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1. 8K conditioning (non-quench training) of a model SSC dipole (open access)

1. 8K conditioning (non-quench training) of a model SSC dipole

The accepted hypothesis is that training quenches are caused by heat generation when conductors move under Lorentz force. Afterwards no conductor motion will occur until a higher field and greater Lorentz force acts. If superior heat transfer and/or greater temperature margin is provided by operating at lower bath temperature, one might expect that the heat generated by conductor motion will not cause a runaway temperature increase, or quench. To test this hypothesis, the central dipole field in SSC model magnets was ramped at 1.8 K to 7.1 tesla without the magnets' quenching. The bath was then raised to 4.4 K and the magnets quenched at their short sample limits of 6.6 tesla or higher. Comparison with similar magnets trained in He I at 4.4 K is made and the significance of the non-quench training on system operation is discussed.
Date: September 1, 1986
Creator: Gilbert, W. S. & Hassenzahl, W. V.
System: The UNT Digital Library
3-body final states in peripheral heavy-ion collisions: nuclear clustering structure and projectile excitation revisited (open access)

3-body final states in peripheral heavy-ion collisions: nuclear clustering structure and projectile excitation revisited

Even though peripheral heavy-ion collisions are less violent than their central counterparts, the large energy exchange between the reactants often leaves the primary products in excited particle-unstable states whose subsequent decay leads to 3 or more nuclei emerging in the final exit channel. These post-reaction, predominantly sequential de-excitation processes can sometimes provide interesting structural information about the parent nuclei. In fact, provided these processes are well understood, one can employ them as probes for studying initial properties of the fragments. This report discusses results of two experiments that deal with (1) nonstatistical, rare decay modes of the projectile, and (2) internal excitation energy of the projectile- and target-like fragments in peripheral collisions. The physics addressed in each is different, but the experimental and data-analysis techniques are so similar that it is relevant to join them together.
Date: February 1, 1986
Creator: Chan, Y.; Chavez, E.; Gazes, S.B.; Kamermans, R.; Schmidt, H.R.; Siwek-Wilczynska, J. et al.
System: The UNT Digital Library
3-D Analysis on Arbitrarily-Shaped Icrf Antennas and Faraday Shields (open access)

3-D Analysis on Arbitrarily-Shaped Icrf Antennas and Faraday Shields

Cavity antennas with Faraday shields are proposed to couple ion cyclotron radio frequency power for heating fusion plasmas. This application requires small, high-power, low-frequency antennas. The results are presented of a theoretical study of the ICRF antennas being developed for this purpose at the Radio Frequency Test Facility (RFTF). The objectives of this work are to optimize experimental designs and to confirm test results. (MOW)
Date: January 1, 1986
Creator: Chen, G. L.; Whealton, J. H.; Baity, F. W.; Hoffman, D. J. & Owens, T. L.
System: The UNT Digital Library
5-cm, no iron SSC 6-m dipole test program (open access)

5-cm, no iron SSC 6-m dipole test program

Magnet Design B for the Superconducting Super Collider (SSC) consists of a 5 cm diameter collared coil assembly 12 m long with concentric aluminum thermal shields at 10 K and 80 K, a G-10 post type support system and a minimal iron vacuum vessel located at a large radius from the coil. In order to determine the behavior of such a magnet under both direct current and quenching conditions, a 6 m model was built using Tevatron tooling to produce a 7.6 cm diameter coil. The dc operation demonstrated that the post type suspension has acceptable rigidity. Distortions in the aluminum thermal shield during quench resulted from stresses in the material below the yield values. Temperature increases in the thermal shield due to eddy currents were larger than those calculated using simple assumptions, demonstrating the value of using a model to verify eddy current behavior in complex situations.
Date: February 1, 1986
Creator: Mazur, P. O.; Carson, J. A.; Engler, N. H.; Fisk, H. E.; Gonczy, J. D.; Hanft, R. W. et al.
System: The UNT Digital Library
35 Years of Electron Scattering (open access)

35 Years of Electron Scattering

A review of the current knowledge of nuclear and nucleon structure gained from electron beam physics is given. Also, the reasons for development of new accelerator facilities (in particular, CEBAF) are discussed.
Date: October 1, 1986
Creator: Walecka, J.
System: The UNT Digital Library
1986 annual information meeting. Abstracts (open access)

1986 annual information meeting. Abstracts

Abstracts are presented for the following papers: Geohydrological Research at the Y-12 Plant (C.S. Haase); Ecological Impacts of Waste Disposal Operations in Bear Creek Valley Near the Y-12 Plant (J.M. Loar); Finite Element Simulation of Subsurface Contaminant Transport: Logistic Difficulties in Handling Large Field Problems (G.T. Yeh); Dynamic Compaction of a Radioactive Waste Burial Trench (B.P. Spalding); Comparative Evaluation of Potential Sites for a High-Level Radioactive Waste Repository (E.D. Smith); Changing Priorities in Environmental Assessment and Environmental Compliance (R.M. Reed); Ecology, Ecotoxicology, and Ecological Risk Assessment (L.W. Barnthouse); Theory and Practice in Uncertainty Analysis from Ten Years of Practice (R.H. Gardner); Modeling Landscape Effects of Forest Decline (V.H. Dale); Soil Nitrogen and the Global Carbon Cycle (W.M. Post); Maximizing Wood Energy Production in Short-Rotation Plantations: Effect of Initial Spacing and Rotation Length (L.L. Wright); and Ecological Communities and Processes in Woodland Streams Exhibit Both Direct and Indirect Effects of Acidification (J.W. Elwood).
Date: January 1, 1986
Creator: unknown
System: The UNT Digital Library
1986 USSR-US Exchange II. 4. Topical meeting: magnetic configurations, plasma equilibrium, and stability of stellarators. Volume I. Soviet presentations (open access)

1986 USSR-US Exchange II. 4. Topical meeting: magnetic configurations, plasma equilibrium, and stability of stellarators. Volume I. Soviet presentations

Separate abstracts for each paper are included in the data base. (MOW)
Date: January 1, 1986
Creator: unknown
System: The UNT Digital Library
1986 USSR-US Exchange II. 4. Topical meeting: magnetic configurations, plasma equilibrium, and stability of stellarators. Volume II. US presentations (open access)

1986 USSR-US Exchange II. 4. Topical meeting: magnetic configurations, plasma equilibrium, and stability of stellarators. Volume II. US presentations

Separate abstracts were prepared for each of the included papers. (MOW)
Date: January 1, 1986
Creator: unknown
System: The UNT Digital Library
3d-3p transitions in (. mu. /sup -/He/sup 4/)/sup +/ (open access)

3d-3p transitions in (. mu. /sup -/He/sup 4/)/sup +/

An experiment to measure the energy of 3d-3p transitions in the (..mu../sup -/He/sup 4/)/sup +/ ion is now in progress. The experiment, which is being performed at the Brookhaven National Laboratory Alternating Gradient Synchrotron, will use an infrared CO/sub 2/ laser to stimulate the transitions. These transitions are of interest because their energy is due almost entirely to the polarization of the vacuum. In a pure Coulomb field, states with the same principal quantum number, n, and total angular momentum, J, are degenerate. Vacuum polarization, because of its nonlinear dependence on electric field strength, results in departure from an inverse square Coulomb field, causing a splitting which depends on the orbital angular momentum, removing the degeneracy. The dominance of vacuum polarization in giving rise to these splittings in the muonic ion is in contrast to the situation in electronic atoms where vacuum polarization makes a very minor contribution to the Lamb shift. 4 refs., 4 figs.
Date: January 1, 1986
Creator: May, M.
System: The UNT Digital Library
5cm aperture dipole studies (open access)

5cm aperture dipole studies

The results obtained during the evolution of the design, construction, and testing program of the design ''B'' dipole are presented here. Design ''B'' is one of the original three competing designs for the Superconducting Super Collider ''SSC'' arc dipoles. The final design parameters were as follows: air cored (less than a few percent of the magnetic field derived from any iron present), aluminum collared, two layered winding, 5.5T maximum operating field, and a 5 cm cold aperture. There have been fourteen 64 cm long 5 cm aperture model dipoles cold tested (at 4.3K and less) in this program so far. There was a half length full size (6m) mechanical analog (M-10) built and tested to check the cryostat's mechanical design under ramping and quench conditions. Several deviations from the ''Tevatron'' dipole fabrication technique were incorporated, for example the use of aluminum collars instead of stainless steel. The winding technique variations explored were ''dry welding,'' a technique with the cable covered with Kapton insulation only and ''wet winding'' where the Kapton was covered with a light coat of ''B'' stage epoxy. Test data include quench currents, field quality (Fourier multipole co-efficients), coil magnetization, conductor current performance, and coil loading. Quench current, …
Date: September 30, 1986
Creator: McInturff, A.D.; Bossert, R.; Carson, J.; Fisk, H.E.; Hanft, R.; Kuchnir, M. et al.
System: The UNT Digital Library
Abstracts of Presentation: Aquatic Species Program Annual Review Meeting, Golden, Colorado, 24-25 September 1986 (open access)

Abstracts of Presentation: Aquatic Species Program Annual Review Meeting, Golden, Colorado, 24-25 September 1986

The goal of the aquatic species program is to produce gasoline and diesel fuels from microalgae grown in saline waters of the desert southwest. Microalgae are known to accumulate lipids in large quantities and can thrive in high salinity water which currently has no other use.
Date: September 1, 1986
Creator: unknown
System: The UNT Digital Library
Accelerated beam experiments with the ORNL SITEX (Surface Ionization with Transverse Extraction) and VITEX (Volume Ionization with Transverse Extraction) H/sup -//D/sup -/ sources (open access)

Accelerated beam experiments with the ORNL SITEX (Surface Ionization with Transverse Extraction) and VITEX (Volume Ionization with Transverse Extraction) H/sup -//D/sup -/ sources

Beam parameters have been measured for both the Surface Ionization with Transverse Extraction (SITEX) and Volume Ionization with Transverse Extraction (VITEX) H/sup -//D/sup -/ ion sources. Both sources use a reflex discharge to generate the main plasma. Beam energies up to 18 keV were used for pulse lengths up to several seconds. For SITEX, Faraday cup magnetically analyzed D/sup -/ beam currents of 110 mA at extraction densities of 48 mA/cm/sup 2/ and at a source ion temperature of 4 eV have been measured. For the VITEX results, Faraday cup magnetically analyzed beam currents of up to 80 mA at extraction densities of 27 mA/cm/sup 2/ and at a source ion temperature of 0.5 eV have been measured. Virtually all extracted electrons were recovered at an energy of 10 to 30% of the accel beam energy, and there were none in the analyzed beam.
Date: January 1, 1986
Creator: Dagenhart, W. K.; Tsai, C. C.; Stirling, W. L.; Ryan, P. M.; Schechter, D. E.; Whealton, J. H. et al.
System: The UNT Digital Library
Acceleration of electrons by the wake field of proton bunches (open access)

Acceleration of electrons by the wake field of proton bunches

This paper discusses a novel idea to accelerate low-intensity bunches of electrons (or positrons) by the wake field of intense proton bunches travelling along the axis of a cylindrical rf structure. Accelerating gradients in excess of 100 MeV/m and large ''transformer ratios'', which allow for acceleration of electrons to energies in the TeV range, are calculated. A possible application of the method is an electron-positron linear collider with luminosity of 10/sup 33/ cm/sup -2/ s/sup -1/. The relatively low cost and power consumption of the method is emphasized.
Date: January 1, 1986
Creator: Ruggiero, Alessandro G.
System: The UNT Digital Library
Accelerator and final focus model for an induction Linac based HIF system study (open access)

Accelerator and final focus model for an induction Linac based HIF system study

An overview of the assumptions and models incorporated in the ongoing Induction-Linac-based, HIF System Assessment is presented. Final transport, compression and final focus pose constraints which form a critical link between the accelerator and target requirements. A recent analysis has shown that system costs may be considerably reduced by the use of multiply charges ions. The assumptions underlying this direction are described.
Date: July 1, 1986
Creator: Lee, Edward P.
System: The UNT Digital Library
Accelerator dynamics and beam aperture (open access)

Accelerator dynamics and beam aperture

We present an analytical method for analyzing accelerator dynamics, including higher order effects of multipoles on the beam. This formalism provides a faster alternative to particle tracking. Simplectic expressions for the emittance and phase describing the dynamical behavior of a particle in a circular accelerator are derived using second order perturbation theory (in the presence of nonlinear elements, e.g., sextupoles, octupoles). These expressions are successfully used to calculate the emittance growth, smear and linear aperture. Our findings compare well with results obtained from tracking programs. In addition perturbation to betatron tune; resonance strengths; stop bandwidth; fixed points; island width; and Chirikov criteria are calculated.
Date: October 1, 1986
Creator: Parsa, Z.
System: The UNT Digital Library
The acceptance of the SSC (Superconducting Supercollider) clustered lattice (open access)

The acceptance of the SSC (Superconducting Supercollider) clustered lattice

The physical apertures of all elements of the SSC storage lattices are considered to determine whether correction of random multipole fields in the triplet quadrupoles is necessary when betatron amplitudes there are no more than the inner radius of the beam pipe. During computer simulated beam tracking the influence of random multiple fields was included as a kick given to the test particle at the center of each quadrupole and at the ends of every dipole. The degree of multipole correction needed is shown. (LEW)
Date: January 1, 1986
Creator: Dell, G.F.
System: The UNT Digital Library
Accuracy of Nodal Transport and Simplified-P3 Fluxes in Benchmark Tests (open access)

Accuracy of Nodal Transport and Simplified-P3 Fluxes in Benchmark Tests

Here we summarize recent work exploring the accuracy of fluxes computed, both by nodal transport methods, and by the simplified-spherical harmonics (SP/sub l/) method. Apparently, significant errors in nodal transport fluxes were first noted by Wagner et al., and attributed to the isotopic-transverse-leakage (ITL) approximation. Later Lawrence detected substantial errors, due to the ITL approximation, in his nodal transport (NTT) solution of the IAEA Stepanek benchmark problem. Gelbard concluded on theoretical grounds that nodal transport fluxes, computed in XY geometry using ITL, should be much more accurate on the coordinate axes than halfway between them and that, at 45/sup 0/ from the axes, nodal transport methods using ITL should give only about half of the true transport correction.
Date: January 1, 1986
Creator: Liu, Y.W.H. & Gelbard, E.M.
System: The UNT Digital Library
Accurate interatomic potentials for Ni, Al and Ni/sub 3/Al (open access)

Accurate interatomic potentials for Ni, Al and Ni/sub 3/Al

To obtain meaningful results from atomistic simulations of materials, the interatomic potentials must be capable of reproducing the thermodynamic properties of the system of interest. Pairwise potentials have known deficiencies that make them unsuitable for quantitative investigations of defective regions such as crack tips and free surfaces. Daw and Baskes (Phys. Rev. B 29, 6443 (1984)) have shown that including a local ''volume'' term for each atom gives the necessary many-body character without the severe computational dependence of explicit n-body potential terms. Using a similar approach, we have fit an interatomic potential to the Ni/sub 3/Al alloy system. This potential can treat diatomic Ni/sub 2/, diatomic Al/sub 2/, fcc Ni, fcc Al and L1/sub 2/ Ni/sub 3/Al on an equal footing. Details of the fitting procedure are presented, along with the calculation of some properties not included in the fit.
Date: January 1, 1986
Creator: Voter, Arthur F. & Chen, Shao Ping
System: The UNT Digital Library
Acid-split flowsheets for uranium-plutonium partitioning without a reductant (open access)

Acid-split flowsheets for uranium-plutonium partitioning without a reductant

The flowsheet discussed has been tested in a hot cell experiment using 10% TBP and a poorly controlled temperature near 15/sup 0/C. The test was carried out in the Solvent Extraction Test Facility at Oak Ridge National Laboratory, using highly irradiated mixed-oxide fuel from the Fast Flux Test Facility reactor at Hanford, Washington. The observed concentration profiles for U, Pu, and acid are shown graphically.
Date: January 1, 1986
Creator: Campbell, D.O.; Crouse, D.J. & Mills, A.L.
System: The UNT Digital Library
Acoustic velocity measurements on fluid metals from two-fold compressions to two-fold expansions (open access)

Acoustic velocity measurements on fluid metals from two-fold compressions to two-fold expansions

Methods used for making acoustic velocity measurements on samples which are destroyed in time scales of milliseconds or less are described. Analytic techniques for using this data to calculate thermodynamic quantities are outlined. New results indicating a linear relationship of acoustic velocity with density over a very large density range are presented. 30 refs., 5 figs. (DWL)
Date: January 1, 1986
Creator: Shaner, J. W.; Hixson, R. S.; Winkler, M. A. & Brown, J. M.
System: The UNT Digital Library
Acoustic wave scattering from a circular crack: comparison of different computational methods (open access)

Acoustic wave scattering from a circular crack: comparison of different computational methods

The work reported was motivated by disagreement between the results obtained from two computations of scattering of an axially incident elastic p-wave on a circular crack. One calculation involves the direct solution of the Helmholtz integral equation, showing an oscillating total cross section. The other uses a program called MOOT, in which the elastic displacement near the crack is expanded in regular spherical eigenfunctions of the elastic wave equation. This calculation shows that the oscillations in total cross section disappear rapidly at high wave numbers. The conjecture that the basis for the MOOT expansion was inappropriate is examined by application to a test problem. Results indicate that there is no inadequacy in the spherical basis set. (LEW)
Date: January 1, 1986
Creator: Visscher, W.M.
System: The UNT Digital Library
The ACP (Advanced Computer Program) multiprocessor system at Fermilab (open access)

The ACP (Advanced Computer Program) multiprocessor system at Fermilab

The Advanced Computer Program at Fermilab has developed a multiprocessor system which is easy to use and uniquely cost effective for many high energy physics problems. The system is based on single board computers which cost under $2000 each to build including 2 Mbytes of on board memory. These standard VME modules each run experiment reconstruction code in Fortran at speeds approaching that of a VAX 11/780. Two versions have been developed: one uses Motorola's 68020 32 bit microprocessor, the other runs with AT and T's 32100. both include the corresponding floating point coprocessor chip. The first system, when fully configured, uses 70 each of the two types of processors. A 53 processor system has been operated for several months with essentially no down time by computer operators in the Fermilab Computer Center, performing at nearly the capacity of 6 CDC Cyber 175 mainframe computers. The VME crates in which the processing ''nodes'' sit are connected via a high speed ''Branch Bus'' to one or more MicroVAX computers which act as hosts handling system resource management and all I/O in offline applications. An interface from Fastbus to the Branch Bus has been developed for online use which has been tested …
Date: September 1986
Creator: Nash, T.; Areti, H.; Atac, R.; Biel, J.; Case, G.; Cook, A. et al.
System: The UNT Digital Library
Actinide removal from nitric acid waste streams (open access)

Actinide removal from nitric acid waste streams

Actinide separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery and americium removal from nitric acid waste streams generated by plutonium purification operations. Capacity and breakthrough studies show anion exchange with Dowex 1x4 (50 to 100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO(tri-n-octyl-phosphine oxide) on XAD-4 removes the final traces of plutonium, including hydrolytic polymer. Partial neutralization and solid supported liquid membrane transfer removes americium for sorption on discardable inorganic ion exchangers, potentially allowing for non-TRU waste disposal.
Date: January 1, 1986
Creator: Muscatello, A.C. & Navratil, J.D.
System: The UNT Digital Library
Activation analysis of the compact ignition tokamak (open access)

Activation analysis of the compact ignition tokamak

The US fusion program has completed the conceptual design of a compact tokamak device that achieves ignition. The high neutron wall loadings associated with this compact deuterium-tritium-burning device indicate that radiation-related issues may be significant considerations in the overall system design. Sufficient shielding will be requied for the radiation protection of both reactor components and occupational personnel. A close-in igloo shield has been designed around the periphery of the tokamak structure to permit personnel access into the test cell after shutdown and limit the total activation of the test cell components. This paper describes the conceptual design of the igloo shield system and discusses the major neutronic concerns related to the design of the Compact Ignition Tokamak.
Date: January 1, 1986
Creator: Selcow, E.C.
System: The UNT Digital Library