The alloy V-15Cr-5Ti was cyclotron-implanted with 80 appM He and subsequently irradiated in the Experimental Breeder Reactor (EBR-II) to 30 dpa. The same alloy was also irradiated in the 10, 20, and 30% cold-worked conditions. Irradiation temperatures ranged from 400 to 700/sup 0/C. No significant effects of helium on mechanical properties were found in this temperature range although the neutron irradiation shifted the temperature of transition from cleavage to ductile fracture to about 625/sup 0/C. Ten percent cold work was found to have a beneficial effect in reducing the tendency for cleavage fracture following irradiation, but high levels (20%) were observed to reduce ductility. Still higher levels (30%) improved ductility by inducing recovery during the elevated-temperature irradiation. Swelling was found to be negligible, but precipitates - titanium oxides or carbonitrides - contained substantial cavities.

This article discusses our measurement of the Lamb shift in heliumlike uranium and outlines future tests of QED using few- electron very high atomic number (Z) ions. Our recently reported Lamb shift value of 70.4 (8.1) eV for the one- electron Lamb shift in uranium is in agreement with the theoretical value of 75.3 (0.4) eV. The experimental value was extracted from a beam-foil time-of-flight measurement of the 54.4 (3.3) ps lifetime of the 1s2p/sub 1/2/ /sup 3/P/sub 0/ state of heliumlike uranium. 24 refs., 5 figs., 1 tab.

The present SLAC accelerator program is summarized briefly, and the future of electron-positron colliders is discussed. Present activities discussed include the PEP storage ring, the SPEAR storage ring, the Linear Accelerator, and the SLAC Linear Collider (SLC) project. Future prospects include a larger scale linear collider. The stability requirements on acceleration are briefly discussed. (LEW)

A new kind of ion source has been developed in which a metal vapor vacuum arc (MEVVA) is used to produce the plasma from which the ion beam is extracted. The novel and exciting feature of this source is the very high metal ion beam current attainable. A total ion beam current of over 1 Ampere has been extracted from the embodiment of the concept that we're presently using, and this is not a limit of the method. The source was developed to upgrade the uranium ion beam intensity of the Bevatron, LBL's heavy ion synchrotron, for basic nuclear physics research. Other important applications include its use within the Heavy Ion Fusion research effort; for ion implantation; and for other basic research uses. In this paper the source is described briefly, its performance outlined, and its poential and limitations for a variety of applications is discussed.

The theory and simulation of collisionless perpendicular supercritical shock structure is reviewed, with major emphasis on recent research results. The primary tool of investigation is the hybrid simulation method, in which the Newtonian orbits of a large number of ion macroparticles are followed numerically, and in which the electrons are treated as a charge neutralizing fluid. The principal results to be presented are (1) electron resistivity is not required to explain the observed quasi-stationarity of the earth's bow shock, (2) the structure of the perpendicular shock at very high Mach numbers (M/sub A/ approx. = 15 - 20 and ..beta.. approx. = 1, where M/sub A/ is the Alfven Mach number of the shock and ..beta.. is the ratio of the thermal to magnetic pressure) depends sensitively on the upstream ..beta.. and electron resistivity, (3) two-dimensional turbulence will become increasingly important as the Mach number is increased, and (4) non-adiabatic bulk electron heating will result when a thermal electron cannot complete a gyro-orbit while transiting the shock. 32 refs., 13 figs.

Once the gross features of a frontline fluid system have been defined, one must consider what support system configuration will provide the best overall system performance. This paper considers different dc bus configurations for a given emergency feedwater system. Results indicate that a four-train support system (i.e., 4 dc buses) gives a lower system unavailability for transients, but a higher system unavailability for Anticipated Transients Without Scram (ATWS), than a two-train support system (i.e., two dc buses). This serves to illustrate that more trains do not necessarily provide higher reliability, and that a configuration choice which is better for one mission success criterion may be worse for another. Because of the small characteristic unreliability of dc buses, the numerical comparisons made here are not dramatic, but the underlying topological point is nevertheless broadly applicable. The EFWS selected in this study consists of two turbine-driven pumps, and two motor-driven pumps, with associated piping, instruments, and valves. There are two divisions of EFWS, each division including one turbine-driven pump train, and one motor-driven pump train with a crosstie that can provide an alternate flow path in case one train is not available. Each of the motor-driven pumps has one ac power bus …

This paper presents recent detector developments and perspectives for positron emission tomography (PET) instrumentation used for medical research, as well as the physical processes in positron annihilation, photon scattering and detection, tomograph design considerations, and the potentials for new advances in detectors. 117 refs., 4 figs., 4 tabs.

No-scale supergravity theories with the minimal low-energy particle content are shown to become untenable for a top quark mass m/sub T/ much less than 40 GeV. For m/sub T/ < 55 GeV, a stringent upper bound operates on the mass of the lowest-lying Higgs scalar. Further, the Higgs pseudoscalar is constrained to be nearly a quarter as massive as the gluino.

This document contains the proceeding of a Workshop on Facility Design that was held between the United States Department of Energy and the United Kingdom Atomic Energy Authority, Albuquerque, New Mexico, October 27--29, 1986. The intention of the workshop was to display relevant design criteria and to demonstrate for various US and UK facilities, current and projected criteria and how these criteria have been satisfied by facility design. Specific examples concern small plants, large plants, and waste stores.

A number of neutron experiments on transuranium materials are reviewed. Purpose of these experiments, which range from studies of crystal fields in the oxides to excitations in PuSb, is to increase our understanding of the 5f electron behavior across the first half of the actinide series. Comparisons are made with the more familiar uranium analogues.

This paper describes experiments designed to evaluate the impact of HDTV on the performance of typical remote tasks. The experiments described in this paper compared the performance of four operators using HDTV with their performance while using other television systems. The experiments included four television systems: (1) high-definition color television, (2) high-definition monochromatic television, (3) standard-resolution monochromatic television, and (4) standard-resolution stereoscopic monochromatic television. The stereo system accomplished stereoscopy by displaying two cross-polarized images, one reflected by a half-silvered mirror and one seen through the mirror. Observers wore a pair of glasses with cross-polarized lenses so that the left eye received only the view from the left camera and the right eye received only the view from the right camera.

The current status and prospects for inertial confinement fusion based on the use of intense beams of heavy ions will be described in the light of results presented at the International Symposium on Heavy Ion Fusion, (Washington, DC, May 27-29, 1986).

Results are reported for an ongoing effort to optimize D/sup +/ beam production by the MATS-III ion source used at the RTNS-II. The oxide cathode assembly originally designed for lower power operation has been modified and redesigned for higher electron current yield, longer life and serviceability. A factor of 2.5 has been gained in cathode lifetime due to these changes. The details of the changes and results and benefits in operation and performance are given. In addition, the technique used for manufacture of the filament is described.

The interplay between atomic and nuclear interactions in heavy ion collisions with nuclear contact is studied. The general theoretical description is outlined and analyzed in a number of different limits (semiclassical approximation, DWBA, fully quantal description). The two most important physical mechanisms for generating atomic-nuclear interference, i.e., energy conservation and the introduction of additional phase shifts by nuclear reactions, are extracted. The resulting typical coupling matrix elements are analyzed for their relative importance in atomic and nuclear excitations. The description of nuclear influence on atomic excitations in terms of a classical time delay caused by nuclear reactions is reviewed, and its relationship to the underlying quantal character of the nuclear reaction is discussed. The theory is applied to spontaneous positron emission in supercritical heavy-ion collisions (Z/sub tot/ greater than or equal to 173). It is shown that nuclear contact can lead to line structures in the positron energy spectra if the probability distribution for nuclear delay times caused by the contact has contributions for T greater than or equal to 10/sup -19/ sec. We explicitly evaluate a model where a pocket in the internuclear potential near the touching configuration leads to formation of nuclear molecules, and predict a resonance-like excitation …

As heavy ion reaction studies have progressed from beam energies below 10 MeV/nucleon to higher energies, many non-equilibrium reaction phenomena have been observed. Among these are nucleon emission with velocities in excess of the beam velocity, incomplete momentum transfer to evaporation residue and fission-like fragments, ..gamma..-rays with energies in excess of 100 MeV, and ..pi../sup 0/ production when beam energies are below the threshold for production by the nucleon-nucleon collision mechanism. Additionally, prefission neutrons have been observed in excess of numbers expected from equilibrium models. A few of the approaches which have been applied to these phenomena are as follows: Intranuclear cascade: two body collisions are assumed to mediate the equilibration. The geometry and momentum space is followed semiclassically. The approach has many successes though it may suffer in a few applications is not following holes; TDHF considers one body processes only; in the energy regime of interest, two body processes are important so that this may not be a viable approach; Boltzmann-Uehling-Uhlenbeck or Vlasov-Uehling-Uhlenbeck (BUU/VUU) equations combine both one body and two body dynamics. The spatial and momentum evolution of the reactions are followed in a mean field. These should be the Cadillacs of the models. They are computationally …

The planned positive-ion injector for ATLAS consists of an ECR ion source on a 350-kV platfrom and a superconducting injector linac of a new kind. The objective is to replace the present tandem injector with a system that can increase beam intensities by two orders of magnitude and extend the mass range up to uranium. In the first, developmental stage of the work, now in progress, the ECR source will be built, the technology of superconducting accelerating structures for low-velocity ions will be developed, and these structures will be used to form a 3-MV prototype injector linac. Even this small system, designed for ions with A < 130, will be superior to the present FN tandem as a heavy-ion injector. In later phases of the work, the injector linac will be enlarged enough to allow ATLAS to effectively accelerate uranium ions. The injector system is expected to provide exceptional beam quality. The status of the work, expected performance of the accelerator system, and the technical issues involved are summarized.

The scheduled 58-day refueling outage in preparation for the seventh operating cycle of the Fast Flux Test Facility (FFTF) was successfully completed three days ahead of schedule. The planning and execution of the outage was greatly aided by Project/2 automated scheduling capabilities. For example, the use of ''maintenance windows'' and resource loading capabilities was particularly effective. The value of the planning process was demonstrated by the smooth transition into the outage phase after an early shutdown and set the stage for our best outage to date.

This paper presents a correlation method for single- and two-phase pump data.

Delayed neutron spectra from individual short pulse (approx.50 ..mu..s) fission of small /sup 235/U samples (50 mg) were measured using a small (5 cm OD x 5 cm length) NE 213 neutron spectrometer. The irradiating fast neutron flux (approx.10/sup 13/ neutrons/cm/sup 2/) for these measurements was provided by the Godiva fast burst reactor at the Los Alamos Critical Experiment Facility (LACEF). A high speed pneumatic transfer system was used to transfer the 50 mg /sup 235/U samples from the irradiation position near the Godiva assembly to a remote shielded counting room containing the NE 213 spectrometer and associated electronics. Data were acquired in sixty-four 0.5 s time bins and over an energy range 1 to 7 MeV. Comparisons between these measurements and a detailed model calculation performed at Los Alamos is presented.

The Two-Beam Accelerator (TBA) consists of a long high-gradient accelerator structure (HGS) adjacent to an equal-length Free Electron Laser (FEL). In the FEL, a beam propagates through a long series of undulators. At regular intervals, waveguides couple microwave power out of the FEL into the HGS. To replenish energy given up by the FEL beam to the microwave field, induction accelerator units are placed periodically along the length of the FEL. In this manner it is expected to achieve gradients of more than 250 MV/m and thus have a serious option for a 1 TeV x 1 TeV linear collider. The state of present theoretical understanding of the TBA is presented with particular emphasis upon operation of the ''steady-state'' FEL, phase and amplitude control of the rf wave, and suppression of sideband instabilities. Experimental work has focused upon the development of a suitable HGS and the testing of this structure using the Electron Laser Facility (ELF). Description is given of a first test at ELF with a seven-cell 2..pi../3 mode structure which without preconditioning and with a not-very-good vacuum nevertheless at 35 GHz yielded an average accelerating gradient of 180 MV/m.

Advanced plasma fueling systems for magnetic confinement devices are being developed at the Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogenic pellets at speeds in the range of 1-2 km/s and higher. Two specific concepts are under development: (1) high-speed pneumatic acceleration; and (2) mechanical (centrifugal) acceleration. Both approaches are being pursued to meet the projected pellet size and delivery rates for major near-term plasma confinement devices, such as the Tokamak Fusion Test Reactor (TFTR), Tore Supra, the Joint European Torus (JET), JT-60, and Doublet III-D (DIII-D), as well as future applications. In addition to these confinement physics related activities, ORNL is pursuing advanced technologies to achieve pellet velocities significantly in excess of the 2-km/s range already attained with pneumatic injectors and has embarked on a development program designed to explore the feasibility of fabricating and accelerating tritium pellets. This paper describes these ongoing activities.

This report contains abstracts of talks and summaries of discussions from a small workshop held to discuss the future of time-of-flight neutron powder diffraction and its implementation at the Los Alamos Neutron Scattering Center. 47 refs., 3 figs.

This paper will discuss the types of devices and system architectures that show promise in providing rf power sources for future space requirements. It will extrapolate these solutions to accelerators that are now being planned for construction and commissioning in the 1990s and will suggest technological advantages of using SDI-developed rf systems. Finally, the present state of the various SDI-sponsored high-powered rf-development programs will be reviewed.

Previous studies conducted under laboratory conditions demonstrated that the type of device used to sample ground water contaminated with volatile organic compounds can significantly influence and analytical results. The purpose of this study was to evaluate, under field conditions, both commercial and developmental ground water sampling devices as part of an ongoing ground water contamination investigation and remediation program at the Savannah River Plant (SRP). Ground water samples were collected using six types of sampling devices in monitoring wells of different depths and concentrations of volatile organic contaminants (primarily trichloroethylene and tetrachloroethylene). The study matrix was designed to statistically compare the reuslts of each sampling device under the test conditions. Quantitative and qualitative evaluation criteria were used to determine the relative performance of each device. Two categories of sampling devices were evaluated in this field study, positive displacement pumps and grab samplers. The positive displacement pumps consisted of a centrifugal (mechanical) pump and a bladder pump. The grab samples tested were a syringe sampler, a dual-check valve bailer, a surface bomb sampler, and a pressurized bailer. Preliminary studies were conducted to establish the analytical and sampling variability associated with each device. All six devices were then used to collect ground …