A new short pulse x-ray calibration facility has been brought on line at Los Alamos. This facility is being used for the development, testing and calibration of fast x-ray diagnostic systems. The x-ray source consists of a moderate size, sub-nanosecond laser focused at high intensity on an appropriate target material to generate short pulses of x-ray emission from the resulting plasma. Dynamic performance parameters of fast x-ray diagnostic instruments, such as x-ray streak cameras, can be conveniently measured using this facility.

The Integral Fast Reactor (IFR) concept is an innovative approach to liquid metal reactor design which is being studied by Argonne National Laboratory. Two of the key features of the IFR design are a metal fuel core design, based on the fuel technology developed at EBR-II, and an integral fuel cycle with a colocated fuel cycle facility based on the compact and simplified process steps made possible by the use of metal fuel. The paper presents the safety characteristics of the IFR concept which derive from the use of metal fuel. Liquid metal reactors, because of the low pressure coolant operating far below its boiling point, the natural circulation capability, and high system heat capacities, possess a high degree of inherent safety. The use of metallic fuel allows the reactor designer to further enhance the system capability for passive accommodation of postulated accidents.

The working group on Multiple Beams and Funneling discussed various topics related to multiple beams and funneling, including (1) design considerations for multiple-beam accelerators; (2) scaling of current, emittance, and brightness for multiple-beam systems; (3) funneling lines using either discrete components or a radiofrequency quadrupole (RFQ) funneling structure; and (4) alternatives to funneling.

The effect of strain rate, and particularly of high strain rates, on deformation mechanisms in materials is of fundamental interest to those who model and analyze dynamic loading. In many materials the strain rate sensitivity is known to increase dramatically when the strain rate is raised above approx.10/sup 3/ s/sup -1/. This increase has been interpreted previously as a transmission in deformation mechanism from thermal activation control at low strain rate to dislocation drag control at high strain rate. In copper, copper-aluminum alloys and stainless steel, recent measurements have shown that the increased rate sensitivity found at high strain rates is not due to a transition in deformation mechanism but rather can be explained with standard thermal activation theory. These findings and their implications regarding the formulation of constitutive behavior are presented.

High-resolution neutron transmission, capture and differential elastic scattering measurements have been made for /sup 58/Ni-enriched targets at the Oak Ridge Electron Linear Accelerator (ORELA) from the eV to the MeV region. The three sets of data were analyzed simultaneously from 10 to 450 keV, and the transmission analysis was extended to 650 keV. For the 52 s-wave resonances observed between 10 and 650 keV, the average level spacing, D/sub 0/, and the strength function, S/sub 0/, are 12.2 +- 1.0 keV and (3.1 +- 0.6) x 10/sup -4/, respectively.

Melter redox control is necessary for safe and continued melter operation. A combination of feed composition control, melter operational controls and monitors, and periodic determination of product glass redox state is sufficient to meet operating and safety requirements. Mossbauer spectroscopy, or other methods which determine the Fe(II)/Fe(III) ratio of the glass product, can be used to determine the oxidation state of the glass and thereby assess operating conditions. Slightly reducing conditions can eliminate radio-Ru volatility by suppressing the formation of RuO4. Reducing conditions also limit foaming resulting from the release of oxygen as transition metal oxides are dissolved in the melt. The calcination and partial combustion of organic compounds in the melter feed generates combustible mixtures of CO, H2 and benzene. The organics must be essentially completely incinerated to avoid the accumulation of combustible offgas mixtures, and prevent fouling of the equipment by soot and tars. Operation of the melter plenum above the autoignition temperature, metering in of purge air in excess of that required for complete combustion, and dilution by water vapor from reacted feed all preclude this occurrence in the melter. Prevention of dangerous offgas compositions after water vapor removal is assured by combustion in the melter, the …

Recent studies show that effective shuttering of photoemissive tubes, such as Silicon-Intensified-Target Vidicons (SITVs) and Microchannel-plate Image Intensifier Tubes (MCPTs), can vary widely depending upon the extent of their opacity to an input flux of photons. Optical feedthrough signals from photon transmission through the photocathode to the target or phosphor ranging from 10/sup -4/ to 10/sup -9/ (when compared with gated signals) were measured for a large sampling of commercially available units. Effective shutter ratios of 10/sup 5/ to 10/sup 8/ measured for units operated in quiescently dark environments can be substantially reduced by optical feedthrough. Furthermore, ineffective suppression of photoemission can cause further reductions in shutter ratio. Reductions are roughly correlated with the ratio of optical gate duration to light pulse duration. Experimentation with various thicknesses of aluminum depositions on MCPT phosphors and chromium layering on SITV silicon targets indicate substantial reductions (2x to 15x) in transmission with minimal increases in threshold voltages required for gain. These results, together with exploratory studies of external coating of output fiber optics with transmission filters spectrally matched to minimize feedthrough to P-20 phosphors are reported. 4 refs., 13 figs., 3 tabs.

Although the ASME code requires the inspection of cast stainless steel (CSS) piping in nuclear reactors, it has not been possible to demonstrate unambiguously that current inspection techniques are adequate. Ultrasonic inspection is difficult because the microstructure of CSS can vary considerably, from elastically isotropic with equiaxed, relatively small grains to elastically anisotropic with a columnar grain structure to a combination of the two. For the near term, improvements that may increase the reliability of ultrasonic inspection include (a) the development of methods to establish the microstructure of the material (to help optimize the inspection technique), (b) the identification of calibration standards that are more representative of the material to be inspected and (c) the use of cracked CSS samples for training purposes. In this paper, the results of experiments to characterize the microstructure of CSS by use of ultrasonic waves will be discussed. Shear waves may be more effective for isotropic material, whereas longitudinal waves may be better for the anisotropic case because of beam-focusing effects. Sound velocity and beam skewing can be measured accurately enough to characterize CSS even in thick-walled reactor components. 5 refs., 6 figs., 2 tabs.

The Los Alamos Wing 9 Hot Cell Facility is in the process of upgrading their metallographic sample preparation and examination capability. The present capability to grind, polish and etch samples from reactor fuels and materials has been in operation for 18 years. Macro photography and alpha and beta-gamma autoradiography are an important part of this capability. Some of the fast breeder reactor experiments have contained sodium as a coolant. Therefore, the capability to distill sodium from some samples scheduled for microstructural examinations is a requirement. Since the reactor fuel samples are highly radioactive and contain plutonium, either as fabricated or as a result of breeding during reactor service, these samples must be handled in shielded hot cells containing alpha boxes to isolate the plutonium and hazardous fission products from personnel and the environment. The present equipment that was designed and built into those alpha boxes has functioned very well for the past 18 years. During that time the technicians have thought of ways to improve the equipment to do the work faster and safer. These ideas and ideas that have been developed during the design of new alpha boxes and new equipment for microstructural sample preparation have provided the concepts …

The influence of inertia on the necking process in the dynamic tensile test has been studied. The equations of motion for a bar of finite length elongation dynamically have been written assuming a one-dimensional state of stress, and a model for rate independent or rate dependent flow has been presented. For rate dependent flow, a description of the stress-strain rate law that takes into account the increase of strain rate sensitivity in the dynamic range has been introduced. The growth of an assumed perturbation located at the middle of the specimen has been simulated with a finite difference code. Predictions of the model have been compared with experimental results obtained on pure copper.

The production of polarized antiproton beams at Fermilab is briefly reviewed. Two types of high-energy anti p polarimeters are described - the Coulomb-nuclear polarimeter and the Primakoff-effect polarimeter. The production of 8.9 GeV/c polarized antiprotons before entering the Fermilab accumulator ring is then discussed. 5 refs., 6 figs. (LEW)

The application of a noise cancelling technique to extract energy storage information from sensors occurring during fusion reactor experiments on the Tandem Mirror Experiment-Upgrade (TMX-U) at the Lawrence Livermore National Laboratory (LLNL) is examined. We show how this technique can be used to decrease the uncertainty in the corresponding sensor measurements used for diagnostics in both real-time and post-experimental environments. We analyze the performance of algorithm on the sensor data and discuss the various tradeoffs. The algorithm suggested is designed using SIG, an interactive signal processing package developed at LLNL.

The Nova laser, in operation since December 1984, is capable of irradiating targets with light at 1.05 ..mu..m, 0.53 ..mu..m, and 0.35 ..mu..m. Correct alignment of these harmonic beams uses a system called a target plane imager (TPI). It is a large microscope (four meters long, weighing one thousand kilograms) that relays images from the target chamber center to a video optics module located on the outside of the chamber. Several modes of operation are possible including: near-field viewing and far-field viewing at three magnifications and three wavelengths. In addition, the entire instrument can be scanned in X,Y,Z to examine various planes near chamber center. Performance of this system and its computer controls will be described.

A risk assessment strategy that is cost effective and minimized human health risks was developed for closure of hazardous waste sites at the Savannah River Plant. The strategy consists of (1) site characterization, (2) contaminant transport modeling, and (3) determination of relative merits of alternative remedial actions according to the degree of health protection they provide.

Precision tests of the electroweak interactions will soon be possible at the SLC and LEP. The SLC will be capable of providing longitudinal polarization of one incoming beam, the electrons, for such tests. Plans at the SLC to provide and monitor these beams are described, and some physics objectives are discussed. 5 refs., 10 figs.

A free-electron laser oscillator, driven by an rf linac, requires a train of electron bunches delivered to an undulator. The brightness requirement exceeds that available from a conventional linac with rf bunchers. The demonstrated high brightness of laser-illuminated photoemitters indicates that the conventional buncher system might be eliminated entirely, thereby avoiding the usual loarge loss in brightness that occurs in bunchers. A photoemitter with a current density of about 200 A/cm/sup 2/ is placed on an end wall of an rf cavity to accelerate a 60-ps bunch of electrons to 1 MeV as rapidly as possible. Preliminary experimental work, simulation calculations, and discussions on emittance measurement techniques and positive ion motion in the rf gun are presented.

It has recently been emphasized that the probability of quantum tunneling is a critical function of the shape of the potential. Applying this observation to physical systems, we point out that in principal information on potential surfaces can be obtained by studying tunneling rates. This is especially true in cases where only spectral data is known, since many potentials yield the same spectrum. 13 refs., 10 figs., 1 tab.

Technical assistance is being provided to Nuclear Materials Safety and Safeguards of the Nuclear Regulatory Commission to evaluate the validity of several guidelines listed in 10 CFR Part 61 for the future burial of low-level radioactive waste. Those guidelines include the requirement that the burial site shall be capable of being modeled. Both laboratory- and field-scale studies are being conducted under unsaturated moisture conditions and under steady-state and unsteady-state flow conditions. This paper reviews the kinds of present experiments in low-level radioactive waste disposal in development at the Los Alamos National Laboratory. Major emphasis is on some of the initial analyses of data for laboratory sorption experiments and for field transport tests. Brief reference is made to leaching and transport studies. Laboratory batch equilibrium sorption studies suggest that adsorption of nonconservative tracers can be described in terms of two empirical constants; one gives an indication of the average K/sub d/ for all adsorption sites and the other gives an indication of the spread of individual K/sub d/'s about the average K/sub d/. This information can be translated into a ''chemical dispersion'' under dynamic flow and equilibrium sorption conditions that is in addition to the traditionally accepted physical dispersion. Laboratory nonequilibrium …

A problem for the Atomic Weights Commission for the past decade has been the controversial battle over the names ''atomic weight'' and ''atomic mass''. The Commission has considered the arguments on both sides over the years and it appears that this meeting will see more of the same discussion taking place. In this paper, I review the situation and offer some alternatives.

The long-lived nuclides of the americium curium elements are of interest for their use in certain safeguard applications and for nuclear reactor burnup studies in waste management. Recommended values are presented for /sup 241,242m,243/Am, and for /sup 242,243,244,245,246,247,248,250/Cm. These values result from a consistent evaluation of all these half-lives. These preliminary estimates were presented earlier. The uncertainties are provided at the 95% confidence limit for each of the recommended values. It will be noted that many of the recommended errors considerably exceed errors quoted by individual authors in their publication, by up to an order of magnitude, e.g., the total half-life of /sup 242,246,248/Cm and the spontaneous fission half-life of /sup 244/Cm. 65 refs., 18 tabs.

High plasma densities have been produced in ohmic and neutral beam heated discharges on TFTR using a repeating pneumatic pellet injector developed at Oak Ridge National Laboratory (ORNL). Line average plasma densities as high as 1 x 10/sup 14/ cm/sup -3/ have been attained by injection of five 2.7 mm deuterium pellets ..delta..n/sub e/ = 2 x 10/sup 14/ cm/sup -3/ over a one-second interval into a stetched neutral beam pulse. Injection of a single large (4 mm) pellet in ohmic discharge has produced highly peaked profiles with nec(o) = 1.8 x 10/sup 14/ cm/sup -3/, n/sub e/(0) tau/sub E/(a) = 6.7 x 10/sup 13/ cm/sup -3/ and n/sub D/(0)Ti(0)tau/sub E/(a) = 8.8 x 10/sup 13/ cm/sup -3/ sKeV. Global confinement in these discharges approaches 0.45 seconds with a central density decay time of 2 seconds. Based on a neoclassical resistivity model and x-ray pulse-height analysis, zeff is <2 in both ohmic and beam-heated plasmas. The energy confinement properties of intermediate density (n/sub e/ (0) = 1 x 10/sup 14/ cm/sup -3/) full beam power (5.7 MW, 80 KVD/sup 0/) discharge have been studied in detail using the TRANSP code. Although the global energy confinement (approx. =2 oums at IP …

This note summarizes the work of the Offline Computing and Networking Group. The report is divided into two sections; the first deals with the computing and networking requirements and the second with the proposed way to satisfy those requirements. In considering the requirements, we have considered two types of computing problems. The first is CPU-intensive activity such as production data analysis (reducing raw data to DST), production Monte Carlo, or engineering calculations. The second is physicist-intensive computing such as program development, hardware design, physics analysis, and detector studies. For both types of computing, we examine a variety of issues. These included a set of quantitative questions: how much CPU power (for turn-around and for through-put), how much memory, mass-storage, bandwidth, and so on. There are also very important qualitative issues: what features must be provided by the operating system, what tools are needed for program design, code management, database management, and for graphics.

Evaluation of the thermohydrological conditions near high-level waste packages is needed for the design of the waste canister and for overall repository design and performance assessment. Most available studies in this area have assumed that the hydrologic properties of the host rock do not change in response to the thermal, mechanical or chemical effects caused by waste emplacement. However, the ramifications of this simplifying assumption have not been substantiated. We have studied dissolution and precipitation of silica in thermally driven flow systems, including changes in formation porosity and permeability. Using numerical simulation, we compare predictions of thermohydrological conditions with and without inclusion of silica redistribution effects. Two cases were studied, namely, a canister-scale problem, a repository-wide thermal convection problem, and different pore models were employed for the permeable medium (fractures with uniform or non-uniform cross sections). We find that silica redistribution generally has insignificant effects on host rock and canister temperatures, pore pressures, or flow velocites.

Guidelines are given for an interactive computer program that will analyze thermochemical decomposition rate data obtained by isothermal differential-scanning calorimetry. Data from any portion of the rate curve may be analyzed, and either normal or autocatalytic rate laws may be used. The computer calculates and displays normalized data listings, rate curves, order plots, and autocatalytic rate law plots. It calculates rate constants by linear regression treatment of data from curve segments chosen by the user. Many options are available, and many forms of the rate laws may be selected. This program was designed primarily for research rather than routine use. 6 figs.