Article from the February 1988 featuring a story about a demonstration raising awareness for people who have died from AIDS.

A model-based beam orbit simulation program has been used successfully to analyze the beam energy errors at the two-mile linear accelerator during commissioning of the SLC system. This simulation program has also been used to develop a nondestructive beam energy error monitoring system. The method of analysis, the simulation program, and a beam energy analysis and monitoring system using expert systems techniques will be described.

The potential for experimentally studying B physics at the proposed INFN 100 TeV ELOISATRON (Euroasiatic Long Intersecting Superconducting Accelerator Synchrotron) is compared with possibilities at 40 TeV at the Superconducting Super Collider. The effect of the increase in center of mass energy on the production and decay of B mesons has been investigated, particularly with respect to the accummulation of large samples of B hadron decays necessary for the detection of CP violating effects. 13 refs., 7 figs., 1 tab.

Twenty-seven papers are presented on beryllium supply, production, fabrication, safe handling, analysis, powder technology, and coatings. Separate abstracts have been prepared for the individual papers. (DLC)

The possibility of baryon number violation at the weak scale and an alternative primordial nucleosynthesis scheme arising from the decay of gravitations are discussed. The minimal low energy supergravity model is defined and a few of its features are described. Renormalization group scaling and flavor physics are mentioned.

Argonne National Laboratory has the largest US program for the development of blanket technology. The goals of the program are to resolve critical issues for different blanket concepts, to develop the understanding and predictive capability of blanket behavior, and to develop the technology needed to build and operate advanced fusion blankets. The projects within the program are liquid metal MHD, breeder neutronics, tritium oxidation, transient electromagnetics, FLIBE chemistry, and insulator coatings. The present status and recent results of the projects are described.

Technical advances which have made Brillouin scattering a useful tool in high pressure diamond anvil cell (DAC) studies, viz. multipassing and tandem operation of Fabry-Perot interferometers, are reviewed. Experimental aspects, such as allowed scattering geometries, are outlined and the data analysis required to transform Brillouin spectra into sound velocities and elastic constants is presented. Experimental results on H/sub 2/, N/sub 2/, Ar, and He are presented, and the close relationship between the Brillouin scattering results and equations of state is highlighted.

A brief review of Brillouin scattering is made emphasizing its advantages and disadvantages over conventional ultrasonic techniques. One of its advantages is that the elastic properties of very thin films (approx. 1..mu..) can be investigated. The authors have used this technique to study changes in shear elastic constants of materials irradiated with high energy ions. These particles only penetrate approx. 1..mu.. into the material but produce very high defect concentrations which, in certain cases, can lead to amorphization. In Nb/sub 3/Ir and Zr/sub 3/Al very large changes are observed before the onset of amorphization, while in Si the changes occur concomitantly with amorphization. The significance of the hardening observed in Zr/sub 3/Al when it becomes amorphous will be discussed.

The Target-4 neutron source at the Los Alamos Meson Physics Facility (LAMPF) has recently been commissioned and used as a )open quotes)white)close quotes) source of fast neutrons from 1 to 500 MeV. A 90-meter flight path at a neutron production angle of 15 degrees has been characterized for neutron flux and spectral shape. The flux and shape agree well with calculated values showing that this is indeed an intense and useful white neutron source. Initial measurements of the /sup 12/C(n,p) reaction at forward angles have been made in the energy range 50 to 500 MeV. The results point the way to improve detector schemes and to a program of (n,p) cross section measurements in the energy range where preequilibrium processes dominate much of the charged-particle emission spectra. 3 refs., 2 figs.

The Chernobyl source term available for long-range transport was estimated by integration of radiological measurements with atmospheric dispersion modeling, and by reactor core radionuclide inventory estimation in conjunction with WASH-1400 release fractions associated with specific chemical groups. These analyses indicated that essentially all of the noble gases, 80% of the radioiodines, 40% of the radiocesium, 10% of the tellurium, and about 1% or less of the more refractory elements were released. Atmospheric dispersion modeling of the radioactive cloud over the Northern Hemisphere revealed that the cloud became segmented during the first day, with the lower section heading toward Scandinavia and the uppper part heading in a southeasterly direction with subsequent transport across Asia to Japan, the North Pacific, and the west coast of North America. The inhalation doses due to direct cloud exposure were estimated to exceed 10 mGy near the Chernobyl area, to range between 0.1 and 0.001 mGy within most of Europe, and to be generally less than 0.00001 mGy within the US. The Chernobyl source term was several orders of magnitude greater than those associated with the Windscale and TMI reactor accidents, while the /sup 137/Cs from the Chernobyl event is about 6% of that released by …

A new tritium recovery concept from lithium has been developed as part of the US/Japan collaboration on Reversed-Field Pinch Reactor Design Studies. This concept combines the ..gamma..-gettering process as the front end to recover tritium from the coolant, and a molten salt recovery process to extract tritium for fuel processing. A secondary lithium is used to regenerate the tritium from the gettering bed and, in the process, increases the tritium concentration by a factor of about 20. That way, the required size of the molten salt process becomes very small. A potential problem is the possible poisoning of the gettering bed by the salt dissolved in lithium. 16 refs., 6 figs.

Sub-keV x-ray photoabsorption cross section measurements in transmission have been made using synchrotron radiation beam lines on the VUV storage ring at the National Synchrotron Light Source (NSLS) and on the SPEAR storage ring at Stanford. The experimental considerations associated with making absolute measurements are reviewed, along with techniques for resolving difficulties. Suggestions for future measurements are included.

A study of self-cooled lithium blankets was carried out to define the performance of these blankets and to determine the potential to operate at the maximum possible values of the performance parameters. The main design parameters considered during the course of the study were the tritium breeding ratio, the blanket energy multiplication factor, the energy fraction lost to the shield, the total blanket thickness, the reflector material selection, and the compositions of the different blanket zones. Another study was carried out to determine materials, compositions, arrangements, and thickness of the shield zone for the reference blanket. Helium and water-cooled shields were optimized for the inboard and outboard sections of the reactor. Based on the above two studies, the reference blanket and shield configurations were developed for the ANL Tokamak Power Systems Study. The helium-cooled shield was selected for use with liquid metal blankets to reduce safety concerns related to lithium-water reactivity. This helium-cooled shield provides shielding characteristics similar to a conventional water-cooled shield. The analyses and results from these studies are the subject of this paper. 12 refs., 4 figs., 2 tabs.

When the matrix of a nuclear waste in porous rock dissolves in ground water, other species in the waste are also released. Some species, such as the actinides and rare-earths, are of such low solubility that they may precipitate as soon as they are dissolved, depending on the rate of matrix dissolution, their concentration in the waste solid, their solubilities, and the ground water transport rate. We have previously studied the solubility-limited dissolution of single species as controlled by the rate of advective mass transfer from the waste surface. When the waste constituents include low-solubility members of a decay chain, the radioactive decay daughter can form a precipitate at the waste surface or in the rock away from the waste surface. Here we present a simplified analysis of the precipitate formation and dissolution of species in a two-member decay chain. For this purpose it is assumed that flowing ground water becomes saturated with the chemical species of the nuclides as it flows past the waste, resulting in a constant rate of solubility-limited dissolution of the waste matrix. Assuming congruent release of other waste constituents from the solid, the time-dependent amounts of precipitates of the first and second member of the …

Waste material in a geologic repository will dissolve and migrate away. For many components, this process will be limited by the solubility of the waste matrix and species involved. In this paper we deal with a single contaminant species and analyze the effect of a precipitation front caused by a discontinuity in the solubility of the contaminant at some distance from the waste package. The precipitation front may be due to local geochemical changes such as changes in temperature, pH or redox potential, caused by nearby geologic features or the waste itself. In contrast with other work on precipitation fronts, we provide analytic solution to the problem of precipitation at a stationary front. Numerical illustrations of these solutions are also presented. 5 refs., 2 figs.

This paper trys to explain the rapid increase in the apparent size of the rubidium isotope nuclei around the magic number N = 50. Droplet and deformation models are used to evaluate the measured data. 6 refs., 4 figs.

A preconceptual design of a tokamak fusion reactor concept called ASPIRE (Advanced Safe Pool Immersed REactor) has been developed. This concept provides many of the attractive features that are needed to enhance the capability of fusion to become the power generation technology for the 21st century. Specifically, these features are: inherent safety, low pressure, environmental compatibility, moderate unit size, high availability, high thermal efficiency, simplicity, low radioactive inventory, Class C radioactive waste disposal, and low cost of electricity. We have based ASPIRE on a second stability tokamak. However, the concept is equally applicable to a first stability tokamak or to most other magnetic fusion systems.

H/sup /minus// and D/sup /minus// ions have useful applications in high-energy accelerators and in neutral beam heating, or for current drive of fusion plasmas. Among the different techniques for producing H/sup /minus// ions, direct extraction from a hydrogen discharge is the most attractive. This method requires no cesium and the H/sup /minus// ions generated by volume processes have lower average energy than those formed by surface conversion or by charge exchange processes. For this reason, intensive research and development of volume H/sup /minus// sources are now being conducted at various accelerator and fusion laboratories.

The detection and the measurement of CP violation in the decays of B hadrons will require the accumulation of large numbers of B decays in particular exclusive modes. The potential of beauty hadroproduction experiments for obtaining these large data samples is examined in the context of various trigger and analysis strategies. The possibilities for doing such experiments at present hadron machines is compared with the potential for such experiments at the SSC. 3 refs., 3 figs., 4 tabs.

The amphoteric native defect model of the Schottky barrier formation is used to analyze the Fermi level pinning at metal/semiconductor interfaces for submonolayer metal coverages. It is assumed that the energy required for defect generation is released in the process of surface back-relaxation. Model calculations for metal/GaAs interfaces show a weak dependence of the Fermi level pinning on the thickness of metal deposited at room temperature. This weak dependence indicates a strong dependence of the defect formation energy on the Fermi level, a unique feature of amphoteric native defects. This result is in very good agreement with experimental data. It is shown that a very distinct asymmetry in the Fermi level pinning on p- and n-type GaAs observed at liquid nitrogen temperatures can be understood in terms of much different recombination rates for amphoteric native defects in those two types of materials. Also, it is demonstrated that the Fermi level stabilization energy, a central concept of the amphoteric defect system, plays a fundamental role in other phenomena in semiconductors such as semiconductor/semiconductor heterointerface intermixing and saturation of free carrier concentration. 33 refs., 6 figs.

First wall/blanket/shield design and optimization system (BSDOS) has been developed to provide a state-of-the-art design tool for fast accurate analysis. In addition, it has been designed to perform several other functions: (1) allowing comparison and evaluation studies for different concepts using the same data bases and ground rules, (2) permitting the use of any figure of merit in the evaluation studies, (3) optimizing the first wall/blanket/shield design parameters for any figure of merit under several design constraints, (4) permitting the use of different reactor parameters in the evaluation and optimization analyses, (5) allowing the use of improved eingineering data bases to study the impact on the design performance for planning future research and development, and (6) evaluating the effect of the data base uncertainties on the design performance. BSDOS is the first design and optimization system to couple the highly interacting neutronics, heat transfer, thermal hydraulics, stress analysis, radioactivity and decay-heat analyses, tritium balance, and capital cost. A brief description of the main features of BSDOS is given in this paper. Also, results from using BSDOS to perform design analysis for several reactor components are presented. 17 refs., 1 fig., 2 tabs.

The scientific feasibility, technological inevitability, and economic necessity of fusion as an energy source are discussed.

The gamma-ray bump observed between 0.5 and 2 MeV in the spectrum of Cygnus X-1 can be interpreted as the thermal emissions from a hot (kT)approximately)400 keV) pair-dominated cloud. We argue that the X-rays and gamma rays are produced in separate emission regions, and calculate the photon-photon pair production rate from X-ray and gamma-ray interactions in the vicinity of Cyg X-1 by employing a simplified geometry for the two emitting regions.

We review the solution and properties of the diffusion equation in a hierarchical or ultrametric space. 11 refs.