedence now make it possible to consider a new class of high current, high emergy linear induction accelerators. The control of the beam breakup and other instabilities by laser guiding and by various magnetic focusing schemes will be discussed along with the scaling laws for the design of such machines to minimize the growth of the beam breakup instability. Many linacs, particularly induction linacs are limited in performance by the beam breakup (BBU) instability. The instability is found in two forms. In the first form the accelerating cavities communicate with one another through interaction with the beam and through propagation of cavity fields through the accelerator structure. In the second form which is the more virulent of the two, the cavities couple to each other only through their interactions with the beam. It is this second form of PPU that will be discussed in this paper.

Shock waves that occur in stellar atmospheres have their origin in some hydrodynamic instability of the atmosphere itself or of the stellar interior. In luminous early-type stars these two possibilities are represented by shocks due to an unstable radiatively-accelerated wind, and to shocks generated by the non-radial pulsations known to be present in many or most OB stars. This review is concerned with the structure and development of the shocks in these two cases, and especially with the mass loss that may be due specifically to the shocks. Pulsation-produced shocks are found to be very unfavorable for causing mass loss, owing to the great radiation efficiency that allows them to remain isothermal. The situation regarding radiatively-driven shocks remains unclear, awaiting detailed hydrodynamics calculations. 20 refs., 2 figs.

This report describes a mathematical model that estimates the rate that cesium and iodine isotopes would migrate from spent fuel rods after emplacement in a geologic repository that is subsequently flooded with ground water. 4 refs., 2 figs. (TEM)

Penetrations may result from corrosion or cracking and may be through the container material or through deposits of corrosion products. The analysis deals with the resultant radionuclide transport, but not with how these penetrations occur. We provide numerical illustrations for diffusive nuclide flux through these apertures from mathematical expressions. 2 refs., 2 figs.

One simulation facility that has been developed is the BNL Plant Analyzer, currently set up for BWR plant simulations at up to seven times faster than real-time process speeds. The principal hardware components of the BNL Plant Analyzer are two units of special-purpose parallel processors, the AD10 of Applied Dynamics International and a PDP-11/34 host computer. The AD10 is specifically designed for time-critical system simulations, utilizing the modern parallel processing technology with pipeline architecture. The simulator employs advanced modeling techniques and efficient integration techniques in conjunction with the parallel processors to achieve high speed performance.

In order to see if there could be agreement between results of stellar evolution theory and those of nonradial pulsation theory, calculations of white dwarf models have been made for hydrogen surface masses of 10/sup -4/ solar masses. Earlier results indicated that surface masses greater than 10/sup -8/ solar masses would not allow nonradial pulsations, even though all the driving and damping is in surface layers only 10/sup -12/ of the mass thick. It is shown that the surface mass of hydrogen in the pulsating white dwarfs (ZZ Ceti variables) can be any value as long as it is thick enough to contain the surface convection zone. 10 refs., 6 figs.

High-spin spectroscopy is the study of the changes in nuclear structure, properties, and behavior with increasing angular momentum. It involves the complex interplay between collective and single-particle motion, between shape and deformation changes, particle alignments, and changes in the pairing correlations. A review of progress in theory, experimentation, and instrumentation in this field is given. (DWL)

The Heavy Ion Fusion Systems Assessment (HIFSA) study was conducted with the specific objective of evaluating the prospects of using induction linac drivers to generate economical electrical power from inertial confinement fusion. The study used algorithmic models of representative components of a fusion system to identify favored areas in the multidimensional parameter space. The resulting cost-of-electricity (COE) projections are comparable to those from other (magnetic) fusion scenarios, at a plant size of 100 MWe.

A brief overview of statistical data analysis is provided with a view towards examining its role in the analysis of astronomy data. 5 figs.

The measurement of the Lamb shift in heliumlike uranium and outlines future experimental tests of QED using few-electron very high atomic number (Z) ions are presented. A discussion of the possibility of using ultrarelativistic atomic collisions to produce very heavy leptons is also presented. 38 refs., 4 figs., 1 tab.

A number of basic conceptual designs are explained for magnet systems that use permanent magnet materials. Included are iron free multipoles and hybrid magnets. Also appended is a discussion of the manufacturing process and magnetic properties of some permanent magnet materials. (LEW)

A deformed and energy dependent phenomenological optical model potential and coupled-channel formalism for deformed nuclei have been used in the analysis of elastic and inelastic (Q = 4.439 MeV) scattering, and analyzing power for neutrons scattered from /sup 12/C in the energy range of 9 to 15 MeV. 6 refs., 1 fig., 1 tab.

The first in-depth investigation of surface modification of materials by continuous, high-flux argon plasma bombardment under simultaneous erosion and redeposition conditions have been carried out for copper and 304 stainless steel using the PISCES facility. The plasma bombardment conditions are: incident ion flux range from 10/sup 17/ to 10/sup 19/ ions sec/sup -1/cm/sup -2/, total ion fluence is controlled between 10/sup 19/ and 10/sup 22/ ions cm/sup -2/, electron temperature range from 5 to 15 eV, and plasma density range from 10/sup 11/ to 10/sup 13/cm/sup -3/. The incident ion energy is 100 eV. The sample temperature is between 300 and 700K. Under redeposition dominated conditions, the material erosion rate due to the plasma bombardment is significantly smaller (by a factor up to 10) than that can be expected from the classical ion beam sputtering yield data. It is found that surface morphologies of redeposited materials strongly depend on the plasma bombardment condition. The effect of impurities on surface morphology is elucidated in detail. First-order modelings are implemented to interpret the reduced erosion rate and the surface evolution. Also, fusion related surface properties of redeposited materials such as hydrogen reemission and plasma driven permeation have been characterized.

The atomic and molecular processes that play a principal role in negative ion formation in a hydrogen negative ion discharge are discussed. The collisions of energetic electrons with gas molecules within the discharge lead to vibrationally excited molecules. Thermal electrons in turn attach to these excited molecules and generate negative ions via the dissociative attachment process. A system geometry chosen to optimize these collision processes is discussed that consists of a high-power discharge in tandem with a low electron temperature bath, the two regions separated by a magnetic filter. The current density extracted from such a system is found to scale inversely with the system scale length provided the gas density and electron density are also increased inversely with scale length. If a system is scaled downward in size to provide a new beamlet but one with increased current density, and these beamlets are packed to fill the original dimension, the new total extracted current will exceed the original total current by the scale factor. The emittance, epsilon, of the new system remains unchanged. The brightness, J/epsilon/sup 2/, of the new system will also be increased in proportion to the scale factor. 4 refs., 2 figs.

In comparing the particle flow in the event plane of three-jet (q anti qg) events and of radiative annihilation events (q anti q..gamma..) for similar kinematic configurations, two PEP experiments find a significant decrease in particle density in the angular region opposite to the gluon jet in q anti qg events, relative to the particle density in the region opposite to the photon in q anti q..gamma.. events. The effect is predicted both by QCD and by phenomenological string models. 5 refs., 5 figs.

There has been a great deal of progress in recent years on the development of solid state and KrF lasers, light ion diodes, and heavy ion accelerators for use as drivers in inertial confinement fusion (ICF) facilities. Two relatively new entries in the ICF driver derby are the free electron laser (FEL) and the compact torus (CT). The status and remaining technological challenges of each potential driver are described. The author discusses driver performance criteria for various reactor applications and then gives his informed opinion in a qualitative rating of the six drivers for each application.

The evolution of six-quark color-singlet state distribution amplitudes is formulated as an application of perturbative quantum chromodynamics to nuclear wave functions. We present a general method of solving the evolution equation for multiquark bound states and predict the asymptotic Q/sup 2/ slope for the deuteron charge form factor as a result.