While the flight hardware is protected by design from the harsh environments of space, its in-air storage often requires special protection from contaminants such as dust, moisture and other gases. One of these components, the radioisotope thermoelectric generator (RTG) which powers the missions, was deemed particularly vulnerable to pre-launch aging because the generators remain operational at core temperatures in excess of 1000 degrees centigrade throughout the storage period. Any oxygen permitted to enter the devices will react with thermally hot components, preferentially with molybdenum in the insulating foils, and with graphites to form CO/CO{sub 2} gases which are corrosive to the thermopile. It was important therefore to minimize the amount of oxygen which could enter, by either limiting the effective in-leakage areas on the generators themselves, or by reducing the relative amount of oxygen within the environment around the generators, or both. With the generators already assembled and procedures in place to assure minimal in-leakage in handling, the approach of choice was to provide a storage environment which contains significantly less oxygen than normal air. 2 refs.

A report is given of a search for tau decays of the W boson in p{bar p} collisions at {radical}s = 1.8 TeV using the Collider Detector at Fermilab (CDF). A description of a hardware trigger specifically designed to enhance the number of events with tau decays is presented along with the results of a preliminary analysis of data taken during the 1988--89 run of CDF. 10 refs., 4 figs.

The preliminary specifications on the glass wasteform to be produced by the Defense Waste Processing Facility (DWPF) require extensive characterization of the glass product both before actual production begins and then during production. To aid in this characterization, a leach test was needed that was easily reproducible, could be performed remotely on highly radioactive samples, and could yield results rapidly. Several standard leach tests were examined with a variety of test configurations. Using existing tests as a starting point, the DWPF Product Consistency Test (PCT) was developed in which crushed glass samples are exposed to 90{degrees}C deionized water for seven days. Based on extensive testing, including a seven-laboratory round robin and confirmatory testing with radioactive samples, the PCT is very reproducible, yields reliable results rapidly, and can be performed in shielded cell facilities with radioactive samples.

The Stanford Linear Collider (SLC) located at the Stanford Linear Accelerator Center collides electrons and positrons produced in the linear accelerator pulse by pulse. We determine the energy of each beam by measuring the angle of deflection of the beam in the SLC extraction lines. Each extraction line consists of two bending magnets that produce synchrotron radiation, and a spectrometer analyzing magnet that deflects the beam. We detect the synchrotron light by using the emission of electrons produced by Compton scattering off Cu-Be wires. We detect the {approximately} 180 fC of charge on the wire by using the electronics system described in this paper. We also discuss the performance of the system, including the equivalent noise charge, cross-talk between channels, stability, and reliability. 4 refs., 7 figs.

Nodal methods play a special role in reactor physics calculations. In recent papers the high computational efficiency of nodal methods has been established and the development of more efficient algorithms tailored to the advanced architectures of modern day computers proposed. The rapidly changing architectures of today's computer influence the way codes have to be programmed so that reasonable speed up and efficiency are attained. We have applied these concepts in solving the one-group neutron diffusion equation in two-dimensional geometry on parallel computers like the Intel iPSC/2 hypercube and the Sequent Balance 8000. The efficiency of the hypercube for the neutron diffusion equation is highly determined by the message passing scheme; on the other hand, on a shared memory processor like the Sequent, it is dependent on the manipulation of variables in shared memory. In this paper, we present a scheme on shared memory processors which produces very high computing efficiencies in agreement with Amdahl's law. 6 refs., 1 fig.

We describe the design and performance of a detector system for tracking charged particles in an environment of high track density and rates up to 1 MHz. The system operates in the forward spectrometer of the BNL Heavy Ion experiment E814 and uses principles of general interest in high rate, high multiplicity applications such as at RHIC or SSC. We require our system to perform over a large dynamic range, detecting singly charged particles as well as fully ionized relativistic {sup 28}Si. Results on gas gain saturation, {delta}-ray suppression, and overall detector performance in the presence of a 14.6 GeV/nucleon {sup 28}Si beam and a 14 GeV proton beam are presented. 6 refs., 9 figs.

A novel full scale production reactor fuel assembly model was designed and built to study thermal-hydraulic effects of postulated Savannah River Site (SRS) nuclear reactor accidents. The electrically heated model was constructed to simulate the unique annular concentric tube geometry of fuel assemblies in SRS nuclear production reactors. Several major design challenges were overcome in order to produce the prototypic geometry and thermal-hydraulic conditions. The two concentric heater tubes (total power over 6 MW and maximum heat flux of 3.5 MW/m{sup 2}) (1.1E+6 BTU/(ft{sup 2}hr)) were designed to closely simulate the thermal characteristics of SRS uranium-aluminum nuclear fuel. The paper discusses the design of the model fuel assembly, which met requirements of maintaining prototypic geometric and hydraulic characteristics, and approximate thermal similarity. The model had a cosine axial power profile and the electrical resistance was compatible with the existing power supply. The model fuel assembly was equipped with a set of instruments useful for code analysis, and durable enough to survive a number of LOCA transients. These instruments were sufficiently responsive to record the response of the fuel assembly to the imposed transient.

Observations of heavy ion interactions at the highest available accelerator energies provide essential information for the analysis and interpretation of cosmic ray interactions. We report on an experiment in which emulsion chamber detectors were exposed to beams of 200A GeV {sup 32}S ions at the CERN SPS. We present statistical features of pseudorapidity distributions from central collisions in the experimental sample and compare them with the predictions from the Lund Model (FRITIOF) which contains only conventional physics. 8 refs., 3 figs.

Particle accelerators are now used in many areas of physics research and in industrial and medical applications. New uses are being studied to address major societal needs in energy production, materials research, generation of intense beams of radiation at optical and suboptical wavelengths, treatment of various kinds of waste, and so on. Many of these modern applications require a high intensity beam at the desired energy, along with a very good beam quality in terms of the beam confinement, aiming, or focusing. Considerations for ion and electron accelerators are often different, but there are also many commonalties, and in fact, techniques derived for one should perhaps more often be considered for the other as well. We discuss some aspects of high-brightness electron sources here from that point of view. 6 refs.

A bath-cooled all-niobium 160 MHz quarter wave resonator prototype was constructed and tested. The objective of this research has been the development of a high performance accelerating element with {beta}{sub opt} {approx equal} 0.11 for the ALPI linac at the Laboratori Nazionali di Legnaro. The design of this resonator was based upon a previous 150 MHz model, with minor changes due to the different frequency and to modified welding procedure. An accelerating field of 5 MV/m was achieved at a power dissipation of 10 W and the low power Q was 2.4 {times} 10{sup 8}. The resonator could dissipate 70 W of power without thermal breakdown. 16 refs., 2 figs., 1 tab.

High energy negative ion-based neutral beam injection is a strong candidate for heating and non-inductive current drive in tokamaks. Many of the questions related to the physics and engineering of this technique remain unanswered. In this paper, we consider the possibility of negative ion-based neutral beam injection on DIII-D. We establish the desired parameter space by examining physics trades. This is combined with potential design constraints and a survey of component technology options to establish an injector concept. Injector performance is estimated assuming particular component technologies, and concept flexibility with respect to incorporating alternate technologies is described. 9 refs., 6 figs., 4 tabs.

New third generation'' synchrotron radiation research facilities are now in construction in France, Italy, Japan, Taiwan and the USA. Designs for such facilities are being developed in several other countries. Third generation facilities are based on storage rings with low electron beam emittance and space for many undulator magnets to produce radiation with extremely high brightness and coherent power. Photon beam from these rings will greatly extend present research capabilities and open up new opportunities in imaging, spectroscopy, structural and dynamic studies and other applications. The technological problems of the third generation of synchrotron radiation facilities are reviewed. These machines are designed to emit radiation of very high intensity, extreme brightness, very short pulses, and partial coherence. These performance goals put severe requirements on the quality of the electron or positron beams. Phenomena affecting the injection process and the beam lifetime are discussed. Gas desorption by synchrotron radiation and collective effects play an important role. Low emittance lattices are more sensitive to quadrupole movements and at the same time, in order not to lose the benefits of high brilliance, require tighter tolerances on the allowed movement of the photon beam source. We discuss some of the ways that should be …

Correlations in the production of charged particles and photons can be examined in detail in the central and forward rapidity range using high multiplicity ({ge}100 charged tracks) events from JACEE emulsion chambers. Results are presented on several forms of correlations studies. 9 refs., 2 figs.

DEPOT has been developed to provide tracking for the Stanford Linear Collider (SLC) control system equipment. For each piece of equipment entered in the database, a complete service, maintenance, modification, certification, location history, and, optionally, a radiation exposure history, can be maintained. To facilitate data entry accuracy, efficiency, and consistency, barcoding technology has been used extensively. DEPOT has been an important tool in improving the reliability of the microsystems controlling SLC. It is now being adopted by other systems at SLAC. 6 refs., 6 figs.

Mixed low-level radioactive and chemically hazardous process treatment wastes from the Portsmouth Gaseous Diffusion Plant are stabilized by solidification in cement-based grouts. Conventional portland cement and fly ash grouts have been shown to be effective for retention of hydrolyzable metals (e.g., lead, cadmium, uranium and nickel) but are marginally acceptable for retention of radioactive Tc-99, which is present in the waste as the highly mobile pertechnate anion. Addition of ground blast furnace slag to the grout is shown to reduce the leachability of technetium by several orders of magnitude. The selective effect of slag is believed to be due to its ability to reduce Tc(VII) to the less soluble Tc(IV) species. 12 refs., 4 tabs.

We present new developments in nonadiabatic geometric phases along two lines for systems undergoing changes of quantum state in intense fields. We first present a geometric representation of the non-Hermitian Schrodinger equation and introduce the notion of a complex multiphoton Aharonov-Anandan (AA) phase associated with dissipative two-level systems driven by periodic fields. The concept is further extended to include field modulation effects. We then develop the AA phase for spin-j systems in periodic fields and find conditions for cyclic evolution for general multi-level systems. In both cases, generalizations of the Floquet formalism lead to general analytical expressions for geometric phases that can be tested by experiments. 16 refs., 5 figs.

With high electron energies a kinematic regime can be reached where it will be possible to separate quasielastic and deep inelastic scattering. We present a short description of these processes which dominate the inclusive spectrum. Using the highest momentum transfer data available to guide our estimates, we give the kinematic requirements and the cross sections expected. These results indicate that inclusive scattering at high q has a yet unfilled potential. 18 refs., 13 figs.

In the late 1970's, the Department of Energy (DOE) assigned Monsanto Research Corporation, Mound Facility, now operated by EG G Mound Applied Technologies, the responsibility for assembling and testing General Purpose Heat Source (GPHS) radioisotope thermoelectric generators (RTGs). Assembled and tested were five RTGs, which included four flight units and one non-flight qualification unit. Figure 1 shows the RTG, which was designed by General Electric AstroSpace Division (GE/ASD) to produce 285 W of electrical power. A detailed description of the processes for RTG assembly and testing is presented by Amos and Goebel (1989). The RTG performance data are described by Bennett, et al. (1986). The flight units will provide electrical power for the National Aeronautics and Space Administration's (NASA) Galileo mission to Jupiter (two RTGs) and the joint NASA/European Space Agency (ESA) Ulysses mission to study the polar regions of the sun (one RTG). The remaining flight unit will serve as the spare for both missions, and a non-flight qualification unit was assembled and tested to ensure that performance criteria were adequately met. 4 refs., 3 figs.

The counterrotating beams in collider rings consist of trains of beam bunches with N{sub B} particles per bunch, spaced a distance S{sub B} apart. When the bunches collide, the interaction rate is determined by the luminosity, which is defined as the interaction rate per unit cross section. For head-on collisions between cylindrical Gaussian beams moving at speed {beta}c, the luminosity is given by L = N{sub B}{sup 2}{beta}c/4{pi}{sigma}{sup 2}S{sub B}, where {sigma} is the rms beam size projected onto a transverse plane (the two transverse planes are assumed identical) at the interaction point. This beam size depends on the rms emittance of the beam and the focusing strength, which is a measure of the 2-D phase-space area in each transverse plane, and is defined in terms of the second moments of the beam distribution. Our convention is to use the rms normalized emittance, without factors of 4 or 6 that are sometimes used. The quantity {tilde {beta}} is the Courant-Synder betatron amplitude function at the interaction point, a characteristic of the focusing lattice and {gamma} is the relativistic Lorentz factor. Achieving high luminosity at a given energy, and at practical values of {tilde {beta}} and S{sub B}, requires a large …

A study is being conducted at NASA Lewis Research Center to determine the feasibility of using a carbide particle strengthened Nb-1% Zr base alloy to meet the anticipated temperature and creep resistance requirements of proposed near term space power systems. In order to provide information to aid in the determination of the suitability of the PWC-11 alloy as an alternative to Nb-1% Zr in space power systems this study investigated (1) the long-time high-vacuum creep behavior of the PWC-11 material and the Nb-1% Zr alloy, (2) the effect of prior stress-free thermal aging on this creep behavior, (3) the effect of electron beam (EB) welding on this creep behavior, and (4) the stability of creep strengthening carbide particles. 14 refs., 5 figs., 2 tabs.

The diffusion length of positrons has been measured in liquid and solid gallium and bismuth using a vertical positron beam. For Ga our results indicate a drop in the diffusion length from 1200 (100) {Angstrom} to 30 (5) {Angstrom} as the sample melts, as the temperature is increased there is a surprising increase in the diffusion length. At the melting point the annihilation parameter S in the bulk increases sharply, and stays constant with temperature, which indicates that vacancy size trapping centers exist in the liquid. For Bi, the diffusion length drops in the liquid from 500 {Angstrom} to 200 {Angstrom}, and increases slightly as the temperature is increased. This drop is interpreted in terms of increased scattering with Bi ions. A small change is observed in bulk S, indicating no trapping of positrons as the sample melts. This behaviour, which is so different in these two metals, indicates the sensitivity of positrons to the liquid structure. 6 refs., 2 figs.

Low photo desorption (PSD) from surfaces of vacuum chambers increases the beam lifetime and reduces the cost of the pumping system of any storage ring. In compact rings where all radiated power ({approximately}10 kW) is incident on a few meters only, low PSD and good thermal conductivity of photon absorbers are of particular importance. An experimental chamber in which one meter long bars can be exposed to white photon beam with 500 eV critical energy has been built and installed on the U10B beamline in the VUV ring at the NSLS. Several reference bars made of high purity copper and a TiN coating on copper have been measured. Subsequent runs will include gold coating on copper, aluminum (200{degree}C baked), diamond coating on copper and uncoated beryllium bars. In this paper the desorption coefficients will be measured and compared. 6 refs., 4 figs.

System owners and operators are increasingly emphasizing the actual amount of time equipment is capable of performing its intended function. For military systems, added complexity, longer service life requirements, reduced periodic maintenance, and less frequent checkouts are increasing system availability requirements. However, these factors compound the difficulty in estimating the system's true availability. With dormant or semi-dormant systems, the amount of time a system appears'' available may differ form the real'' availability. The difference in real'' and apparent'' availability is often the result of a transition from an operational but dormant state to an inoperational but dormant state. The major contributions from this research are: the development of the concept of complex'' availability that applies to systems which combine two or more elements of instantaneous, mission system, or steady-state availability; and the development of modeling technique to estimate the real'' availability for a system which involves complex'' availability. 28 refs., 2 figs.

This paper is documentation of a video presentation and provides a brief summary of the Virginia power/US Department of Energy Cooperative Cask Testing/Demonstration Program. The program consists of two phases. The first phase has been completed and involved the unlicensed performance testing (heat transfer and shielding) of three metal spent fuel storage casks at the federally owned Idaho National Engineering Laboratory. The second phase is ongoing and consists of licensed demonstrations of standard casks from two different vendors and of one or two enhanced capacity casks. 6 refs., 1 tab.