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Distributed data acquisition for BNL802 II: Software

Description: Multiple processes running on a VAX and on VME-based processors allow up to 16 detector sub-systems to run independently or coupled, with an aggregate throughput of 600 Kbytes/sec. VMS facilities are used extensively for command definition, message passing, controlling access to CAMAC and high voltage modules, and maintaining shared data structures.
Date: January 1, 1987
Creator: Watson, W.A. III & LeVine, M.J.
Partner: UNT Libraries Government Documents Department

The CEBAF control system

Description: CEBAF has recently upgraded its accelerator control system to use EPICS, a control system toolkit being developed by a collaboration among laboratories in the US and Europe. The migration to EPICS has taken place during a year of intense commissioning activity, with new and old control systems operating concurrently. Existing CAMAC hardware was preserved by adding a CAMAC serial highway link to VME; newer hardware developments are now primarily in VME. Software is distributed among three tiers of computers: first, workstations and X terminals for operator interfaces and high level applications; second, VME single board computers for distributed access to hardware and for local control processing; third, embedded processors where needed for faster closed loop operation. This system has demonstrated the ability to scale EPICS to controlling thousands of devices, including hundreds of embedded processors, with control distributed among dozens of VME processors executing more than 125,000 EPICS database records. To deal with the large size of the control system, CEBAF has integrated an object oriented database, providing data management capabilities for both low level I/O and high level machine modeling. A new callable interface which is control system independent permits access to live EPICS data, data in other Unix processes, and data contained in the object oriented database.
Date: December 31, 1995
Creator: Watson, W.A. III
Partner: UNT Libraries Government Documents Department

Managing control algorithms with an object-oriented database

Description: The Continuous Electron Beam Accelerator Facility (CEBAF) uses the Experimental Physics and Industrial Control System (EPICS) for accelerator control. In EPICS, the atomic element of a control algorithm is a record. Records are grouped together to form generic applications, for example to control a single magnet. The generic applications are then instantiated for each specific item of machine hardware. Instantiated applications are executed on one of the 30 data acquisition and control computers that are used in the control system. There are roughly 125,000 unique, instantiated records at CEBAF, each associated with a specific piece of hardware. Management of these records in a database simplifies the task of application developers by allowing them to concentrate on algorithmic development instead of instantiation details. In addition, it decouples algorithmic development from the specification of operational parameters, allowing responsibility for those parameters to pass to machine operations staff. CEBAF needed an environment to provide support for development of EPICS database management tools. An object- oriented database (OODB) was chosen for two reasons: higher performance and the ability to smoothly manage objects of different types. 3 refs., 1 fig.
Date: December 31, 1995
Creator: Bickley, M. & Watson, W.
Partner: UNT Libraries Government Documents Department

Proof of principle report for in-tank moisture monitoring using an active neutron probe

Description: This document establishes the proof of principle for use of a neutron probe to measure moisture concentrations in ferrocyanide waste tanks at the Hanford Site. Computer modeling and experiments with a modified neutron probe have shown that neutron-based measurements will provide accurate moisture determinations in Hanford Site ferrocyanide waste tanks. Moisture measurement using neutron moderation and diffusion is an established and extensively documented technology for the well logging industry. Sophisticated neutron transport modeling and calibrations with known moisture concentrations have provided the necessary developmental analyses and validations. Proof of principle was accomplished using the existing in-tank neutron surveillance tool and its support equipment. A minor, inexpensive hardware modification permitted extending the use of the existing probe to moisture measurements. A limited moisture calibration was performed using the modified in-tank neutron probe, and the results were used to adjust model parameters. Scan data from three ferrocyanide tanks have been obtained using the modified in-tank neutron probe, and interpretation of these scans is in progress. Modeling analyses and experimental test results have provided information that will be used to develop a prototype neutron device for improved in-tank moisture monitoring at the Hanford Site. Now a prototype device must be assembled, tested, and fully calibrated in known moisture ferrocyanide waste simulants.
Date: December 1, 1993
Creator: Watson, W. T.
Partner: UNT Libraries Government Documents Department

Managing control algorithms with an object-oriented database

Description: The Continuous Electron Beam Accelerator Facility (CEBAF) uses the Experimental Physics and Industrial Control System (EPICS) for accelerator control. In EPICS, the atomic element of a control algorithm is a record. Records are grouped together to form generic applications, for example to control a single magnet. The generic applications are then instantiated for each specific item of machine hardware. Instantiated applications are executed on one of the 30 data acquisition and control computers that are used in the control system. There are roughly 125,000 unique, instantiated records at CEBAF, each associated with a specific piece of hardware. Management of these records in a database simplifies the task of application developers by allowing them to concentrate on algorithmic development instead of instantiation details. In addition, it decouples algorithmic development from the specification of operational parameters, allowing responsibility for those parameters to pass to machine operations staff. CEBAF needed an environment to provide support for development of EPICS database management tools. An object- oriented database (OODB) was chosen for two reasons: higher performance and the ability to smoothly manage objects of different types. 3 refs., 1 fig.
Date: December 31, 1995
Creator: Bickley, M. & Watson, W.
Partner: UNT Libraries Government Documents Department

A portable accelerator control toolkit

Description: In recent years, the expense of creating good control software has led to a number of collaborative efforts among laboratories to share this cost. The EPICS collaboration is a particularly successful example of this trend. More recently another collaborative effort has addressed the need for sophisticated high level software, including model driven accelerator controls. This work builds upon the CDEV (Common DEVice) software framework, which provides a generic abstraction of a control system, and maps that abstraction onto a number of site-specific control systems including EPICS, the SLAC control system, CERN/PS and others. In principle, it is now possible to create portable accelerator control applications which have no knowledge of the underlying and site-specific control system. Applications based on CDEV now provide a growing suite of tools for accelerator operations, including general purpose displays, an on-line accelerator model, beamline steering, machine status displays incorporating both hardware and model information (such as beam positions overlaid with beta functions) and more. A survey of CDEV compatible portable applications will be presented, as well as plans for future development.
Date: June 1, 1997
Creator: Watson, W.A. III
Partner: UNT Libraries Government Documents Department

Moisture measurement perturbations of the surface neutron probe resulting from waste material properties and arrangements

Description: Experimental tests and computer simulations of a surface neutron moisture measurement probe have been performed to determine the effects that different material variations and arrangements are expected to have upon probe moisture measurement error. This work supplements the existing probe calibration to changes in waste moisture concentration and should aid in the selection of the best in-tank measurement locations.
Date: October 29, 1996
Creator: Watson, W.T.
Partner: UNT Libraries Government Documents Department

Design and implementation of a slow orbit control package at Thomas Jefferson National Accelerator Facility

Description: The authors describe the design and implementation of a C++ client/server based slow orbit and energy control package based on the CDEV software control bus. Several client applications are described and operational experience is given.
Date: June 1, 1997
Creator: Zeijts, J. van; Witherspoon, S. & Watson, W.A.
Partner: UNT Libraries Government Documents Department

Centrally managed name resolution schemes for EPICS

Description: The Experimental Physics and Industrial Control System (EPICS) uses a broadcast method to locate resources and controls distributed across control servers. There are many advantages offered by using a centrally managed name resolution method, in which resources are located using a repository. The suitability of DCE Directory Service as a name resolution method is explored, and results from a study involving DCE are discussed. An alternative nameserver method developed and in use at the Thomas Jefferson national Accelerator Facility (Jefferson Lab) is described and results of integrating this new method with existing EPICS utilities presented. The various methods discussed in the paper are compared.
Date: December 1, 1997
Creator: Jun, D.; Bryan, D. & Watson, W.
Partner: UNT Libraries Government Documents Department

Data archiving in experimental physics

Description: In experimental physics, data is archived from a wide variety of sources and used for a wide variety of purposes. In each of these environments, trade-offs are made between data storage rate, data availability, and retrieval rate. This paper presents archive alternatives in EPICS, the overall archiver design and details on the data collection and retrieval requirements, performance studies, design choices, design alternatives, and measurements made on the beta version of the archiver.
Date: July 1998
Creator: Dalesio, L. R.; Watson, W., III; Bickley, M. & Clausen, M.
Partner: UNT Libraries Government Documents Department

Elemental Analyses of Hanford Surface Neutron Moisture Measurement Calibration Standard Samples

Description: Elemental analyses have been performed on twenty samples taken from the moisture standards prepared to use in performing experimental calibrations of the surface neutron moisture measurement system. These standards consisted of mixtures of sand, hydrated alumina, and boron carbide. Elemental analyses were performed primarily to discover the quantities of any strong thermal neutron absorbers that may have been present in the mixture in unknown trace quantities.
Date: July 31, 1996
Creator: Watson, W.T., Westinghouse Hanford
Partner: UNT Libraries Government Documents Department

The evolution of Jefferson Lab's control system

Description: Thomas Jefferson National Accelerator Facility's (Jefferson Lab) accelerator controls were initially implemented as a proprietary in-house system. During machine commissioning, problems were encountered leading to a decision to migrate to the Experimental Physics and Industrial Controls System (EPICS). Since then, the accelerator and all other laboratory controls have been successfully converted. In addition to implementing Jefferson Lab's controls using EPICS, new data visualization tools have been developed and existing programs have been enhanced with new capabilities. In order to provide a more generic interface for high level applications development, a device abstraction layer, called Common DEVice (CDEV), was implemented. These additions have been made available to other laboratories and are in use at many sites, including some that do not use EPICS. Control System development is not limited to computer scientists; operators, engineers and physicists frequently add capabilities using EPICS, CDEV, Tel/tk, and other tools. These contributions have tailored the control system for many different types of customers. For the future, the authors envision more intelligent processing and more capable tools for data storage, retrieval and visualization.
Date: October 1, 1999
Creator: White, K. S.; Bickley, M. & Watson, W.
Partner: UNT Libraries Government Documents Department

CSER 96-027: storage of cemented plutonium residue containers in 55 gallon drums

Description: A nuclear criticality safety analysis has been performed for the storage of residual plutonium cementation containers, produced at the Plutonium Finishing Plant, in 55 gallon drums. This CSER increases the limit of total plutonium stored in each 55 gallon drum from 100 to 200 grams.
Date: January 20, 1997
Creator: Watson, W.T.
Partner: UNT Libraries Government Documents Department

Integrated on-line accelerator modeling at CEBAF

Description: An on-line accelerator modeling facility is currently under development at CEBAF. The model server, which is integrated with the EPICS control system, provides coupled and 2nd-order matrices for the entire accelerator, and forms the foundation for automated model- based control and diagnostic applications. Four types of machine models are provided, including design, golden or certified, live, and scratch or simulated model. Provisions are also made for the use of multiple lattice modeling programs such as DIMAD, PARMELA, and TLIE. Design and implementation details are discussed. 2 refs., 4 figs.
Date: December 31, 1995
Creator: Bowling, B.A.; Shoaee, H.; Van Zeijts, J.; Witherspoon, S. & Watson, W.
Partner: UNT Libraries Government Documents Department

Upper critical field of Mo-Ni heterostructures

Description: Upper critical field and its anisotropy have been measured on two very short wavelength Mo-Ni heterostructures of different degrees of perfection, lambda = 13.8A (disordered structure) and lambda = 16.6A (layered structure). In both cases the parallel critical field has an unexpected temperature dependence, a large and temperature dependent anisotropy, and over 60% enhancement over the Clogston-Chandrasekhar limit. Data are fit to the Werthamer-Helfand-Hohenberg theory and the spin-orbit scattering times are found to be 1.79 x 10 T s and 2 x 10 T s, respectively.
Date: December 1, 1985
Creator: Uher, C.; Watson, W.J.; Cohn, J.L. & Schuller, I.K.
Partner: UNT Libraries Government Documents Department

Neutron pulse simulation in nuclear waste for waste characterization

Description: The numerical simulations discussed in this paper show how analysis with computer-generated illustrations can be used to explain the concepts and advantages of pulsed neutron systems for tank waste evaluations. Furthermore, the analysis-illustration approach lends itself to parametric studies evaluating design features of hardware before it is fabricated. Nuclear material characteristics of hazardous or toxic simulants can be evaluated before preparing them or finding nontoxic or nonhazardous substitutes that will exhibit similar nuclear properties. Pulsed neutron systems hold significant promise for partial characterization of tank waste. The device could operate in a high background gamma radiation field and provide important information on moisture concentrations, fissionable material contents, and material interfaces quickly and at considerably less cost than obtainable from sample analyses.
Date: December 1, 1993
Creator: Toffer, H.; Watson, W. T. & Roetman, V. E.
Partner: UNT Libraries Government Documents Department

CMLOG: A common message logging system

Description: The Common Message Logging (CMLOG) system is an object-oriented and distributed system that not only allows applications and systems to log data (messages) of any type into a centralized database but also lets applications view incoming messages in real-time or retrieve stored data from the database according to selection rules. It consists of a concurrent Unix server that handles incoming logging or searching messages, a Motif browser that can view incoming messages in real-time or display stored data in the database, a client daemon that buffers and sends logging messages to the server, and libraries that can be used by applications to send data to or retrieve data from the database via the server. This paper presents the design and implementation of the CMLOG system meanwhile it will also address the issue of integration of CMLOG into existing control systems.
Date: December 1, 1997
Creator: Chen, J.; Akers, W.; Bickley, M.; Wu, D. & Watson, W. III
Partner: UNT Libraries Government Documents Department

Operational experience with the CEBAF control system

Description: The CEBAF accelerator at Thomas Jefferson National Accelerator Facility (Jefferson Lab) successfully began its experimental nuclear physics program in November of 1995 and has since surpassed predicted machine availability. Part of this success can be attributed to using the EPICS (Experimental Physics and Industrial Control System) control system toolkit. The CEBAF control system is one of the largest accelerator control system now operating. It controls approximately 338 SRF cavities, 2,300 magnets, 500 beam position monitors and other accelerator devices, such as gun hardware and other beam monitoring devices. All told, the system must be able to access over 125,000 database records. The system has been well received by both operators and the hardware designers. The EPICS utilities have made the task of troubleshooting systems easier. The graphical and test-based creation tools have allowed operators to custom build control screens. In addition, the ability to integrate EPICS with other software packages, such as Tcl/Tk, has allowed physicists to quickly prototype high-level application programs, and to provide GUI front ends for command line driven tools. Specific examples of the control system applications are presented in the areas of energy and orbit control, cavity tuning and accelerator tune up diagnostics.
Date: October 1, 1996
Creator: Hovater, C.; Chowdhary, M.; Karn, J.; Tiefenback, M.; Zeijts, J. van & Watson, W.
Partner: UNT Libraries Government Documents Department

Results of experimental tests and calibrations of the surface neutron moisture measurement probe

Description: The surface neutron moisture probe has been tested both to demonstrate that is is able to operate in the expected in-tank temperature and gamma-ray fields and to provide detector responses to known moisture concentration materials. The probe will properly function in a simultaneous high temperature (80 degrees C) and high gamma radiation field (210 rad/hr)environment. Comparisons between computer model predicted and experimentally measured detector responses to changes in moisture provide a basis for the probe calibration to in-tank moisture concentrations.
Date: August 13, 1996
Creator: Watson, W.T. & Bussell, J.H., Westinghouse Hanford
Partner: UNT Libraries Government Documents Department

A prototype fast feedback system for energy lock at CEBAF

Description: The beam energy at CEBAF must be controlled accurately against phase and gradient fluctuations in RF cavities in order to achieve a 2.5 {times} 10{sup {minus}5} relative energy spread. A prototype fast feedback system based on the concepts of Modern Control Theory has been implemented in the CEBAF control system to function as an energy lock. Measurements performed during the pulsed mode operations indicate presence of noise components at 4 Hz and 12 Hz on beam energy. This fast feedback prototype operates at 60 Hz rate and is integrated with EPICS. This paper describes the implementation of the fast feedback prototype, and operational experience with this system at CEBAF. 5 refs., 3 figs.
Date: December 31, 1995
Creator: Chowdhary, M.; Krafft, G.A.; Shoaee, H.; Simrock, S.N. & Watson, W.A.
Partner: UNT Libraries Government Documents Department

A Directory Service for the CERN PS/SL Java Programming Interface

Description: The CERN PS and SL accelerator control groups developed a common application programming interface (API) in Java [1]. Part of this API is a directory service that provide information about the underlying hardware and software. With this information, it is possible to write generic programs that do general actions on lists of devices without hard coding of device names. And, starting from a device name, full details about related devices, the device itself and its class and properties, can be obtained, including the meaning of bits and bit-patterns in status words. The interface definition is independent of any implementation but a reference implementation is provided using Java Database Connectivity (JDBC) against a set of tables in a relational database. Data from very different systems can be brought together and presented in a uniform way to the user. The full potential of the directory service is reached when it is used in software components (Java Beans).
Date: October 1, 1999
Creator: Cuperus, J.; Charrue, P.; DiMaio, F.; Kostro, K. & Watson, W.
Partner: UNT Libraries Government Documents Department

Orbit correction using virtual monitors at Jefferson Lab

Description: An orbit correction algorithm is developed to achieve the following goals for the CEBAF accelerator at Jefferson Lab.: (1) Pre-processing of orbit input to account for estimated misalignment and monitor errors. (2) Automatic elimination of blind spots caused by response matrix degeneracy. (3) Transparency of exception handling to interchangeable generic steering engines. (4) CEBAF-specific demands on control of injection angle, path length, orbit effects on optics, simultaneous multiple pass steering, and orbit control at un-monitored locations. All of the above can be accomplished by the introduction of virtual monitors into the processed input orbit, whose theoretical basis is to be discussed in this report. Implementation of all or part of these features and operational experience during the CEBAF variable energy runs will also be discussed.
Date: August 1, 1997
Creator: Chao, Yu-Chiu; Bowling, B.; Witherspoon, S.; Zeijts, J. van & Watson, W.A. III
Partner: UNT Libraries Government Documents Department