Resource Type

2,307 Matching Results

Results open in a new window/tab.

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
Proceedings of the LAMPF workshop on physics with polarized nuclear targets (open access)

Proceedings of the LAMPF workshop on physics with polarized nuclear targets

Topics of discussion included static and dynamic methods for polarizing nuclei, proton and pion nucleus scattering experiments, and possible future experiments at LAMPF. Separate abstracts were prepared for 11 papers in this report. (DWL)
Date: August 1, 1986
Creator: Burleson, G.; Gibbs, W.; Hoffmann, G.; Jarmer, J. J. & Tanaka, N. (eds.)
System: The UNT Digital Library
Analysis of the results of the Midland PRA (open access)

Analysis of the results of the Midland PRA

This paper presents the results of a limited review of the Midland PRA (MPRA), aimed at facilitating regulatory analyses and at providing insights into safety related plant failures. In particular, stress was laid on the root causes of accident sequences, particularly their failure modes, viz., hardware, human, maintenance, test, and repair. Because this information was difficult to extract in this detailed and sophisticated PRA (and in certain others) a special algorithm was developed to display the leading sequences contributing to core damage and/or to public risk in terms of the above generic failure modes. This was done in a hierarchical fashion to allow tracing the important accident sequences to the systems failures. The weighted core damage frequency (CDF) values of the sequences considered then provided a (quantitative) ranked importance listing of these failure modes, led by hardware failures (in 78%) and human factors (in 37%), etc. Multiple maintenance situations (reflecting on test and maintenance specifications) were also evaluated, but played only a small role (less than or equal to3%). Similar tabulations were also made of the (weighted) importance of the support systems (such as the electric power system, the component cooling water systems, etc.) and of the role of the …
Date: January 1, 1986
Creator: Bozoki, G. & Teichmann, T.
System: The UNT Digital Library
Use of molybdenum ion source electrodes at RTNS-II (open access)

Use of molybdenum ion source electrodes at RTNS-II

Reports are reported for an ongoing effort to optimize D+ beam production by the MATS-III ion source used at RTNS-II. The three seven-aperture electrodes, originally consisting of water-cooled copper, have now been tested using uncooled molybdenum and with water cooling on the second (decel) electrode only. Details of the change, the results of the testing, and the benefits in operation, performance and cost are given.
Date: September 29, 1986
Creator: Massoletti, D.J.; Harter, G.A. & Heikkinen, D.W.
System: The UNT Digital Library
Manipulator comparative testing program (open access)

Manipulator comparative testing program

The Manipulator Comparative Testing Program examined differences among manipulator systems from the United States and Japan. The manipulator systems included the Meidensha BILARM 83A, the Model M-2 of Central Research Laboratories Division of Sargent Industries (CRL), and the GCA Corporation PaR Systems Model 6000. The site of testing was the Remote Operations Maintenance Demonstration (ROMD) facility, operated by the Fuel Recycle Division in the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory (ORNL). In all stages of testing, operators using the CRL Model M-2 manipulator had consistently lower times to completion and error rates than they did using other machines. Performance was second best with the Meidensha BILARM 83A in master-slave mode. Performance with the BILARM in switchbox mode and the PaR 6000 manipulator was approximately equivalent in terms of criteria recorded in testing. These data show no impact of force reflection on task performance.
Date: January 1, 1986
Creator: Draper, J. V.; Handel, S. J.; Sundstrom, E.; Herndon, J. N.; Fujita, Y. & Maeda, M.
System: The UNT Digital Library
Construction and testing of the Mirror Fusion Test Facility magnets (open access)

Construction and testing of the Mirror Fusion Test Facility magnets

This paper describes the construction and testing of the Mirror Fusion Test Facility superconducting magnet set. Construction of the first Yin Yang magnet was started in 1978. And although this particular magnet was later modified, the final construction of these magnets was not completed until 1985. When completed these 42 magnets weighed over 1200 tonnes and had a maximum stored energy of approximately 1200 MJ at full field. Together with power supplies, controls and liquid nitrogen radiation shields the cost of the fabrication of this system was over $100M. General Dynamics/Convair Division was responsible for the system design and the fabrication of 20 of the magnets. This contract was the largest single procurement action at the Lawrence Livermore National Laboratory. During the PACE acceptance tests, the 26 major magnets were operated at full field for more than 24 hours while other MFTF subsystems were tested. From all of the data, the magnets operated to the performance specifications. For physics operation in the future, additional helium and nitrogen leak checking and repair will be necessary. In this report we will discuss the operation and testing of the MFTF Magnet System, the world's largest superconducting magnet set built to date. The topics …
Date: August 1, 1986
Creator: Kozman, T.; Shimer, D.; VanSant, J. & Zbasnik, J.
System: The UNT Digital Library
Physics of antimatter-matter reactions for interstellar propulsion (open access)

Physics of antimatter-matter reactions for interstellar propulsion

At the stage of the antiproton-nucleon annihilation chain of events relevant to propulsion the annihilation produces energetic charged pions and gamma rays. If annihilation occurs in a complex nucleus, protons, neutrons, and other nuclear fragments are also produced. The charge, number, and energy of the annihilation products are such that annihilation rocket engine concepts involving relatively low specific impulse (I/sub sp/ approx. = 1000 to 2000 s) and very high I/sub sp/ (3 x 10/sup 7/ s) appear feasible and have efficiencies on the order of 50% for annihilation energy to propulsion energy conversion. At I/sub sp/'s of around 15,000 s, however, it may be that only the kinetic energy of the charged nuclear fragments can be utilized for propulsion in engines of ordinary size. An estimate of this kinetic energy was made from known pieces of experimental and theoretical information. Its value is about 10% of the annihilation energy. Control over the mean penetration depth of protons into matter prior to annihilation is necessary so that annihilation occurs in the proper region within the engine. Control is possible by varying the antiproton kinetic energy to obtain a suitable annihilation cross section. The annihilation cross section at low energies is …
Date: August 22, 1986
Creator: Morgan, D.L. Jr.
System: The UNT Digital Library
In-Vitro and in-Vivo Characterization of Ruthenium-Bleomycin Compared to Cobalt- and Copper-Bleomycin (open access)

In-Vitro and in-Vivo Characterization of Ruthenium-Bleomycin Compared to Cobalt- and Copper-Bleomycin

Bleomycin (BLM) has undergone extensive investigation both as a cancer chemotherapeutic agent, and as a carrier for radionuclides for tumor imaging. The available methods or the radionuclides used, however, have had limited effectiveness. Although labeling of BLM with /sup 103/Ru has been reported earlier, we carried out a study to develop a more reproducible method of labeling particularly for use with Brookhaven Linac Isotope Producer produced /sup 97/Ru. Ruthenium-97 has favorable physical properties that make it ideal for imaging applications: decay by electron capture; ..gamma.. 216 keV, 85%; t/sub 1/2/ 2.9 d. A novel method based on the reduction of Ru/sup 3 +/ to Ru/sup 2 +/ using stannous chloride was investigated for labeling BLM with /sup 97/Ru and/or /sup 103/Ru. In-vitro and in vivo comparisons of the product(s) with /sup 57/Co and /sup 67/Cu-labeled BLM were also carried out. 4 refs., 3 tabs.
Date: January 1, 1986
Creator: Shao, H. S.; Meinken, G. E.; Srivastava, S. C.; Slosman, D.; Sacker, D. F.; Som, P. et al.
System: The UNT Digital Library
Radiation-induced segregation in HT-9 martensitic steel (open access)

Radiation-induced segregation in HT-9 martensitic steel

Miniature notched-bar specimens of normalized and tempered HT-9 were neutron irradiated to approx.13 dpa and broken at liquid nitrogen temperatures in a UHV chamber. Fracture surfaces were analyzed using scanning Auger electron spectroscopy. Following irradiation at 410/sup 0/C, the fracture surface contained a small number of large relatively smooth facets, which are thought to be prior austenite grain boundaries. Strong segregation of Ni, Cr, Si, and P was detected at these surfaces, the remainder of the fracture surface showing no evidence of segregation. At irradiation temperatures of 520/sup 0/ and 565/sup 0/C, there was relatively little segregation and none was found in thermal controls.
Date: January 1, 1986
Creator: Clausing, R.E.; Heatherly, L.; Faulkner, R.G.; Rowcliffe, A.F. & Farrell, K.
System: The UNT Digital Library
Insights from an overview of four PRAs (open access)

Insights from an overview of four PRAs

This paper summarizes the findings of an investigation of four probabilistic risk assessments (PRAs), those for Millstone 3, Seabrook, Shoreham, and Oconee 3, performed by Brookhaven National Laboratory (BNL) for the Reliability and Risk Assessment Branch of the US Nuclear Regulatory Commission (NRC). This group of four PRAs was subjected to an overview process with the basic goal of ascertaining what insights might be gained (beyond those already documented within the individual PRAs) by an independent evaluation of the group with respect to nuclear plant safety and vulnerability. Specifically, the objectives of the study were (1) to identify and rank initiators, systems, components, and failure modes from dominant accident sequences according to their contribution to core melt probability and public risk; and (2) to derive from this process plant-specific and generic insights. The effort was not intended to verify the specific details and results of each PRA but rather - having accepted the results - to see what they might mean in a more global context. The NRC had previously sponsored full detailed reviews of each of these PRAs, but only two, those for Millstone 3 and Shoreham, were completed and documented in time to allow their consideration within the …
Date: January 1, 1986
Creator: Fitzpatrick, R.; Arrieta, L.; Teichmann, T. & Davis, P.
System: The UNT Digital Library
Control room habitability study: findings and recommendations (open access)

Control room habitability study: findings and recommendations

The Advisory Committee on Reactor Safeguards (ACRS) has raised a number of concerns related to control room habitability and has recommended actions which they believe could alleviate these concerns. As a result of the ACRS's concerns, the US Nuclear Regulatory Commission's (NRC) Office of Nuclear Reactor Regulation (NRR) in conjunction with the Offices of Research and Inspection and Enforcement, and the NRC regional offices, embarked upon a program to reevaluate Control Room Habitability. Argonne National Laboratory was contracted by the NRC to perform a Control Room Habitability Study on twelve licensed power reactors. The plants selected for the study were chosen based upon architect engineer, nuclear steam system supplier, utility, and plant location. Participants in the study review the plant design as contained in the Updated Safety Analysis Report, Technical Specifications, Three Mile Island action item III.D.3.4 submittal on Control Room Habitability, NRC staff evaluation of the III.D.3.4 submittal, appropriate plant operating procedures, system drawings, and significant Licensee Event Reports on Loss of Cooling to the Control Room Envelope. A two-day visit is then made to the plant to determine if the as-built systems are built, operated, and surveillance performed as described in the documentation reviewed prior to the visit. …
Date: January 1, 1986
Creator: Driscoll, J.W.
System: The UNT Digital Library
Massive sulfide deposits and hydrothermal solutions: incremental reaction modeling of mineral precipitation and sulfur isotopic evolution (open access)

Massive sulfide deposits and hydrothermal solutions: incremental reaction modeling of mineral precipitation and sulfur isotopic evolution

Incremental reaction path modeling of chemical and sulfur isotopic reactions occurring in active hydrothermal vents on the seafloor, in combination with chemical and petrographic data from sulfide samples from the seafloor and massive sulfide ore deposits, allows a detailed examination of the processes involved. This paper presents theoretical models of reactions of two types: (1) adiabatic mixing between hydrothermal solution and seawater, and (2) reaction of hydrothermal solution with sulfide deposit materials. In addition, reaction of hydrothermal solution with sulfide deposit minerals and basalt in feeder zones is discussed.
Date: January 1, 1986
Creator: Janecky, D.R.
System: The UNT Digital Library
Nuclear alkali metal Rankine power systems for space applications (open access)

Nuclear alkali metal Rankine power systems for space applications

Nucler power systems utilizing alkali metal Rankine power conversion cycles offer the potential for high efficiency, lightweight space power plants. Conceptual design studies are being carried out for both direct and indirect cycle systems for steady state space power applications. A computational model has been developed for calculating the performance, size, and weight of these systems over a wide range of design parameters. The model is described briefly and results from parametric design studies, with descriptions of typical point designs, are presented in this paper.
Date: August 1, 1986
Creator: Moyers, J. C. & Holcomb, R. S.
System: The UNT Digital Library
Quark deconfinement and high energy nuclear collisions (open access)

Quark deconfinement and high energy nuclear collisions

Statistical QCD predicts that with increasing density, strongly interacting matter will undergo a transition to a plasma of deconfined quarks and gluons. High energy heavy ion collisions are expected to permit experimental studies of this transition and of the predicted new state of matter. 22 refs., 6 figs.
Date: July 1, 1986
Creator: Satz, H.
System: The UNT Digital Library
Advanced accelerator research at Argonne (open access)

Advanced accelerator research at Argonne

A facility with which to experimentally measure methods of advanced acceleration is at the point of completion at Argonne National Laboratory. The new facility consists a system which produces pulse ''doublets'' of energetic electrons, pulse shaping hardware, a space for experimental apparatus, and a high resolution spectrometer. The leading 21 MeV pulse in a doublet can contain up to 15 nano-coulombs of charge and can be adjusted to be from 6 to over 100 pic-seconds in length. The trailing doublet pulse is at 15 MeV, contains about 10/sup 6/ electrons, and can be precisely positioned behind the first from 0 to more than 2000 pico-seconds. This second pulse serves as a probe of fields produced by the intense leading pulse. The initial experimental program includes studies of wake field effects in structures and in plasma. The high resolution of the spectrometer will also make possible measurements of the wakes of various components such as bellows, beam signal pickups, and vacuum connections. Commissioning of the facility is to begin in September, 1986. Tests using cavities and plasma are expected to begin soon thereafter.
Date: January 1, 1986
Creator: Konecny, R.; MacLachlan, J.; Norem, J.; Ruggiero, A.; Schoessow, P. & Simpson, J.
System: The UNT Digital Library
RIMS diagnostics for laser desorption/laser ablation (open access)

RIMS diagnostics for laser desorption/laser ablation

Laser desorption mass spectrometry is a useful method for interrogating materials and events at or near surfaces. Laser desorption/ablation combined with Resonance Ionization Mass Spectrometry (RIMS) provides a powerful tool to obtain information on chemical composition and speciation and, in some cases, internal and translational energy distributions. The application of this technique to the interrogation of materials and interfaces is discussed for several systems, including the analysis of conventional analytical samples, and the study of optical damage events. 8 refs., 2 figs., 1 tab.
Date: January 1, 1986
Creator: Apel, E. C.; Nogar, N. S.; Miller, C. M. & Estler, R. C.
System: The UNT Digital Library
Some effects on the kinetics of muon-catalyzed fusion (open access)

Some effects on the kinetics of muon-catalyzed fusion

Two important stages in the kinetics of muon-catalyzed d-t fusion are discussed: (1) atomic thermalization and hyperfine-state relaxation preceding molecular formation and (2) muon stripping and x-ray production if sticking occurs after nuclear fusion. Thermalization is accurately treated by Monte Carlo simulation. It is shown that thermalization and triplet quenching of the ..cap alpha mu.. atom may not finish before dt..mu.. formation in low-tritium targets, but that epithermal transients are most important in high-tritium targets. A complete kinetic treatment of muon stripping from ..cap alpha mu.. is made using newly calculated stripping (ionization and charge transfer) and inelastic excitation cross sections and explicitly treating the 2s-2p Stark mixing. The calculated values of the sticking probability and K..cap alpha.. ..cap alpha mu.. x-rays per fusion are ..omega../sub s/ = 0.53% (0.59%) and I/sub K..cap alpha..//chi = 0.23% (0.28%) at density phi = 1.2 (0.1) times liquid-hydrogen density. Sensitivities to the various kinetic rates are evaluated, and error bars are estimated.
Date: January 1, 1986
Creator: Cohen, J.S.
System: The UNT Digital Library
Giotto observations of the bow shock at Comet Halley (open access)

Giotto observations of the bow shock at Comet Halley

Preliminary results from the JPA instrument on Giotto indicate that Comet Halley, even on the flanks, has a bow shock which moves backwards and forwards over the spacecraft. To understand the structure properly will require more detailed investigation of the relationships between three particle populations, cometary ions, solar wind ions and electrons.
Date: January 1, 1986
Creator: Formisano, V.; Amata, E.; Wilken, B.; Jockers, K.; Johnstone, A.; Coates, A. et al.
System: The UNT Digital Library
Source-term development for commercial low-level radioactive waste (open access)

Source-term development for commercial low-level radioactive waste

Generic source terms base don historical data have been developed for commerical low-level radioactive waste (LLRW) from fuel-cycle and non-fuel-cycle facilities. These source terms are used in DOE's Integrated Data Base (IDB) Program to estimate historical and projected volumes, radioactivity, and thermal power (from radioactive decay) of LLRW to the year 2020. Periodically, the source terms are updated as new waste is generated and as information on older waste is reviewed, redefined, and upgraded by the generator. Other segments of the nuclear industry also use source terms in planning for waste treatment, transportation, and storage systems. Several uses of source terms are illustrated. For example, the reported volume and radioactivity of LLRW added annually to commerical burial sites are compared with the calculated annual values obtained by summing contributions based on source terms for each generator. Likewise, accumulative radioactivity and thermal power of buried LLRW obtained by using an average source term and a synthesis of individual source terms are compared. 6 refs., 8 figs, 5 tabs.
Date: January 1, 1986
Creator: Godbee, H. W.; Kibbey, A. H.; Forsberg, C. W.; Storch, S. N. & Clower, T. J.
System: The UNT Digital Library
Theoretical understanding of charm decays (open access)

Theoretical understanding of charm decays

A detailed description of charm decays has emerged. The various concepts involved are sketched. Although this description is quite successful in reproducing the data the chapter on heavy flavour decays is far from closed. Relevant questions like on th real strength of weak annihilation, Penguin operators, etc. are still unanswered. Important directions in future work, both on the experimental and theoretical side are identified.
Date: August 1, 1986
Creator: Bigi, I. I.
System: The UNT Digital Library
Probing nuclear matter with dileptons (open access)

Probing nuclear matter with dileptons

Dileptons are shown to be of interest in helping probe extreme conditions of temperature and density in nuclear matter. The current state of experimental knowledge about dileptons is briefly described, and their use in upcoming experiments with light ions at CERN SPS are reviewed, including possible signatures of quark matter formation. Use of dileptons in an upcoming experiment with a new spectrometer at Berkeley is also discussed. This experiment will probe the nuclear matter equation of state at high temperature and density. 16 refs., 8 figs. (LEW)
Date: June 1, 1986
Creator: Schroeder, L. S.
System: The UNT Digital Library
Strange particle production in neutrino-neon charged current interactions (open access)

Strange particle production in neutrino-neon charged current interactions

Neutral strange particle production in charged-current muon-neutrino interactions have been studied in the Fermilab 15-foot neon bubble chamber. Associated production is expected to be the major source of strange particles in charged-current neutrino interactions. sigma-neutral and xi-minus production by neutrinos was observed. The dependence on various leptonic and hadronic variables is investigated. A fit to single and associated production of s, s/anti-s, and c quarks is described based on the number of single and double strange particle production events. Inclusive neutral strange particle decays (V/sup 0/) production rates as a fraction of all charged-current events are measured and are tabulated. The lambda/K ratio is found to be 0.39 +- 0.04 and the fraction of lambda coming from sigma-neutral is (16 +- 5)%. The single- and double V/sup 0/ production was used to determine the associated s anti-s production rate and single s-quark production rate. 13 refs., 7 figs., 3 tabs. (LEW)
Date: January 1, 1986
Creator: Plano, R.; Baker, N. J.; Connolly, P. L.; Kahn, S. A.; Murtagh, M. J.; Palmer, R. B. et al.
System: The UNT Digital Library
Estimated risk from exposure to radon decay products in US homes (open access)

Estimated risk from exposure to radon decay products in US homes

Recent analyses now permit direct estimation of the risks of lung cancer from radon decay products in US homes. Analysis of data from indoor monitoring in single-family homes yields a tentative frequency distribution of annual-average /sup 222/Rn concentrations averaging 55 Bq m/sup -3/ and having 2% of homes exceeding 300 Bq m/sup -3/. Application of the results of occupational epidemiological studies, either directly or using recent advances in lung dosimetry, to indoor exposures suggests that the average indoor concentration entails a lifetime risk of lung cancer of 0.3% or about 10% of the total risk of lung cancer. The risk to individuals occupying the homes with 300 Bq m/sup -3/ or more for their lifetimes is estimated to exceed 2%, with risks from the homes with thousands of Bq m/sup -3/ correspondingly higher, even exceeding the total risk of premature death due to cigarette smoking. The potential for such average and high-level risks in ordinary homes forces development of a new perspective on environmental exposures.
Date: May 1, 1986
Creator: Nero, A.V. Jr.
System: The UNT Digital Library
Dose-rate models for human survival after exposure to ionizing radiation (open access)

Dose-rate models for human survival after exposure to ionizing radiation

This paper reviews new estimates of the L/sub 50/ in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD/sub 50/s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively.
Date: January 1, 1986
Creator: Jones, T.D.; Morris, M.D. & Young, R.W.
System: The UNT Digital Library