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Probing the possibility of a /sup 12/C/sup 13/C abundance gradient from observations of interstellar CH/sup +/ (open access)

Probing the possibility of a /sup 12/C/sup 13/C abundance gradient from observations of interstellar CH/sup +/

I have performed high signal-to-noise (SN /equals/ 300 to 500) observations of interstellar CH/sup /plus// at Lick Observatory and at CTIO of the reddened, early-type stars HD 183143, HD 24432, and HD 157038 in an effort to probe the existence of a /sup 12/C/sup 13/C abundance gradient in our Galaxy.
Date: September 16, 1987
Creator: Hawkins, I.
System: The UNT Digital Library
Injection septum magnets for the Loma Linda medical accelerator (open access)

Injection septum magnets for the Loma Linda medical accelerator

The injection beamline runs over the last magnet before a long straight section and is then displaced downward 55.88 cm to the accelerator beamline. The displacement is magnetic and the final deflection onto the synchrotron orbit is by an electric kicker. The first component, the reverse septum magnet, bends the injection beam 25)degree) downward. This is followed by the injection septum (20)degree) bend upward) and the final injection kicker (5)degree) bend upward). The septum magnets produce a peak field of 3.4 K gauss at a current of 28,000 amperes within a 0.1 msec long pulse. The electric kicker produces a field of 7.3 KV/cm with a pulse length of 0.0011 msec. The septum magnets are similar to each other in construction with a bending radium of 72.7 cm. The curvature is required to increase the effective aperture. Each magnet has a single-turn copper coil bonded to a stainless steel plate for reinforcement. This eliminates insulating material, which could be subject to radiation damage, at the septum. The stainless steel plate is welded to the magnet laminations. The current is confined to the septum by the insulation between the laminations, which are a standard core material. The total septum thickness with …
Date: September 22, 1987
Creator: Satti, J.A.
System: The UNT Digital Library
Experimental review of J/psi decays (open access)

Experimental review of J/psi decays

This is a review of J/psi physics from e/sup +/e/sup -/ colliders presented at the Charm Workshop in Beijing, China. The review includes a brief historical summary of J/psi physics, a general discussion of theoretical models and detailed results on radiative and hadronic J/psi decays from the Mark III, DM2, Crystal Ball and MARK II groups. 119 refs., 13 figs., 10 tabs.
Date: September 1, 1987
Creator: Toki, W.H.
System: The UNT Digital Library
Residual radioactivity measurements along the PB target pile (open access)

Residual radioactivity measurements along the PB target pile

In this brief note, measurements of residual radioactivity made along the PB target pile will be described. This was done as a test of the methods described by P. Gollon (Go76) for predicting such radioactivity based upon surface star density calculations using CASIM. These methods have been extensively used at Fermilab, especially in the design of the Tevatron II target piles. 4 refs., 2 figs.
Date: September 1, 1987
Creator: Cossairt, J.D.
System: The UNT Digital Library
Fabrication of isotopic heat and radiation sources for the Federal Republic of Germany (open access)

Fabrication of isotopic heat and radiation sources for the Federal Republic of Germany

Pacific Northwest Laboratory (PNL) has filled 30 German-made canisters with highly radioactive borosilicate glass. These canisters, containing specified amounts of /sup 137/Cs and /sup 90/Sr, will be sealed using a gas tungsten arc welder and will be decontaminated to nonsmearable limits using an electropolishing system. They are to be characterized in a series of nondestructive tests: surface dose rate measurement, axial gamma scanning, canister mass determination, and canister surface temperature measurement. The canisters will then be transported to the Asse Salt Mine located in the Federal Republic of Germany (FRG) for a 5-year repository testing program. 3 refs., 2 figs., 1 tab.
Date: September 1, 1987
Creator: McElroy, J. L.; Holton, L. K., Jr.; Burkholder, H. C.; Bryan, G. H. & Minor, J. E.
System: The UNT Digital Library
The use of toroidal boundary conditions in the program POISSON (open access)

The use of toroidal boundary conditions in the program POISSON

In circular particle accelerators of moderate size, one cannot entirely neglect the curvature of the structure and of the guide field. In practice, one may wish to restrict the region of analysis to that near the working aperture, while excluding a very substantial area closer to (and including) the axis of rotational symmetry. In this way, a more efficient mesh can be generated for a program such as POISSON. In restricting the solution to the region of interest, there must be concern regarding a suitable termination of the problem at the boundary of the mesh. For these reasons, we have employed toroidal coordinates in constructing the boundary to a relaxation mesh, and in formulating the boundary conditions that then would be imposed at such boundaries. 11 refs., 6 figs.
Date: September 1, 1987
Creator: Caspi, S.; Helm, M. & Laslett, L.J.
System: The UNT Digital Library
The purposes, achievements, and priorities of arms control (open access)

The purposes, achievements, and priorities of arms control

Arms control purposes include strengthening the framework of deterrence and reducing the threat of the use of nuclear weapons, reducing the dangers of attack and accidental nuclear war, and allowing more resources for the civilian economy. The paper briefly describes achievements in arms control since World War II. These include the Limited Test Ban Treaty (LTBT), Nonproliferation Treaty (NPT), Anti-Ballistic Missile Treaty (ABMT)-SALT I, SALT II, Threshold Test Ban Treaty (TTBT), Peaceful Nuclear Explosions Treaty (PNET), and Nuclear-Free Zones treaties. The author also discusses his views on what the priorities of arms control activities should be. (ACR)
Date: September 1, 1987
Creator: Brown, P.S.
System: The UNT Digital Library
Results from shallow research drilling at Inyo Domes, Long Valley Caldera, California and Salton Sea geothermal field, Salton Trough, California (open access)

Results from shallow research drilling at Inyo Domes, Long Valley Caldera, California and Salton Sea geothermal field, Salton Trough, California

This report reviews the results from two shallow drilling programs recently completed as part of the United States Department of Energy Continental Scientific Drilling Program. The purpose is to provide a broad overview of the objectives and results of the projects, and to analyze these results in the context of the promise and potential of research drilling in crustal thermal regimes. The Inyo Domes drilling project has involved drilling 4 shallow research holes into the 600-year-old Inyo Domes chain, the youngest rhyolitic event in the coterminous United States and the youngest volcanic event in Long Valley Caldera, California. The purpose of the drilling at Inyo was to understand the thermal, chemical and mechanical behavior of silicic magma as it intrudes the upper crust. This behavior, which involves the response of magma to decompression and cooling, is closely related to both eruptive phenomena and the establishment of hydrothermal circulation. The Salton Sea shallow research drilling project involved drilling 19 shallow research holes into the Salton Sea geothermal field, California. The purpose of this drilling was to bound the thermal anomaly, constrain hydrothermal flow pathways, and assess the thermal budget of the field. Constraints on the thermal budget links the local hydrothermal …
Date: September 1, 1987
Creator: Younker, L.W.; Eichelberger, J.C.; Kasameyer, P.W.; Newmark, R.L. & Vogel, T.A.
System: The UNT Digital Library
Numerical simulations of multiphoton processes in many electron atoms (open access)

Numerical simulations of multiphoton processes in many electron atoms

In this report, we will present some details of two numerical methods which we have been pursuing for treating the multi-electron case. Both involve a numerical representation of the time dependent Hartree Fock electronic orbitals and a direct time integration of the coupled equations. Using these methods we will be able to determine the dynamics of the energy absorption process (preionization dynamics and the mechanism of ionization, i.e. whether it is direct multi-electron emission or sequential). 6 refs.
Date: September 1, 1987
Creator: Kulander, K.C. & Cerjan, C.
System: The UNT Digital Library
SSC (Superconducting Super Collider) magnet technology (open access)

SSC (Superconducting Super Collider) magnet technology

To minimize cost of the SSC facility, small-bore high field dipole magnets have been developed;some of the new technology that has been developed at several U.S. national laboratories and in industry is summarized. Superconducting wire with high J/sub c/ and filaments as small as 5..mu..m diameter is not produced iwht mechanical properties suitable for reliable cable production. A variety of collar designs of both aluminum and stainless steel have been used in model magnets. A low-heat leak post-type cryostat support system is used and a system for accurate alignment of coil-collar-yoke in the cryostat has been developed. Model magnets of 1-m, 1.8 m, 4.5 m, and 17 m lengths have been build during the past two years. 23 refs., 5 figs., 2 tabs
Date: September 1, 1987
Creator: Taylor, C.
System: The UNT Digital Library
Zero temperature quark matter equation of state (open access)

Zero temperature quark matter equation of state

An equation of state is computed for a plasma of one flavor quarks interacting through some phenomenological potential, in the Hartree approximation, at zero temperature. Assuming that the confining potential is scalar and color-independent, it is shown that the quarks undergo a first-order mass phase transition. In addition, due to the way screening is introduced, all the thermodynamic quantities computed are independent of the actual shape of the interquark potential. This equation of state is then generalized to a potential with scalar and vector components, Fock corrections are discussed and the case of a several quark flavor plasma is studied. 19 refs., 2 figs.
Date: September 1, 1987
Creator: Grassi, F.
System: The UNT Digital Library
The Direct Application of Geothermal Energy to Provide Process Heat in Guatemala (open access)

The Direct Application of Geothermal Energy to Provide Process Heat in Guatemala

One part of an energy and resource development program in Central America is a geothermal process heat project in Guatemala. The feasibility of the direct heat application depends upon the production characteristics and reliability of the geothermal source. Other factors are the distance from the heat source, quantity of use, and capacity factor of the use facilities. Favorable conditions would be distances of under 5 km, heat requirements approximately equal to the well capacity, and high capacity factors (say 60% or higher) in the industrial plants. Depending upon the values of these factors, energy costs of less than $1.00/million Btus to greater than $5.00/million Btus have been estimated. This can be compared to about $5.00/million Btus for petroleum-based fuels in Guatemala in mid 1987. A survey was made of existing industries in the Amatitlan and Zunil geothermal areas. In both Amatitlan and Zunil the existing industries are spread out over an area too large to be called an optimum. The most promising situation for an industrial park development is at Amatitlan, except that proven production wells are not yet available. At Zunil, production wells exist, but a diverse nearby industrial base does not. However, both of these two areas are …
Date: September 1, 1987
Creator: Altseimer, John H. & Edeskuty, Frederick J.
System: The UNT Digital Library
Experimental results on QCD (Quantum Chromodynamics) from e/sup +/e/sup -/ annihilation (open access)

Experimental results on QCD (Quantum Chromodynamics) from e/sup +/e/sup -/ annihilation

A review is given on QCD results from studying e/sup +/e/sup -/ annihilation with the PEP and PETRA storage rings with special emphasis on jet physics and the determination of the strong coupling constant ..cap alpha../sub s/. 92 refs., 28 figs., 3 tabs.
Date: September 1, 1987
Creator: de Boer, W.
System: The UNT Digital Library
Irradiation creep and swelling of AISI 316 to exposures of 130 dpa at 385 to 400/sup 0/C (open access)

Irradiation creep and swelling of AISI 316 to exposures of 130 dpa at 385 to 400/sup 0/C

The creep and swelling of AISI 316 stainless steel have been studied at 385 to 400/sup 0/C in EBR-II to doses of 130 dpa. Most creep capsules were operated at constant stress and temperature but mid-life changes in these variable were also made. This paper concentrates on the behavior of the 20% cold-worked condition but five other conditions were also studied. Swelling at less than or equal to00/sup 0/C was found to lose the sensitivity to stress exhibited at higher temperatures while the creep rate was found to retain linear dependencies on both stress and swelling rate. The creep coefficients extracted at 400/sup 0/C agree with those found in other experiments conducted at higher temperatures. In the temperature range of less than or equal to400/sup 0/C, swelling is in the recombination-dominated regime and the swelling rate falls strongly away from the approx.1%/dpa rate observed at higher temperatures. These lower rates of creep and swelling, coupled with the attainment of high damage levels without failure, encourage the use of AISI 316 in the construction of water-cooled fusion first walls operating at temperatures below 400/sup 0/C. 23 refs., 8 figs.
Date: September 1, 1987
Creator: Garner, F. A. & Porter, D. L.
System: The UNT Digital Library
Positron-annihilation 2D-ACAR studies of disordered and defected alloys (open access)

Positron-annihilation 2D-ACAR studies of disordered and defected alloys

Theoretical and experimental progess in connection with 2D-ACAR positron annihilation studies of ordered, disordered, and defected alloys is discussed. We present, in particular, some of the recent developments concerning the electronic structure of disordered alloys, and the work in the area of annihilation from positrons trapped at vacancy-type defects in metals and alloys. The electronic structure and properties of a number of compounds are also discussed briefly; we comment specifically on high T/sub c/ ceramic superconductors, Heusler alloys, and transition-metal aluminides. 58 refs., 116 figs.
Date: September 1, 1987
Creator: Bansil, A.; Prasad, R.; Smedskjaer, L. C.; Benedek, R. & Mijnarends, P. E.
System: The UNT Digital Library
Charm Hadroproduction Results From Fermilab E-400 (open access)

Charm Hadroproduction Results From Fermilab E-400

Results are presented from Fermilab E-400 on the production of charmed baryons and mesons at a mean energy of 640 GeV. We show evidence for the charm-strange baryon, ..xi../sub c//sup +/, and present our measurements of its mass, width, lifetime, cross section and relative branching fractions, and the A, x/sub f/, p/sub t/, and particle/antiparticle dependence of the state. We show evidence for both the ..sigma../sub c//sup 2 +/ and ..sigma../sub c//sup 0/, and present measurements of three mass differences, ..sigma../sub c//sup 2 +/ - ..sigma../sub c//sup 0/, ..sigma../sub c//sup 0/ - ..lambda../sub c//sup +/, and ..sigma../sub c//sup 2 +/ - ..lambda../sub c//sup +/. Measurements of the A dependence and particle/antiparticle ratios for ..sigma../sub c/ production are also presented. We show preliminary results on the ratio of two decay modes of the D/sup 0/, D/sup 0/ ..-->.. K/sup +/K/sup -/ and D/sup 0/ ..-->.. K/sub 0/anti K/sub 0/. The latter mode has not been previously observed. 8 refs., 10 figs.
Date: September 1, 1987
Creator: Coteus, P.; Binkley, M.; Bossi, F.; Butler, J.; Cumalat, J. P.; DiCorato, M. et al.
System: The UNT Digital Library
Analysis of exposure due to work on activated components (open access)

Analysis of exposure due to work on activated components

In this brief note the author summarized analysis of the exposure incurred in various maintenance jobs involving activated accelerator and beam line components at Fermilab. A tabulation was made of parameters associated with each job. Included are rather terse descriptions of the various tasks. The author presented various plots of the quantities in the table. All exposure rates are mR/hr while all exposures accumulated are mR. The exposure rates were generally measured at the Fermilab standard one foot distance from the activated component. Accumulated exposures are taken from the self-reading pocket dosimeter records maintained by the radiation control technicians.
Date: September 1, 1987
Creator: Cossairt, J.D.
System: The UNT Digital Library
ECRH (electron-cyclotron resonance heating)-heated distributions in thermal-barrier tandem mirrors (open access)

ECRH (electron-cyclotron resonance heating)-heated distributions in thermal-barrier tandem mirrors

The distribution function is calculated for electrons subjected to strong electron-cyclotron resonance heating (ECRH) at the plug and barrier in a tandem-mirror thermal-barrier cell. When ECRH diffusion locally dominates over collisions and a boundary condition (associated with electrons passing to the center cell) imposes variations on the distribution function rapid compared to the variation of the ECRH and collisional diffusion coefficients, the kinetic equation can be reduced approximately to Laplace's equation. For the typical case where velocity space is divided into distinct regions in which plug and barrier ECRH dominate, the solution in each region can be expressed in terms of the plasma dispersion function or exponential integrals, according to whether the passing electrons are dominated by collisions or ECRH, respectively. The analytic results agree well with Fokker-Planck code results, in terms of both velocity-space structure and values of moments. 10 refs., 4 figs.
Date: September 1, 1987
Creator: Cohen, R. H. & LoDestro, L. L.
System: The UNT Digital Library
Jet physics at PEP and PETRA (open access)

Jet physics at PEP and PETRA

Recent data on the fragmentation of quarks at PEP and PETRA energies is discussed in the context of phenomenological models of parton fragmentation. Emphasis is placed on the experimental evidence for parton showers as compared to a fixed order QCD treatment, on new data on inclusive hadron production and on detailed studies of baryon production in jets. 63 refs., 22 figs., 3 tabs.
Date: September 1, 1987
Creator: Hofmann, W.
System: The UNT Digital Library
Effect of the subgap conductance on the metastable states in a Josephson tunnel junction (open access)

Effect of the subgap conductance on the metastable states in a Josephson tunnel junction

An investigation of the decay rate of metastable states in Josephson tunnel junctions in presence of thermal noise is presented. We have observed that, in the extremely underdamped regime, there is an exponential temperature dependence of the best fit value for the shunt conductance. Such a dependence shows a close relation with the temperature dependence of the subgap conductance, suggesting that the effective conductance for the escape from the metastable states obeys to a quasi-particle thermal activation mechanism. The introduction of this effective conductance into the lifetime expression for the zero-voltage states leads to significant changes in the width of the switching current distributions. A comparisons of the experimental data with the proposed model is reported. 7 refs., 2 figs.
Date: September 1, 1987
Creator: Cristiano, R.; Pagano, S.; Silvestrini, P.; Gray, K.E. & Liengme, O.
System: The UNT Digital Library
[Dialog, September 1987: President's Message] (open access)

[Dialog, September 1987: President's Message]

President's message from the September 1987 edition of Diaog. Some sentences are highlighted.
Date: September 1987
Creator: Dallas Gay Alliance
System: The UNT Digital Library
Measurement of Same-Sign Dimuon Production in High-Energy Neutrino Interactions (open access)

Measurement of Same-Sign Dimuon Production in High-Energy Neutrino Interactions

We present rates for same-sign dimuon production in neutrino-iron interactions with energies of 30 to 600 GeV. We find 101 neutrino and 15 anti-neutrino induced same-sign dimuons with muon momenta above 9 GeV/c. A detailed calculation indicates that the overall level and kinematic distributions of conventional backgrounds are consistent with the data. There is no convincing indication of new physical processes. 16 refs., 11 figs., 1 tab.
Date: September 1, 1987
Creator: Merritt, F. S.; Oreglia, M.; Schellman, H.; Schumm, B. A.; Bachmann, K. T.; Bernstein, R. H. et al.
System: The UNT Digital Library
Charmless B decays to baryons (open access)

Charmless B decays to baryons

We attempt an estimate of vertical bar V/sub ub//V/sub cb/vertical bar from the recent ARGUS observation of B/sup + -/ ..-->.. p anti p..pi../sup + -/ and B/sup 0/ ..-->.. p anti p..pi../sup +/..pi../sup -/ by studying general processes of the type B ..-->.. N anti N + n..pi.. (n greater than or equal to 0). The main ingredients of the analysis are the pion multiplicity distribution and a few models for the isospin structure of the final state. It is concluded quite generally that vertical bar V/sub ub//V/sub cb/vertical bar = 0.25 +- 0.10 and vertical bar V/sub ub//V/sub cb/vertical bar greater than or equal to 0.08. The ratio may become lower only in the event that both the relevant experimental and theoretical quantities obtain the extreme values considered in our study. We also discuss briefly a possible realization of a ..delta..I = 1/2 rule in these processes.
Date: September 1, 1987
Creator: Gronau, M.
System: The UNT Digital Library
Fusion neutron irradiation of Ni(Si) alloys at high temperature (open access)

Fusion neutron irradiation of Ni(Si) alloys at high temperature

Two Ni-4% Si alloys, with different cold work levels, are irradiated with 14 MeV fusion neutrons at 623 K, and their Curie temperatures are monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2 MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14 MeV fusion neutrons is only 6 to 7% of that for an identical alloy irradiated by 2 MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6 to 7% for the fusion neutron irradiated sample. 17 refs., 4 figs., 1 tab.
Date: September 1, 1987
Creator: Huang, J.S.; Guinan, M.W. & Hahn, P.A.
System: The UNT Digital Library