EPICS System: An Overview (open access)

EPICS System: An Overview

This paper presents an overview of the EPICS control system at FERMILAB. EPICS is a distributed, multi-user, interactive system for the control and monitoring of particle beamlines at a high-energy experimental physics laboratory. The overview discusses the operating environment of the control system, the requirements which determined the design decisions, the hardware and software configurations, and plans for the future growth and enhancement of the present system. This paper is the first of three related papers on the EPICS system. The other two cover (1) the system structure and user interface and (2) RSX implementation issues.
Date: February 1, 1984
Creator: Bartlett, J. F.; Bobbitt, J. S.; Kramper, B. J.; Lahey, T. E.; MacKinnon, B. A. & West, R. E.
System: The UNT Digital Library
Sample environments at IPNS: present and future capabilities (open access)

Sample environments at IPNS: present and future capabilities

Argonne's Intense Pulsed Neutron Source, IPNS, was dedicated as a major user-oriented neutron scattering facility two years ago. Most instruments are now equipped to provide for sample environments in the temperature range 1.5 < T < 1300K. A special facility provides T < 1mK, and another provides pressures to 30kbar. Several environmental equipment designs are described that emphasize time-of-flight technique. Methods for achieving time-resolved experiments which take advantage of the IPNS pulsed source characteristics are discussed. 6 references, 7 figures.
Date: February 1, 1984
Creator: Faber, J. Jr.
System: The UNT Digital Library
Estimating and coping with public response to radioactive waste repository siting (open access)

Estimating and coping with public response to radioactive waste repository siting

The siting and construction of a radioactive waste disposal operation is likely to be controversial in the communities being considered, and at the state and national levels as well. Public response can be conceptualized at two levels: individual, and group or organizational. At the individual level, public response is the behavior of people motivated by their attitudes, knowledge, and perceptions of radioactive waste and its hazards and risks. On the group or organizational level, public response is the organized activity of individuals. Organizations provide the ability to pool resources and talents, set up a division of labor, hire experts, develop a skilled leadership, take legal action, and so on. A broad range of organizations is possible: ad hoc, existing community groups with an added purpose, nationally-recognized organizations, or government offices and agencies. Two cases of response to radioactive waste disposal sites illustrate these sources and kinds of response and lead to indicators to estimate the nature and level of response. Finally, drawing from the theoretical discussion of the sources and levels of public response, on the estimation techniques, and on the examples, specific coping strategies are developed. These strategies take different forms, based on the nature and level of response …
Date: February 7, 1984
Creator: Payne, B.A.
System: The UNT Digital Library
EPICS System: RSX Implementation Issues (open access)

EPICS System: RSX Implementation Issues

This paper presents implementation details of the Experimental Physics Interactive Control System (EPICS). EPICS is used to control accelerated particle beams for high-energy physics experiments at the Fermi National Accelerator Laboratory. The topics discussed are: interprocessor communication, support of beamline terminals and devices, resource management, mapping, various problems, some solutions to the problems, performance measurement, and modifications and extensions to RSX-11M. This paper is the third of three related papers on the EPICS system. The other two cover (1) the system overview and (2) the system structure and user interface.
Date: February 1, 1984
Creator: Lahey, T. E.; Bartlett, J. F.; Bobbitt, J. S.; Kramper, B. J.; MacKinnon, B. A. & West, R. E.
System: The UNT Digital Library
Alloys in energy development (open access)

Alloys in energy development

The development of new and advanced energy systems often requires the tailoring of new alloys or alloy combinations to meet the novel and often stringent requirements of those systems. Longer life at higher temperatures and stresses in aggressive environments is the most common goal. Alloy theory helps in achieving this goal by suggesting uses of multiphase systems and intermediate phases, where solid solutions were traditionally used. However, the use of materials under non-equilibrium conditions is now quite common - as with rapidly solidified metals - and the application of alloy theory must be modified accordingly. Under certain conditions, as in a reactor core, the rate of approach to equilibrium will be modified; sometimes a quasi-equilibrium is established. Thus an alloy may exhibit enhanced general diffusion at the same time as precipitate particles are being dispersed and solute atoms are being carried to vacancy sinks. We are approaching an understanding of these processes and can begin to model these complex systems.
Date: February 1, 1984
Creator: Frost, B.R.T.
System: The UNT Digital Library
650 mm long liquid hydrogen target for use in a high intensity electron beam (open access)

650 mm long liquid hydrogen target for use in a high intensity electron beam

This paper describes a 650 mm long liquid hydrogen targetr constructed for use in the high intensity electron beam at the Stanford Linear Accelerator Center (SLAC). The main design problem was to construct a target that would permit the heat deposited by the electron beam to be removed rapidly without boiling the hydrogen so as to maintain constant target density for optimum data taking. Design requirements, cosntruction details and operating experience are discussed.
Date: February 1, 1984
Creator: Mark, J.W.
System: The UNT Digital Library
EPICS System: System Structure and User Interface (open access)

EPICS System: System Structure and User Interface

This paper present the user's view of and the general organization of the EPICS control system at Fermilab. Various subsystems of the EPICS control system are discussed. These include the user command language, software protection, the device database, remote computer interfaces, and several application utilities. This paper is related to two other papers on EPICS: an overview paper and a detailed implementation paper.
Date: February 1, 1984
Creator: West, R. E.; Bartlett, J. F.; Bobbitt, J. S.; Lahey, T. E.; Kramper, B. J. & MacKinnon, B. A.
System: The UNT Digital Library
Particel substructure. A common theme of discovery in this century (open access)

Particel substructure. A common theme of discovery in this century

Some example of modern developments in particel physics are given which demonstrate that the fundamental rules of quantum mechanics, applied to all forces in nature as they became understood, have retained their validity. The well-established laws of electricity and magnetism, reformulated in terms of quantum mechanics, have exhibited a truly remarkable numerical agreement between theory and experiment over an enormous range of observation. As experimental techniques have grown from the top of a laboratory bench to the large accelerators of today, the basic components of experimentation have changed vastly in scale but only little in basic function. More important, the motivation of those engaged in this type of experimentation has hardly changed at all.
Date: February 1, 1984
Creator: Panofsky, W.K.H.
System: The UNT Digital Library
Progress report on future accelerators (open access)

Progress report on future accelerators

SLAC intends to pursue high energy physics work in the future along three lines: (1) continued exploration of electron and photon physics on stationary targets; (2) colliding beam physics using electron-positron storage rings; (3) single-pass collider physics with electrons using first the Stanford Linear Collider (SLC) and eventually a single-pass collider operating near the highest practical upper limit for such devices. These long-range plans are discussed.
Date: February 1, 1984
Creator: Panofsky, W.K.H.
System: The UNT Digital Library
Selection of fluids for tritium pumping systems (open access)

Selection of fluids for tritium pumping systems

The degradation characteristics of three types of vacuum pump fluids, polyphenyl ethers, perfluoropolyethers and hydrocarbon oils were reviewed. Fluid selection proved to be a critical factor in the long-term performance of tritium pumping systems and subsequent tritium recovery operations. Thermal degradation and tritium radiolysis of pump fluids produce contaminants which can damage equipment and interfere with tritium recovery operations. General characteristics of these fluids are as follows: polyphenyl ether has outstanding radiation resistance, is very stable under normal diffusion pump conditions, but breaks down in the presence of oxygen at anticipated operating temperatures. Perfluoropolyether fluids are very stable and do not react chemically with most gases. Thermal and mechanical degradation products are inert, but the radiolysis products are very corrosive. Most of the degradation products of hydrogen oils are volatile and the principal radiolysis product is methane. Our studies show that polyphenyl ethers and hydrocarbon oils are the preferred fluids for use in tritium pumping systems. No corrosive materials are formed and most of the degradation products can be removed with suitable filter systems.
Date: February 1, 1984
Creator: Chastagner, P
System: The UNT Digital Library
Geothermal hydrogen sulfide and health in Rotorua, New Zealand (open access)

Geothermal hydrogen sulfide and health in Rotorua, New Zealand

Rotorua, New Zealand, lies inside a volcanic caldera. Natural steam is extensively used for space and water heating, and electric power generation. This report presents results of a preliminary reconnaissance survey of atmospheric H/sub 2/S levels in the area and attempts to relate these levels to health statistics in the region. 5 refs., 8 tabs. (ACR)
Date: February 15, 1984
Creator: Siegel, S. M. & Siegel, B. Z.
System: The UNT Digital Library
Sodium technology activities at HEDL in support of fast reactor development and the FFTF (open access)

Sodium technology activities at HEDL in support of fast reactor development and the FFTF

Activities of the Hanford Engineering Development Laboratory are presented. A brief description of FFTF and some highlights of reactor operations are reviewed. The sodium technology work at HEDL is summarized by discussing several facets of the program and their tie-ins to breeder reactor development.
Date: February 27, 1984
Creator: Atwood, J.M.
System: The UNT Digital Library
Equation of state of strongly coupled plasma mixtures (open access)

Equation of state of strongly coupled plasma mixtures

Thermodynamic properties of strongly coupled (high density) plasmas of mixtures of light elements have been obtained by Monte Carlo simulations. For an assumed uniform charge background the equation of state of ionic mixtures is a simple extension of the one-component plasma EOS. More realistic electron screening effects are treated in linear response theory and with an appropriate electron dielectric function. Results have been obtained for the ionic pair distribution functions, and for the electric microfield distribution.
Date: February 3, 1984
Creator: DeWitt, H.E.
System: The UNT Digital Library
Analysis of surface currents on the CTX mesh flux conserver (open access)

Analysis of surface currents on the CTX mesh flux conserver

The use of discharge cleaning and a mesh structure for the flux conserver have led to hotter, less resistive, spheromak configurations in the CTX experiment. Achievement of these conditions has been accompanied by the appearance of oscillations - most notably seen on magnetic probe signals - that were previously not present. These oscillations are observed both during the sustainment (V/sub gun/ not equal to 0) and the decaying (V/sub gun/ = 0) phases of the discharge and are attributed to the presence of internal kink modes driven by the departure of the plasma current distribution from the Taylor state: j/B = const. Computations suggest that an n-1 mode becomes unstable when j/B increases away from the magnetic axis (sustained spheromak) whereas an n=2 mode becomes unstable for radially decreasing j/B (decaying spheromak). The results reported are from an 80-cm-diameter mesh flux conserver constructed form 0.5''-diameter copper stock. It is of the same oblate rooftop design as used for previous work with a dimension of 40 cm from front to back.
Date: February 1, 1984
Creator: Wright, B.L.
System: The UNT Digital Library
Transport of radon from soil into residences (open access)

Transport of radon from soil into residences

To develop effective monitoring and control programs for indoor radon it is important to understand the causes of the broad range of concentrations that has been observed. Measurements of indoor radon concentration and air-exchange rate in dwellings in several countries indicate that this variability arises largely from differences among structures in the rate of radon entry. Recent evidence further suggests that the major source of indoor radon in many circumstances is the soil adjacent to the building foundation and that pressure-driven flow, rather than molecular diffusion, is the dominant transport process by which radon enters the buildings. Key factors affecting radon transport from soil are radon production in soil, flow-inducing mechanisms, soil permeability, and building substructure type. 24 references, 1 figure.
Date: February 1, 1984
Creator: Nazaroff, W.W. & Nero, A.V.
System: The UNT Digital Library
Toward a non-bureaucratic approach to qualtiy assurance in data processing (open access)

Toward a non-bureaucratic approach to qualtiy assurance in data processing

A quality assurance program for applications software has been developed within the Administrative Data Processing Division at Los Alamos National Laboratory. The goal of this program is that maintainable, flexible, and reliable software be produced in a cost effective manner, thereby increasing user satisfaction. The difference between this program and other, sometimes less than successful Q/A programs is that the developers have attempted to make it flexible and non-bureaucratic. By building in this flexibility, it is hoped that data processing personnel will be more likely to adhere to the established standards. This paper describes the philosophy, development and implementation of this Q/A program. Techniques and the key elements used to ensure adherence to the standards are covered in detail.
Date: February 1, 1984
Creator: Brice, L.; Anderson, L. & Connell, J.
System: The UNT Digital Library
Magnetic fusion: planning for the future (open access)

Magnetic fusion: planning for the future

A brief review of international cooperation in the fusion program is given. The author shares his views on the technical prospects and future potential of fusion as a practical energy source. (MOW)
Date: February 7, 1984
Creator: Fowler, T.K.
System: The UNT Digital Library
Modeling of solid-side mass transfer in desiccant particle beds (open access)

Modeling of solid-side mass transfer in desiccant particle beds

A model is proposed for heat and mass transfer in a packed bed of desiccant particles and accounts for both Knudsen and surface diffusion within the particles. Using the model, predictions are made for the response of thin beds of silica gel particles to a step change in air inlet conditions compared to mental results. The predictions are found to be satisfactory and, in general, superior to those of pseudogas-side controlled models commonly used for the design of desiccant dehumidifiers for solar air conditioning application.
Date: February 1, 1984
Creator: Pesaran, A.A. & Mills, A.F.
System: The UNT Digital Library
Developing models for simulation of pinched-beam dynamics in heavy ion fusion. Revision 1 (open access)

Developing models for simulation of pinched-beam dynamics in heavy ion fusion. Revision 1

For heavy-ion fusion energy applications, Mark and Yu have derived hydrodynamic models for numerical simulation of energetic pinched-beams including self-pinches and external-current pinches. These pinched-beams are applicable to beam propagation in fusion chambers and to the US High Temperature Experiment. The closure of the Mark-Yu model is obtained with adiabatic assumptions mathematically analogous to those of Chew, Goldberger, and Low for MHD. Features of this hydrodynamic beam model are compared with a kinetic treatment.
Date: February 22, 1984
Creator: Boyd, J. K.; Mark, J. W. K.; Sharp, W. M. & Yu, S. S.
System: The UNT Digital Library
Heavy ion inertial fusion: interface between target gain, accelerator phase space and reactor beam transport revisited (open access)

Heavy ion inertial fusion: interface between target gain, accelerator phase space and reactor beam transport revisited

Recently revised estimates of target gain have added additional optimistic inputs to the interface between targets, accelerators and fusion chamber beam transport. But it remains valid that neutralization of the beams in the fusion chamber is useful if ion charge state Z > 1 or if > 1 kA per beamlet is to be propagated. Some engineering and economic considerations favor higher currents.
Date: February 22, 1984
Creator: Barletta, W. A.; Fawley, W. M.; Judd, D. L.; Mark, J. W. K. & Yu, S. S.
System: The UNT Digital Library
LOWER LEVEL INFERENCE CONTROL IN STATISTICAL DATABASE SYSTEMS (open access)

LOWER LEVEL INFERENCE CONTROL IN STATISTICAL DATABASE SYSTEMS

An inference is the process of transforming unclassified data values into confidential data values. Most previous research in inference control has studied the use of statistical aggregates to deduce individual records. However, several other types of inference are also possible. Unknown functional dependencies may be apparent to users who have 'expert' knowledge about the characteristics of a population. Some correlations between attributes may be concluded from 'commonly-known' facts about the world. To counter these threats, security managers should use random sampling of databases of similar populations, as well as expert systems. 'Expert' users of the DATABASE SYSTEM may form inferences from the variable performance of the user interface. Users may observe on-line turn-around time, accounting statistics. the error message received, and the point at which an interactive protocol sequence fails. One may obtain information about the frequency distributions of attribute values, and the validity of data object names from this information. At the back-end of a database system, improved software engineering practices will reduce opportunities to bypass functional units of the database system. The term 'DATA OBJECT' should be expanded to incorporate these data object types which generate new classes of threats. The security of DATABASES and DATABASE SySTEMS must …
Date: February 1, 1984
Creator: Lipton, D. L. & Wong, H. K. T.
System: The UNT Digital Library
Laser separation of hydrogen isotopes: Tritium-from-deuterium recovery (open access)

Laser separation of hydrogen isotopes: Tritium-from-deuterium recovery

Single-step enrichment factors exceeding 15,000 have been observed in the removal of tritium-from-deuterium by 12 ..mu..m laser multiple-photon dissociation of chloroform. The photochemistry and photophysics of this process is discussed along with prospects for implementation of this method in practical heavy water reactor detritiation. 7 refs., 7 figs., 1 tab.
Date: February 1, 1984
Creator: Magnotta, F.; Herman, I.P.; Aldridge, F.T. & Maienschein, J.L.
System: The UNT Digital Library
Calculation of molecular final states and their effect on a precision neutrino mass experiment (open access)

Calculation of molecular final states and their effect on a precision neutrino mass experiment

An experiment to determine the electron neutrino mass is being performed with the precision of a few electron volts by measuring the tritium beta decay energy distribution near the endpoint. At the few electron volt level, a major consideration in the choice of a tritium source is the effect of excited final atomic or molecular states on the beta decay distribution. It is important to choose a source for which the initial and final states can be accurately calculated. Frozen tritium was chosen as the source since the states of molecular tritium and those of the HeT/sup +/ daughter ion have electronic wavefunctions that can be calculated with high accuracy. The effects of final excited states on the neutrino mass determination and the results of these calculations are described.
Date: February 1, 1984
Creator: Fackler, O.; Mugge, M.; Sticker, H.; Winter, N. & Woerner, R.
System: The UNT Digital Library
Volatile organic emissions from adhesives with indoor applications (open access)

Volatile organic emissions from adhesives with indoor applications

Studies have shown that volatile organic compounds (VOC) emitted from building materials are a potentially important source of indoor air pollution. In this study, we investigated emissions of VOC from both solvent- and water-based adhesives. Adhesives were applied to an inert substrate and dried for at least a week. VOC were cryogenically trapped and identified by GC-MS or sorbent trapped, solvent extracted, and quantified by GC-FID. Among the compounds emitted by adhesives were toluene, styrene, and a variety of normal, branched, and cyclic alkanes. The measured emission rates ranged from below the limit of detection for some adhesives to a total alkane emission rate of over 700 ..mu..g g/sup -1/h/sup -1/ for a water-based adhesive. A simple, well-mixed tank model was used to assess the potential impacts of the adhesives studied and to demonstrate that adhesives can be significant sources of VOC. 8 references, 1 figure, 2 tables.
Date: February 1, 1984
Creator: Girman, J. R.; Hodgson, A. T.; Newton, A. S. & Winkes, A. W.
System: The UNT Digital Library