Estimates of radionuclide release from glass waste forms in a tuff repository and the effects on regulatory compliance (open access)

Estimates of radionuclide release from glass waste forms in a tuff repository and the effects on regulatory compliance

This paper discusses preliminary estimates of the release of radionuclides from waste packages containing glass-based waste forms under the expected conditions at Yucca Mountain. These estimates can be used to evaluate the contribution of waste package performance toward meeting repository regulatory restrictions on radionuclide release. Glass waste will be held in double stainless steel canisters. After failure of the container sometime after the 300 to 1000 year containment period, the open headspace in these cans will provide the only area where standing water can accumulate and react with the glass. A maximum release rate of 0.177 g/m{sup 2} x year or 1.3 grams per year was obtained. Normalized loss of 1.3 grams per year corresponds to 0.08 parts in 100,000 per year of the 1660 kg reference weight of DWPF glass.
Date: April 1, 1986
Creator: Aines, R. D.
System: The UNT Digital Library
TERMINATION OF IDEAL COS m phi WINDING (open access)

TERMINATION OF IDEAL COS m phi WINDING

Configurations are proposed, and illustrated, for terminating the 'cosine {phi}' windings of an ideal iron-free dipole magnet so as to preserve the quality of the internal field integrated (vs. z) through the entire magnet. The end windings are placed on a surface of the same radius as that on which the conductors lie in the central (2-D) portion of the structure. The desired pure dipole quality of the integrated field then is assured by requiring that the z-component of current, after projection onto the y-z plane, shall have in that plane a density distribution whose integral is independent of y. As a result of the analysis, end-winding configurations that satisfy this requirement are proposed in which each conductor filament follows through the transition region a locus whose y-z projection is of the form z(y;Y{sub 0}) = f(y{sub 0}) - f(y-y{sub 0}), with f(0) = 0, wherein Y{sub 0} serves as an index to identify the location of the filament in the central (2-D) portion of the structure. Simple solutions of this nature are indicated in which the function f has the form f(y-y{sub 0}) = k (y-y{sub 0}{sup p}/a) for windings on the surface of a cylinder of radius {und …
Date: April 1, 1986
Creator: Laslett, L.J.; Caspi, S. & Helm, M.
System: The UNT Digital Library
Free-Electron Lasers (open access)

Free-Electron Lasers

We can now produce intense, coherent light at wavelengths where no conventional lasers exist. The recent successes of devices known as free-electron lasers mark a striking confluence of two conceptual developments that themselves are only a few decades old. The first of these, the laser, is a product of the fifties and sixties whose essential characteristics have made it a staple resource in almost every field of science and technology. In a practical sense, what defines a laser is its emission of monochromatic, coherent light (that is, light of a single wavelength, with its waves locked in step) at a wavelength in the infrared, visible, or ultraviolet region of the electromagnetic spectrum. A second kind of light, called synchrotron radiation, is a by-product of the age of particle accelerators and was first observed in the laboratory in 1947. As the energies of accelerators grew in the 1960s and 70s, intense, incoherent beams of ultraviolet radiation and x--rays became available at machines built for high-energy physics research. Today, several facilities operate solely as sources of synchrotron light. Unlike the well-collimated monochromatic light emitted by lasers, however, this incoherent radiation is like a sweeping searchlight--more accurately, like the headlight of a train …
Date: April 1, 1986
Creator: Sessler, A. M. & Vaughan, D.
System: The UNT Digital Library
Short Range Phenomena: Summary of Working Group IV (open access)

Short Range Phenomena: Summary of Working Group IV

None
Date: April 1, 1986
Creator: Gross, Franz & Gross, Franz
System: The UNT Digital Library
Particle identification in ultrarelativistic nuclear collisions (open access)

Particle identification in ultrarelativistic nuclear collisions

The role of particle identification (PID) in both fixed-target and colliding-beam studies of ultrarelativistic nuclear (URN) collisions is examined. The demands placed on the PID systems by peculiarities of URN collisions, such as large multiplicities and the need for simultaneous measurement of a number of observables, are discussed. A variety of PID techniques are reviewed, with emphasis on their applicability and efficiency in the environment of such collisions. Two examples of PID as incorporated into existing fixed-target nuclear-beam experiments are presented. 18 refs., 5 figs.
Date: April 1, 1986
Creator: DiGiacomo, N.J.
System: The UNT Digital Library
Recent developments in positron emission tomography (PET) instrumentation (open access)

Recent developments in positron emission tomography (PET) instrumentation

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.
Date: April 1, 1986
Creator: Derenzo, S.E. & Budinger, T.F.
System: The UNT Digital Library
Photon-Photon Physics with the Mark II at PEP (open access)

Photon-Photon Physics with the Mark II at PEP

Photon-photon interactions are studied with the Mark II detector at PEP. The inclusive production of charged hadrons at large transverse momenta and the exclusive production of meson pairs at large invarient mass are compared with recent hard scattering calculations. Copious inclusive production of K/sup 0/'s at large transverse momenta provides evidence for charm production. The radiative width of the f'(1520) is measured via its K/sub s//sup 0/ anti K/sub s//sup 0/ decay mode.
Date: April 1, 1986
Creator: Gidal, G.
System: The UNT Digital Library
Nucleon exchange in damped nuclear reactions (open access)

Nucleon exchange in damped nuclear reactions

Starting from the general context of one-body nuclear dynamics, the nucleon-exchange mechanism in damped nuclear reactions is discussed. Some of its characteristic effects on various dinuclear observables are highlighted and a few recent advances are described.
Date: April 1, 1986
Creator: Randrup, J.
System: The UNT Digital Library
Rf breakdown studies in a SLAC disk-loaded structure (open access)

Rf breakdown studies in a SLAC disk-loaded structure

Rf breakdown studies in an S-band standing-wave disk-loaded accelerator structure have been completed. An equivalent traveling-wave accelerating gradient as high as 147 MV/m and a peak field in excess of 300 MV/m have been obtained. At these high gradients, considerable amounts of field emission and x-ray radiation are observed. Some of the field-emitted electrons are captured and focused by the rf fields and can be extracted on the axis of the structure. Their current, energy distribution and the x-ray radiation they produce are given. Rf processing as measured by the frequency of breakdown and the reduction in field emitted electron currents inside the structure can be speeded up considerably by the presence of argon. Some conjectures on the causes of breakdown are presented.
Date: April 1, 1986
Creator: Wang, J.W.; Nguyen-Tuong, V. & Loew, G.A.
System: The UNT Digital Library
Hyperons in neutron stars (open access)

Hyperons in neutron stars

Generalized beta equilibrium involving nucleons, hyperons, and isobars is examined for neutron star matter. The hyperons produce a considerable softening of the equation of state. It is shown that the observed masses of neutron stars can be used to settle a recent controversy concerning the nuclear compressibility. Compressibilities less than 200 MeV are incompatible with observed masses. 7 refs., 9 figs.
Date: April 1, 1986
Creator: Glendenning, N.K.
System: The UNT Digital Library
Comparison of standing-wave and traveling-wave structures (open access)

Comparison of standing-wave and traveling-wave structures

The controversy over the relative advantages of standing-wave and traveling-wave linear accelerators is now in its fourth decade. It has been fed by a considerable body of misinformation. The author hopes in this paper to shed some light on the subject, and expose some of the falsehoods. The discussion is directed toward the question of which structure to use for short pulse high field electron accelerators since it is almost universally accepted that standing-wave structures are appropriate for CW and long pulse accelerators. Three arguments against standing-wave accelerators are discussed and shown to be invalid.
Date: April 1, 1986
Creator: Miller, R. H.
System: The UNT Digital Library
Proceedings of the workshop on radiation damage to wire chambers (open access)

Proceedings of the workshop on radiation damage to wire chambers

Separate abstracts were prepared for 24 papers in these workshop proceedings. (LEW)
Date: April 1, 1986
Creator: Kadyk, J.
System: The UNT Digital Library
Transfer and breakup reactions at intermediate energies (open access)

Transfer and breakup reactions at intermediate energies

The origin of the quasi-elastic peak in peripheral heavy-ion reactions is discussed in terms of inelastic scattering and transfer reactions to unbound states of the primary projectile-like fragment. The situation is analogous to the use of reverse kinematics in fusion reactions, a technique in which the object of study is moving with nearly the beam velocity. It appears that several important features of the quasi-elastic peak may be explained by this approach. Projectile-breakup reactions have attractive features for the study of nuclear structure. They may also be used to determine the partition of excitation energy in peripheral reactions. At intermediate energies, neutron-pickup reactions leading to four-body final states become important. Examples of experiments are presented that illustrate these points. 15 refs., 14 figs.
Date: April 1, 1986
Creator: Stokstad, R.G.
System: The UNT Digital Library
Aerodynamic Size Associations of Natural Radioactivity With Ambient Aerosols (open access)

Aerodynamic Size Associations of Natural Radioactivity With Ambient Aerosols

The aerodynamic size of /sup 214/Pb, /sup 212/Pb, /sup 210/Pb, /sup 7/Be, /sup 32/P, /sup 35/S (as SO/sub 4//sup 2 -/), and stable SO/sub 4//sup 2 -/ was measured using cascade impactors. The activity distribution of /sup 212/Pb and /sup 214/Pb, measured by alpha spectroscopy, was largely associated with aerosols smaller than 0.52 ..mu..m. Based on 46 measurements, the activity median aerodynamic diameter of /sup 212/Pb averaged 0.13 ..mu..m (sigma/sub g/ = 2.97), while /sup 214/Pb averaged 0.16 ..mu..m (sigma/sub g/ = 2.86). The larger median size of /sup 214/Pb was attributed to ..cap alpha..-recoil depletion of smaller aerosols following decay of aerosol-associated /sup 218/Po. Subsequent /sup 214/Pb condensation on all aerosols effectively enriches larger aerosols. /sup 212/Pb does not undergo this recoil-driven redistribution. Low-pressure impactor measurements indicated that the mass median aerodynamic diameter of SO/sub 4//sup 2 -/ was about three times larger than the activity median diameter /sup 212/Pb, reflecting differences in atmospheric residence times as well as the differences in surface area and volume distributions of the atmospheric aerosol. Cosmogenic radionuclides, especially /sup 7/Be, were associated with smaller aerosols than SO/sub 4//sup 2 -/ regardless of season, while /sup 210/Pb distributions in summer measurements were similar to …
Date: April 1, 1986
Creator: Bondietti, E. A.; Papastefanou, C. & Rangarajan, C.
System: The UNT Digital Library
Design of a high-power density Ljungstrom turbine using potassium as a working fluid (open access)

Design of a high-power density Ljungstrom turbine using potassium as a working fluid

The ability to generate large quantities of high-quality power in space will be necessary to meet the needs of many proposed future space programs. The Pacific Northwest Laboratory is studying an advanced multi-megawatt space power system employing a liquid metal Rankine power cycle. This paper examines more closely one component of the system, the power turbine. The turbine design selected for this system is a counter-rotating radial-outflow machine developed in the early twentieth century by two brothers, Fredrik and Birger Ljungstroem turbine was selected because it provides a compact, high-power-density turbine with balanced rotational inertia and is tolerant of moisture in the working fluid. In commercial operation, Ljungstroem turbines have demonstrated excellent rapid start capabilities and good overall efficiency. Moreover, the disadvantages that have hindered its use in conventional power plants are tied to the steam's very large change in specific volume. These disadvantages are circumvented in a machine using potassium for a working fluid. A preliminary design study indicates that high-power turbines, using potassium as a working fluid, are feasible for the Ljungstroem turbine, and that Ljungstroem turbines of 200 MW and greater could easily fit into the cargo bay of the space shuttle. 10 refs., 5 figs. 3 …
Date: April 1, 1986
Creator: Coomes, E. P.; Dodge, R. E.; Wilson, D. G. & McCabe, S. J.
System: The UNT Digital Library
Special SLC linac developments (open access)

Special SLC linac developments

The linac of the SLAC Linear Collider (SLC) is required to accelerate several intense electron and positron bunches to high energy while maintaining their small transverse dimensions and energy spectra. Many of the linac systems have been upgraded to the new stringent SLC design criteria. The remaining systems will be completed in the summer of 1986. Special instruments and controls have been developed to monitor and manipulate these small but potent beams. A brief review of the SLC requirements is given. A broad survey of the recent development is made encompassing longitudinal and transverse wakefield reductions, Landau damping, energy and position feedback systems, beam diagnostic and beam current fluctuations.
Date: April 1, 1986
Creator: Seeman, J. T. & Sheppard, J. C.
System: The UNT Digital Library
Adaptive dynamic networks as models for the immune system and autocatalytic sets (open access)

Adaptive dynamic networks as models for the immune system and autocatalytic sets

A general class of network models is described that can be used to present complex adaptive systems. These models have two purposes: On a practical level they are closely based on real biological phenomena, and are intended to model detailed aspects of them. On a more general level, however, they provide a framework to address broader questions concerning evolution, pattern recognition, and other properties of living systems. This paper concentrates on the more general level, illustrating the basic concepts with two examples, a model of the immune system and a model for the spontaneous emergence of autocatalytic sets in a chemically reactive polymer soup. 10 refs., 3 figs.
Date: April 1, 1986
Creator: Farmer, J. Doyne; Kauffman, Stuart A.; Packard, Norman H. & Perelson, Alan S.
System: The UNT Digital Library
Operational experience with SLAC energy upgrade (open access)

Operational experience with SLAC energy upgrade

To produce energies of over 50 GeV for SLC, all klystron stations on the accelerator are being upgraded to produce 250 MeV energy contribution per station. This involves installing new, higher power, longer pulse klystrons, upgrading klystron modulators to provide these higher voltage, longer klystron beam pulses, and a new interlock and protection system. A new VAX based diagnostic system including automated microwave measurements, klystron beam monitors, and modulator performance checks is being implemented. Figure 1 shows a block diagram of the klystron-modulator system. To date, over half of the new klystrons have been installed and tested, the modulator upgrade program has converted 22 sectors (8 stations each) of modulators out of 30, and a four sector sampling of klystrons has been run at full SLC specs, namely 350 kV beam voltage, 3.5 microsecond pulse duration, peak output power in excess of 60 MW, and PRF of 120 pps. This paper discusses the klystron design, modulator design, interlock and diagnostic systems, and the results of the initial operation.
Date: April 1, 1986
Creator: Allen, M. A.; Cassel, R. L.; Dean, N. R.; Konrad, G. T.; Koontz, R. F.; Schwarz, H. D. et al.
System: The UNT Digital Library
Bombardment-Induced Segregation and Redistribution (open access)

Bombardment-Induced Segregation and Redistribution

During ion bombardment, a number of processes can alter the compositional distribution and microstructure in near-surface regions of alloys. The relative importance of each process depends principally on the target composition, temperature, and ion characteristics. In addition to displacement mixing leading to a randomization of atomic locations, and preferential loss of alloying elements by sputtering, which are dominant at relatively low temperatures, several thermally-activated processes, including radiation-enhanced diffusion, radiation-induced segregation and Gibbsian adsorption, also play important roles. At elevated temperatures, nonequilibrium point defects induced by ion impacts become mobile and tend to anneal out by recombination and diffusion to extended sinks, such as dislocations, grain boundaries and free surfaces. The high defect concentrations, far exceeding the thermodynamic equilbrium values, can enhance diffusion-controlled processes, while persistent defect fluxes, originating from the spatial non-uniformity in defect production and annihilation, give rise to local redistribution of alloy constituents because of radiation-induced segregation. Moreover, when the alloy is maintained at high temperature, Gibbsian adsorption, driven by the reduction in free energy of the system, occurs even without irradiation; it involves a compositional perturbation in a few atom layers near the alloy surface. The combination of these processes leads to the complex development of a …
Date: April 1, 1986
Creator: Lam, N. Q. & Wiedersich, H.
System: The UNT Digital Library
Combined Core/Boundary Layer Transport Simulations in Tokamaks (open access)

Combined Core/Boundary Layer Transport Simulations in Tokamaks

Significant new numerical results are presented from self-consistent core and boundary or scrape-off layer plasma simulations with 3-D neutral transport calculations. For a symmetric belt limiter it is shown that, for plasma conditions considered here, the pump limiter collection efficiency increases from 11% to 18% of the core efflux as a result of local reionization of blade deflected neutrals. This hitherto unobserved effect causes a significant amplification of upstream ion flux entering the pump limiter. Results from coupling of an earlier developed two-zone edge plasma model ODESSA to the PROCTR core plasma simulation code indicates that intense recycling divertor operation may not be possible because of stagnation of upstream flow velocity. This results in a self-consistent reduction of density gradient in an intermediate region between the central plasma and separatrix, and a concomitant reduction of core-efflux. There is also evidence of increased recycling at the first wall.
Date: April 1, 1986
Creator: Prinja, A. K.; Schafer, R. F., Jr.; Conn, R. W. & Howe, H. C.
System: The UNT Digital Library
Effects of a new heavy neutral vector boson at SLC and LEP (open access)

Effects of a new heavy neutral vector boson at SLC and LEP

Models with an extra neutral gauge boson (Z') are discussed. We constrain the Z' mass as a function of its mixing angle with the known Z/sup 0/ by requiring that the Z/sup 0/ mass not be shifted excessively by this mixing, and from the Higgs vacuum expectation value structure of the mass matrix. We compare these limits with those previously found from neutral current experiments. We discuss possible effects of non-excluded models on e/sup +/e/sup -/ physics at SLC and LEP. 8 refs., 3 figs.
Date: April 1, 1986
Creator: Franzini, P. J.
System: The UNT Digital Library
SLC energy spectrum monitor using synchrotron radiation (open access)

SLC energy spectrum monitor using synchrotron radiation

The SLAC Linac is being upgraded for the use in the SLAC Linear Collider (SLC). The improved Linac must accelerate electron and positron bunches from 1.2 GeV to 50 GeV while producing output energy spectra of about 0.2%. The energy spectra must be maintained during operation to provide for good beam transmission and to minimize chromatic effects in the SLC ARCs and Final Focus. the energy spectra of these beams are determined by the bunch length and intensity, the RF phase and waveform and the intra-bunch longitudinal wakefields. A non-destructive energy spectrum monitor has been designed using a vertical wiggler magnet located downstream of the horizontal beam splitter at the end of the SLC Linac. It produces synchrotron radiation which is viewed in an off-axis x-ray position sensitive detector. The expected resolution is 0.08%. The design considerations of this monitor are presented in this paper. A pair of these monitors is under construction with an installation date set for late summer 1986. 5 refs., 6 figs.
Date: April 1, 1986
Creator: Seeman, J.; Brunk, W.; Early, R.; Ross, M.; Tillmann, E. & Walz, D.
System: The UNT Digital Library
Circular machine design techniques and tools (open access)

Circular machine design techniques and tools

Some of the basic optics principles involved in the design of circular accelerators such as Alternating Gradient Synchrotrons, Storage and Collision Rings, and Pulse Stretcher Rings are outlined. Typical problems facing a designer are defined, and the main references and computational tools are reviewed that are presently available. Two particular classes of problems that occur typically in accelerator design are listed - global value problems, which affect the control of parameters which are characteristic of the complete closed circular machine, and local value problems. Basic mathematical formulae are given that are considered useful for a first draft of a design. The basic optics building blocks that can be used to formulate an initial machine design are introduced, giving only the elementary properties and transfer matrices only in one transverse plane. Solutions are presented for some first-order and second-order design problems. (LEW)
Date: April 1, 1986
Creator: Servranckx, R.V. & Brown, K.L.
System: The UNT Digital Library
Detector issues for relativistic heavy ion experimentation (open access)

Detector issues for relativistic heavy ion experimentation

Several aspects of experiments using relativistic heavy ion beams are discussed. The problems that the current generation of light ion experiments would face in using gold beams are noted. A brief review of colliding beam experiments for heavy ion beams is contrasted with requirements for SSC detectors. 11 refs., 13 figs.
Date: April 1, 1986
Creator: Gordon, H.
System: The UNT Digital Library