The stellarator configuration can be greatly simplified when toroidal harmonics are introduced. The toroidal function satisfies Laplace's equation and together with toroidal field and vertical field, a small-aspect-ratio stellarator can be constructed with an aspect ratio as low as 3.6. This functional presentation suggests a very fast computation of particle orbits and magnetic configuration.

Core level angle-resolved photoemission intensity oscillates sinusoidally with increasing photoelectron momentum. Interference between direct and scattered photo-emission causes this angle-resolved photoemission extended fine structure (ARPEFS). We will discuss an analytic single-scattering theory which quantitatively describes the oscillations. The procedures for extracting surface geometry information from photoemission measurements will be illustrated with S(1s) ARPEFS from S on Ni(100) and Cu(100) obtained with the soft X-ray double crystal monochromator at the Stanford Synchrotron Radiation Laboratory. Building on the surface sensitivity and chemical selectivity of photoemission, ARPEFS analysis provides direct geometrical information from the oscillation frequencies (derived with auto-regressive Fourier analysis), from intensity changes with polarization and analyzer position, and from analysis of scattering phase-shift zero-crossings.

Damage to conventional mirror materials exposed to the harsh synchrotron radiation (SR) environment has prompted the SR user community to search for more suitable materials. Next-generation insertion devices, with their attendant flux increases, will make the problem of mirror design even more difficult. A parallel effort in searching for better materials has been underway within the laser community for several years. The technology for dealing with high thermal loads is highly developed among laser manufacturers. Performance requirements for laser heat exchangers are remarkably similar to SR mirror requirements. We report on the application of laser heat exchanger technology to the solution of typical SR mirror design problems. The superior performance of silicon carbide for laser applications is illustrated by various material trades studies, and its superior performance for SR applications is illustrated by means of model calculations.

The system design is given in terms of the following: (1) conventional aspects, (2) architecture, (3) electronic interfaces, (4) operator interfaces, (5) unconventional aspects, (6) electrical energy, (7) electrical noise, (8) operating flexibility, and (9) command procedure development. (MOW)

Basically there are two areas of accelerator applications that involve beam polarization. One is the acceleration of a polarized beam (most likely a proton beam) in a synchrotron. Another concerns polarized beams in an electron storage ring. In both areas, numerical techniques have been very useful.

In contrasting the title of this paper with a second paper to be presented at this conference entitled Distributed Digital Control of Accelerators, a potential reader might be led to believe that this paper will focus on systems whose computing intelligence is centered in one or more computers in a centralized location. Instead, this paper will describe the architectural evolution of SLAC's computer based accelerator control systems with respect to the distribution of their intelligence. However, the use of the word centralized in the title is appropriate because these systems are based on the use of centralized large and computationally powerful processors that are typically supported by networks of smaller distributed processors.

Average indoor radon concentrations range over more than two orders of magnitude, largely because of variability in the rate at which radon enters from building materials, soil, and water supplies. Determining the indoor source magnitude requires knowledge of the generation of radon in source materials, its movement within materials by diffusion and convection, and the means of its entry into buildings. This paper reviews the state of understanding of indoor radon sources and transport. Our understanding of generation rates in and movement through building materials is relatively complete and indicates that, except for materials with unusually high radionuclide contents, these sources can account for observed indoor radon concentrations only at the low end of the range observed. Our understanding of how radon enters buildings from surrounding soil is poorer, however recent experimental and theoretical studies suggest that soil may be the predominant source in many cases where the indoor radon concentration is high. 73 references, 3 figures, 1 table.

This article provides comments on "Generalized corresponding-states method for the prediction of surface tension of pure liquids and liquid mixtures," published in the 'Journal of Colloid and Interface Science' in 1982.

X-ray computed tomography (CT) is a widely used method of obtaining cross-sectional views of objects. The high intensity, natural collimation, monochromaticity and energy tunability of synchrotron x-ray sources could potentially be used to provide CT images of improved quality. The advantages of these systems would be that images could be produced more rapidly with better spatial resolution and reduced beam artifacts. In addition, images, in some cases, could be acquired with elemental sensitivity. As a demonstration of the capability of such a system, CT images were obtained of four slices of an excised pig heart in which the arteries and the cardiac chambers were filled with an iodinated medium. Images were taken with incident x-rays tuned successively to energies just above and below the iodine K edge. Iodine specific images were obtained by logarithmically subtracting the low energy image data from the high energy data and then reconstructing the image. CT imaging using synchrotron radiation may become a convenient and non-destructive method of imaging samples difficult to study by other methods.

Constant extension rate tests have been performed on sensitized Type 316 stainless steel in oxygenated water (8 ppM O/sub 2/) containing chloride ion impurities (0.5 ppM) over a range of strain rates from 10/sup -5/ to 2 x 10/sup -7/ s/sup -1/. The susceptibility to IGSCC (as quantified by parameters such as crack length at failure) increases with a decrease in strain rate. A model consistent with the observed and postulated crack growth behavior and with a fracture criterion is presented and used to derive power laws that relate the IGSCC susceptibility parameters and strain rate. The predicted strain rate exponents are in agreement with the experimental results of this and other studies. The correlations between IGSCC susceptibility and strain rate can be used to predict susceptibility to cracking outside the range of conditions used in the laboratory. In addition, it is shown that the average crack-tip strain rate in CERT experiments can be estimated by use of a J-integral approach. It is observed that the average crack growth rate is proportional to the square root of the estimated average crack-tip strain rate. The experimentally observed correlation is in good agreement with that deduced from a slip-dissolution model proposed by …

These lectures come in five sections. The first is this introduction. The second is a short chronology of what are viewed as important milestones in the field. The third covers proton linacs. It introduces elementary concepts such as transit time, shunt impedance, and Q. Critical issues such as phase stability and transverse forces are discussed. The fourth section contains an elementary discussion of waveguide accelerating structures. It can be regarded as an introduction to some of the more advanced treatments of the subject. The final section is devoted to electron accelerators. Taking SLAC as an example, various topics are discussed such as structure design, choice of parameters, frequency optimization, beam current, emittance, bunch length and beam loading. Recent developments and future challenges are mentioned briefly. 41 figures, 4 tables.

Separate abstracts were prepared for 20 papers in this report. For several years the Department of Energy (DOE), Office of Health and Environmental Research (OHER), has supported a research program aimed at developing new experimental approaches for the improvement of cancer risk assessments. The central issue is to overcome the organizational, species and other barriers that make it difficult to extrapolate laboratory-based data to predict risk to man. Most of the participants at the meeting are involved in research aimed at understanding the mechanism(s) of chemical carcinogenesis. Complex mixtures of chemicals are associated with many energy technologies. DOE's initial program emphasis focused on semi-applied research aimed at quantitative evaluation of carcinogenic activity of complex materials. Since much progress has been made in DOE integrated technology-specific chemical-biological characterization studies, the number and kinds of chemicals of concern has been reduced to a relatively few well-defined classes. Although the classes of compounds seem to be unique to some of the synfuel technologies, they are quite similar to compounds of general interest, for example, poly-nuclear aromatic hydrocarbons. Special emphasis was placed on molecular and cellular dosimetry as one of the key requirements for quantitative comparison of effects at the cell level in vivo …

The symmetry of incommensurate crystals can be described by higher dimensional space groups in the so called superspace approach. The basic ideas are explained and used for showing that superspace groups provide an adequate frame for analyzing experimental results on incommensurate crystals.

Recent progress in proving the validity of factorization for inclusive reactions in QCD is reviewed. A new necessary condition involving the target length is emphasized. We also discuss a number of novel effects in gauge theory including null zone phenomena, color transparency, formation zone conditions, and possible heavy quark Fock states components in ordinary hadrons. 36 references.

The proposed Stanford Linear Collider (SLC) has been designed to provide 50 on 50 GeV electron-positron collisions. The performance of the 240 klystrons driving the two-mile long linac must be upgraded to achieve at least 50 Megawatts of peak power output at a pulse of 5 ..mu..sec and a pulse repetition frequency of 180 pulses per second. The operating frequency of the upgraded linac will continue to be 2856 MHz. A klystron amplifier meeting these new requirements has been designed to operate at 315 kV, ..mu..k = 2, with a computed efficiency of slightly greater than 50%. Initial tests indicate the achievement of the basic power objectives; however, observed parasitic instabilities make beam focusing, RF drive frequency and drive level extremely critical. High electric fields in the electron gun, output gap and output window are all potential problems. Steps taken in the design to overcome these problems are discussed and test results are presented.

The MARK III detector, operating at SPEAR, has collected approx. 2.7 x 10/sup 6/ phi decays and 4500 nb/sup -1/ of phi'' decays. Preliminary results from the full phi samples are presented.

A novel configuration of free electron laser system is proposed that is capable of generating coherent radiation whose polarization is arbitrary and rapidly adjustable. The magnet configuration is similar to that of the optical klystron except that the undulators are placed perpendicular rather than parallel to each other. The gain of the system is analyzed in the small signal regime, and is found to be similar to that of the optical klystron. The polarization of the laser radiation at maximum gain is found to be different from the polarization of the spontaneous radiation.

Mechanistic fuel performance models are used in high-temperature gas-cooled reactor core design and licensing to predict failure and fission product release. Fuel particles manufactured with defective or missing SiC, IPyC, or fuel dispersion in the buffer fail at a level of less than 5 x 10/sup -4/ fraction. These failed particles primarily release metallic fission products because the OPyC remains intact on 90% of the particles and retains gaseous isotopes. The predicted failure of particles using performance models appears to be conservative relative to operating reactor experience.

A summary is presented of typical gas-phase photoemission studies based on synchrotron radiation in the 50-5000 eV range, using beam lines at the Stanford Synchrotron Radiation Laboratory. Three topics are addressed: atomic inner-shell photoelectron cross sections and asymmetries, correlation peaks in rare gases, and core-level shape resonances in molecules.

Session topics were: quarks and nuclear physics; anomalons and anti-protons; the independent particle structure of nuclei; relativistic descriptions of nuclear structure and scattering; nuclear structure at high excitation; advances in nuclear astrophysics; properties of nuclear material; the earliest moments of the universe; and pions and spin excitations in nuclei.

A brief description of the Bevatron is given, and plans for the Relativistic Nuclear Collider (RNC) are described. The RNC would utilize the SuperHILAC as the heavy ion injector and two superconducting storage rings to produce colliding heavy ion beams. (WHK)

RF sources with high peak power output and relatively short pulse lengths will be required for future high gradient e/sup +/e/sup -/ linear colliders. The required peak power and pulse length depend on the operating frequency, energy gradient and geometry of the collider linac structure. The frequency and gradient are in turn constrained by various parameters which depend on the beam-beam collision dynamics, and on the total ac wall-plug power that has been committed to the linac rf system. Various rf sources which might meet these requirements are reviewed. Existing source types (e.g., klystrons, gyrotrons) and sources which show future promise based on experimental prototypes are first considered. Finally, several proposals for high peak power rf sources based on unconventional concepts are discussed. These are an FEL source (two beam accelerator), rf energy storage cavities with switching, and a photocathode device which produces an rf current by direct emission modulation of the cathode.

Low-cycle fatigue and tensile data have been obtained on Type 316 stainless steel in a flowing lithium environment of controlled purity. The results show that the fatigue life of the steel in flowing lithium at 755 K is greater than in air. Preexposure of the material to lithium reduces fatigue life. The reduction in fatigue life may be attributed to the formation of a weak ferrite layer after lithium exposure. Tensile data for cold-worked Type 316 stainless steel indicate that at temperatures between 476 and 755 K, a flowing lithium environment has little or no effect on the tensile properties of the steel.

The dosimetry of A-bomb survivors at Hiroshima and Nagasaki is discussed in light of the new dosimetry developed in 1980 by the author. The important changes resulting from the new dosimetry are the ratios of neutron to gamma doses, particularly at Hiroshima. The implications of these changes in terms of epidemiology and radiation protection standards are discussed. (ACR)