Vacuum Bellows, Vacuum Piping, Cryogenic Break, and Copper Joint Failure Rate Estimates for ITER Design Use

Energy Technology Data Exchange (ETDEWEB)

L. C. Cadwallader

2010-06-01

The ITER international project design teams are working to produce an engineering design in preparation for construction of the International Thermonuclear Experimental Reactor (ITER) tokamak. During the course of this work, questions have arisen in regard to safety barriers and equipment reliability as important facets of system design. The vacuum system designers have asked several questions about the reliability of vacuum bellows and vacuum piping. The vessel design team has asked about the reliability of electrical breaks and copper-copper joints used in cryogenic piping. Research into operating experiences of similar equipment has been performed to determine representative failure rates for these components. The following chapters give the research results and the findings for vacuum system bellows, power plant stainless steel piping (amended to represent vacuum system piping), cryogenic system electrical insulating breaks, and copper joints.

Reconfiguration of NASA GRC's Vacuum Facility 6 for Testing of Advanced Electric Propulsion System (AEPS) Hardware

Science.gov (United States)

Peterson, Peter Y.; Kamhawi, Hani; Huang, Wensheng; Yim, John T.; Haag, Thomas W.; Mackey, Jonathan A.; McVetta, Michael S.; Sorrelle, Luke T.; Tomsik, Thomas M.; Gilligan, Ryan P.;

Hardware resilience: a way to achieve reliability and safety in new nuclear reactors I and C systems

Energy Technology Data Exchange (ETDEWEB)

Farias, Marcos S.; Carvalho, Paulo Victor R. de, E-mail: msantana@ien.gov.br, E-mail: paulov@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Divisão de Engenharia Nuclear. Serviço de Instrumentação; Nedjah, Nadia, E-mail: nadia@eng.uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Departamento de Engenharia de Sistemas e Telecomunicações

2017-07-01

The idea that systems have a property called ‘resilience’ has emerged in the last decade [1]. In this paper we intend to bring the idea of resilient systems for the hardware applied in safety-critical systems, such as the new nuclear reactor instrumentation and control (I and C) systems. The new systems (based in hardware description language (HDL) programmable devices) have been developed in response to the obsolescence of old analog technologies and current microprocessor-based digital technologies. Although HDL programmable devices have been widely used in various other industries for decades, they are still very new in nuclear reactors systems, which can be seen as a challenge and risk in the safety analyses and licensing efforts for utilities and designers. The goal of this work is to develop and test hardware architectures to tolerate the occurrence of faults, including multiple faults, minimizing the impact of the recovery process on system availability. Basic concepts of resilience in complex systems, as 'return to equilibrium', 'robustness' and 'extra adaptive capacity' were analyzed from the point of view of hardware architectures, leading to linkages between concepts and methods for resilience using an approach that increases reliability and simplifies the licensing process of systems based in HDL programmable devices in nuclear plants. (author)

Hardware resilience: a way to achieve reliability and safety in new nuclear reactors I and C systems

International Nuclear Information System (INIS)

Farias, Marcos S.; Carvalho, Paulo Victor R. de; Nedjah, Nadia

2017-01-01

The idea that systems have a property called ‘resilience’ has emerged in the last decade [1]. In this paper we intend to bring the idea of resilient systems for the hardware applied in safety-critical systems, such as the new nuclear reactor instrumentation and control (I and C) systems. The new systems (based in hardware description language (HDL) programmable devices) have been developed in response to the obsolescence of old analog technologies and current microprocessor-based digital technologies. Although HDL programmable devices have been widely used in various other industries for decades, they are still very new in nuclear reactors systems, which can be seen as a challenge and risk in the safety analyses and licensing efforts for utilities and designers. The goal of this work is to develop and test hardware architectures to tolerate the occurrence of faults, including multiple faults, minimizing the impact of the recovery process on system availability. Basic concepts of resilience in complex systems, as 'return to equilibrium', 'robustness' and 'extra adaptive capacity' were analyzed from the point of view of hardware architectures, leading to linkages between concepts and methods for resilience using an approach that increases reliability and simplifies the licensing process of systems based in HDL programmable devices in nuclear plants. (author)

Hardware based redundant multi-threading inside a GPU for improved reliability

Science.gov (United States)

Sridharan, Vilas; Gurumurthi, Sudhanva

2015-05-05

A system and method for verifying computation output using computer hardware are provided. Instances of computation are generated and processed on hardware-based processors. As instances of computation are processed, each instance of computation receives a load accessible to other instances of computation. Instances of output are generated by processing the instances of computation. The instances of output are verified against each other in a hardware based processor to ensure accuracy of the output.

Development and Testing of an ISRU Soil Mechanics Vacuum Test Facility

Science.gov (United States)

Kleinhenz, Julie E.; Wilkinson, R. Allen

2014-01-01

For extraterrestrial missions, earth based testing in relevant environments is key to successful hardware development. This is true for both early component level development and system level integration. For In-Situ Resource Utilization (ISRU) on the moon, hardware must interface with the surface material, or regolith, in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, properly conditioned bed of lunar regolith simulant. However, in earth-based granular media, such as lunar regolith simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. A mid-size chamber (3.66 m tall, 1.5 m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64 m deep by 0.914 m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types were used. Data obtained from an electric cone penetrometer can be used to determine strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off-gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5 Torr, regardless of the pump rate. The slow off-gassing of the soil at low pressure lead to long test times; a full week to reach 10(exp -5) Torr. Robotic soil manipulation would enable multiple ISRU hardware test within the same vacuum cycle. The feasibility of a robotically controlled auger and tamper was explored at vacuum conditions.

Vacuum-integrated electrospray deposition for highly reliable polymer thin film.

Science.gov (United States)

Park, Soohyung; Lee, Younjoo; Yi, Yeonjin

2012-10-01

Vacuum electrospray deposition (ESD) equipment was designed to prepare polymer thin films. The polymer solution can be injected directly into vacuum system through multi-stage pumping line, so that the solvent residues and ambient contaminants are highly reduced. To test the performance of ESD system, we fabricated organic photovoltaic cells (OPVCs) by injecting polymer solution directly onto the substrate inside a high vacuum chamber. The OPVC fabricated has the structure of Al∕P3HT:PCBM∕PEDOT:PSS∕ITO and was optimized by varying the speed of solution injection and concentration of the solution. The power conversion efficiency (PCE) of the optimized OPVC is 3.14% under AM 1.5G irradiation without any buffer layer at the cathode side. To test the advantages of the vacuum ESD, we exposed the device to atmosphere between the deposition steps of the active layer and cathode. This showed that the PCE of the vacuum processed device is 24% higher than that of the air exposed device and confirms the advantages of the vacuum prepared polymer film for high performance devices.

Re-circulating linac vacuum system

International Nuclear Information System (INIS)

Wells, Russell P.; Corlett, John N.; Zholents, Alexander A.

2003-01-01

The vacuum system for a proposed 2.5 GeV, 10ΜA recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10ΜA average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing

A study of digital hardware architectures for nuclear reactors protection systems applications - reliability and safety analysis methods; Um estudo de arquiteturas de hardware para aplicacao em sistemas digitais de protecao de reatores nucleares - metodos de analise de confiabilidade e seguranca

Energy Technology Data Exchange (ETDEWEB)

Benko, Pedro Luiz

1997-07-01

A study of digital hardware architectures, including experience in many countries, topologies and solutions to interface circuits for protection systems of nuclear reactors is presented. Methods for developing digital systems architectures based on fault tolerant and safety requirements is proposed. Directives for assessing such conditions are suggested. Techniques and the most common tools employed in reliability, safety evaluation and modeling of hardware architectures is also presented. Markov chain modeling is used to evaluate the reliability of redundant architectures. In order to estimate software quality, several mechanisms to be used in design, specification, and validation and verification (V and V) procedures are suggested. A digital protection system architecture has been analyzed as a case study. (author)

ISRU Soil Mechanics Vacuum Facility: Soil Bin Preparation and Simulant Strength Characterization

Science.gov (United States)

Kleinhenz, Julie; Wilkinson, Allen

2012-01-01

Testing in relevant environments is key to exploration mission hardware development. This is true on both the component level (in early development) and system level (in late development stages). During ISRU missions the hardware will interface with the soil (digging, roving, etc) in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, conditioned simulant bed. However, in earth-based granular media, such as lunar soil simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. The Vacuum Facility #13, a mid-size chamber (3.66m tall, 1.5m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64m deep by 0.914m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types have been used. An electric cone penetrometer was used to measure simulant strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5Torr, regardless of the pump rate. However, slow off gassing of the soil lead to long test times, a full week, to reach 10-5Torr. This work highlights the need for robotic machine-simulant hardware and operations in vacuum to expeditiously perform (sub-)systems tests.

Experience with the TRIUMF Main Tank Vacuum Control System

International Nuclear Information System (INIS)

Sarkar, S.; Yandon, J.C.; Sievers, W.; Bennett, P.; Gurd, D.P.; Harmer, P.; Nelson, J.

1993-01-01

The TRIUMF Main Tank Vacuum Control System was upgraded in 1984. The earlier system, which consisted of a collection of hardwired relay logic boxes housed in three standard instrumentation racks, was replaced with a compact and flexible microprocessor-based control system. The user interface, previously distributed over the three racks, was consolidated into a single hardwired control and mimic panel. Since 1984, the Main Tank Vacuum System has undergone a series of changes in configuration and vacuum pumping hardware with necessary changes being implemented in the control system logic. Corresponding changes to the user interface were sometimes difficult to implement and in time exhausted the spare input/output capacity which had been built into the panel. The availability of inexpensive personal computers with adequate graphics capability and the ease of modifying, or adding to a programmable user interface precipitated the retirement of the hardwired panel and its replacement by a PC-based graphics user interface. System configuration, safety considerations, the hardware and the software implementation using the open-quote C close-quote programming language are described. The evolution of the control system and its performance, both over the years and in adapting to the vacuum system changes, are discussed

PC driven integrated vacuum system

International Nuclear Information System (INIS)

Curuia, M.; Culcer, M.; Brandea, I.; Anghel, M.

2001-01-01

The paper presents a integrated vacuum system which was designed and manufactured in our institute. The main parts of this system are the power supply unit for turbo-melecular pumps and the vacuummeter. Both parts of the system are driven by means of a personal computer using a serial communication, according to the RS 232 hardware standard.(author)

Vacuum mechatronics

Science.gov (United States)

Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

1989-01-01

The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

Vacuum science, technology, and applications

CERN Document Server

Naik, Pramod K

2018-01-01

Vacuum plays an important role in science and technology. The study of interaction of charged particles, neutrals and radiation with each other and with solid surfaces requires a vacuum environment for reliable investigations. Vacuum has contributed immensely to advancements made in nuclear science, space, metallurgy, electrical/electronic technology, chemical engineering, transportation, robotics and many other fields. This book is intended to assist students, scientists, technicians and engineers to understand the basics of vacuum science and technology for application in their projects. The fundamental theories, concepts, devices, applications, and key inventions are discussed.

Hardware and software maintenance strategies for upgrading vintage computers

International Nuclear Information System (INIS)

Wang, B.C.; Buijs, W.J.; Banting, R.D.

1992-01-01

The paper focuses on the maintenance of the computer hardware and software for digital control computers (DCC). Specific design and problems related to various maintenance strategies are reviewed. A foundation was required for a reliable computer maintenance and upgrading program to provide operation of the DCC with high availability and reliability for 40 years. This involved a carefully planned and executed maintenance and upgrading program, involving complementary hardware and software strategies. The computer system was designed on a modular basis, with large sections easily replaceable, to facilitate maintenance and improve availability of the system. Advances in computer hardware have made it possible to replace DCC peripheral devices with reliable, inexpensive, and widely available components from PC-based systems (PC = personal computer). By providing a high speed link from the DCC to a PC, it is now possible to use many commercial software packages to process data from the plant. 1 fig

Requirements and guidelines for NSLS experimental beam line vacuum systems: Revision A

International Nuclear Information System (INIS)

Foerster, C.; Halama, H.; Thomlinson, W.

1986-10-01

Requirements are provided for NSLS beam line front ends and vacuum interlocks. Guidelines are provided for UHV beam line vacuum systems, including materials, vacuum hardware (pumps, valves, and flanges), acoustic delay lines and beam line fast valves, instrumentation, fabrication and testing, and the NSLS cleaning facility. Also discussed are the design review for experimenters' equipment that would be connected to the NSLS and acceptance tests for any beam line to be connected with the ring vacuum. Also appended are a description of the acoustic delay line as well as the NSLS vacuum standards and NSLS procedures

Hardware-oriented reliability centered maintenance for the diesel generators of Wolsong unit 1

International Nuclear Information System (INIS)

Bae, Sang Min; Park, Jin Hee; Kim, Tae Woon; Lee, Yoon Kee; Song, Jin Bae

1997-01-01

The DGs (Diesel Generators) in NPP (Nuclear Power Plant) has been used for the emergency electric power source to shut down the nuclear reactor safely in case of station blackout. The RCM (Reliability Centered Maintenance) has been applied to DGs for increasing the safety of NPP. The structured defects of DG were not remedied by the improvement of maintenance method. As the first stage of RCM, to find the structured defects, its failure modes were searched and analyzed through the ten year maintenance information. The structured defects such as the air compressor, the lubricating oil pressure, and the insufficient load were the root causes of main failures. The air reservoir reinstallation, the lubricating oil tube modification, the load bank installation, and the qualitative instrumentation were the solutions for the hardware oriented RCM of DGs. There remains the software oriented RCM such as the rejection of useless maintenance, the preventive maintenance, the database of maintenance information, and the predictive maintenance

X-Window for process control in a mixed hardware environment

International Nuclear Information System (INIS)

Clausen, M.; Rehlich, K.

1992-01-01

X-Window is a common standard for display purposes on the current workstations. The possibility to create more than one window on a single screen enables the operators to gain more information about the process. Multiple windows from different control systems using mixed hardware is one of the problems this paper will describe. The experience shows that X-Window is a standard per definition, but not in any case. But it is an excellent tool to separate data-acquisition and display from each other over long distances using different types of hardware and software for communications and display. Our experience with X-Window displays for the cryogenic control system and the vacuum control system at HERA on DEC and SUN hardware will be described. (author)

The vacuum system of the Karlsruhe magnetic spectrograph 'Little John'

International Nuclear Information System (INIS)

Buschmann, J.; Gils, H.J.; Jelitto, H.; Krisch, J.; Ludwig, G.; Manger, D.; Rebel, H.; Seith, W.; Zagromski, S.

1985-02-01

The vacuum equipment of the magnetic spectrograph Little John is described. The system is characterized by the following special features: The sliding exit flange of the target chamber can be moved to the desired angle of observation without affecting the high vacuum. The pressure maintained is less by a factor of ten than the pressure in the incoming beam tubing. The vacuum system is divided into several separate pumping sections. Ground loops are strictly avoided. All actual states of relevance are fed back to the control panels. The vacuum installation is protected by hardware interlocking systems as well as by a real time program written in FORTRAN in cooperation with CAMAC interfacing. (orig.) [de

Reliability of software

International Nuclear Information System (INIS)

Kopetz, H.

1980-01-01

Common factors and differences in the reliability of hardware and software; reliability increase by means of methods of software redundancy. Maintenance of software for long term operating behavior. (HP) [de

Field Programmable Gate Array Reliability Analysis Guidelines for Launch Vehicle Reliability Block Diagrams

Science.gov (United States)

Al Hassan, Mohammad; Britton, Paul; Hatfield, Glen Spencer; Novack, Steven D.

2017-01-01

Field Programmable Gate Arrays (FPGAs) integrated circuits (IC) are one of the key electronic components in today's sophisticated launch and space vehicle complex avionic systems, largely due to their superb reprogrammable and reconfigurable capabilities combined with relatively low non-recurring engineering costs (NRE) and short design cycle. Consequently, FPGAs are prevalent ICs in communication protocols and control signal commands. This paper will identify reliability concerns and high level guidelines to estimate FPGA total failure rates in a launch vehicle application. The paper will discuss hardware, hardware description language, and radiation induced failures. The hardware contribution of the approach accounts for physical failures of the IC. The hardware description language portion will discuss the high level FPGA programming languages and software/code reliability growth. The radiation portion will discuss FPGA susceptibility to space environment radiation.

Some remarks on software reliability

International Nuclear Information System (INIS)

Gonzalez Hernando, J.; Sanchez Izquierdo, J.

1978-01-01

Trend in modern NPPCI is toward a broad use of programmable elements. Some aspects concerning present status of programmable digital systems reliability are reported. Basic differences between software and hardware concept require a specific approach in all the reliability topics concerning software systems. The software reliability theory was initialy developed upon hardware models analogies. At present this approach is changing and specific models are being developed. The growing use of programmable systems necessitates emphasizing the importance of more adequate regulatory requirements to include this technology in NPPCI. (author)

A vacuum microgripping tool with integrated vibration releasing capability

Energy Technology Data Exchange (ETDEWEB)

Rong, Weibin; Fan, Zenghua, E-mail: zenghua-fan@163.com; Wang, Lefeng; Xie, Hui; Sun, Lining [State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, Heilongjiang (China)

2014-08-01

Pick-and-place of micro-objects is a basic task in various micromanipulation demands. Reliable releasing of micro-objects is usually disturbed due to strong scale effects. This paper focuses on a vacuum micro-gripper with vibration releasing functionality, which was designed and assembled for reliable micromanipulation tasks. Accordingly, a vibration releasing strategy of implementing a piezoelectric actuator on the vacuum microgripping tool is presented to address the releasing problem. The releasing mechanism was illustrated using a dynamic micro contact model. This model was developed via theoretical analysis, simulations and pull-off force measurement using atomic force microscopy. Micromanipulation experiments were conducted to verify the performance of the vacuum micro-gripper. The results show that, with the assistance of the vibration releasing, the vacuum microgripping tool can achieve reliable release of micro-objects. A releasing location accuracy of 4.5±0.5 μm and a successful releasing rate of around 100% (which is based on 110 trials) were achieved for manipulating polystyrene microspheres with radius of 35–100 μm.

A vacuum microgripping tool with integrated vibration releasing capability

International Nuclear Information System (INIS)

Rong, Weibin; Fan, Zenghua; Wang, Lefeng; Xie, Hui; Sun, Lining

2014-01-01

Pick-and-place of micro-objects is a basic task in various micromanipulation demands. Reliable releasing of micro-objects is usually disturbed due to strong scale effects. This paper focuses on a vacuum micro-gripper with vibration releasing functionality, which was designed and assembled for reliable micromanipulation tasks. Accordingly, a vibration releasing strategy of implementing a piezoelectric actuator on the vacuum microgripping tool is presented to address the releasing problem. The releasing mechanism was illustrated using a dynamic micro contact model. This model was developed via theoretical analysis, simulations and pull-off force measurement using atomic force microscopy. Micromanipulation experiments were conducted to verify the performance of the vacuum micro-gripper. The results show that, with the assistance of the vibration releasing, the vacuum microgripping tool can achieve reliable release of micro-objects. A releasing location accuracy of 4.5±0.5 μm and a successful releasing rate of around 100% (which is based on 110 trials) were achieved for manipulating polystyrene microspheres with radius of 35–100 μm

Technical specification for vacuum systems

International Nuclear Information System (INIS)

Khaw, J.

1987-01-01

The vacuum systems at the Stanford Linear Accelerator Center (SLAC) are primarily of all-metal construction and operate at pressures from 10 -5 to 10 -11 Torr. The primary gas loads during operation result from thermal desorption and beam-induced desorption from the vacuum chamber walls. These desorption rates can be extremely high in the case of hydrocarbons and other contaminants. These specifications place a major emphasis on eliminating contamination sources. The specifications and procedures have been written to insure the cleanliness and vacuum integrity of all SLAC vacuum systems, and to assist personnel involved with SLAC vacuum systems in choosing and designing components that are compatible with existing systems and meet the quality and reliability of SLAC vacuum standards. The specification includes requirements on design, procurement, fabrication, chemical cleaning, clean room practices, welding and brazing, helium leak testing, residual gas analyzer testing, bakeout, venting, and pumpdown. Also appended are specifications regarding acceptable vendors, isopropyl alcohol, bakeable valve cleaning procedure, mechanical engineering safety inspection, notes on synchrotron radiation, and specifications of numerous individual components

Vacuum-plasma coverings on the aircraft

International Nuclear Information System (INIS)

Shvetsov, V.D.; Teksin, Eh.K.; Lysyak, A.A.

1998-01-01

In the article are considered the perspectives of vacuum-plasma coverings using for engine components protection. The influence of operating factors on the durability of components which has the vacuum-plasma coverings is show.Leads in using the concept of informational parameter of quality.The recommendation about organization of engine with abolished components maintenance by methods of flyable conditions or reliability level are given

In-vacuum long-wavelength macromolecular crystallography.

Science.gov (United States)

Wagner, Armin; Duman, Ramona; Henderson, Keith; Mykhaylyk, Vitaliy

2016-03-01

Structure solution based on the weak anomalous signal from native (protein and DNA) crystals is increasingly being attempted as part of synchrotron experiments. Maximizing the measurable anomalous signal by collecting diffraction data at longer wavelengths presents a series of technical challenges caused by the increased absorption of X-rays and larger diffraction angles. A new beamline at Diamond Light Source has been built specifically for collecting data at wavelengths beyond the capability of other synchrotron macromolecular crystallography beamlines. Here, the theoretical considerations in support of the long-wavelength beamline are outlined and the in-vacuum design of the endstation is discussed, as well as other hardware features aimed at enhancing the accuracy of the diffraction data. The first commissioning results, representing the first in-vacuum protein structure solution, demonstrate the promising potential of the beamline.

Reliability Estimation for Digital Instrument/Control System

Energy Technology Data Exchange (ETDEWEB)

Yang, Yaguang; Sydnor, Russell [U.S. Nuclear Regulatory Commission, Washington, D.C. (United States)

2011-08-15

Digital instrumentation and controls (DI and C) systems are widely adopted in various industries because of their flexibility and ability to implement various functions that can be used to automatically monitor, analyze, and control complicated systems. It is anticipated that the DI and C will replace the traditional analog instrumentation and controls (AI and C) systems in all future nuclear reactor designs. There is an increasing interest for reliability and risk analyses for safety critical DI and C systems in regulatory organizations, such as The United States Nuclear Regulatory Commission. Developing reliability models and reliability estimation methods for digital reactor control and protection systems will involve every part of the DI and C system, such as sensors, signal conditioning and processing components, transmission lines and digital communication systems, D/A and A/D converters, computer system, signal processing software, control and protection software, power supply system, and actuators. Some of these components are hardware, such as sensors and actuators, their failure mechanisms are well understood, and the traditional reliability model and estimation methods can be directly applied. But many of these components are firmware which has software embedded in the hardware, and software needs special consideration because its failure mechanism is unique, and the reliability estimation method for a software system will be different from the ones used for hardware systems. In this paper, we will propose a reliability estimation method for the entire DI and C system reliability using a recently developed software reliability estimation method and a traditional hardware reliability estimation method.

Reliability Estimation for Digital Instrument/Control System

International Nuclear Information System (INIS)

Yang, Yaguang; Sydnor, Russell

2011-01-01

Digital instrumentation and controls (DI and C) systems are widely adopted in various industries because of their flexibility and ability to implement various functions that can be used to automatically monitor, analyze, and control complicated systems. It is anticipated that the DI and C will replace the traditional analog instrumentation and controls (AI and C) systems in all future nuclear reactor designs. There is an increasing interest for reliability and risk analyses for safety critical DI and C systems in regulatory organizations, such as The United States Nuclear Regulatory Commission. Developing reliability models and reliability estimation methods for digital reactor control and protection systems will involve every part of the DI and C system, such as sensors, signal conditioning and processing components, transmission lines and digital communication systems, D/A and A/D converters, computer system, signal processing software, control and protection software, power supply system, and actuators. Some of these components are hardware, such as sensors and actuators, their failure mechanisms are well understood, and the traditional reliability model and estimation methods can be directly applied. But many of these components are firmware which has software embedded in the hardware, and software needs special consideration because its failure mechanism is unique, and the reliability estimation method for a software system will be different from the ones used for hardware systems. In this paper, we will propose a reliability estimation method for the entire DI and C system reliability using a recently developed software reliability estimation method and a traditional hardware reliability estimation method

Survey of hardware supported by the Control System at the Advanced Photon Source

International Nuclear Information System (INIS)

Coulter, K.J.; Nawrocki, G.J.

1993-01-01

The Experimental Physics and Industrial control System (EPICS) has been under development at Los Alamos and Argonne National Laboratories for over six years. A wide variety of instrumentation is now supported. This presentation will give an overview of the types of hardware and subsystems which are currently supported and will discuss future plans for addressing additional hardware requirements at the APS. Supported systems to be discussed include: motion control, vacuum pump control and system monitoring, standard laboratory instrumentation (ADCs, DVMs, pulse generators, etc.), image processing, discrete binary and analog I/O, and standard temperature, pressure and flow monitoring

The contribution of instrumentation and control software to system reliability

International Nuclear Information System (INIS)

Fryer, M.O.

1984-01-01

Advanced instrumentation and control systems are usually implemented using computers that monitor the instrumentation and issue commands to control elements. The control commands are based on instrument readings and software control logic. The reliability of the total system will be affected by the software design. When comparing software designs, an evaluation of how each design can contribute to the reliability of the system is desirable. Unfortunately, the science of reliability assessment of combined hardware and software systems is in its infancy. Reliability assessment of combined hardware/software systems is often based on over-simplified assumptions about software behavior. A new method of reliability assessment of combined software/hardware systems is presented. The method is based on a procedure called fault tree analysis which determines how component failures can contribute to system failure. Fault tree analysis is a well developed method for reliability assessment of hardware systems and produces quantitative estimates of failure probability based on component failure rates. It is shown how software control logic can be mapped into a fault tree that depicts both software and hardware contributions to system failure. The new method is important because it provides a way for quantitatively evaluating the reliability contribution of software designs. In many applications, this can help guide designers in producing safer and more reliable systems. An application to the nuclear power research industry is discussed

High Reliability R-10 Windows Using Vacuum Insulating Glass Units

Energy Technology Data Exchange (ETDEWEB)

Stark, David

2012-08-16

The objective of this effort was for EverSealed Windows (“EverSealed” or “ESW”) to design, assemble, thermally and environmentally test and demonstrate a Vacuum Insulating Glass Unit (“VIGU” or “VIG”) that would enable a whole window to meet or exceed the an R-10 insulating value (U-factor ≤ 0.1). To produce a VIGU that could withstand any North American environment, ESW believed it needed to design, produce and use a flexible edge seal system. This is because a rigid edge seal, used by all other know VIG producers and developers, limits the size and/or thermal environment of the VIG to where the unit is not practical for typical IG sizes and cannot withstand severe outdoor environments. The rigid-sealed VIG’s use would be limited to mild climates where it would not have a reasonable economic payback when compared to traditional double-pane or triple-pane IGs. ESW’s goals, in addition to achieving a sufficiently high R-value to enable a whole window to achieve R-10, included creating a VIG design that could be produced for a cost equal to or lower than a traditional triple-pane IG (low-e, argon filled). ESW achieved these goals. EverSealed produced, tested and demonstrated a flexible edge-seal VIG that had an R-13 insulating value and the edge-seal system durability to operate reliably for at least 40 years in the harshest climates of North America.

A Hybrid Hardware and Software Component Architecture for Embedded System Design

Science.gov (United States)

Marcondes, Hugo; Fröhlich, Antônio Augusto

Embedded systems are increasing in complexity, while several metrics such as time-to-market, reliability, safety and performance should be considered during the design of such systems. A component-based design which enables the migration of its components between hardware and software can cope to achieve such metrics. To enable that, we define hybrid hardware and software components as a development artifact that can be deployed by different combinations of hardware and software elements. In this paper, we present an architecture for developing such components in order to construct a repository of components that can migrate between the hardware and software domains to meet the design system requirements.

Hardware for Accelerating N-Modular Redundant Systems for High-Reliability Computing

Science.gov (United States)

Dobbs, Carl, Sr.

2012-01-01

A hardware unit has been designed that reduces the cost, in terms of performance and power consumption, for implementing N-modular redundancy (NMR) in a multiprocessor device. The innovation monitors transactions to memory, and calculates a form of sumcheck on-the-fly, thereby relieving the processors of calculating the sumcheck in software

Development of a highly reliable CRT processor

International Nuclear Information System (INIS)

Shimizu, Tomoya; Saiki, Akira; Hirai, Kenji; Jota, Masayoshi; Fujii, Mikiya

1996-01-01

Although CRT processors have been employed by the main control board to reduce the operator's workload during monitoring, the control systems are still operated by hardware switches. For further advancement, direct controller operation through a display device is expected. A CRT processor providing direct controller operation must be as reliable as the hardware switches are. The authors are developing a new type of highly reliable CRT processor that enables direct controller operations. In this paper, we discuss the design principles behind a highly reliable CRT processor. The principles are defined by studies of software reliability and of the functional reliability of the monitoring and operation systems. The functional configuration of an advanced CRT processor is also addressed. (author)

Utilizing IXP1200 hardware and software for packet filtering

OpenAIRE

Lindholm, Jeffery L.

2004-01-01

As network processors have advanced in speed and efficiency they have become more and more complex in both hardware and software configurations. Intel's IXP1200 is one of these new network processors that has been given to different universities worldwide to conduct research on. The goal of this thesis is to take the first step in starting that research by providing a stable system that can provide a reliable platform for further research. This thesis introduces the fundamental hardware of In...

PC driven integrated vacuum system

International Nuclear Information System (INIS)

Curuia, Marian; Culcer, Mihai; Brandea, Iulian; Anghel, Mihai

2001-01-01

The monitoring of industrial plants by virtual instrumentation represents the most modern trend in the domain of electronic equipment. The integrated vacuum system presented here has several facilities, including the automated data storing of measurement results on hard disk and providing warning messages for operators when the measured parameters are lower or higher upper than the fixed values. The system can also work stand-alone, receiving the commands from the keyboards placed on his front panel but, when it is included in a automation complex system, a remote control from PC is necessary . Both parts of the system, power supply unit for turbo-molecular pump and the vacuum gage, are controlled by an 80C31 microcontroller. Because this microcontroller has a built-in circuitry for a serial communication, we established a serial communication between the PC and the power supply unit for turbo-molecular pump and the vacuum gage, according to the RS-232 hardware standard. As software, after careful evaluation of several options, we chose to develop a hybrid software packing using two different software development tools: LabVIEW, and assembly language. We chose LabVIEW because it is dedicated to data acquisition and communications, containing libraries for data collection, analysis, display and storage. (authors)

Reliability Growth in Space Life Support Systems

Science.gov (United States)

Jones, Harry W.

2014-01-01

A hardware system's failure rate often increases over time due to wear and aging, but not always. Some systems instead show reliability growth, a decreasing failure rate with time, due to effective failure analysis and remedial hardware upgrades. Reliability grows when failure causes are removed by improved design. A mathematical reliability growth model allows the reliability growth rate to be computed from the failure data. The space shuttle was extensively maintained, refurbished, and upgraded after each flight and it experienced significant reliability growth during its operational life. In contrast, the International Space Station (ISS) is much more difficult to maintain and upgrade and its failure rate has been constant over time. The ISS Carbon Dioxide Removal Assembly (CDRA) reliability has slightly decreased. Failures on ISS and with the ISS CDRA continue to be a challenge.

NASA Applications and Lessons Learned in Reliability Engineering

Science.gov (United States)

Safie, Fayssal M.; Fuller, Raymond P.

2011-01-01

Since the Shuttle Challenger accident in 1986, communities across NASA have been developing and extensively using quantitative reliability and risk assessment methods in their decision making process. This paper discusses several reliability engineering applications that NASA has used over the year to support the design, development, and operation of critical space flight hardware. Specifically, the paper discusses several reliability engineering applications used by NASA in areas such as risk management, inspection policies, components upgrades, reliability growth, integrated failure analysis, and physics based probabilistic engineering analysis. In each of these areas, the paper provides a brief discussion of a case study to demonstrate the value added and the criticality of reliability engineering in supporting NASA project and program decisions to fly safely. Examples of these case studies discussed are reliability based life limit extension of Shuttle Space Main Engine (SSME) hardware, Reliability based inspection policies for Auxiliary Power Unit (APU) turbine disc, probabilistic structural engineering analysis for reliability prediction of the SSME alternate turbo-pump development, impact of ET foam reliability on the Space Shuttle System risk, and reliability based Space Shuttle upgrade for safety. Special attention is given in this paper to the physics based probabilistic engineering analysis applications and their critical role in evaluating the reliability of NASA development hardware including their potential use in a research and technology development environment.

Reliability training

Science.gov (United States)

Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Dillard, Richard B.; Wong, Kam L.; Barber, Frank J.; Barina, Frank J.

1992-01-01

Discussed here is failure physics, the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low cost reliable products. A review of reliability for the years 1940 to 2000 is given. Next, a review of mathematics is given as well as a description of what elements contribute to product failures. Basic reliability theory and the disciplines that allow us to control and eliminate failures are elucidated.

High-vacuum plasma pump

International Nuclear Information System (INIS)

Dorodnov, A.M.; Minajchev, V.E.; Miroshkin, S.I.

1980-01-01

The action of an electric-arc high-vacuum pump intended for evacuating the volumes in which the operation processes are followed by a high gas evolution is considered. The operation of the pump is based on the principle of controlling the getter feed according to the gas load and effect of plasma sorbtion pumping. The pump performances are given. The starting pressure is about 5 Pa, the limiting residual pressure is about 5x10 -6 Pa, the pumping out rate of nitrogen in the pressure range 5x10 -5 -5x10 -3 Pa accounts for about 4000 l/s, the power consumption comes to 6 kW. Analyzing the results of the test operation of the pump, it has been concluded that its principal advantages are the high starting pressure, controlled getter feed rate and possibility of pumping out the gases which are usually pumped out with difficulty. The operation reliability of the pump is defined mainly by reliable operation of the ignition system of the vacuum arc [ru

Reliable computer systems.

Science.gov (United States)

Wear, L L; Pinkert, J R

1993-11-01

In this article, we looked at some decisions that apply to the design of reliable computer systems. We began with a discussion of several terms such as testability, then described some systems that call for highly reliable hardware and software. The article concluded with a discussion of methods that can be used to achieve higher reliability in computer systems. Reliability and fault tolerance in computers probably will continue to grow in importance. As more and more systems are computerized, people will want assurances about the reliability of these systems, and their ability to work properly even when sub-systems fail.

Vacuum system operating experience review for fusion applications

International Nuclear Information System (INIS)

Cadwallader, L.C.

1994-03-01

This report presents a review of vacuum system operating experiences from particle accelerator, fusion experiment, space simulation chamber, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of vacuum system component failure rates and accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with vacuum systems are discussed, including personnel safety, foreign material intrusion, and factors relevant to vacuum systems being the primary confinement boundary for tritium and activated dusts. This information should be useful to fusion system designers and safety analysts, such as the team working on the Engineering Design Activities for the International Thermonuclear Experimental Reactor

Software error masking effect on hardware faults

International Nuclear Information System (INIS)

Choi, Jong Gyun; Seong, Poong Hyun

1999-01-01

Based on the Very High Speed Integrated Circuit (VHSIC) Hardware Description Language (VHDL), in this work, a simulation model for fault injection is developed to estimate the dependability of the digital system in operational phase. We investigated the software masking effect on hardware faults through the single bit-flip and stuck-at-x fault injection into the internal registers of the processor and memory cells. The fault location reaches all registers and memory cells. Fault distribution over locations is randomly chosen based on a uniform probability distribution. Using this model, we have predicted the reliability and masking effect of an application software in a digital system-Interposing Logic System (ILS) in a nuclear power plant. We have considered four the software operational profiles. From the results it was found that the software masking effect on hardware faults should be properly considered for predicting the system dependability accurately in operation phase. It is because the masking effect was formed to have different values according to the operational profile

Use of vacuum assisted closure in instrumented spinal deformities for children with postoperative deep infections

Directory of Open Access Journals (Sweden)

Canavese Federico

2010-01-01

Full Text Available Background: Postoperative deep infections are relatively common in children with instrumented spinal deformities, whose healing potential is somewhat compromised. Children with underlying diagnosis of cerebral palsy, spina bifida and other chronic debilitating conditions are particularly susceptible. Vacuum-assisted closure (VAC is a newer technique to promote healing of wounds resistant to treatment by established methods. This article aims to review the efficacy of the VAC system in the treatment of deep spinal infections following spinal instrumentation and fusion in children and adolescents. Materials and Methods: We reviewed 33 patients with deep postoperative surgical site infection treated with wound VAC technique. We reviewed clinical and laboratory data, including the ability to retain the spinal hardware, loss of correction and recurrent infections. Results : All patients successfully completed their wound VAC treatment regime. None had significant loss of correction and one had persistent infection requiring partial hardware removal. The laboratory indices normalized in all but three patients. Conclusions: Wound VAC technique is a useful tool in the armamentarium of the spinal surgeon dealing with patients susceptible to wound infections, especially those with neuromuscular diseases. It allows for retention of the instrumentation and maintenance of the spinal correction. It is reliable and easy to use.

An environmental testing facility for Space Station Freedom power management and distribution hardware

Science.gov (United States)

Jackola, Arthur S.; Hartjen, Gary L.

1992-01-01

The plans for a new test facility, including new environmental test systems, which are presently under construction, and the major environmental Test Support Equipment (TSE) used therein are addressed. This all-new Rocketdyne facility will perform space simulation environmental tests on Power Management and Distribution (PMAD) hardware to Space Station Freedom (SSF) at the Engineering Model, Qualification Model, and Flight Model levels of fidelity. Testing will include Random Vibration in three axes - Thermal Vacuum, Thermal Cycling and Thermal Burn-in - as well as numerous electrical functional tests. The facility is designed to support a relatively high throughput of hardware under test, while maintaining the high standards required for a man-rated space program.

Tests of a vacuum breaker for the FTU commutation system

International Nuclear Information System (INIS)

Andreani, R.; Lovisetto, L.; Cornago, F.

1984-01-01

A two poles vacuum breaker, equipped with saturable inductances and capacitor banks to produce an artificial current zero, appears the most suitable solution to satisfy these requirements with high reliability of operation and limited maintenance. Two series of tests have been conducted to evaluate the performance and reliability of the system and in particular the erosion of the electrodes as a function of number of operations. The test results have been very satisfactory. At least 1000 full power pulses can be envisaged before replacing the vacuum bottles. (author)

Development of a Modified Vacuum Cleaner for Lunar Surface Systems

Science.gov (United States)

Toon, Katherine P.; Lee, Steve A.; Edgerly, Rachel D.

2010-01-01

The National Aeronautics and Space Administration (NASA) mission to expand space exploration will return humans to the Moon with the goal of maintaining a long-term presence. One challenge that NASA will face returning to the Moon is managing the lunar regolith found on the Moon's surface, which will collect on extravehicular activity (EVA) suits and other equipment. Based on the Apollo experience, the issues astronauts encountered with lunar regolith included eye/lung irritation, and various hardware failures (seals, screw threads, electrical connectors and fabric contamination), which were all related to inadequate lunar regolith mitigation. A vacuum cleaner capable of detaching, transferring, and efficiently capturing lunar regolith has been proposed as a method to mitigate the lunar regolith problem in the habitable environment on lunar surface. In order to develop this vacuum, a modified "off-the-shelf' vacuum cleaner will be used to determine detachment efficiency, vacuum requirements, and optimal cleaning techniques to ensure efficient dust removal in habitable lunar surfaces, EVA spacesuits, and air exchange volume. During the initial development of the Lunar Surface System vacuum cleaner, systematic testing was performed with varying flow rates on multiple surfaces (fabrics and metallics), atmospheric (14.7 psia) and reduced pressures (10.2 and 8.3 psia), different vacuum tool attachments, and several vacuum cleaning techniques in order to determine the performance requirements for the vacuum cleaner. The data recorded during testing was evaluated by calculating particulate removal, relative to the retained simulant on the tested surface. In addition, optical microscopy was used to determine particle size distribution retained on the surface. The scope of this paper is to explain the initial phase of vacuum cleaner development, including historical Apollo mission data, current state-of-the-art vacuum cleaner technology, and vacuum cleaner testing that has

Reliability engineering for nuclear and other high technology systems

International Nuclear Information System (INIS)

Lakner, A.A.; Anderson, R.T.

1985-01-01

This book is written for the reliability instructor, program manager, system engineer, design engineer, reliability engineer, nuclear regulator, probability risk assessment (PRA) analyst, general manager and others who are involved in system hardware acquisition, design and operation and are concerned with plant safety and operational cost-effectiveness. It provides criteria, guidelines and comprehensive engineering data affecting reliability; it covers the key aspects of system reliability as it relates to conceptual planning, cost tradeoff decisions, specification, contractor selection, design, test and plant acceptance and operation. It treats reliability as an integrated methodology, explicitly describing life cycle management techniques as well as the basic elements of a total hardware development program, including: reliability parameters and design improvement attributes, reliability testing, reliability engineering and control. It describes how these elements can be defined during procurement, and implemented during design and development to yield reliable equipment. (author)

Pre-Flight Tests with Astronauts, Flight and Ground Hardware, to Assure On-Orbit Success

Science.gov (United States)

Haddad Michael E.

2010-01-01

On-Orbit Constraints Test (OOCT's) refers to mating flight hardware together on the ground before they will be mated on-orbit or on the Lunar surface. The concept seems simple but it can be difficult to perform operations like this on the ground when the flight hardware is being designed to be mated on-orbit in a zero-g/vacuum environment of space or low-g/vacuum environment on the Lunar/Mars Surface. Also some of the items are manufactured years apart so how are mating tasks performed on these components if one piece is on-orbit/on Lunar/Mars surface before its mating piece is planned to be built. Both the Internal Vehicular Activity (IVA) and Extra-Vehicular Activity (EVA) OOCT's performed at Kennedy Space Center will be presented in this paper. Details include how OOCT's should mimic on-orbit/Lunar/Mars surface operational scenarios, a series of photographs will be shown that were taken during OOCT's performed on International Space Station (ISS) flight elements, lessons learned as a result of the OOCT's will be presented and the paper will conclude with possible applications to Moon and Mars Surface operations planned for the Constellation Program.

Novel SU-8 based vacuum wafer-level packaging for MEMS devices

DEFF Research Database (Denmark)

Murillo, Gonzalo; Davis, Zachary James; Keller, Stephan Urs

2010-01-01

This work presents a simple and low-cost SU-8 based wafer-level vacuum packaging method which is CMOS and MEMS compatible. Different approaches have been investigated by taking advantage of the properties of SU-8, such as chemical resistance, optical transparence, mechanical reliability and versa......This work presents a simple and low-cost SU-8 based wafer-level vacuum packaging method which is CMOS and MEMS compatible. Different approaches have been investigated by taking advantage of the properties of SU-8, such as chemical resistance, optical transparence, mechanical reliability...

HISTRAP [Heavy Ion Storage Ring for Atomic Physics] prototype hardware studies

International Nuclear Information System (INIS)

Olsen, D.K.; Atkins, W.H.; Dowling, D.T.; Johnson, J.W.; Lord, R.S.; McConnell, J.W.; Milner, W.T.; Mosko, S.W.; Tatum, B.A.

1989-01-01

HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 2.67-Tm synchrotron/cooler/storage ring optimized for advanced atomic physics research which will be injected with ions from either the HHIRF 25-MV tandem accelerator or a dedicated ECR source and RFQ linac. Over the last two years, hardware prototypes have been developed for difficult and long lead-time components. A vacuum test stand, the rf cavity, and a prototype dipole magnet have been designed, constructed, and tested. 7 refs., 8 figs., 2 tabs

The Acquisition and Control Design for Vacuum Unit of an Electron Beam Machine Using Remote Manual, Software and Hardware

International Nuclear Information System (INIS)

Sudiyanto; Prajitno

2002-01-01

The Acquisition and Control design for vacuum unit of an Electron Beam Machine using Remote manual, Software and Hardwire have been done. For Remote Manual system open/close of pneumatic valves can be done by using 220 Vac/12 Vdc relay equipped with long cable and switches on the control panel. An indicator lamp mentioning ready/not ready status of the vacuum unit would be the main indicator in making decisions to open/close the pneumatic valves. On the software method the acquisition and controlled would be done by using the Distributed Control System which have already been developed recently. The references voltage on he vacuum level of 10 -2 Torr and 10 -6 Torr would be proceeded by using ADC techniques of PCL-718 and recorded on the software system as a references data base in making an open/closed pneumatic decision. On the Hardwire method, on/off controlling of the pneumatic valves could be done by using voltage comparison by using logic circuitry where the vacuum references level of 10 -2 Torr and 10 -6 Torr have already been taken, monitored by penning gauge. The hardwire method is the fastest in response time than the others. (author)

Test Hardware Design for Flight-Like Operation of Advanced Stirling Convertors

Science.gov (United States)

Oriti, Salvatore M.

2012-01-01

NASA Glenn Research Center (GRC) has been supporting development of the Advanced Stirling Radioisotope Generator (ASRG) since 2006. A key element of the ASRG project is providing life, reliability, and performance testing of the Advanced Stirling Convertor (ASC). For this purpose, the Thermal Energy Conversion branch at GRC has been conducting extended operation of a multitude of free-piston Stirling convertors. The goal of this effort is to generate long-term performance data (tens of thousands of hours) simultaneously on multiple units to build a life and reliability database. The test hardware for operation of these convertors was designed to permit in-air investigative testing, such as performance mapping over a range of environmental conditions. With this, there was no requirement to accurately emulate the flight hardware. For the upcoming ASC-E3 units, the decision has been made to assemble the convertors into a flight-like configuration. This means the convertors will be arranged in the dual-opposed configuration in a housing that represents the fit, form, and thermal function of the ASRG. The goal of this effort is to enable system level tests that could not be performed with the traditional test hardware at GRC. This offers the opportunity to perform these system-level tests much earlier in the ASRG flight development, as they would normally not be performed until fabrication of the qualification unit. This paper discusses the requirements, process, and results of this flight-like hardware design activity.

Hardware Resource Allocation for Hardware/Software Partitioning in the LYCOS System

DEFF Research Database (Denmark)

Grode, Jesper Nicolai Riis; Knudsen, Peter Voigt; Madsen, Jan

1998-01-01

as a designer's/design tool's aid to generate good hardware allocations for use in hardware/software partitioning. The algorithm has been implemented in a tool under the LYCOS system. The results show that the allocations produced by the algorithm come close to the best allocations obtained by exhaustive search.......This paper presents a novel hardware resource allocation technique for hardware/software partitioning. It allocates hardware resources to the hardware data-path using information such as data-dependencies between operations in the application, and profiling information. The algorithm is useful...

The target vacuum storage facility at iThemba LABS

Science.gov (United States)

Neveling, R.; Kheswa, N. Y.; Papka, P.

2018-05-01

A number of nuclear physics experiments at iThemba LABS require target foils that consist of specific isotopes of elements which are reactive in air. Not only is it important to prepare these targets in a suitable environment to prevent oxidation, but consideration should also be given to the long term storage and handling facilities of such targets. The target vacuum storage facility at iThemba LABS, as well as additional hardware necessary to transport and install the target foils in the experimental chamber, will be discussed.

A remote joint system for large vacuum ducts

International Nuclear Information System (INIS)

Hagmann, D.B.; Coughlan, J.B.

1983-01-01

A large remote vacuum duct joining system has been developed for fusion machines that uses several two-jaw screwdriven clamps. The preferred location for clamp installation is inside the vacuum duct where access space is available for the actuating device. It also decreases space needed for handling operations exterior to the duct. The clamp system is unique in that it is low cost, applies force directly over the seal, permits leak testing to the seal annulus, is highly reliable, can be remotely replaced, and is usable on a variety of other applications

Data acquisition from vacuum gage controlled by RS-232 standard using LabVIEW

International Nuclear Information System (INIS)

Brandea, Iulian; Culcer, Mihai; Steflea, Dumitru

1999-01-01

This paper deals with the problem of connecting a microcontroller-based vacuum gage to a personal computer, using the RS-232 hardware standard and the software LabVIEW and his collection of virtual instruments from National Instruments. To solve the problem an instrument driver was created. This provided the customer with a perfect solution for the remote control and data acquisition from an Intel 80CXX microcontroller-based vacuum gage. The remote control making use of an IBM-PC was design and manufactured in our institute. In order to make it intelligent the device was provided with a microprocessor or a microcontroller. To fulfill the requirements a vacuum gage with an 80C31 microcontroller and two Bayard-Alpert ion gauges, for very low pressures (10 -3 to 10 -7 mbar) and low pressure (10 mbar to 10 -3 mbar) was built. Because this microcontroller has a built-in circuitry for a serial communication, we established a serial communication between the PC (Pentium -166 MHz) and the vacuum gage, according to the RS-232 hardware standard. Optimum selection of software development tools however, was not as straightforward. Most producers use the C/C ++ - language programming tool for developing instrument drivers for their intelligent devices. One of the advantages of C/C ++ is its speed, but the compilation and the high-level skill required for optimum programming do not fit well with some requirements, particularly those of versatility, upgradability and user friendliness. After careful evaluation of several options, a final decision was to develop a hybrid software package using two different software development tools: LabVIEW, and assembly language. We chose LabVIEW because it is dedicated to data acquisition and communications, containing libraries for data collection, analysis, presentation and storage. The assembly language for Intel 8051's microcontrollers family is used to write the firmware for the vacuum gage and arithmetic routines. (authors)

Hardware for soft computing and soft computing for hardware

CERN Document Server

Nedjah, Nadia

2014-01-01

Single and Multi-Objective Evolutionary Computation (MOEA),  Genetic Algorithms (GAs), Artificial Neural Networks (ANNs), Fuzzy Controllers (FCs), Particle Swarm Optimization (PSO) and Ant colony Optimization (ACO) are becoming omnipresent in almost every intelligent system design. Unfortunately, the application of the majority of these techniques is complex and so requires a huge computational effort to yield useful and practical results. Therefore, dedicated hardware for evolutionary, neural and fuzzy computation is a key issue for designers. With the spread of reconfigurable hardware such as FPGAs, digital as well as analog hardware implementations of such computation become cost-effective. The idea behind this book is to offer a variety of hardware designs for soft computing techniques that can be embedded in any final product. Also, to introduce the successful application of soft computing technique to solve many hard problem encountered during the design of embedded hardware designs. Reconfigurable em...

Hardware Evaluation of the Horizontal Exercise Fixture with Weight Stack

Science.gov (United States)

Newby, Nate; Leach, Mark; Fincke, Renita; Sharp, Carwyn

2009-01-01

HEF with weight stack seems to be a very sturdy and reliable exercise device that should function well in a bed rest training setting. A few improvements should be made to both the hardware and software to improve usage efficiency, but largely, this evaluation has demonstrated HEF's robustness. The hardware offers loading to muscles, bones, and joints, potentially sufficient to mitigate the loss of muscle mass and bone mineral density during long-duration bed rest campaigns. With some minor modifications, the HEF with weight stack equipment provides the best currently available means of performing squat, heel raise, prone row, bench press, and hip flexion/extension exercise in a supine orientation.

Ambipolarity reduction in DMG asymmetric vacuum dielectric Schottky Barrier GAA MOSFET to improve hot carrier reliability

Science.gov (United States)

Kumar, Manoj; Haldar, Subhasis; Gupta, Mridula; Gupta, R. S.

2017-11-01

An explicit surface potential and subthreshold current model for novel Dual Metal Gate (DMG) Asymmetric Vacuum (AV) as gate dielectric Schottky Barrier (SB) Cylindrical Gate All Around (CGAA) MOSFET with the incorporation of localized charges (Nf) is developed to provide excellent immunity against threshold voltage (Vth) degradation due to hot carriers. Hot carrier induced Localized Charges (LC) either positive or negative leads to degrade the threshold of the device. The major advantage of the proposed DMG-AV-SB-CGAA MOSFET is that it mitigates the ambipolar behavior thus offering very good on current to off current ratio; and also reduces the electron temperature which leads to less hot carrier generation thus lesser degradation in Vth and improved Hot Carrier reliability. The surface potential is determined for three different regions by solving 1-D Poisson's and 2-D Laplace equation through separation of variable method to facilitate an optimal model for calculating the subthreshold drain current from Si-SiO2 interface boundary. The developed model results are in good agreement with that of ATLAS-TCAD simulation.

Hardware in the Loop Testing of an Iodine-Fed Hall Thruster

Science.gov (United States)

Polzin, Kurt A.; Peeples, Steven R.; Cecil, Jim; Lewis, Brandon L.; Molina Fraticelli, Jose C.; Clark, James P.

2015-01-01

initiated from an operator's workstation outside the vacuum chamber and passed through the Cortex 160 to exercise portions of the flight avionics. Two custom-designed pieces of electronics hardware have been designed to operate the propellant feed system. One piece of hardware is an auxiliary board that controls a latch valve, proportional flow control valves (PFCVs) and valve heaters as well as measuring pressures, temperatures and PFCV feedback voltage. An onboard FPGA provides a serial link for issuing commands and manages all lower level input-output functions. The other piece of hardware is a power distribution board, which accepts a standard bus voltage input and converts this voltage into all the different current-voltage types required to operate the auxiliary board. These electronics boards are located in the vacuum chamber near the thruster, exposing this hardware to both the vacuum and plasma environments they would encounter during a mission, with these components communicating to the flight computer through an RS-422 interface. The auxiliary board FPGA provides a 28V MOSFET switch circuit with a 20ms pulse to open or close the iodine propellant feed system latch valve. The FPGA provides a pulse width modulation (PWM) signal to a DC/DC boost converter to produce the 12-120V needed for control of the proportional flow control valve. There are eight MOSFET-switched heating circuits in the system. Heaters are 28V and located in the latch valve, PFCV, propellant tank and propellant feed lines. Both the latch valve and PFCV have thermistors built into them for temperature monitoring. There are also seven resistance temperature device (RTD) circuits on the auxiliary board that can be used to measure the propellant tank and feedline temperatures. The signals are conditioned and sent to an analog to digital converter (ADC), which is directly commanded and controlled by the FPGA.

Investigating steam penetration using thermometric methods in dental handpieces with narrow internal lumens during sterilizing processes with non-vacuum or vacuum processes.

Science.gov (United States)

Winter, S; Smith, A; Lappin, D; McDonagh, G; Kirk, B

2017-12-01

Dental handpieces are required to be sterilized between patient use. Vacuum steam sterilization processes with fractionated pre/post-vacuum phases or unique cycles for specified medical devices are required for hollow instruments with internal lumens to assure successful air removal. Entrapped air will compromise achievement of required sterilization conditions. Many countries and professional organizations still advocate non-vacuum sterilization processes for these devices. To investigate non-vacuum downward/gravity displacement, type-N steam sterilization of dental handpieces, using thermometric methods to measure time to achieve sterilization temperature at different handpiece locations. Measurements at different positions within air turbines were undertaken with thermocouples and data loggers. Two examples of widely used UK benchtop steam sterilizers were tested: a non-vacuum benchtop sterilizer (Little Sister 3; Eschmann, Lancing, UK) and a vacuum benchtop sterilizer (Lisa; W&H, Bürmoos, Austria). Each sterilizer cycle was completed with three handpieces and each cycle in triplicate. A total of 140 measurements inside dental handpiece lumens were recorded. The non-vacuum process failed (time range: 0-150 s) to reliably achieve sterilization temperatures within the time limit specified by the international standard (15 s equilibration time). The measurement point at the base of the handpiece failed in all test runs (N = 9) to meet the standard. No failures were detected with the vacuum steam sterilization type B process with fractionated pre-vacuum and post-vacuum phases. Non-vacuum downward/gravity displacement, type-N steam sterilization processes are unreliable in achieving sterilization conditions inside dental handpieces, and the base of the handpiece is the site most likely to fail. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Power electronics reliability analysis.

Energy Technology Data Exchange (ETDEWEB)

Smith, Mark A.; Atcitty, Stanley

2009-12-01

This report provides the DOE and industry with a general process for analyzing power electronics reliability. The analysis can help with understanding the main causes of failures, downtime, and cost and how to reduce them. One approach is to collect field maintenance data and use it directly to calculate reliability metrics related to each cause. Another approach is to model the functional structure of the equipment using a fault tree to derive system reliability from component reliability. Analysis of a fictitious device demonstrates the latter process. Optimization can use the resulting baseline model to decide how to improve reliability and/or lower costs. It is recommended that both electric utilities and equipment manufacturers make provisions to collect and share data in order to lay the groundwork for improving reliability into the future. Reliability analysis helps guide reliability improvements in hardware and software technology including condition monitoring and prognostics and health management.

Test Program for Stirling Radioisotope Generator Hardware at NASA Glenn Research Center

Science.gov (United States)

Lewandowski, Edward J.; Bolotin, Gary S.; Oriti, Salvatore M.

2015-01-01

Stirling-based energy conversion technology has demonstrated the potential of high efficiency and low mass power systems for future space missions. This capability is beneficial, if not essential, to making certain deep space missions possible. Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG), a 140-W radioisotope power system. A variety of flight-like hardware, including Stirling convertors, controllers, and housings, was designed and built under the ASRG flight development project. To support future Stirling-based power system development NASA has proposals that, if funded, will allow this hardware to go on test at the NASA Glenn Research Center. While future flight hardware may not be identical to the hardware developed under the ASRG flight development project, many components will likely be similar, and system architectures may have heritage to ASRG. Thus, the importance of testing the ASRG hardware to the development of future Stirling-based power systems cannot be understated. This proposed testing will include performance testing, extended operation to establish an extensive reliability database, and characterization testing to quantify subsystem and system performance and better understand system interfaces. This paper details this proposed test program for Stirling radioisotope generator hardware at NASA Glenn. It explains the rationale behind the proposed tests and how these tests will meet the stated objectives.

System Configuration Management Implementation Procedure for the Cold Vacuum Drying Facility Monitoring and Control System

International Nuclear Information System (INIS)

ANGLESEY, M.O.

2000-01-01

The purpose of this document is to establish the System Configuration Management Implementation Procedure (SCMIP) for the Cold Vacuum Drying Facility (CVDF) Monitoring and Control System (MCS). This procedure provides configuration management for the process control system. The process control system consists of equipment hardware and software that controls and monitors the instrumentation and equipment associated with the CVDF processes. Refer to SNF-3090, Cold Vacuum Drying Facility Monitoring and Control System Design Description, HNF-3553, Annex B, Safety Analysis Report for the Cold Vacuum Drying Facility, and AP-CM-6-037-00, SNF Project Process Automation Software and Equipment Configuration. This SCMIP identifies and defines the system configuration items in the control system, provides configuration control throughout the system life cycle, provides configuration status accounting, physical protection and control, and verifies the completeness and correctness of these items

Introduction to Hardware Security

Directory of Open Access Journals (Sweden)

Yier Jin

2015-10-01

Full Text Available Hardware security has become a hot topic recently with more and more researchers from related research domains joining this area. However, the understanding of hardware security is often mixed with cybersecurity and cryptography, especially cryptographic hardware. For the same reason, the research scope of hardware security has never been clearly defined. To help researchers who have recently joined in this area better understand the challenges and tasks within the hardware security domain and to help both academia and industry investigate countermeasures and solutions to solve hardware security problems, we will introduce the key concepts of hardware security as well as its relations to related research topics in this survey paper. Emerging hardware security topics will also be clearly depicted through which the future trend will be elaborated, making this survey paper a good reference for the continuing research efforts in this area.

Test Hardware Design for Flightlike Operation of Advanced Stirling Convertors (ASC-E3)

Science.gov (United States)

Oriti, Salvatore M.

2012-01-01

NASA Glenn Research Center (GRC) has been supporting development of the Advanced Stirling Radioisotope Generator (ASRG) since 2006. A key element of the ASRG project is providing life, reliability, and performance testing of the Advanced Stirling Convertor (ASC). For this purpose, the Thermal Energy Conversion branch at GRC has been conducting extended operation of a multitude of free-piston Stirling convertors. The goal of this effort is to generate long-term performance data (tens of thousands of hours) simultaneously on multiple units to build a life and reliability database. The test hardware for operation of these convertors was designed to permit in-air investigative testing, such as performance mapping over a range of environmental conditions. With this, there was no requirement to accurately emulate the flight hardware. For the upcoming ASC-E3 units, the decision has been made to assemble the convertors into a flight-like configuration. This means the convertors will be arranged in the dual-opposed configuration in a housing that represents the fit, form, and thermal function of the ASRG. The goal of this effort is to enable system level tests that could not be performed with the traditional test hardware at GRC. This offers the opportunity to perform these system-level tests much earlier in the ASRG flight development, as they would normally not be performed until fabrication of the qualification unit. This paper discusses the requirements, process, and results of this flight-like hardware design activity.

RAVONSICS-challenging for assuring software reliability of nuclear I and C system

International Nuclear Information System (INIS)

Hai Zeng; Ming Yang; Yoshikawa, Hidekazu

2015-01-01

As the “central nerve system”, the highly reliable Instrumentation and Control (I and C) systems, which provide the right functions and functions correctly, are always desirable not only for the end users of NPPs but also the suppliers of I and C systems. The Digitalization of nuclear I and C system happened in recent years brought a lot of new features for nuclear I and C system. On one side digital technology provides more functionalities, and it should be more reliable and robust; on the other side, digital technology brings new challenge for nuclear I and C system, especially the software running in the hardware component. The software provides flexible functionalities for nuclear I and C system, but it also brings the difficulties to evaluate the reliability and safety of it because of the complexity of software. The reliability of software, which is indispensable part of I and C system, will have essential impact on the reliability of the whole system, and people definitely want to know what the reliability of this intangible part is. The methods used for the evaluation of reliability of system and hardware hardly work for software, because the inherent difference of failure mechanism exists between software and hardware. Failure in software is systematically induced by design error, but failure in hardware is randomly induced by material and production. To continue the effort on this hot topic and to try to achieve consensus on the potential methodology for software reliability evaluation, a cooperative research project called RAVONSICS (Reliability and Verification and Validation of Nuclear Safety I and C Software) is being carried on by 7 Chinese partners, which includes University, research institute, utility, vendor, and safety regulatory body. The objective of RAVONSICS is to bring forwards the methodology for the software reliability evaluation, and the software verification technique. RAVONSICS works cooperatively with its European sister project

Using vacuum in the treatment of surgical wounds complications

Directory of Open Access Journals (Sweden)

Drašković Miroljub

2011-01-01

Full Text Available Background/Aim. Using vacuum in medicine has been known from long ago, however, it has not been used for the treatment of wounds. The first experiments in this field were performed by Wagner Fleischmann, University of Ulm, Ulm, West Germany, in 1993. The aim of this study was to present our clinical experience with the treatment of surgical wounds complications in vascular patients by the use of controled vacuum. Method. In a period October 2006 - December 2009 a total of 18 patients with infection and surgical wound dehiscence were treated by the use of vacuum. Vacuum was applied to wounds by placing a polyurethane sponge on them and by fixing a polyurethane foil and a sponge to the surrounding healthy skin so to completely airtight wounds. Over a foil vacuum of - 150 mmHg was applied for a 5-day period, and on the day 6 a foil and a sponge were removed. Results. In all the 18 wounds treated by the use of vacuum secondary wound closing was achieved with no complications and with a significantly shortened time period treatment. Wound infections were healed using this method and only in 2 patients antibiotics were used at the same time. Conclusion. The use of vacuum in the treatment of operative wounds complications is an easy and reliable method contributing significantly to wounds better healing.

Design and construction of vacuum control system on EAST

International Nuclear Information System (INIS)

Wang, L.; Zhang, Y.; Hu, Q.S.; Wang, X.M.; Zhang, X.D.; Hu, J.S.; Yang, Y.; Gu, X.M.

2008-01-01

The construction of experimental advanced superconducting tokamak (EAST) was finished at the end of 2006 in Hefei, China. Its vacuum system, an important subsystem, has been commissioned in February 2006. The design and construction of this vacuum control system are described in this paper. The requirements for remote automation, distributed control and centralized management, high reliability and expansibility have been taken into account in the design. There are three levels of control in vacuum control system. The bottom level control is performed on the local instruments manually; the medium level control is based on Siemens S7-400 PLC; the top level control is conducted on IPCs with communication through profi b us network. In addition remote handling and centralized monitoring could be realized by a remote control server. The control system could achieve pumping and fueling of the whole vacuum system. Besides that, it also includes the data acquisition of the pressure and temperature. The details are discussed on the monitoring of vacuum system states including cooling water, power and compressed air, etc., safeguards of plasma chamber and cryostat chamber and vacuum equipments, choosing of control modes corresponding to the plasma discharge and wall conditioning. At the end, the parts of EAST device protection system related to vacuum and gas injection system will also be introduced

Standard high-reliability integrated circuit logic packaging. [for deep space tracking stations

Science.gov (United States)

Slaughter, D. W.

1977-01-01

A family of standard, high-reliability hardware used for packaging digital integrated circuits is described. The design transition from early prototypes to production hardware is covered and future plans are discussed. Interconnections techniques are described as well as connectors and related hardware available at both the microcircuit packaging and main-frame level. General applications information is also provided.

FY1995 evolvable hardware chip; 1995 nendo shinkasuru hardware chip

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

This project aims at the development of 'Evolvable Hardware' (EHW) which can adapt its hardware structure to the environment to attain better hardware performance, under the control of genetic algorithms. EHW is a key technology to explore the new application area requiring real-time performance and on-line adaptation. 1. Development of EHW-LSI for function level hardware evolution, which includes 15 DSPs in one chip. 2. Application of the EHW to the practical industrial applications such as data compression, ATM control, digital mobile communication. 3. Two patents : (1) the architecture and the processing method for programmable EHW-LSI. (2) The method of data compression for loss-less data, using EHW. 4. The first international conference for evolvable hardware was held by authors: Intl. Conf. on Evolvable Systems (ICES96). It was determined at ICES96 that ICES will be held every two years between Japan and Europe. So the new society has been established by us. (NEDO)

FY1995 evolvable hardware chip; 1995 nendo shinkasuru hardware chip

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

This project aims at the development of 'Evolvable Hardware' (EHW) which can adapt its hardware structure to the environment to attain better hardware performance, under the control of genetic algorithms. EHW is a key technology to explore the new application area requiring real-time performance and on-line adaptation. 1. Development of EHW-LSI for function level hardware evolution, which includes 15 DSPs in one chip. 2. Application of the EHW to the practical industrial applications such as data compression, ATM control, digital mobile communication. 3. Two patents : (1) the architecture and the processing method for programmable EHW-LSI. (2) The method of data compression for loss-less data, using EHW. 4. The first international conference for evolvable hardware was held by authors: Intl. Conf. on Evolvable Systems (ICES96). It was determined at ICES96 that ICES will be held every two years between Japan and Europe. So the new society has been established by us. (NEDO)

Data Applicability of Heritage and New Hardware For Launch Vehicle Reliability Models

Science.gov (United States)

Al Hassan, Mohammad; Novack, Steven

2015-01-01

Bayesian reliability requires the development of a prior distribution to represent degree of belief about the value of a parameter (such as a component's failure rate) before system specific data become available from testing or operations. Generic failure data are often provided in reliability databases as point estimates (mean or median). A component's failure rate is considered a random variable where all possible values are represented by a probability distribution. The applicability of the generic data source is a significant source of uncertainty that affects the spread of the distribution. This presentation discusses heuristic guidelines for quantifying uncertainty due to generic data applicability when developing prior distributions mainly from reliability predictions.

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR)

International Nuclear Information System (INIS)

Gilbert, B.G.; Reece, W.J.; Gertman, D.I.; Gilmore, W.E.; Galyean, W.J.

1990-12-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability and hardware component failure data. The NUCLARR system software resides on an IBM (or compatible) personal computer. NUCLARR can furnish the end user with data inputs for both human and hardware reliability analysis in support of a variety of risk assessment activities. The NUCLARR system is documented in a five-volume series of reports. Volume 5: Data Manual provides a hard-copy representation of all data and related information available within the NUCLARR system software. This document is organized in three sections. Part 1 is the summary description, which presents an overview of the NUCLARR system and data processing procedures. Part 2 contains all data and information relevant to the human error probability (HEP) data side of NUCLARR. Data and information for the hardware component failure data (HCFD) side are presented in Part 3. 7 refs

Mercury Conditions for the MESSENGER Mission Simulated in High- Solar-Radiation Vacuum Tests

Science.gov (United States)

Wong, Wayne A.

2003-01-01

The MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) spacecraft, planned for launch in March 2004, will perform two flybys of Mercury before entering a year-long orbit of the planet in September 2009. The mission will provide opportunities for detailed characterization of the surface, interior, atmosphere, and magnetosphere of the closest planet to the Sun. The NASA Glenn Research Center and the MESSENGER spacecraft integrator, the Johns Hopkins University Applied Physics Laboratory, have partnered under a Space Act Agreement to characterize a variety of critical components and materials under simulated conditions expected near Mercury. Glenn's Vacuum Facility 6, which is equipped with a solar simulator, can simulate the vacuum and high solar radiation anticipated in Mercury orbit. The MESSENGER test hardware includes a variety of materials and components that are being characterized during the Tank 6 vacuum tests, where the hardware will be exposed to up to 11 suns insolation, simulating conditions expected in Mercury orbit. In 2002, ten solar vacuum tests were conducted, including beginning of life, end of life, backside exposure, and solar panel thermal shock cycling tests. Components tested include candidate solar array panels, sensors, thermal shielding materials, and communication devices. As an example, for the solar panel thermal shock cycling test, two candidate solar array panels were suspended on a lift mechanism that lowered the panels into a liquid-nitrogen-cooled box. After reaching -140 C, the panels were then lifted out of the box and exposed to the equivalent of 6 suns (8.1 kilowatts per square meters). After five cold soak/heating cycles were completed successfully, there was no apparent degradation in panel performance. An anticipated 100-hr thermal shield life test is planned for autumn, followed by solar panel flight qualification tests in winter. Glenn's ongoing support to the MESSENGER program has been instrumental in

Hardware availability calculations and results of the IFMIF accelerator facility

International Nuclear Information System (INIS)

Bargalló, Enric; Arroyo, Jose Manuel; Abal, Javier; Beauvais, Pierre-Yves; Gobin, Raphael; Orsini, Fabienne; Weber, Moisés; Podadera, Ivan; Grespan, Francesco; Fagotti, Enrico; De Blas, Alfredo; Dies, Javier; Tapia, Carlos; Mollá, Joaquín; Ibarra, Ángel

2014-01-01

Highlights: • IFMIF accelerator facility hardware availability analyses methodology is described. • Results of the individual hardware availability analyses are shown for the reference design. • Accelerator design improvements are proposed for each system. • Availability results are evaluated and compared with the requirements. - Abstract: Hardware availability calculations have been done individually for each system of the deuteron accelerators of the International Fusion Materials Irradiation Facility (IFMIF). The principal goal of these analyses is to estimate the availability of the systems, compare it with the challenging IFMIF requirements and find new paths to improve availability performances. Major unavailability contributors are highlighted and possible design changes are proposed in order to achieve the hardware availability requirements established for each system. In this paper, such possible improvements are implemented in fault tree models and the availability results are evaluated. The parallel activity on the design and construction of the linear IFMIF prototype accelerator (LIPAc) provides detailed design information for the RAMI (reliability, availability, maintainability and inspectability) analyses and allows finding out the improvements that the final accelerator could have. Because of the R and D behavior of the LIPAc, RAMI improvements could be the major differences between the prototype and the IFMIF accelerator design

Hardware availability calculations and results of the IFMIF accelerator facility

Energy Technology Data Exchange (ETDEWEB)

Bargalló, Enric, E-mail: enric.bargallo-font@upc.edu [Fusion Energy Engineering Laboratory (FEEL), Technical University of Catalonia (UPC), Barcelona (Spain); Arroyo, Jose Manuel [Laboratorio Nacional de Fusión por Confinamiento Magnético – CIEMAT, Madrid (Spain); Abal, Javier [Fusion Energy Engineering Laboratory (FEEL), Technical University of Catalonia (UPC), Barcelona (Spain); Beauvais, Pierre-Yves; Gobin, Raphael; Orsini, Fabienne [Commissariat à l’Energie Atomique, Saclay (France); Weber, Moisés; Podadera, Ivan [Laboratorio Nacional de Fusión por Confinamiento Magnético – CIEMAT, Madrid (Spain); Grespan, Francesco; Fagotti, Enrico [Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); De Blas, Alfredo; Dies, Javier; Tapia, Carlos [Fusion Energy Engineering Laboratory (FEEL), Technical University of Catalonia (UPC), Barcelona (Spain); Mollá, Joaquín; Ibarra, Ángel [Laboratorio Nacional de Fusión por Confinamiento Magnético – CIEMAT, Madrid (Spain)

2014-10-15

Highlights: • IFMIF accelerator facility hardware availability analyses methodology is described. • Results of the individual hardware availability analyses are shown for the reference design. • Accelerator design improvements are proposed for each system. • Availability results are evaluated and compared with the requirements. - Abstract: Hardware availability calculations have been done individually for each system of the deuteron accelerators of the International Fusion Materials Irradiation Facility (IFMIF). The principal goal of these analyses is to estimate the availability of the systems, compare it with the challenging IFMIF requirements and find new paths to improve availability performances. Major unavailability contributors are highlighted and possible design changes are proposed in order to achieve the hardware availability requirements established for each system. In this paper, such possible improvements are implemented in fault tree models and the availability results are evaluated. The parallel activity on the design and construction of the linear IFMIF prototype accelerator (LIPAc) provides detailed design information for the RAMI (reliability, availability, maintainability and inspectability) analyses and allows finding out the improvements that the final accelerator could have. Because of the R and D behavior of the LIPAc, RAMI improvements could be the major differences between the prototype and the IFMIF accelerator design.

Calculator: A Hardware Design, Math and Software Programming Project Base Learning

Directory of Open Access Journals (Sweden)

F. Criado

2015-03-01

Full Text Available This paper presents the implementation by the students of a complex calculator in hardware. This project meets hardware design goals, and also highly motivates them to use competences learned in others subjects. The learning process, associated to System Design, is hard enough because the students have to deal with parallel execution, signal delay, synchronization … Then, to strengthen the knowledge of hardware design a methodology as project based learning (PBL is proposed. Moreover, it is also used to reinforce cross subjects like math and software programming. This methodology creates a course dynamics that is closer to a professional environment where they will work with software and mathematics to resolve the hardware design problems. The students design from zero the functionality of the calculator. They are who make the decisions about the math operations that it is able to resolve it, and also the operands format or how to introduce a complex equation into the calculator. This will increase the student intrinsic motivation. In addition, since the choices may have consequences on the reliability of the calculator, students are encouraged to program in software the decisions about how implement the selected mathematical algorithm. Although math and hardware design are two tough subjects for students, the perception that they get at the end of the course is quite positive.

Reliability issues in PACS

Science.gov (United States)

Taira, Ricky K.; Chan, Kelby K.; Stewart, Brent K.; Weinberg, Wolfram S.

1991-07-01

Reliability is an increasing concern when moving PACS from the experimental laboratory to the clinical environment. Any system downtime may seriously affect patient care. The authors report on the several classes of errors encountered during the pre-clinical release of the PACS during the past several months and present the solutions implemented to handle them. The reliability issues discussed include: (1) environmental precautions, (2) database backups, (3) monitor routines of critical resources and processes, (4) hardware redundancy (networks, archives), and (5) development of a PACS quality control program.

Design and analysis of the PBFA-Z vacuum insulator stack

International Nuclear Information System (INIS)

Shoup, R.W.; Long, F.; Martin, T.H.; Stygar, W.A.; Spielman, R.B.; Struve, K.W.; Mostrom, M.; Corcoran, P.; Smith, I.

1996-01-01

Sandia is developing PBFA-Z, a 20-MA driver for z-pinch experiments by replacing the water lines, insulator stack, and MITLs on PBFA II with new hardware. The design of the vacuum insulator stack was dictated by the drive voltage, the electric field stress and grading requirements, the water line and MITL interface requirements, and the machine operations and maintenance requirements. The insulator stack will consist of four separate modules, each of a different design because of different voltage drive and hardware interface requirements. The shape of the components in each module, i.e., grading rings, insulator rings, flux excluders, anode and cathode conductors, and the design of the water line and MITL interfaces, were optimized by using the electrostatic analysis codes, ELECTRO and JASON. The time-dependent performance of the insulator stack was evaluated using IVORY, a 2-D PIC code. The insulator stack design and present the results of the ELECTRO and IVORY analyses are described. (author). 2 tabs., 9 figs., 3 refs

Design and analysis of the PBFA-Z vacuum insulator stack

Energy Technology Data Exchange (ETDEWEB)

Shoup, R W [Field Command Defense Nuclear Agency, Kirtland AFB, NM (United States); Long, F; Martin, T H; Stygar, W A; Spielman, R B [Sandia National Laboratories, Albuquerque, NM (United States). Dept 9573; Ives, H [EG and G, Albuquerque, NM (United States); Struve, K W; Mostrom, M [Mission Research Corp., Albuquerque, NM (United States); Corcoran, P; Smith, I [Pulse Sciences, Inc., San Leandro, CA (United States)

1997-12-31

Sandia is developing PBFA-Z, a 20-MA driver for z-pinch experiments by replacing the water lines, insulator stack, and MITLs on PBFA II with new hardware. The design of the vacuum insulator stack was dictated by the drive voltage, the electric field stress and grading requirements, the water line and MITL interface requirements, and the machine operations and maintenance requirements. The insulator stack will consist of four separate modules, each of a different design because of different voltage drive and hardware interface requirements. The shape of the components in each module, i.e., grading rings, insulator rings, flux excluders, anode and cathode conductors, and the design of the water line and MITL interfaces, were optimized by using the electrostatic analysis codes, ELECTRO and JASON. The time-dependent performance of the insulator stack was evaluated using IVORY, a 2-D PIC code. The insulator stack design and present the results of the ELECTRO and IVORY analyses are described. (author). 2 tabs., 9 figs., 3 refs.

Vacuum die attach for integrated circuits

Science.gov (United States)

Schmitt, E.H.; Tuckerman, D.B.

1991-09-10

A thin film eutectic bond for attaching an integrated circuit die to a circuit substrate is formed by coating at least one bonding surface on the die and substrate with an alloying metal, assembling the die and substrate under compression loading, and heating the assembly to an alloying temperature in a vacuum. A very thin bond, 10 microns or less, which is substantially void free, is produced. These bonds have high reliability, good heat and electrical conduction, and high temperature tolerance. The bonds are formed in a vacuum chamber, using a positioning and loading fixture to compression load the die, and an IR lamp or other heat source. For bonding a silicon die to a silicon substrate, a gold silicon alloy bond is used. Multiple dies can be bonded simultaneously. No scrubbing is required. 1 figure.

Distally based saphenous neurocutaneous perforator flap combined with vac therapy for soft tissue reconstruction and hardware salvage in the lower extremities.

Science.gov (United States)

Wen, Gen; Wang, Chun-Yang; Chai, Yi-Min; Cheng, Liang; Chen, Ming; Yi-Min, L V

2013-11-01

The complex wound with the exposed hardware and infection is one of the common complications after the internal fixation of the tibia fracture. The salvage of hardware and reconstruction of soft tissue defect remain challenging. In this report, we presented our experience on the use of the distally based saphenous neurocutaneous perforator flap combined with vacuum-assisted closure (VAC) therapy for the coverage of the soft tissue defect and the exposed hardware in the lower extremity with fracture. Between January 2008 and July 2010, seven patients underwent the VAC therapy followed by transferring a reversed saphenous neurocutaneous perforator flap for reconstruction of the wound with exposed hardware around the distal tibia. The sizes of the flaps ranged from 6 × 3 cm to 15 × 6 cm. Six flaps survived completely. Partial necrosis occurred in one patient. There were no other complications of repair and donor sites. Bone healing was achieved in all patients. In conclusion, the reversed saphenous neurocutaneous perfortor flaps combined with the VAC therapy might be one of the options to cover the complex wound with exposed hardware in the lower extremities. © 2013 Wiley Periodicals, Inc.

A comparison of molding procedures - Contact, injection and vacuum injection

Science.gov (United States)

Cathiard, G.

1980-06-01

The technical and economic aspects of the contact, injection and vacuum injection molding of reinforced plastic components are compared for the example of a tractor roof with a gel-coated surface. Consideration is given to the possibility of reinforcement, number of smooth faces, condition of the gel-coated surface, reliability, and labor and workplace requirements of the three processes, and advantages of molding between the mold and a countermold in smooth faces, reliability, labor requirements, working surface and industrial hygiene are pointed out. The times and labor requirements of each step in the molding cycles are examined, and material requirements and yields, investment costs, amortization and product cost prices of the processes are compared. It is concluded that, for the specific component examined, the processes of vacuum injection and injection molding appear very interesting, with injection molding processes resulting in lower cost prices than contact molding for any production volume.

Hardware description languages

Science.gov (United States)

Tucker, Jerry H.

1994-01-01

Hardware description languages are special purpose programming languages. They are primarily used to specify the behavior of digital systems and are rapidly replacing traditional digital system design techniques. This is because they allow the designer to concentrate on how the system should operate rather than on implementation details. Hardware description languages allow a digital system to be described with a wide range of abstraction, and they support top down design techniques. A key feature of any hardware description language environment is its ability to simulate the modeled system. The two most important hardware description languages are Verilog and VHDL. Verilog has been the dominant language for the design of application specific integrated circuits (ASIC's). However, VHDL is rapidly gaining in popularity.

Reliable computer systems design and evaluatuion

CERN Document Server

Siewiorek, Daniel

2014-01-01

Enhance your hardware/software reliabilityEnhancement of system reliability has been a major concern of computer users and designers ¦ and this major revision of the 1982 classic meets users' continuing need for practical information on this pressing topic. Included are case studies of reliablesystems from manufacturers such as Tandem, Stratus, IBM, and Digital, as well as coverage of special systems such as the Galileo Orbiter fault protection system and AT&T telephone switching processors.

REQUIREMENTS AND GUIDELINES FOR NSLS EXPERIMENTAL BEAM LINE VACUUM SYSTEMS-REVISION B

International Nuclear Information System (INIS)

FOERSTER, C.

1999-01-01

Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas after a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, more energetic photons of the x-ray ring, beryllium windows are used at various beam line locations so that the monochromator, mirror box or sample chamber may be used in a helium atmosphere or rough vacuum. The window separates ring vacuum from the environment of the downstream beam line components. The stored beam lifetime in the storage rings and the maintenance of desirable reflection properties of optical surfaces depend upon hydrocarbon-free, ultra-high vacuum systems. Storage ring vacuum systems will operate at pressures of ∼ 1 x 10 -10 Torr without beam and ∼ 1 x 10 -9 Torr with beam. Systems are free of hydrocarbons in the sense that no pumps, valves, etc. containing organics are used. Components are all-metal, chemically cleaned and bakeable. To the extent that beam lines share a common vacuum with the storage ring, the same criteria will hold for beam line components. The design philosophy for NSLS beam lines is to use all-metal, hydrocarbon-free front end components and recommend that experimenters use this approach for common vacuum hardware downstream of front ends. O-ring-sealed valves, if used, are not

Motor actuated vacuum door. [for photography from sounding rockets

Science.gov (United States)

Hanagud, A. V.

1986-01-01

Doors that allow scientific instruments to record and retrieve the observed data are often required to be designed and installed as a part of sounding rocket hardware. The motor-actuated vacuum door was designed to maintain a medium vacuum of the order of 0.0001 torr or better while closed, and to provide an opening 15 inches long x 8.5 inches wide while open for cameras to image Halley's comet. When the electric motor receives the instruction to open the door through the payload battery, timer, and relay circuit, the first operation is to unlock the door. After unlatching, the torque transmitted by the motor to the main shaft through the links opens the door. A microswitch actuator, which rides on the linear motion conversion mechanism, is adjusted to trip the limit switch at the end of the travel. The process is repeated in the reverse order to close the door. 'O' rings are designed to maintain the seal. Door mechanisms similar to the one described have flown on Aerobee 17.018 and Black Brant 27.047 payloads.

Leybold vacuum handbook

CERN Document Server

Diels, K; Diels, Kurt

1966-01-01

Leybold Vacuum Handbook presents a collection of data sets that are essential for numerical calculation of vacuum plants and vacuum processes. The title first covers vacuum physics, which includes gas kinetics, flow phenomena, vacuum gauges, and vapor removal. Next, the selection presents data on vacuum, high vacuum process technology, and gas desorption and gettering. The text also deals with materials, vapor pressure, boiling and melting points, and gas permeability. The book will be of great interest to engineers and technicians that deals with vacuum related technologies.

Vacuum Technology

Energy Technology Data Exchange (ETDEWEB)

Biltoft, P J

2004-10-15

The environmental condition called vacuum is created any time the pressure of a gas is reduced compared to atmospheric pressure. On earth we typically create a vacuum by connecting a pump capable of moving gas to a relatively leak free vessel. Through operation of the gas pump the number of gas molecules per unit volume is decreased within the vessel. As soon as one creates a vacuum natural forces (in this case entropy) work to restore equilibrium pressure; the practical effect of this is that gas molecules attempt to enter the evacuated space by any means possible. It is useful to think of vacuum in terms of a gas at a pressure below atmospheric pressure. In even the best vacuum vessels ever created there are approximately 3,500,000 molecules of gas per cubic meter of volume remaining inside the vessel. The lowest pressure environment known is in interstellar space where there are approximately four molecules of gas per cubic meter. Researchers are currently developing vacuum technology components (pumps, gauges, valves, etc.) using micro electro mechanical systems (MEMS) technology. Miniature vacuum components and systems will open the possibility for significant savings in energy cost and will open the doors to advances in electronics, manufacturing and semiconductor fabrication. In conclusion, an understanding of the basic principles of vacuum technology as presented in this summary is essential for the successful execution of all projects that involve vacuum technology. Using the principles described above, a practitioner of vacuum technology can design a vacuum system that will achieve the project requirements.

Indian Vacuum Society: The Indian Vacuum Society

Science.gov (United States)

Saha, T. K.

2008-03-01

The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of

Hardware emulation of Memristor based Ternary Content Addressable Memory

KAUST Repository

Bahloul, Mohamed A.

2017-12-13

MTCAM (Memristor Ternary Content Addressable Memory) is a special purpose storage medium in which data could be retrieved based on the stored content. Using Memristors as the main storage element provides the potential of achieving higher density and more efficient solutions than conventional methods. A key missing item in the validation of such approaches is the wide spread availability of hardware emulation platforms that can provide reliable and repeatable performance statistics. In this paper, we present a hardware MTCAM emulation based on 2-Transistors-2Memristors (2T2M) bit-cell. It builds on a bipolar memristor model with storing and fetching capabilities based on the actual current-voltage behaviour. The proposed design offers a flexible verification environment with quick design revisions, high execution speeds and powerful debugging techniques. The proposed design is modeled using VHDL and prototyped on Xilinx Virtex® FPGA.

Hardware emulation of Memristor based Ternary Content Addressable Memory

KAUST Repository

Bahloul, Mohamed A.; Naous, Rawan; Masmoudi, M.

2017-01-01

MTCAM (Memristor Ternary Content Addressable Memory) is a special purpose storage medium in which data could be retrieved based on the stored content. Using Memristors as the main storage element provides the potential of achieving higher density and more efficient solutions than conventional methods. A key missing item in the validation of such approaches is the wide spread availability of hardware emulation platforms that can provide reliable and repeatable performance statistics. In this paper, we present a hardware MTCAM emulation based on 2-Transistors-2Memristors (2T2M) bit-cell. It builds on a bipolar memristor model with storing and fetching capabilities based on the actual current-voltage behaviour. The proposed design offers a flexible verification environment with quick design revisions, high execution speeds and powerful debugging techniques. The proposed design is modeled using VHDL and prototyped on Xilinx Virtex® FPGA.

Development of Hardware and Software for Automated Ultrasonic Testing

International Nuclear Information System (INIS)

Choi, Sung Nam; Lee, Hee Jong; Yang, Seung Ok

2012-01-01

Nondestructive testing (NDT) for the construction and operating of NPPs plays an important role in confirming the integrity of the NPPs. Especially, Automated ultrasonic testing (AUT) is one of the primary nondestructive examination methods for in-service inspection of the welding parts in major components in NPPs. AUT is a reliable nondestructive testing because the data of AUT are saved and reviewed with other examiners. Korea Hydro and Nuclear Power-Central Research Institute (KHNP-CRI) has developed an automated ultrasonic testing (AUT) system based on a high speed pulser-receiver. In combination with the designed software and hardware architecture, this new system permits user configurations for a wide range of user-specific applications through fully automated inspections using compact portable systems with up to eight channels. This paper gives an overview of hardware (H/W) and software (S/W) for the AUT system to inspect welds in NPPs

Analytical approach for confirming the achievement of LMFBR reliability goals

International Nuclear Information System (INIS)

Ingram, G.E.; Elerath, J.G.; Wood, A.P.

1981-01-01

The approach, recommended by GE-ARSD, for confirming the achievement of LMFBR reliability goals relies upon a comprehensive understanding of the physical and operational characteristics of the system and the environments to which the system will be subjected during its operational life. This kind of understanding is required for an approach based on system hardware testing or analyses, as recommended in this report. However, for a system as complex and expensive as the LMFBR, an approach which relies primarily on system hardware testing would be prohibitive both in cost and time to obtain the required system reliability test information. By using an analytical approach, results of tests (reliability and functional) at a low level within the specific system of interest, as well as results from other similar systems can be used to form the data base for confirming the achievement of the system reliability goals. This data, along with information relating to the design characteristics and operating environments of the specific system, will be used in the assessment of the system's reliability

Testing FlexRay ECUs with a hardware-in-the-loop simulator; Test von FlexRay-Steuergeraeten am Hardware-in-the-Loop Simulator

Energy Technology Data Exchange (ETDEWEB)

Stroop, J.; Koehl, S. [dSPACE GmbH, Paderborn (Germany); Peller, M.; Riedesser, P. [BMW AG, Muenchen (Germany)

2005-07-01

To master the data communication of complex and safety relevant systems within future vehicles, the BMW Group prepares the application of FlexRay. The accompanying development process plays an important role for the quality, stability and reliability of those systems. Hardware-in-the-loop simulation and test stands are indispensable constituents and they are an integral part of the validation process. The following contribution describes the technology that is used within the BMW Group in more detail, especially in terms of communication networks with FlexRay. (orig.)

Design and hardware alternatives for a Safety-Parameter Display System

International Nuclear Information System (INIS)

Honeycutt, F.; Merten, W.T.; Roy, G.M.; Segraves, E.; Stone, G.P.

1981-05-01

The SPDS is a dedicated control room operator aid and is viewed as an important safety improvement within the context of other post-TMI fixes. Hardware configurations and components to implement the NSAC display format of a Safety Parameter Display System (SPDS) are evaluated. The evaluation was made on the basis of five alternative hardware configurations which use commercially available components. Four of the alternatives use computer/video display architecture. The fifth alternative is a simple hardwired system which uses strip chart recorders. SPDS regulatory requirements are defined by NUREG 0696. Overall feasibility of the NSAC concept was evaluated in terms of performance, reliability, cost, licensability, and flexibility. The flexibility evaluation relates to the ability to handle other display formats, the data acquisition needs of the other emergency facilities and the impact of expected future NRC requirements

Foundations of hardware IP protection

CERN Document Server

Torres, Lionel

2017-01-01

This book provides a comprehensive and up-to-date guide to the design of security-hardened, hardware intellectual property (IP). Readers will learn how IP can be threatened, as well as protected, by using means such as hardware obfuscation/camouflaging, watermarking, fingerprinting (PUF), functional locking, remote activation, hidden transmission of data, hardware Trojan detection, protection against hardware Trojan, use of secure element, ultra-lightweight cryptography, and digital rights management. This book serves as a single-source reference to design space exploration of hardware security and IP protection. · Provides readers with a comprehensive overview of hardware intellectual property (IP) security, describing threat models and presenting means of protection, from integrated circuit layout to digital rights management of IP; · Enables readers to transpose techniques fundamental to digital rights management (DRM) to the realm of hardware IP security; · Introduce designers to the concept of salutar...

Hardware security and trust design and deployment of integrated circuits in a threatened environment

CERN Document Server

Chaves, Ricardo; Natale, Giorgio; Regazzoni, Francesco

2017-01-01

This book provides a comprehensive introduction to hardware security, from specification to implementation. Applications discussed include embedded systems ranging from small RFID tags to satellites orbiting the earth. The authors describe a design and synthesis flow, which will transform a given circuit into a secure design incorporating counter-measures against fault attacks. In order to address the conflict between testability and security, the authors describe innovative design-for-testability (DFT) computer-aided design (CAD) tools that support security challenges, engineered for compliance with existing, commercial tools. Secure protocols are discussed, which protect access to necessary test infrastructures and enable the design of secure access controllers. Covers all aspects of hardware security including design, manufacturing, testing, reliability, validation and utilization; Describes new methods and algorithms for the identification/detection of hardware trojans; Defines new architectures capable o...

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Data manual

International Nuclear Information System (INIS)

Gilbert, B.G.; Reece, W.J.; Gertman, D.I.; Gilmore, W.E.; Galyean, W.J.

1990-12-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability and hardware component failure data. The NUCLARR system software resides on an IBM (or compatible) personal computer. NUCLARR can furnish the end user with data inputs for both human and hardware reliability analysis in support of a variety of risk assessment activities. The NUCLARR system is documented is a five-volume series of reports. Volume V: Data Manual provides a hard-copy representation of all data and related information available within the NUCLARR system software. This document is organized in three sections. Part 1 is the summary description, which presents an overview of the NUCLARR system and data processing procedures. Part 2 contains all data and information relevant to the human error probability (HEP) data side of NUCLARR. Data and information for the hardware component failure data (HCFD) side are presented in Part 3. 7 refs

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Data manual

International Nuclear Information System (INIS)

Gilbert, B.G.; Reece, W.J.; Gertman, D.I.; Gilmore, W.E.; Galyean, W.J.

1990-12-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability and hardware component failure data. The NUCLARR system software resides on an IBM (or compatible) personal computer. NUCLARR can furnish the end user with data inputs for both human and hardware reliability analysis in support of a variety of risk assessment activities. The NUCLARR system is documented in a five-volume series of reports. Volume V: Data Manual provides a hard-copy representation of all data and related information available within the NUCLARR system software. This document is organized in three sections. Part 1 is the summary description, which presents an overview of the NUCLARR system and data processing procedures. Part 2 contains all data and information relevant to the human error probability (HEP) side of NUCLARR. Data and information for the hardware component failure data (HCFD) side are presented in Part 3. 7 refs., 1 fig

Low mass large aperture vacuum window development at CEBAF

International Nuclear Information System (INIS)

Keppel, C.

1995-01-01

Large aperture low mass vacuum windows are being developed for the HMS (High Momentum Spectrometer) and SOS (Short Orbit Spectrometer) spectrometers in Hall C at CEBAF. Because multiple scattering degrades the performance of a spectrometer it is important that the volume be evacuated and that the entrance and exit windows be as low mass as possible. The material used for such windows must be thin and light enough so as to have minimum effect of the beam, and at the same time, be thick and strong enough to operate reliably and safely. To achieve these goals, composite vacuum windows have been constructed of a thin sheet of Mylar with a reinforcing fabric. Reinforcing fabrics such as Kevlar and Spectra are available with tensile strengths significantly greater than that of Mylar. A thin layer of Myler remains necessary since the fabrics cannot achieve any sort of vacuum seal. The design, fabrication, testing, and operating experience with such composite windows for the Hall C spectrometers will be discussed

At Home in Service Discovery

NARCIS (Netherlands)

Sundramoorthy, V.

2006-01-01

Modern computer systems (since 1950s) evolved from being bulky, unreliable and expensive, to being tiny, reliable, cheaper and faster. Improvements in size, expense and performance was due to the evolution in computer hardware; from vacuum tubes, magnetic tapes, integrated circuits, to very

Open hardware for open science

CERN Multimedia

CERN Bulletin

2011-01-01

Inspired by the open source software movement, the Open Hardware Repository was created to enable hardware developers to share the results of their R&D activities. The recently published CERN Open Hardware Licence offers the legal framework to support this knowledge and technology exchange.   Two years ago, a group of electronics designers led by Javier Serrano, a CERN engineer, working in experimental physics laboratories created the Open Hardware Repository (OHR). This project was initiated in order to facilitate the exchange of hardware designs across the community in line with the ideals of “open science”. The main objectives include avoiding duplication of effort by sharing results across different teams that might be working on the same need. “For hardware developers, the advantages of open hardware are numerous. For example, it is a great learning tool for technologies some developers would not otherwise master, and it avoids unnecessary work if someone ha...

REQUIREMENTS AND GUIDELINES FOR NSLS EXPERIMENTAL BEAM LINE VACUUM SYSTEMS-REVISION B.

Energy Technology Data Exchange (ETDEWEB)

FOERSTER,C.

1999-05-01

Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas after a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, more energetic photons of the x-ray ring, beryllium windows are used at various beam line locations so that the monochromator, mirror box or sample chamber may be used in a helium atmosphere or rough vacuum. The window separates ring vacuum from the environment of the downstream beam line components. The stored beam lifetime in the storage rings and the maintenance of desirable reflection properties of optical surfaces depend upon hydrocarbon-free, ultra-high vacuum systems. Storage ring vacuum systems will operate at pressures of {approximately} 1 x 10{sup {minus}10} Torr without beam and {approximately} 1 x 10{sup {minus}9} Torr with beam. Systems are free of hydrocarbons in the sense that no pumps, valves, etc. containing organics are used. Components are all-metal, chemically cleaned and bakeable. To the extent that beam lines share a common vacuum with the storage ring, the same criteria will hold for beam line components. The design philosophy for NSLS beam lines is to use all-metal, hydrocarbon-free front end components and recommend that experimenters use this approach for common vacuum hardware

Studies of structural material degassing in cryogenic vacuum technique

International Nuclear Information System (INIS)

Koshmarov, Yu.A.; Kupriyanov, V.I.; Ivanov, A.E.; Chubarov, E.V.; Dryamov, V.A.

1976-01-01

The choice and design of cryogenic vacuum pumping equipment require a reliable knowledge of qualitative and quantitative gassing parameters characteristic of the structural materials now in use. The gassing study has been made on the plates of stainless steel, copper and aluminium at a pressure of 1.33 (10 -3 -10 -5 ) Pa (10 -5 -10 -7 mm Hg) at room temperature and degassing duration up to 50 hours. An approximate method is proposed for the determination of the diffusion coefficients initial concentration of dissolved in metals gases, and gaseous exchange coefficient for various components of the gas dissolved in steel copper and aluminium alloys. The data obtained permit the designing of pumping equipment for various vacuum systems

Open Hardware Business Models

OpenAIRE

Edy Ferreira

2008-01-01

In the September issue of the Open Source Business Resource, Patrick McNamara, president of the Open Hardware Foundation, gave a comprehensive introduction to the concept of open hardware, including some insights about the potential benefits for both companies and users. In this article, we present the topic from a different perspective, providing a classification of market offers from companies that are making money with open hardware.

Evolution of gettering technologies for vacuum tubes to getters for MEMS

Science.gov (United States)

Amiotti, M.

2008-05-01

Getter materials are technically proven and industrially accepted practical ways to maintain vacuum inside hermetically sealed tubes or devices to assure high reliability and long lifetime of the operating devices. The most industrially proven vacuum tube is the cathode rays tubes (CRTs), where large surfaces are available for the deposition of an evaporated barium film by a radio frequency inductive heating of a stainless steel container filled with a BaAl4 powder mixed to Ni powder. The evolution of the CRTs manufacturing technologies required also new types of barium getters able to withstand some thermal process in air without any deterioration of the evaporation characteristics. In other vacuum tubes such as traveling waves tubes, the space available for the evaporation of a barium film and the sorption capacity required to assure the vacuum for the lifetime of the devices did not allow the use of the barium film, prompting the development of sintered non evaporable getter pills that can be activated during the manufacturing process or by flowing current through an embedded resistance. The same sintered non evaporable getter pills could find usage also in evacuated parts to thermally isolate the infrared sensors for different final applications. In high energy physics particle accelerators, the getter technology moved from localized vacuum getter pumps or getter strips to a getter coating over the surface of vacuum chambers in order to guarantee a more uniform pumping speed. With the advent of solid state electronics, new challenges faced the getter technology to assure long life to vacuum or inert gas filled hermetical packages containing microelectronic devices, especially in the telecommunication and military applications. A well known problem of GaAs devices with Pd or Pt metalization is the H2 poisoning of the metal gate: to prevent this degradation a two layer getter film has been develop to absorb a large quantity of H2 per unit of getter surface. The

Reliability and protection against failure in computer systems

International Nuclear Information System (INIS)

Daniels, B.K.

1979-01-01

Computers are being increasingly integrated into the control and safety systems of large and potentially hazardous industrial processes. This development introduces problems which are particular to computer systems and opens the way to new techniques of solving conventional reliability and availability problems. References to the developing fields of software reliability, human factors and software design are given, and these subjects are related, where possible, to the quantified assessment of reliability. Original material is presented in the areas of reliability growth and computer hardware failure data. The report draws on the experience of the National Centre of Systems Reliability in assessing the capability and reliability of computer systems both within the nuclear industry, and from the work carried out in other industries by the Systems Reliability Service. (author)

Open Hardware Business Models

Directory of Open Access Journals (Sweden)

Edy Ferreira

2008-04-01

Full Text Available In the September issue of the Open Source Business Resource, Patrick McNamara, president of the Open Hardware Foundation, gave a comprehensive introduction to the concept of open hardware, including some insights about the potential benefits for both companies and users. In this article, we present the topic from a different perspective, providing a classification of market offers from companies that are making money with open hardware.

Contamination due to memory effects in filtered vacuum arc plasma deposition systems

CERN Document Server

Martins, D R; Verdonck, P; Brown, I G

2002-01-01

Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.

Contamination due to memory effects in filtered vacuum arc plasma deposition systems

International Nuclear Information System (INIS)

Martins, D.R.; Salvadori, M.C.; Verdonck, P.; Brown, I.G.

2002-01-01

Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the stopping and range of ions in matter code. We find film contamination of the order of 10 -4 -10 -3 , and the memory of the prior history of the deposition hardware can be relatively long lasting

Contamination due to memory effects in filtered vacuum arc plasma deposition systems

Energy Technology Data Exchange (ETDEWEB)

Martins, D.R.; Salvadori, M.C.; Verdonck, P.; Brown, I.G.

2002-08-13

Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.

Review of Software Reliability Assessment Methodologies for Digital I and C Software of Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Cho, Jae Hyun; Lee, Seung Jun; Jung, Won Dea [KAERI, Daejeon (Korea, Republic of)

2014-08-15

Digital instrumentation and control (I and C) systems are increasingly being applied to current nuclear power plants (NPPs) due to its advantages; zero drift, advanced data calculation capacity, and design flexibility. Accordingly, safety issues of software that is main part of the digital I and C system have been raised. As with hardware components, the software failure in NPPs could lead to a large disaster, therefore failure rate test and reliability assessment of software should be properly performed, and after that adopted in NPPs. However, the reliability assessment of the software is quite different with that of hardware, owing to the nature difference between software and hardware. The one of the most different thing is that the software failures arising from design faults as 'error crystal', whereas the hardware failures are caused by deficiencies in design, production, and maintenance. For this reason, software reliability assessment has been focused on the optimal release time considering the economy. However, the safety goal and public acceptance of the NPPs is so distinctive with other industries that the software in NPPs is dependent on reliability quantitative value rather than economy. The safety goal of NPPs compared to other industries is exceptionally high, so conventional methodologies on software reliability assessment already used in other industries could not adjust to safety goal of NPPs. Thus, the new reliability assessment methodology of the software of digital I and C on NPPs need to be developed. In this paper, existing software reliability assessment methodologies are reviewed to obtain the pros and cons of them, and then to assess the usefulness of each method to software of NPPs.

Review of Software Reliability Assessment Methodologies for Digital I and C Software of Nuclear Power Plants

International Nuclear Information System (INIS)

Cho, Jae Hyun; Lee, Seung Jun; Jung, Won Dea

2014-01-01

Digital instrumentation and control (I and C) systems are increasingly being applied to current nuclear power plants (NPPs) due to its advantages; zero drift, advanced data calculation capacity, and design flexibility. Accordingly, safety issues of software that is main part of the digital I and C system have been raised. As with hardware components, the software failure in NPPs could lead to a large disaster, therefore failure rate test and reliability assessment of software should be properly performed, and after that adopted in NPPs. However, the reliability assessment of the software is quite different with that of hardware, owing to the nature difference between software and hardware. The one of the most different thing is that the software failures arising from design faults as 'error crystal', whereas the hardware failures are caused by deficiencies in design, production, and maintenance. For this reason, software reliability assessment has been focused on the optimal release time considering the economy. However, the safety goal and public acceptance of the NPPs is so distinctive with other industries that the software in NPPs is dependent on reliability quantitative value rather than economy. The safety goal of NPPs compared to other industries is exceptionally high, so conventional methodologies on software reliability assessment already used in other industries could not adjust to safety goal of NPPs. Thus, the new reliability assessment methodology of the software of digital I and C on NPPs need to be developed. In this paper, existing software reliability assessment methodologies are reviewed to obtain the pros and cons of them, and then to assess the usefulness of each method to software of NPPs

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Guide to data processing and revision: Part 3, Hardware component failure data entry and revision procedures

International Nuclear Information System (INIS)

Gilmore, W.E.; Gertman, D.I.; Gilbert, B.G.; Reece, W.J.

1988-11-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability (HEP) and hardware component failure data (HCFD). The NUCLARR system software resides on an IBM (or compatible) personal micro-computer. Users can perform data base searches to furnish HEP estimates and HCFD rates. In this manner, the NUCLARR system can be used to support a variety of risk assessment activities. This volume, Volume 3 of a 5-volume series, presents the procedures used to process HEP and HCFD for entry in NUCLARR and describes how to modify the existing NUCLARR taxonomy in order to add equipment types of action verbs. Volume 3 also specifies the various roles of the administrative staff on assignment to the NUCLARR Clearinghouse who are tasked with maintaining the data base, dealing with user requests, and processing NUCLARR data

Mass and Reliability System (MaRS)

Science.gov (United States)

Barnes, Sarah

2016-01-01

The Safety and Mission Assurance (S&MA) Directorate is responsible for mitigating risk, providing system safety, and lowering risk for space programs from ground to space. The S&MA is divided into 4 divisions: The Space Exploration Division (NC), the International Space Station Division (NE), the Safety & Test Operations Division (NS), and the Quality and Flight Equipment Division (NT). The interns, myself and Arun Aruljothi, will be working with the Risk & Reliability Analysis Branch under the NC Division's. The mission of this division is to identify, characterize, diminish, and communicate risk by implementing an efficient and effective assurance model. The team utilizes Reliability and Maintainability (R&M) and Probabilistic Risk Assessment (PRA) to ensure decisions concerning risks are informed, vehicles are safe and reliable, and program/project requirements are realistic and realized. This project pertains to the Orion mission, so it is geared toward a long duration Human Space Flight Program(s). For space missions, payload is a critical concept; balancing what hardware can be replaced by components verse by Orbital Replacement Units (ORU) or subassemblies is key. For this effort a database was created that combines mass and reliability data, called Mass and Reliability System or MaRS. The U.S. International Space Station (ISS) components are used as reference parts in the MaRS database. Using ISS components as a platform is beneficial because of the historical context and the environment similarities to a space flight mission. MaRS uses a combination of systems: International Space Station PART for failure data, Vehicle Master Database (VMDB) for ORU & components, Maintenance & Analysis Data Set (MADS) for operation hours and other pertinent data, & Hardware History Retrieval System (HHRS) for unit weights. MaRS is populated using a Visual Basic Application. Once populated, the excel spreadsheet is comprised of information on ISS components including

Wafer-level vacuum/hermetic packaging technologies for MEMS

Science.gov (United States)

Lee, Sang-Hyun; Mitchell, Jay; Welch, Warren; Lee, Sangwoo; Najafi, Khalil

2010-02-01

An overview of wafer-level packaging technologies developed at the University of Michigan is presented. Two sets of packaging technologies are discussed: (i) a low temperature wafer-level packaging processes for vacuum/hermeticity sealing, and (ii) an environmentally resistant packaging (ERP) technology for thermal and mechanical control as well as vacuum packaging. The low temperature wafer-level encapsulation processes are implemented using solder bond rings which are first patterned on a cap wafer and then mated with a device wafer in order to encircle and encapsulate the device at temperatures ranging from 200 to 390 °C. Vacuum levels below 10 mTorr were achieved with yields in an optimized process of better than 90%. Pressures were monitored for more than 4 years yielding important information on reliability and process control. The ERP adopts an environment isolation platform in the packaging substrate. The isolation platform is designed to provide low power oven-control, vibration isolation and shock protection. It involves batch flip-chip assembly of a MEMS device onto the isolation platform wafer. The MEMS device and isolation structure are encapsulated at the wafer-level by another substrate with vertical feedthroughs for vacuum/hermetic sealing and electrical signal connections. This technology was developed for high performance gyroscopes, but can be applied to any type of MEMS device.

Vacuum Large Current Parallel Transfer Numerical Analysis

Directory of Open Access Journals (Sweden)

Enyuan Dong

2014-01-01

Full Text Available The stable operation and reliable breaking of large generator current are a difficult problem in power system. It can be solved successfully by the parallel interrupters and proper timing sequence with phase-control technology, in which the strategy of breaker’s control is decided by the time of both the first-opening phase and second-opening phase. The precise transfer current’s model can provide the proper timing sequence to break the generator circuit breaker. By analysis of the transfer current’s experiments and data, the real vacuum arc resistance and precise correctional model in the large transfer current’s process are obtained in this paper. The transfer time calculated by the correctional model of transfer current is very close to the actual transfer time. It can provide guidance for planning proper timing sequence and breaking the vacuum generator circuit breaker with the parallel interrupters.

Microwave and RF vacuum electronic power sources

CERN Document Server

Carter, Richard G

2018-01-01

Do you design and build vacuum electron devices, or work with the systems that use them? Quickly develop a solid understanding of how these devices work with this authoritative guide, written by an author with over fifty years of experience in the field. Rigorous in its approach, it focuses on the theory and design of commercially significant types of gridded, linear-beam, crossed-field and fast-wave tubes. Essential components such as waveguides, resonators, slow-wave structures, electron guns, beams, magnets and collectors are also covered, as well as the integration and reliable operation of devices in microwave and RF systems. Complex mathematical analysis is kept to a minimum, and Mathcad worksheets supporting the book online aid understanding of key concepts and connect the theory with practice. Including coverage of primary sources and current research trends, this is essential reading for researchers, practitioners and graduate students working on vacuum electron devices.

Open Hardware at CERN

CERN Multimedia

CERN Knowledge Transfer Group

2015-01-01

CERN is actively making its knowledge and technology available for the benefit of society and does so through a variety of different mechanisms. Open hardware has in recent years established itself as a very effective way for CERN to make electronics designs and in particular printed circuit board layouts, accessible to anyone, while also facilitating collaboration and design re-use. It is creating an impact on many levels, from companies producing and selling products based on hardware designed at CERN, to new projects being released under the CERN Open Hardware Licence. Today the open hardware community includes large research institutes, universities, individual enthusiasts and companies. Many of the companies are actively involved in the entire process from design to production, delivering services and consultancy and even making their own products available under open licences.

Design and Construction of the NSTX Bakeout, Cooling and Vacuum Systems

International Nuclear Information System (INIS)

Dudek, L.E.; Kalish, M.; Gernhardt, R.; Parsells, R.F.; Blanchard, W.

1999-01-01

This paper will describe the design, construction and initial operation of the NSTX bakeout, water cooling and vacuum systems. The bakeout system is designed for two modes of operation. The first mode allows heating of the first wall components to 350 degrees C while the external vessel is cooled to 150 degrees C. The second mode cools the first wall to 150 degrees C and the external vessel to 50 degrees C. The system uses a low viscosity heat transfer oil which is capable of high temperature low pressure operation. The NSTX Torus Vacuum Pumping System (TVPS) is designed to achieve a base pressure of approximately 1x10 (superscript -8) Torr and to evacuate the plasma fuel gas loads in less than 5 minutes between discharges. The vacuum pumping system is capable of a pumping speed of approximately 3400 l/s for deuterium. The hardware consists of two turbo molecular pumps (TMPs) and a mechanical pump set consisting of a mechanical and a Roots blower pump. A PLC is used as the control system to provide remote monitoring, control and software interlock capability. The NSTX cooling water provides chilled, de ionized water for heat removal in the TF, OH and PF, power supplies, bus bar systems, and various diagnostics. The system provides flow monitoring via a PLC to prevent damage due to loss of flow

Reliability and Maintainability (RAM) Training

Science.gov (United States)

Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Packard, Michael H. (Editor)

2000-01-01

The theme of this manual is failure physics-the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low-cost reliable products. In a broader sense the manual should do more. It should underscore the urgent need CI for mature attitudes toward reliability. Five of the chapters were originally presented as a classroom course to over 1000 Martin Marietta engineers and technicians. Another four chapters and three appendixes have been added, We begin with a view of reliability from the years 1940 to 2000. Chapter 2 starts the training material with a review of mathematics and a description of what elements contribute to product failures. The remaining chapters elucidate basic reliability theory and the disciplines that allow us to control and eliminate failures.

Evolution of gettering technologies for vacuum tubes to getters for MEMS

Energy Technology Data Exchange (ETDEWEB)

Amiotti, M [SAES Getters S.p.A., Viale Italia 77, 20020 Lainate, Milano (Italy)], E-mail: Marco_Amiotti@saes-group.com

2008-05-01

Getter materials are technically proven and industrially accepted practical ways to maintain vacuum inside hermetically sealed tubes or devices to assure high reliability and long lifetime of the operating devices. The most industrially proven vacuum tube is the cathode rays tubes (CRTs), where large surfaces are available for the deposition of an evaporated barium film by a radio frequency inductive heating of a stainless steel container filled with a BaAl{sub 4} powder mixed to Ni powder. The evolution of the CRTs manufacturing technologies required also new types of barium getters able to withstand some thermal process in air without any deterioration of the evaporation characteristics. In other vacuum tubes such as traveling waves tubes, the space available for the evaporation of a barium film and the sorption capacity required to assure the vacuum for the lifetime of the devices did not allow the use of the barium film, prompting the development of sintered non evaporable getter pills that can be activated during the manufacturing process or by flowing current through an embedded resistance. The same sintered non evaporable getter pills could find usage also in evacuated parts to thermally isolate the infrared sensors for different final applications. In high energy physics particle accelerators, the getter technology moved from localized vacuum getter pumps or getter strips to a getter coating over the surface of vacuum chambers in order to guarantee a more uniform pumping speed. With the advent of solid state electronics, new challenges faced the getter technology to assure long life to vacuum or inert gas filled hermetical packages containing microelectronic devices, especially in the telecommunication and military applications. A well known problem of GaAs devices with Pd or Pt metalization is the H{sub 2} poisoning of the metal gate: to prevent this degradation a two layer getter film has been develop to absorb a large quantity of H{sub 2} per unit of

Mission Management Computer and Sequencing Hardware for RLV-TD HEX-01 Mission

Science.gov (United States)

Gupta, Sukrat; Raj, Remya; Mathew, Asha Mary; Koshy, Anna Priya; Paramasivam, R.; Mookiah, T.

2017-12-01

Reusable Launch Vehicle-Technology Demonstrator Hypersonic Experiment (RLV-TD HEX-01) mission posed some unique challenges in the design and development of avionics hardware. This work presents the details of mission critical avionics hardware mainly Mission Management Computer (MMC) and sequencing hardware. The Navigation, Guidance and Control (NGC) chain for RLV-TD is dual redundant with cross-strapped Remote Terminals (RTs) interfaced through MIL-STD-1553B bus. MMC is Bus Controller on the 1553 bus, which does the function of GPS aided navigation, guidance, digital autopilot and sequencing for the RLV-TD launch vehicle in different periodicities (10, 20, 500 ms). Digital autopilot execution in MMC with a periodicity of 10 ms (in ascent phase) is introduced for the first time and successfully demonstrated in the flight. MMC is built around Intel i960 processor and has inbuilt fault tolerance features like ECC for memories. Fault Detection and Isolation schemes are implemented to isolate the failed MMC. The sequencing hardware comprises Stage Processing System (SPS) and Command Execution Module (CEM). SPS is `RT' on the 1553 bus which receives the sequencing and control related commands from MMCs and posts to downstream modules after proper error handling for final execution. SPS is designed as a high reliability system by incorporating various fault tolerance and fault detection features. CEM is a relay based module for sequence command execution.

PCI hardware support in LIA-2 control system

International Nuclear Information System (INIS)

Bolkhovityanov, D.; Cheblakov, P.

2012-01-01

The control system of the LIA-2 accelerator is built on cPCI crates with *86- compatible processor boards running Linux. Slow electronics is connected via CAN-bus, while fast electronics (4 MHz and 200 MHz fast ADCs and 200 MHz timers) are implemented as cPCI/PMC modules. Several ways to drive PCI control electronics in Linux were examined. Finally a user-space drivers approach was chosen. These drivers communicate with hardware via a small kernel module, which provides access to PCI BARs and to interrupt handling. This module was named USPCI (User-Space PCI access). This approach dramatically simplifies creation of drivers, as opposed to kernel drivers, and provides high reliability (because only a tiny and thoroughly-debugged piece of code runs in kernel). LIA-2 accelerator was successfully commissioned, and the solution chosen has proven adequate and very easy to use. Besides, USPCI turned out to be a handy tool for examination and debugging of PCI devices direct from command-line. In this paper available approaches to work with PCI control hardware in Linux are considered, and USPCI architecture is described. (authors)

Controlling the net charge on a nanoparticle optically levitated in vacuum

Science.gov (United States)

Frimmer, Martin; Luszcz, Karol; Ferreiro, Sandra; Jain, Vijay; Hebestreit, Erik; Novotny, Lukas

2017-06-01

Optically levitated nanoparticles in vacuum are a promising model system to test physics beyond our current understanding of quantum mechanics. Such experimental tests require extreme control over the dephasing of the levitated particle's motion. If the nanoparticle carries a finite net charge, it experiences a random Coulomb force due to fluctuating electric fields. This dephasing mechanism can be fully excluded by discharging the levitated particle. Here, we present a simple and reliable technique to control the charge on an optically levitated nanoparticle in vacuum. Our method is based on the generation of charges in an electric discharge and does not require additional optics or mechanics close to the optical trap.

MEA vacuum system

International Nuclear Information System (INIS)

Stroo, R.; Schwebke, H.; Heine, E.

1984-01-01

This report describes construction and operation of the MEA vacuum system of NIKHEF (Netherlands). First, the klystron vacuum system, beam transport system, diode pump and a triode pump are described. Next, the isolation valve and the fast valves of the vacuum system are considered. Measuring instruments, vacuum system commands and messages of failures are treated in the last chapter. (G.J.P.)

Coupling impedance of an in-vacuum undulator: Measurement, simulation, and analytical estimation

Science.gov (United States)

Smaluk, Victor; Fielder, Richard; Blednykh, Alexei; Rehm, Guenther; Bartolini, Riccardo

2014-07-01

One of the important issues of the in-vacuum undulator design is the coupling impedance of the vacuum chamber, which includes tapered transitions with variable gap size. To get complete and reliable information on the impedance, analytical estimate, numerical simulations and beam-based measurements have been performed at Diamond Light Source, a forthcoming upgrade of which includes introducing additional insertion device (ID) straights. The impedance of an already existing ID vessel geometrically similar to the new one has been measured using the orbit bump method. The measurement results in comparison with analytical estimations and numerical simulations are discussed in this paper.

Insulation vacuum and beam vacuum overpressure release

CERN Document Server

Parma, V

2009-01-01

There is evidence that the incident of 19th September caused a high pressure build-up inside the cryostat insulation vacuum which the existing overpressure devices could not contain. As a result, high longitudinal forces acting on the insulation vacuum barriers developed and broke the floor and the floor fixations of the SSS with vacuum barriers. The consequent large longitudinal displacements of the SSS damaged chains of adjacent dipole cryo-magnets. Estimates of the helium mass flow and the pressure build- up experienced in the incident are presented together with the pressure build-up for an even more hazardous event, the Maximum Credible Incident (MCI). The strategy of limiting the maximum pressure by the installation of addition pressure relieve devices is presented and discussed. Both beam vacuum lines were ruptured during the incident in sector 3-4 giving rise to both mechanical damage and pollution of the system. The sequence, causes and effects of this damage will be briefly reviewed. We will then an...

Conceptual Software Reliability Prediction Models for Nuclear Power Plant Safety Systems

International Nuclear Information System (INIS)

Johnson, G.; Lawrence, D.; Yu, H.

2000-01-01

The objective of this project is to develop a method to predict the potential reliability of software to be used in a digital system instrumentation and control system. The reliability prediction is to make use of existing measures of software reliability such as those described in IEEE Std 982 and 982.2. This prediction must be of sufficient accuracy to provide a value for uncertainty that could be used in a nuclear power plant probabilistic risk assessment (PRA). For the purposes of the project, reliability was defined to be the probability that the digital system will successfully perform its intended safety function (for the distribution of conditions under which it is expected to respond) upon demand with no unintended functions that might affect system safety. The ultimate objective is to use the identified measures to develop a method for predicting the potential quantitative reliability of a digital system. The reliability prediction models proposed in this report are conceptual in nature. That is, possible prediction techniques are proposed and trial models are built, but in order to become a useful tool for predicting reliability, the models must be tested, modified according to the results, and validated. Using methods outlined by this project, models could be constructed to develop reliability estimates for elements of software systems. This would require careful review and refinement of the models, development of model parameters from actual experience data or expert elicitation, and careful validation. By combining these reliability estimates (generated from the validated models for the constituent parts) in structural software models, the reliability of the software system could then be predicted. Modeling digital system reliability will also require that methods be developed for combining reliability estimates for hardware and software. System structural models must also be developed in order to predict system reliability based upon the reliability

Development of core technology for KNGR system design; development of quantitative reliability evaluation methodologies of KNGR digital I and C components

Energy Technology Data Exchange (ETDEWEB)

Seong, Poong Hyun; Choi, Jong Gyun; Kim, Ung Soo; Kim, Jong Hyun; Kim, Man Cheol; Lee, Seung Jun; Lee, Young Je; Ha, Jun Soo [Korea Advanced Institute of Science and Technology, Taejeon (Korea)

2002-03-01

For the digital systems to be applied to the nuclear industry, which has its unique conservertive to safety, reliability assessment of digital systems is a prerequisite. But, because digital systems show different failure modes from compared to existing analog systems, the existing reliability assessment method cannot be applied to digital systems. It means that a new reliability assessment method for digital systems should be developed. The goal of this study is development of reliability assessment method for digital systems on board level and related software tool. To achieve the goal, we have conducted researches on development of a database for hardware components for digital I and C systems, development of a reliability assessment model for the reliability prediction of digital systems on board level, and the applicability to KNGR digital I and C systems. We developed a database for reliability assessment of digital hardware components, a reliability assessment method for digital systems with consideration of software and hardware together, and a software tool for the reliability assessment of digital systems, which is named as RelPredic. We plan to apply the results of this study to the reliability assessment of digital systems in KNGR digital I and C systems. 13 refs., 71 figs., 31 tabs. (Author)

Vacuum seals design and testing for a linear accelerator of the National Spallation Neutron Source

Energy Technology Data Exchange (ETDEWEB)

Z. Chen; C. Gautier; F. Hemez; N. K. Bultman

2000-02-01

Vacuum seals are very important to ensure that the Spallation Neutron Source (SNS) Linac has an optimum vacuum system. The vacuum joints between flanges must have reliable seals to minimize the leak rate and meet vacuum and electrical requirements. In addition, it is desirable to simplify the installation and thereby also simplify the maintenance required. This report summarizes an investigation of the metal vacuum seals that include the metal C-seal, Energized Spring seal, Helcoflex Copper Delta seal, Aluminum Delta seal, delta seal with limiting ring, and the prototype of the copper diamond seals. The report also contains the material certifications, design, finite element analysis, and testing for all of these seals. It is a valuable reference for any vacuum system design. To evaluate the suitability of several types of metal seals for use in the SNS Linac and to determine the torque applied on the bolts, a series of vacuum leak rate tests on the metal seals have been completed at Los Alamos Laboratory. A copper plated flange, using the same type of delta seal that was used for testing with the stainless steel flange, has also been studied and tested. A vacuum seal is desired that requires significantly less loading than a standard ConFlat flange with a copper gasket for the coupling cavity assembly. To save the intersegment space the authors use thinner flanges in the design. The leak rate of the thin ConFlat flange with a copper gasket is a baseline for the vacuum test on all seals and thin flanges. A finite element analysis of a long coupling cavity flange with a copper delta seal has been performed in order to confirm the design of the long coupling cavity flange and the welded area of a cavity body with the flange. This analysis is also necessary to predict a potential deformation of the cavity under the combined force of atmospheric pressure and the seating load of the seal. Modeling of this assembly has been achieved using both HKS/Abaqus and COSMOS

Vacuum seals design and testing for a linear accelerator of the National Spallation Neutron Source

International Nuclear Information System (INIS)

Chen, Z.; Gautier, C.; Hemez, F.; Bultman, N.K.

2000-01-01

Vacuum seals are very important to ensure that the Spallation Neutron Source (SNS) Linac has an optimum vacuum system. The vacuum joints between flanges must have reliable seals to minimize the leak rate and meet vacuum and electrical requirements. In addition, it is desirable to simplify the installation and thereby also simplify the maintenance required. This report summarizes an investigation of the metal vacuum seals that include the metal C-seal, Energized Spring seal, Helcoflex Copper Delta seal, Aluminum Delta seal, delta seal with limiting ring, and the prototype of the copper diamond seals. The report also contains the material certifications, design, finite element analysis, and testing for all of these seals. It is a valuable reference for any vacuum system design. To evaluate the suitability of several types of metal seals for use in the SNS Linac and to determine the torque applied on the bolts, a series of vacuum leak rate tests on the metal seals have been completed at Los Alamos Laboratory. A copper plated flange, using the same type of delta seal that was used for testing with the stainless steel flange, has also been studied and tested. A vacuum seal is desired that requires significantly less loading than a standard ConFlat flange with a copper gasket for the coupling cavity assembly. To save the intersegment space the authors use thinner flanges in the design. The leak rate of the thin ConFlat flange with a copper gasket is a baseline for the vacuum test on all seals and thin flanges. A finite element analysis of a long coupling cavity flange with a copper delta seal has been performed in order to confirm the design of the long coupling cavity flange and the welded area of a cavity body with the flange. This analysis is also necessary to predict a potential deformation of the cavity under the combined force of atmospheric pressure and the seating load of the seal. Modeling of this assembly has been achieved using both HKS/Abaqus and COSMOS

Hardware protection through obfuscation

CERN Document Server

Bhunia, Swarup; Tehranipoor, Mark

2017-01-01

This book introduces readers to various threats faced during design and fabrication by today’s integrated circuits (ICs) and systems. The authors discuss key issues, including illegal manufacturing of ICs or “IC Overproduction,” insertion of malicious circuits, referred as “Hardware Trojans”, which cause in-field chip/system malfunction, and reverse engineering and piracy of hardware intellectual property (IP). The authors provide a timely discussion of these threats, along with techniques for IC protection based on hardware obfuscation, which makes reverse-engineering an IC design infeasible for adversaries and untrusted parties with any reasonable amount of resources. This exhaustive study includes a review of the hardware obfuscation methods developed at each level of abstraction (RTL, gate, and layout) for conventional IC manufacturing, new forms of obfuscation for emerging integration strategies (split manufacturing, 2.5D ICs, and 3D ICs), and on-chip infrastructure needed for secure exchange o...

Advanced light source vacuum policy and vacuum guidelines for beamlines and experiment endstations

International Nuclear Information System (INIS)

Hussain, Z.

1995-08-01

The purpose of this document is to: (1) Explain the ALS vacuum policy and specifications for beamlines and experiment endstations. (2) Provide guidelines related to ALS vacuum policy to assist in designing beamlines which are in accordance with ALS vacuum policy. This document supersedes LSBL-116. The Advanced Light Source is a third generation synchrotron radiation source whose beam lifetime depends on the quality of the vacuum in the storage ring and the connecting beamlines. The storage ring and most of the beamlines share a common vacuum and are operated under ultra-high-vacuum (UHV) conditions. All endstations and beamline equipment must be operated so as to avoid contamination of beamline components, and must include proper safeguards to protect the storage ring vacuum from an accidental break in the beamline or endstation vacuum systems. The primary gas load during operation is due to thermal desorption and electron/photon induced desorption of contaminants from the interior of the vacuum vessel and its components. The desorption rates are considerably higher for hydrocarbon contamination, thus considerable emphasis is placed on eliminating these sources of contaminants. All vacuum components in a beamline and endstation must meet the ALS vacuum specifications. The vacuum design of both beamlines and endstations must be approved by the ALS Beamline Review Committee (BRC) before vacuum connections to the storage ring are made. The vacuum design is first checked during the Beamline Design Review (BDR) held before construction of the beamline equipment begins. Any deviation from the ALS vacuum specifications must be approved by the BRC prior to installation of the equipment on the ALS floor. Any modification that is incorporated into a vacuum assembly without the written approval of the BRC is done at the user's risk and may lead to rejection of the whole assembly

The vacuum system for technological unit development and design

Science.gov (United States)

Zhukeshov, A. M.; Gabdullina, A. T.; Amrenova, A. U.; Giniyatova, Sh G.; Kaibar, A.; Sundetov, A.; Fermakhan, K.

2015-11-01

The paper shows results of development of plasma technological unit on the basis of accelerator of vacuum arc and automated system. During the previous years, the authors investigated the operation of pulsed plasma accelerator and developed unique technologies for hardening of materials. Principles of plasma formation in pulsed plasma accelerator were put into basis of the developed unit. Operation of the pulsed arc accelerator was investigated at different parameters of the charge. The developed vacuum system is designed for production of hi-tech plasma units in high technologies in fields of nanomaterials, mechanical and power engineering and production with high added value. Unlike integrated solutions, the system is a module one to allow its low cost, high reliability and simple maintenance. The problems of use of robots are discussed to modernize the technological process.

The vacuum system for technological unit development and design

International Nuclear Information System (INIS)

Zhukeshov, A M; Gabdullina, A T; Amrenova, A U; Giniyatova, Sh G; Kaibar, A; Sundetov, A; Fermakhan, K

2015-01-01

The paper shows results of development of plasma technological unit on the basis of accelerator of vacuum arc and automated system. During the previous years, the authors investigated the operation of pulsed plasma accelerator and developed unique technologies for hardening of materials. Principles of plasma formation in pulsed plasma accelerator were put into basis of the developed unit. Operation of the pulsed arc accelerator was investigated at different parameters of the charge. The developed vacuum system is designed for production of hi-tech plasma units in high technologies in fields of nanomaterials, mechanical and power engineering and production with high added value. Unlike integrated solutions, the system is a module one to allow its low cost, high reliability and simple maintenance. The problems of use of robots are discussed to modernize the technological process. (paper)

Thermoelectric Efficiency Improvement in Vacuum Tubes of Decomposing Liquid Lithium-Ammonia Solutions

International Nuclear Information System (INIS)

Lee, Jungyoon; Kim, Miae; Shim, Kyuchol; Kim, Jibeom; Jeon, Joonhyeon

2013-01-01

Lithium-ammonia (Li-NH 3 ) solutions are possible to be successfully made under the vacuum condition but there still remains a problem of undergoing stable and reliable decomposition in vacuum for high-efficiency thermoelectric power generation. This paper describes a new method for improving the thermoelectric conversion efficiency of Li-NH 3 solutions in vacuum. The proposed method uses a ‘U’-shaped Pyrex vacuum tube for the preparation and decomposition of pure fluid Li-NH 3 solutions. The tube is shaped so that a gas passageway (‘U’) connecting both legs of the ‘U’ helps to balance pressure inside both ends of the tube (due to NH 3 gasification) during decomposition on the hot side. Thermoelectric experimental results show that solution reaction in the ‘U’-shaped tube proceeds more stably and efficiently than in the ‘U’-shaped tube, and consequently, thermoelectric conversion efficiency is improved. It is also proved that the proposed method can provide a reversible reaction, which can rotate between synthesis and decomposition in the tube, for deriving the long-time, high-efficiency thermoelectric power

Battery Management System Hardware Concepts: An Overview

Directory of Open Access Journals (Sweden)

Markus Lelie

2018-03-01

Full Text Available This paper focuses on the hardware aspects of battery management systems (BMS for electric vehicle and stationary applications. The purpose is giving an overview on existing concepts in state-of-the-art systems and enabling the reader to estimate what has to be considered when designing a BMS for a given application. After a short analysis of general requirements, several possible topologies for battery packs and their consequences for the BMS’ complexity are examined. Four battery packs that were taken from commercially available electric vehicles are shown as examples. Later, implementation aspects regarding measurement of needed physical variables (voltage, current, temperature, etc. are discussed, as well as balancing issues and strategies. Finally, safety considerations and reliability aspects are investigated.

Expert System analysis of non-fuel assembly hardware and spent fuel disassembly hardware: Its generation and recommended disposal

International Nuclear Information System (INIS)

Williamson, D.A.

1991-01-01

Almost all of the effort being expended on radioactive waste disposal in the United States is being focused on the disposal of spent Nuclear Fuel, with little consideration for other areas that will have to be disposed of in the same facilities. one area of radioactive waste that has not been addressed adequately because it is considered a secondary part of the waste issue is the disposal of the various Non-Fuel Bearing Components of the reactor core. These hardware components fall somewhat arbitrarily into two categories: Non-Fuel Assembly (NFA) hardware and Spent Fuel Disassembly (SFD) hardware. This work provides a detailed examination of the generation and disposal of NFA hardware and SFD hardware by the nuclear utilities of the United States as it relates to the Civilian Radioactive Waste Management Program. All available sources of data on NFA and SFD hardware are analyzed with particular emphasis given to the Characteristics Data Base developed by Oak Ridge National Laboratory and the characterization work performed by Pacific Northwest Laboratories and Rochester Gas ampersand Electric. An Expert System developed as a portion of this work is used to assist in the prediction of quantities of NFA hardware and SFD hardware that will be generated by the United States' utilities. Finally, the hardware waste management practices of the United Kingdom, France, Germany, Sweden, and Japan are studied for possible application to the disposal of domestic hardware wastes. As a result of this work, a general classification scheme for NFA and SFD hardware was developed. Only NFA and SFD hardware constructed of zircaloy and experiencing a burnup of less than 70,000 MWD/MTIHM and PWR control rods constructed of stainless steel are considered Low-Level Waste. All other hardware is classified as Greater-ThanClass-C waste

Progress on the Design of the Storage Ring Vacuum System for the Advanced Photon Source Upgrade Project

Energy Technology Data Exchange (ETDEWEB)

Stillwell, B.; Billett, B.; Brajuskovic, B.; Carter, J.; Kirkus, E.; Lale, M.; Lerch, J.; Noonan, J.; O' Neill, M.; Rocke, B.; Suthar, K.; Walters, D.; Wiemerslage, G.; Zientek, J.

2017-06-20

Recent work on the design of the storage ring vacuum system for the Advanced Photon Source Upgrade project (APS-U) includes: revising the vacuum system design to accommodate a new lattice with reverse bend magnets, modifying the designs of vacuum chambers in the FODO sections for more intense incident synchrotron radiation power, modifying the design of rf-shielding bellows liners for better performance and reliability, modifying photon absorber designs to make better use of available space, and integrated planning of components needed in the injection, extraction and rf cavity straight sections. An overview of progress in these areas is presented.

The interaction of vacuum arcs with magnetic fields and applications

International Nuclear Information System (INIS)

Gorman, J.G.; Kimblin, C.W.; Slade, P.G.; Voshall, R.E.; Wien, R.E.

1983-01-01

Vacuum arc/magnetic field interactions are reviewed and extended. An axial magnetic field (parallel to current flow) produces a stable and diffuse vacuum arc. These properties have been used to build a reliable dc switch for the Tokamak Fusion Test Reactor at Princeton. The switching duty for this Ohmic Heating Interrupter involves repetitive interruption of 24kA dc against a 27kV recovery voltage. A transverse magnetic field (perpendicular to current flow) produces an unstable arc with an ensuing high arc voltage. This property has been used to complete a metallic return transfer breaker for the Pacific HVDC Intertie, here the switching duty involves interruption of currents up to 2200A dc against an 80kV recovery voltage

A 'LEGO' Hybrid Photon Detector - assembled from standard mass-produced vacuum components

International Nuclear Information System (INIS)

Ferenc, Daniel; Lorenz, Eckart; Mirzoyan, Razmik

2000-01-01

Motivated primarily by the MAGIC atmospheric Cherenkov telescope project, we have developed a 'LEGO' Hybrid Photon Detector (HPD) comprising excellent focusing properties and protection against positive ion feedback. LEGO-HPD is supposed to be assembled from standard high vacuum components, which insures simplicity in the assembly procedure and reliability of operation

Hardware Support for Embedded Java

DEFF Research Database (Denmark)

Schoeberl, Martin

2012-01-01

The general Java runtime environment is resource hungry and unfriendly for real-time systems. To reduce the resource consumption of Java in embedded systems, direct hardware support of the language is a valuable option. Furthermore, an implementation of the Java virtual machine in hardware enables...... worst-case execution time analysis of Java programs. This chapter gives an overview of current approaches to hardware support for embedded and real-time Java....

3D Design Tools for Vacuum Electron Devices

International Nuclear Information System (INIS)

Levush, Baruch

2003-01-01

A reduction of development costs will have a significant impact on the total cost of the vacuum electron devices. Experimental testing cycles can be reduced or eliminated through the use of simulation-based design methodology, thereby reducing the time and cost of development. Moreover, by use of modern optimization tools for automating the process of seeking specific solution parameters and for studying dependencies of performance on parameters, new performance capabilities can be achieved, without resorting to expensive cycles of hardware fabrication and testing. Simulation-based-design will also provide the basis for sensitivity studies for determining the manufacturing tolerances associated with a particular design. Since material properties can have a critical effect on the performance of the vacuum electron devices, the design tools require precise knowledge of material characteristics, such as dielectric properties of the support rods, loss profile etc. Sensitivity studies must therefore include the effects of materials properties variation on device performance. This will provide insight for choosing the proper technological processes in order to achieve these tolerances, which is of great importance for achieving cost reduction. A successful design methodology depends on the development of accurate and efficient design tools with predictive capabilities. These design tools must be based on realistic models capable of high fidelity representation of geometry and materials, they must have optimization capabilities, and they must be easy to use

Study of ITER equatorial port plug handling system and vacuum sealing interface

Energy Technology Data Exchange (ETDEWEB)

Martins, Jean-Pierre [Association Euratom CEA, CEA/DSM/IRFM, Cadarache, F-13108 Saint-Paul-lez-Durance (France)], E-mail: jean-pierre.martins@cea.fr; Doceul, Louis; Marol, Sebastien; Delchie, Elise [Association Euratom CEA, CEA/DSM/IRFM, Cadarache, F-13108 Saint-Paul-lez-Durance (France); Cordier, Jean-Jacques; Levesy, Bruno; Tesini, Alessandro [ITER International Organization, F-13108 Saint-Paul-lez-Durance cedex (France); Ciattaglia, Emanuela [EFDA CSU - Garching, Boltzmannstr. 2, D-85748 Garching (Germany); Tivey, Richard [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Gillier, Rene; Abbes, Christophe [GARLOCK - Sealing Technologies - 90, rue de la roche du Geai, F-42029 St-Etienne cedex 1 (France)

2009-06-15

In the field of the ITER port plug engineering and integration task, CEA has contributed to define proposals concerning the port plugs vacuum sealing interface with the vessel flange and the equatorial plug handling. The 2001 baseline vacuum flange sealing consisted of TIG welding of a 316L strip plate on to U shapes. This arrangement presented some issues like welding access, implementation of tools, lip consumption, complex local leak test, continuous leak checking. Therefore, an alternate sealing solution based on the use of metallic gaskets is proposed. The different technical aspects are discussed to explain how this design can simplify the maintenance and deal with safety and vacuum requirements. The design of the mechanical attachment and vacuum sealing of the plug has constantly evolved, but the associated remote handling equipment was not systematically reviewed. An update of the cask and maintenance procedure was studied in order to design it in accordance with the last generic plug flange design. This includes a concept of a gripping system that uses the plug flange bolting area and, to help the remote handling process, a cantilever assisting system is suggested to increase the reliability of the transfer operation between vacuum vessel and cask.

Modulator reliability and bandwidth improvement: replacing tetrodes with MOSFETs

International Nuclear Information System (INIS)

Donaldson, A.R.

1982-01-01

Three types of power MOS field effect transistors were studied with the intent of replacing a parallel pair of vacuum tube tetrodes in a linear modulator. The tetrodes have the shortest lifetimes of any other tubes in the system. The FETs offer definite performance advantages when compared to bipolar transistors and definite cost advantages when compared to vacuum tubes. Replacement of the tetrodes does however require careful consideration of voltage, current and to a lesser extent bandwidth capability in order to enhance overall modulator reliability without compromising present performance

Vacuum mechatronics first international workshop

Energy Technology Data Exchange (ETDEWEB)

Belinski, S.E.; Shirazi, M.; Hackwood, S.; Beni, G. (eds.) (California Univ., Santa Barbara, CA (USA))

1989-01-01

This report contains papers on the following topics: proposed epitaxial thin film growth in the ultra-vacuum of space; particle monitoring and control in vacuum processing equipment; electrostatic dust collector for use in vacuum systems; materials evaluation of an electrically noisy vacuum slip ring assembly; an overview of lubrication and associated materials for vacuum service; the usage of lubricants in a vacuum environment; guidelines and practical applications for lubrication in vacuum; recent development in leak detector and calibrator designs; the durability of ballscrews for ultrahigh vacuum; vacuum-compatible robot for self-contained manufacturing systems; the design, fabrication, and assembly of an advanced vacuum robotics system for space payload calibration; design criteria for mechanisms used in space; and concepts and requirements for semiconductor multiprocess integration in vacuum. These papers are indexed separately elsewhere.

TRL Assessment of Solar Sail Technology Development Following the 20-Meter System Ground Demonstrator Hardware Testing

Science.gov (United States)

Young, Roy M.; Adams, Charles L.

2010-01-01

The NASA In-Space Propulsion Technology (ISPT) Projects Office sponsored two separate, independent solar sail system design and development demonstration activities during 2002-2005. ATK Space Systems of Goleta, CA was the prime contractor for one development team and L' Garde, Inc. of Tustin, CA was the prime contractor for the other development team. The goal of these activities was to advance the technology readiness level (TRL) of solar sail propulsion from 3 towards 6 by the year 2006. Component and subsystem fabrication and testing were completed successfully, including the ground deployment of 10-meter and 20-meter demonstration hardware systems under vacuum conditions. The deployment and structural testing of the 20-meter solar sail systems was conducted in the 30 meter diameter Space Power Facility thermal-vacuum chamber at NASA Glenn Plum Brook in April though August, 2005. This paper will present the results of the TRL assessment following the solar sail technology development activities associated with the design, development, analysis and testing of the 20-meter system ground demonstrators.

Hardware realization of a fast neural network algorithm for real-time tracking in HEP experiments

International Nuclear Information System (INIS)

Leimgruber, F.R.; Pavlopoulos, P.; Steinacher, M.; Tauscher, L.; Vlachos, S.; Wendler, H.

1995-01-01

A fast pattern recognition system for HEP experiments, based on artificial neural network algorithms (ANN), has been realized with standard electronics. The multiplicity and location of tracks in an event are determined in less than 75 ns. Hardware modules of this first level trigger were extensively tested for performance and reliability with data from the CPLEAR experiment. (orig.)

HARDWARE TROJAN IDENTIFICATION AND DETECTION

OpenAIRE

Samer Moein; Fayez Gebali; T. Aaron Gulliver; Abdulrahman Alkandari

2017-01-01

ABSTRACT The majority of techniques developed to detect hardware trojans are based on specific attributes. Further, the ad hoc approaches employed to design methods for trojan detection are largely ineffective. Hardware trojans have a number of attributes which can be used to systematically develop detection techniques. Based on this concept, a detailed examination of current trojan detection techniques and the characteristics of existing hardware trojans is presented. This is used to dev...

Technological plasma source equipped with combined system of vacuum-arc discharge initiation

International Nuclear Information System (INIS)

Sysoev, Yu.O.

2013-01-01

The construction and the operation principle of erosion plasma source with a three-stage system of vacuum-arc discharge excitation is described. As first two step was used the modified contactless start system with plasma injector, which was widely used in standard plasma sources of the ''Bulat'' systems. The operation principle of the third stage was based on the transition of glow discharge to arc discharge. Coordinated operation of three stages during various stages of coating deposition provided significant increasing of service life and reliability of the system of vacuum-arc discharge initiation and extended the functionality of the plasma source

Coupling impedance of an in-vacuum undulator: Measurement, simulation, and analytical estimation

Directory of Open Access Journals (Sweden)

Victor Smaluk

2014-07-01

Full Text Available One of the important issues of the in-vacuum undulator design is the coupling impedance of the vacuum chamber, which includes tapered transitions with variable gap size. To get complete and reliable information on the impedance, analytical estimate, numerical simulations and beam-based measurements have been performed at Diamond Light Source, a forthcoming upgrade of which includes introducing additional insertion device (ID straights. The impedance of an already existing ID vessel geometrically similar to the new one has been measured using the orbit bump method. The measurement results in comparison with analytical estimations and numerical simulations are discussed in this paper.

Hunting for hardware changes in data centres

International Nuclear Information System (INIS)

Coelho dos Santos, M; Steers, I; Szebenyi, I; Xafi, A; Barring, O; Bonfillou, E

2012-01-01

With many servers and server parts the environment of warehouse sized data centres is increasingly complex. Server life-cycle management and hardware failures are responsible for frequent changes that need to be managed. To manage these changes better a project codenamed “hardware hound” focusing on hardware failure trending and hardware inventory has been started at CERN. By creating and using a hardware oriented data set - the inventory - with detailed information on servers and their parts as well as tracking changes to this inventory, the project aims at, for example, being able to discover trends in hardware failure rates.

Assessment of proposed electromagnetic quantum vacuum energy extraction methods

OpenAIRE

Moddel, Garret

2009-01-01

In research articles and patents several methods have been proposed for the extraction of zero-point energy from the vacuum. None has been reliably demonstrated, but the proposals remain largely unchallenged. In this paper the feasibility of these methods is assessed in terms of underlying thermodynamics principles of equilibrium, detailed balance, and conservation laws. The methods are separated into three classes: nonlinear processing of the zero-point field, mechanical extraction using Cas...

Open-source hardware for medical devices.

Science.gov (United States)

Niezen, Gerrit; Eslambolchilar, Parisa; Thimbleby, Harold

2016-04-01

Open-source hardware is hardware whose design is made publicly available so anyone can study, modify, distribute, make and sell the design or the hardware based on that design. Some open-source hardware projects can potentially be used as active medical devices. The open-source approach offers a unique combination of advantages, including reducing costs and faster innovation. This article compares 10 of open-source healthcare projects in terms of how easy it is to obtain the required components and build the device.

MRI - From basic knowledge to advanced strategies: Hardware

International Nuclear Information System (INIS)

Carpenter, T.A.; Williams, E.J.

1999-01-01

There have been remarkable advances in the hardware used for nuclear magnetic resonance imaging scanners. These advances have enabled an extraordinary range of sophisticated magnetic resonance MR sequences to be performed routinely. This paper focuses on the following particular aspects: (a) Magnet system. Advances in magnet technology have allowed superconducting magnets which are low maintenance and have excellent homogeneity and very small stray field footprints. (b) Gradient system. Optimisation of gradient design has allowed gradient coils which provide excellent field for spatial encoding, have reduced diameter and have technology to minimise the effects of eddy currents. These coils can now routinely provide the strength and switching rate required by modern imaging methods. (c) Radio-frequency (RF) system. The advances in digital electronics can now provide RF electronics which have low noise characteristics, high accuracy and improved stability, which are all essential to the formation of excellent images. The use of surface coils has increased with the availability of phased-array systems, which are ideal for spinal work. (d) Computer system. The largest advance in technology has been in the supporting computer hardware which is now affordable, reliable and with performance to match the processing requirements demanded by present imaging sequences. (orig.)

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Summary description

International Nuclear Information System (INIS)

Gertman, D.I.; Gilmore, W.E.; Galyean, W.J.; Groh, M.R.; Gentillon, C.D.; Gilbert, B.G.; Reece, W.J.

1990-05-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automate data base management system for storing and processing human error probability and hardware component failure rate data. The NUCLARR system software resides on an IBM (or compatible) personal microcomputer. NUCLARR can be accessed by the end user to furnish data suitable for input in human and/or hardware reliability analysis to support a variety of risk assessment activities. The NUCLARR system is documented in a five-volume series of reports. This document Volume 1, of this series is the Summary Description, which presents an overview of the data management system, including a description of data collection, data qualification, data structure, and taxonomies. Programming activities, procedures for processing data, a user's guide, and hard copy data manual are presented in Volumes 2 through 5, NUREG/CR-4639

Magnetically induced vacuum decay

International Nuclear Information System (INIS)

Xue Shesheng

2003-01-01

We study the fermionic vacuum energy of vacua with and without application of an external magnetic field. The energetic difference of two vacua leads to the vacuum decaying and the vacuum energy being released. In the context of quantum field theories, we discuss why and how the vacuum energy can be released by spontaneous photon emission and/or paramagnetically screening the external magnetic field. In addition, we quantitatively compute the vacuum energy released, the paramagnetic screening effect, and the rate and spectrum of spontaneous photon emission. The possibilities of experimentally detecting such an effect of vacuum-energy release and that this effect accounts for the anomalous x-ray pulsar are discussed

An evaluation of Skylab habitability hardware

Science.gov (United States)

Stokes, J.

1974-01-01

For effective mission performance, participants in space missions lasting 30-60 days or longer must be provided with hardware to accommodate their personal needs. Such habitability hardware was provided on Skylab. Equipment defined as habitability hardware was that equipment composing the food system, water system, sleep system, waste management system, personal hygiene system, trash management system, and entertainment equipment. Equipment not specifically defined as habitability hardware but which served that function were the Wardroom window, the exercise equipment, and the intercom system, which was occasionally used for private communications. All Skylab habitability hardware generally functioned as intended for the three missions, and most items could be considered as adequate concepts for future flights of similar duration. Specific components were criticized for their shortcomings.

R&D ERL: Vacuum

Energy Technology Data Exchange (ETDEWEB)

Mapes, M.; Smart, L.; Weiss, D.; Steszyn, A.; Todd, R.

2010-01-01

The ERL Vacuum systems are depicted in a figure. ERL has eight vacuum volumes with various sets of requirements. A summary of vacuum related requirements is provided in a table. Five of the eight volumes comprise the electron beamline. They are the 5-cell Superconducting RF Cavity, Superconducting e-gun, injection, loop and beam dump. Two vacuum regions are the individual cryostats insulating the 5-cell Superconducting RF Cavity and the Superconducting e-gun structures. The last ERL vacuum volume not shown in the schematic is the laser transport line. The beamline vacuum regions are separated by electropneumatic gate valves. The beam dump is common with loop beamline but is considered a separate volume due to geometry and requirements. Vacuum in the 5-cell SRF cavity is maintained in the {approx}10{sup -9} torr range at room temperature by two 20 l/s ion pumps and in the e-gun SRF cavity by one 60 l/s ion pump. Vacuum in the SRF cavities operated at 2{sup o}K is reduced to low 10{sup -11} torr via cryopumping of the cavity walls. The cathode of the e-gun must be protected from poisoning, which can occur if vacuum adjacent to the e-gun in the injection line exceeds 10-11 torr range in the injection warm beamline near the e-gun exit. The vacuum requirements for beam operation in the loop and beam dump are 10-9 torr range. The beamlines are evacuated from atmospheric pressure to high vacuum level with a particulate free, oil free turbomolecular pumping cart. 25 l/s shielded ion pumps distributed throughout the beamlines maintain the vacuum requirement. Due to the more demanding vacuum requirement of the injection beamline proximate to the e-gun, a vacuum bakeout of the injection beamline is required. In addition, two 200 l/s diode ion pumps and supplemental pumping provided by titanium sublimation pumps are installed in the injection line just beyond the exit of the e-gun. Due to expected gas load a similar pumping arrangement is planned for the beam dump. The

Reconfigurable ATCA hardware for plasma control and data acquisition

Energy Technology Data Exchange (ETDEWEB)

Carvalho, B.B., E-mail: bernardo@ipfn.ist.utl.p [Associacao EURATOM/IST Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Batista, A.J.N.; Correia, M.; Neto, A.; Fernandes, H.; Goncalves, B.; Sousa, J. [Associacao EURATOM/IST Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

2010-07-15

The IST/EURATOM Association is developing a new generation of control and data acquisition hardware for fusion experiments based on the ATCA architecture. This emerging open standard offers a significantly higher data throughput over a reliable High Availability (HA) mechanical and electrical platform. One of this ATCA boards has 32 galvanically isolated ADC channels (18 bit) each mounted on a swappable plug-in card, 8 DAC channels (16 bit), 8 digital I/O channels and embeds a high performance XILINX Virtex 4 family field programmable gate array (FPGA). The specific modular and configurable hardware design enables adaptable utilization of the board in dissimilar applications. The first configuration, specially developed for tokamak plasma Vertical Stabilization, consists of a Multiple-Input-Multiple-Output (MIMO) controller that is capable of feedback loops faster than 1 ms using a multitude of input signals fed from different boards communicating through the Aurora{sup TM} point-to-point protocol. Massive parallel algorithms can be implemented on the FPGA either with programmed digital logic, using a HDL hardware description language, or within its internal silicon PowerPC{sup TM} running a full fledged real-time operating system. The second board configuration is dedicated for transient recording of the entire 32 channels at 2 MSamples/s to the on-board 512 MB DDR2 memory. Signal data retrieval is accelerated by a DMA-driven PCI Express{sup TM} x1 Interface to the ATCA system controller, providing an overall throughput in excess of 100 MB/s. This paper illustrates these developments and discusses possible configurations for foreseen applications.

Electroweak vacuum instability and renormalized Higgs field vacuum fluctuations in the inflationary universe

Energy Technology Data Exchange (ETDEWEB)

Kohri, Kazunori [Institute of Particle and Nuclear Studies, KEK, 1-1 Oho, Tsukuba 305-0801 (Japan); Matsui, Hiroki, E-mail: kohri@post.kek.jp, E-mail: matshiro@post.kek.jp [The Graduate University for Advanced Studies (SOKENDAI), 1-1 Oho, Tsukuba 305-0801 (Japan)

2017-08-01

In this work, we investigated the electroweak vacuum instability during or after inflation. In the inflationary Universe, i.e., de Sitter space, the vacuum field fluctuations < δ φ {sup 2} > enlarge in proportion to the Hubble scale H {sup 2}. Therefore, the large inflationary vacuum fluctuations of the Higgs field < δ φ {sup 2} > are potentially catastrophic to trigger the vacuum transition to the negative-energy Planck-scale vacuum state and cause an immediate collapse of the Universe. However, the vacuum field fluctuations < δ φ {sup 2} >, i.e., the vacuum expectation values have an ultraviolet divergence, and therefore a renormalization is necessary to estimate the physical effects of the vacuum transition. Thus, in this paper, we revisit the electroweak vacuum instability from the perspective of quantum field theory (QFT) in curved space-time, and discuss the dynamical behavior of the homogeneous Higgs field φ determined by the effective potential V {sub eff}( φ ) in curved space-time and the renormalized vacuum fluctuations < δ φ {sup 2} >{sub ren} via adiabatic regularization and point-splitting regularization. We simply suppose that the Higgs field only couples the gravity via the non-minimal Higgs-gravity coupling ξ(μ). In this scenario, the electroweak vacuum stability is inevitably threatened by the dynamical behavior of the homogeneous Higgs field φ, or the formations of AdS domains or bubbles unless the Hubble scale is small enough H < Λ {sub I} .

Is Hardware Removal Recommended after Ankle Fracture Repair?

Directory of Open Access Journals (Sweden)

Hong-Geun Jung

2016-01-01

Full Text Available The indications and clinical necessity for routine hardware removal after treating ankle or distal tibia fracture with open reduction and internal fixation are disputed even when hardware-related pain is insignificant. Thus, we determined the clinical effects of routine hardware removal irrespective of the degree of hardware-related pain, especially in the perspective of patients’ daily activities. This study was conducted on 80 consecutive cases (78 patients treated by surgery and hardware removal after bony union. There were 56 ankle and 24 distal tibia fractures. The hardware-related pain, ankle joint stiffness, discomfort on ambulation, and patient satisfaction were evaluated before and at least 6 months after hardware removal. Pain score before hardware removal was 3.4 (range 0 to 6 and decreased to 1.3 (range 0 to 6 after removal. 58 (72.5% patients experienced improved ankle stiffness and 65 (81.3% less discomfort while walking on uneven ground and 63 (80.8% patients were satisfied with hardware removal. These results suggest that routine hardware removal after ankle or distal tibia fracture could ameliorate hardware-related pain and improves daily activities and patient satisfaction even when the hardware-related pain is minimal.

Vacuum system for ISABELLE

International Nuclear Information System (INIS)

Hobson, J.P.

1975-01-01

An analysis is presented of the proposed vacuum system for the planned ISABELLE storage rings with respect to acceptability and practicality from the vacuum viewport. A comparison is made between the proposed vacuum system and the vacuum system at the CERN ISR, and some comments on various design and operational parameters are made

Door Hardware and Installations; Carpentry: 901894.

Science.gov (United States)

Dade County Public Schools, Miami, FL.

The curriculum guide outlines a course designed to provide instruction in the selection, preparation, and installation of hardware for door assemblies. The course is divided into five blocks of instruction (introduction to doors and hardware, door hardware, exterior doors and jambs, interior doors and jambs, and a quinmester post-test) totaling…

Vacuum extraction

DEFF Research Database (Denmark)

Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne

2012-01-01

Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two-part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validation of the developed OSATS scale for vac...

Elastomer seal for a large toroidal vacuum chamber

International Nuclear Information System (INIS)

Skellett, S.; Casey, F.; Blake, H.

1978-07-01

An aluminium toroidal vacuum chamber for use at 10(-6) torr, whose overall diameter is in the region of 5 metres, was built from 4 component parts which resulted in joint lines in the horizontal and vertical planes crossing each other in 4 places. A viton seal was developed which allows a vacuum tight joint to be made without the need for tightly toleranced fitting of the mating faces and also overcomes the difficulty of ensuring a reliable seal at cross-over joints. Ease of maintenance and repair in situ are important factors of the design. An assembly which presented the geometry of the sealing problem was tested and is described here. Various adhesives for bonding viton were examined for the manufacture of the seal. The most suitable adhesive was found to be Loctite S496, chosen for its bond strength and convenience in use. A device for preparing and bonding the viton in situ is described. (author)

A hardware-software system for the automation of verification and calibration of oil metering units secondary equipment

Science.gov (United States)

Boyarnikov, A. V.; Boyarnikova, L. V.; Kozhushko, A. A.; Sekachev, A. F.

2017-08-01

In the article the process of verification (calibration) of oil metering units secondary equipment is considered. The purpose of the work is to increase the reliability and reduce the complexity of this process by developing a software and hardware system that provides automated verification and calibration. The hardware part of this complex carries out the commutation of the measuring channels of the verified controller and the reference channels of the calibrator in accordance with the introduced algorithm. The developed software allows controlling the commutation of channels, setting values on the calibrator, reading the measured data from the controller, calculating errors and compiling protocols. This system can be used for checking the controllers of the secondary equipment of the oil metering units in the automatic verification mode (with the open communication protocol) or in the semi-automatic verification mode (without it). The peculiar feature of the approach used is the development of a universal signal switch operating under software control, which can be configured for various verification methods (calibration), which allows to cover the entire range of controllers of metering units secondary equipment. The use of automatic verification with the help of a hardware and software system allows to shorten the verification time by 5-10 times and to increase the reliability of measurements, excluding the influence of the human factor.

UPGRADE FOR HARDWARE/SOFTWARE SERVER AND NETWORK TOPOLOGY IN INFORMATION SYSTEMS

Directory of Open Access Journals (Sweden)

Oleksii O. Kaplun

2011-02-01

Full Text Available The network modernization, educational information systems software and hardware updates problem is actual in modern term of information technologies prompt development. There are server applications and network topology of Institute of Information Technology and Learning Tools of National Academy of Pedagogical Sciences of Ukraine analysis and their improvement methods expound in the article. The article materials represent modernization results implemented to increase network efficiency and reliability, decrease response time in Institute’s network information systems. The article gives diagrams of network topology before upgrading and after finish of optimization and upgrading processes.

Monitoring and Hardware Management for Critical Fusion Plasma Instrumentation

Directory of Open Access Journals (Sweden)

Carvalho Paulo F.

2018-01-01

Full Text Available Controlled nuclear fusion aims to obtain energy by particles collision confined inside a nuclear reactor (Tokamak. These ionized particles, heavier isotopes of hydrogen, are the main elements inside of plasma that is kept at high temperatures (millions of Celsius degrees. Due to high temperatures and magnetic confinement, plasma is exposed to several sources of instabilities which require a set of procedures by the control and data acquisition systems throughout fusion experiments processes. Control and data acquisition systems often used in nuclear fusion experiments are based on the Advanced Telecommunication Computer Architecture (AdvancedTCA® standard introduced by the Peripheral Component Interconnect Industrial Manufacturers Group (PICMG®, to meet the demands of telecommunications that require large amount of data (TB transportation at high transfer rates (Gb/s, to ensure high availability including features such as reliability, serviceability and redundancy. For efficient plasma control, systems are required to collect large amounts of data, process it, store for later analysis, make critical decisions in real time and provide status reports either from the experience itself or the electronic instrumentation involved. Moreover, systems should also ensure the correct handling of detected anomalies and identified faults, notify the system operator of occurred events, decisions taken to acknowledge and implemented changes. Therefore, for everything to work in compliance with specifications it is required that the instrumentation includes hardware management and monitoring mechanisms for both hardware and software. These mechanisms should check the system status by reading sensors, manage events, update inventory databases with hardware system components in use and maintenance, store collected information, update firmware and installed software modules, configure and handle alarms to detect possible system failures and prevent emergency

Monitoring and Hardware Management for Critical Fusion Plasma Instrumentation

Science.gov (United States)

Carvalho, Paulo F.; Santos, Bruno; Correia, Miguel; Combo, Álvaro M.; Rodrigues, AntÓnio P.; Pereira, Rita C.; Fernandes, Ana; Cruz, Nuno; Sousa, Jorge; Carvalho, Bernardo B.; Batista, AntÓnio J. N.; Correia, Carlos M. B. A.; Gonçalves, Bruno

2018-01-01

Controlled nuclear fusion aims to obtain energy by particles collision confined inside a nuclear reactor (Tokamak). These ionized particles, heavier isotopes of hydrogen, are the main elements inside of plasma that is kept at high temperatures (millions of Celsius degrees). Due to high temperatures and magnetic confinement, plasma is exposed to several sources of instabilities which require a set of procedures by the control and data acquisition systems throughout fusion experiments processes. Control and data acquisition systems often used in nuclear fusion experiments are based on the Advanced Telecommunication Computer Architecture (AdvancedTCA®) standard introduced by the Peripheral Component Interconnect Industrial Manufacturers Group (PICMG®), to meet the demands of telecommunications that require large amount of data (TB) transportation at high transfer rates (Gb/s), to ensure high availability including features such as reliability, serviceability and redundancy. For efficient plasma control, systems are required to collect large amounts of data, process it, store for later analysis, make critical decisions in real time and provide status reports either from the experience itself or the electronic instrumentation involved. Moreover, systems should also ensure the correct handling of detected anomalies and identified faults, notify the system operator of occurred events, decisions taken to acknowledge and implemented changes. Therefore, for everything to work in compliance with specifications it is required that the instrumentation includes hardware management and monitoring mechanisms for both hardware and software. These mechanisms should check the system status by reading sensors, manage events, update inventory databases with hardware system components in use and maintenance, store collected information, update firmware and installed software modules, configure and handle alarms to detect possible system failures and prevent emergency scenarios

High temperature vacuum furnace for the preparation of graphite targets for 14C dating by tandem accelerator mass spectrometry

International Nuclear Information System (INIS)

Lowe, D.C.; Bristow, P.; Judd, W.J.

1985-02-01

A simple and reliable furnace design capable of producing temperatures of up to 2800 deg. C is presented. The furnace has been specifically designed for the rapid and reliable production of graphite targets for 14 C dating purposes but may be used in a variety of applications requiring high temperatures under vacuum conditions

From Open Source Software to Open Source Hardware

OpenAIRE

Viseur , Robert

2012-01-01

Part 2: Lightning Talks; International audience; The open source software principles progressively give rise to new initiatives for culture (free culture), data (open data) or hardware (open hardware). The open hardware is experiencing a significant growth but the business models and legal aspects are not well known. This paper is dedicated to the economics of open hardware. We define the open hardware concept and determine intellectual property tools we can apply to open hardware, with a str...

Working Group summary reports from the Advanced Photon Source reliability workshop

International Nuclear Information System (INIS)

1992-05-01

A workshop was held at APS to address reliability goals for accelerator systems. Seventy-one individuals participated in the workshop, including 30 from other institutions. The goals of the workshop were to: (1) Give attendees an introduction to the basic concepts of reliability analysis. (2) Exchange information on operating experience at existing accelerator facilities and strategies for achieving reliability at facilities under design or in construction. (3) Discuss reliability goals for APS and the means of their achievement. This report contains the working group summary report an APS's following systems: RF Systems; Power Supplies; Magnet Systems; Interlock and Diagnostics; and Vacuum Systems

Cosmic vacuum

International Nuclear Information System (INIS)

Chernin, Artur D

2001-01-01

Recent observational studies of distant supernovae have suggested the existence of cosmic vacuum whose energy density exceeds the total density of all the other energy components in the Universe. The vacuum produces the field of antigravity that causes the cosmological expansion to accelerate. It is this accelerated expansion that has been discovered in the observations. The discovery of cosmic vacuum radically changes our current understanding of the present state of the Universe. It also poses new challenges to both cosmology and fundamental physics. Why is the density of vacuum what it is? Why do the densities of the cosmic energy components differ in exact value but agree in order of magnitude? On the other hand, the discovery made at large cosmological distances of hundreds and thousands Mpc provides new insights into the dynamics of the nearby Universe, the motions of galaxies in the local volume of 10 - 20 Mpc where the cosmological expansion was originally discovered. (reviews of topical problems)

Cosmic vacuum

Energy Technology Data Exchange (ETDEWEB)

Chernin, Artur D [P.K. Shternberg State Astronomical Institute at the M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

2001-11-30

Recent observational studies of distant supernovae have suggested the existence of cosmic vacuum whose energy density exceeds the total density of all the other energy components in the Universe. The vacuum produces the field of antigravity that causes the cosmological expansion to accelerate. It is this accelerated expansion that has been discovered in the observations. The discovery of cosmic vacuum radically changes our current understanding of the present state of the Universe. It also poses new challenges to both cosmology and fundamental physics. Why is the density of vacuum what it is? Why do the densities of the cosmic energy components differ in exact value but agree in order of magnitude? On the other hand, the discovery made at large cosmological distances of hundreds and thousands Mpc provides new insights into the dynamics of the nearby Universe, the motions of galaxies in the local volume of 10 - 20 Mpc where the cosmological expansion was originally discovered. (reviews of topical problems)

Evolving Reliability and Maintainability Allocations for NASA Ground Systems

Science.gov (United States)

Munoz, Gisela; Toon, T.; Toon, J.; Conner, A.; Adams, T.; Miranda, D.

2016-01-01

This paper describes the methodology and value of modifying allocations to reliability and maintainability requirements for the NASA Ground Systems Development and Operations (GSDO) programs subsystems. As systems progressed through their design life cycle and hardware data became available, it became necessary to reexamine the previously derived allocations. This iterative process provided an opportunity for the reliability engineering team to reevaluate allocations as systems moved beyond their conceptual and preliminary design phases. These new allocations are based on updated designs and maintainability characteristics of the components. It was found that trade-offs in reliability and maintainability were essential to ensuring the integrity of the reliability and maintainability analysis. This paper discusses the results of reliability and maintainability reallocations made for the GSDO subsystems as the program nears the end of its design phase.

Vacuum level effects on gait characteristics for unilateral transtibial amputees with elevated vacuum suspension.

Science.gov (United States)

Xu, Hang; Greenland, Kasey; Bloswick, Donald; Zhao, Jie; Merryweather, Andrew

2017-03-01

The elevated vacuum suspension system has demonstrated unique health benefits for amputees, but the effect of vacuum pressure values on gait characteristics is still unclear. The purpose of this study was to investigate the effects of elevated vacuum levels on temporal parameters, kinematics and kinetics for unilateral transtibial amputees. Three-dimensional gait analysis was conducted in 9 unilateral transtibial amputees walking at a controlled speed with five vacuum levels ranging from 0 to 20inHg, and also in 9 able-bodied subjects walking at self-preferred speed. Repeated ANOVA and Dunnett's t-test were performed to determine the effect of vacuum level and limb for within subject and between groups. The effect of vacuum level significantly affected peak hip external rotation and external knee adduction moment. Maximum braking and propulsive ground reaction forces generally increased for the residual limb and decreased for the intact limb with increasing vacuum. Additionally, the intact limb experienced an increased loading due to gait asymmetry for several variables. There was no systematic vacuum level effect on gait. Higher vacuum levels, such as 15 and 20inHg, were more comfortable and provided some relief to the intact limb, but may also increase the risk of osteoarthritis of the residual limb due to the increased peak external hip and knee adduction moments. Very low vacuum should be avoided because of the negative effects on gait symmetry. A moderate vacuum level at 15inHg is suggested for unilateral transtibial amputees with elevated vacuum suspension. Copyright © 2017 Elsevier Ltd. All rights reserved.

Introduction to vacuum technology: supplementary study material developed for IVS sponsored vacuum courses

International Nuclear Information System (INIS)

Bhusan, K.G.

2008-01-01

Vacuum technology has advanced to a large extent mainly from the demands of experimental research scientists who have more than ever understood the need for clean very low pressure environments. This need only seems to increase as the lowest pressures achievable in a laboratory setup are dropping down by the decade. What is not usually said is that conventional techniques of producing ultrahigh vacuum have also undergone a metamorphosis in order to cater to the multitude of restrictions in modern day scientific research. This book aims to give that practical approach to vacuum technology. The basics are given in the first chapter with more of a definition oriented approach - which is practically useful. The second chapter deals with the production of vacuum and ultrahigh vacuum with an emphasis on the working principles of several pumps and their working pressure ranges. Measurement of low pressures, both total and partial is presented in the third chapter with a note on leak detection and mass spectrometric techniques. Chapter 4 gives an overview of the materials that are vacuum compatible and their material properties. Chapter 5 gives the necessary methods to be followed for cleaning of vacuum components especially critical if ultrahigh vacuum environment is required. The practical use of a ultrahigh vacuum environment is demonstrated in Chapter 6 for production of high quality thin films through vapour deposition

ZEUS hardware control system

Science.gov (United States)

Loveless, R.; Erhard, P.; Ficenec, J.; Gather, K.; Heath, G.; Iacovacci, M.; Kehres, J.; Mobayyen, M.; Notz, D.; Orr, R.; Orr, R.; Sephton, A.; Stroili, R.; Tokushuku, K.; Vogel, W.; Whitmore, J.; Wiggers, L.

1989-12-01

The ZEUS collaboration is building a system to monitor, control and document the hardware of the ZEUS detector. This system is based on a network of VAX computers and microprocessors connected via ethernet. The database for the hardware values will be ADAMO tables; the ethernet connection will be DECNET, TCP/IP, or RPC. Most of the documentation will also be kept in ADAMO tables for easy access by users.

ZEUS hardware control system

International Nuclear Information System (INIS)

Loveless, R.; Erhard, P.; Ficenec, J.; Gather, K.; Heath, G.; Iacovacci, M.; Kehres, J.; Mobayyen, M.; Notz, D.; Orr, R.; Sephton, A.; Stroili, R.; Tokushuku, K.; Vogel, W.; Whitmore, J.; Wiggers, L.

1989-01-01

The ZEUS collaboration is building a system to monitor, control and document the hardware of the ZEUS detector. This system is based on a network of VAX computers and microprocessors connected via ethernet. The database for the hardware values will be ADAMO tables; the ethernet connection will be DECNET, TCP/IP, or RPC. Most of the documentation will also be kept in ADAMO tables for easy access by users. (orig.)

A conservative bound for the probability of failure of a 1-out-of-2 protection system with one hardware-only and one software-based protection train

International Nuclear Information System (INIS)

Bishop, Peter; Bloomfield, Robin; Littlewood, Bev; Popov, Peter; Povyakalo, Andrey; Strigini, Lorenzo

2014-01-01

Redundancy and diversity have long been used as means to obtain high reliability in critical systems. While it is easy to show that, say, a 1-out-of-2 diverse system will be more reliable than each of its two individual “trains”, assessing the actual reliability of such systems can be difficult because the trains cannot be assumed to fail independently. If we cannot claim independence of train failures, the computation of system reliability is difficult, because we would need to know the probability of failure on demand (pfd) for every possible demand. These are unlikely to be known in the case of software. Claims for software often concern its marginalpfd, i.e. average across all possible demands. In this paper we consider the case of a 1-out-of-2 safety protection system in which one train contains software (and hardware), and the other train contains only hardware equipment. We show that a useful upper (i.e. conservative) bound can be obtained for the system pfd using only the unconditional pfd for software together with information about the variation of hardware failure probability across demands, which is likely to be known or estimatable. The worst-case result is obtained by “allocating” software failure probability among demand “classes” so as to maximize system pfd

Experiments with vacuum interrupters used for large dc-current interruption

International Nuclear Information System (INIS)

Warren, R.W.

1977-10-01

Vacuum interrupters have been tested in circuits similar to those used in theta-pinch and Tokamak fusion devices. The effects on performance of auxiliary circuit components and axial magnetic fields have been determined, and limits to lifetime caused by mechanical and electrical wear have been measured. Results show that the upper reliable limit of interruption is independent of the auxiliary components but quite dependent on interrupter size and on the axial field

Cryo-Vacuum Testing of the Integrated Science Instrument Module for the James Webb Space Telescope

Science.gov (United States)

Kimble, Randy A.; Davila, P. S.; Drury, M. P.; Glazer, S. D.; Krom, J. R.; Lundquist, R. A.; Mann, S. D.; McGuffey, D. B.; Perry, R. L.; Ramey, D. D.

2011-01-01

With delivery of the science instruments for the James Webb Space Telescope (JWST) to Goddard Space Flight Center (GSFC) expected in 2012, current plans call for the first cryo-vacuum test of the Integrated Science Instrument Module (ISIM) to be carried out at GSFC in early 2013. Plans are well underway for conducting this ambitious test, which will perform critical verifications of a number of optical, thermal, and operational requirements of the IS 1M hardware, at its deep cryogenic operating temperature. We describe here the facilities, goals, methods, and timeline for this important Integration & Test milestone in the JWST program.

NDAS Hardware Translation Layer Development

Science.gov (United States)

Nazaretian, Ryan N.; Holladay, Wendy T.

2011-01-01

The NASA Data Acquisition System (NDAS) project is aimed to replace all DAS software for NASA s Rocket Testing Facilities. There must be a software-hardware translation layer so the software can properly talk to the hardware. Since the hardware from each test stand varies, drivers for each stand have to be made. These drivers will act more like plugins for the software. If the software is being used in E3, then the software should point to the E3 driver package. If the software is being used at B2, then the software should point to the B2 driver package. The driver packages should also be filled with hardware drivers that are universal to the DAS system. For example, since A1, A2, and B2 all use the Preston 8300AU signal conditioners, then the driver for those three stands should be the same and updated collectively.

Hardware standardization for embedded systems

International Nuclear Information System (INIS)

Sharma, M.K.; Kalra, Mohit; Patil, M.B.; Mohanty, Ashutos; Ganesh, G.; Biswas, B.B.

2010-01-01

Reactor Control Division (RCnD) has been one of the main designers of safety and safety related systems for power reactors. These systems have been built using in-house developed hardware. Since the present set of hardware was designed long ago, a need was felt to design a new family of hardware boards. A Working Group on Electronics Hardware Standardization (WG-EHS) was formed with an objective to develop a family of boards, which is general purpose enough to meet the requirements of the system designers/end users. RCnD undertook the responsibility of design, fabrication and testing of boards for embedded systems. VME and a proprietary I/O bus were selected as the two system buses. The boards have been designed based on present day technology and components. The intelligence of these boards has been implemented on FPGA/CPLD using VHDL. This paper outlines the various boards that have been developed with a brief description. (author)

Hardware for dynamic quantum computing.

Science.gov (United States)

Ryan, Colm A; Johnson, Blake R; Ristè, Diego; Donovan, Brian; Ohki, Thomas A

2017-10-01

We describe the hardware, gateware, and software developed at Raytheon BBN Technologies for dynamic quantum information processing experiments on superconducting qubits. In dynamic experiments, real-time qubit state information is fed back or fed forward within a fraction of the qubits' coherence time to dynamically change the implemented sequence. The hardware presented here covers both control and readout of superconducting qubits. For readout, we created a custom signal processing gateware and software stack on commercial hardware to convert pulses in a heterodyne receiver into qubit state assignments with minimal latency, alongside data taking capability. For control, we developed custom hardware with gateware and software for pulse sequencing and steering information distribution that is capable of arbitrary control flow in a fraction of superconducting qubit coherence times. Both readout and control platforms make extensive use of field programmable gate arrays to enable tailored qubit control systems in a reconfigurable fabric suitable for iterative development.

Vacuum fluctuations in an ancestor vacuum: A possible dark energy candidate

Science.gov (United States)

Aoki, Hajime; Iso, Satoshi; Lee, Da-Shin; Sekino, Yasuhiro; Yeh, Chen-Pin

2018-02-01

We consider an open universe created by bubble nucleation, and study possible effects of our "ancestor vacuum," a de Sitter space in which bubble nucleation occurred, on the present universe. We compute vacuum expectation values of the energy-momentum tensor for a minimally coupled scalar field, carefully taking into account the effect of the ancestor vacuum by the Euclidean prescription. We pay particular attention to the so-called supercurvature mode, a non-normalizable mode on a spatial slice of the open universe, which has been known to exist for sufficiently light fields. This mode decays in time most slowly, and may leave residual effects of the ancestor vacuum, potentially observable in the present universe. We point out that the vacuum energy of the quantum field can be regarded as dark energy if mass of the field is of order the present Hubble parameter or smaller. We obtain preliminary results for the dark energy equation of state w (z ) as a function of the redshift.

Hardware device binding and mutual authentication

Science.gov (United States)

Hamlet, Jason R; Pierson, Lyndon G

2014-03-04

Detection and deterrence of device tampering and subversion by substitution may be achieved by including a cryptographic unit within a computing device for binding multiple hardware devices and mutually authenticating the devices. The cryptographic unit includes a physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generates a binding PUF value. The cryptographic unit uses the binding PUF value during an enrollment phase and subsequent authentication phases. During a subsequent authentication phase, the cryptographic unit uses the binding PUF values of the multiple hardware devices to generate a challenge to send to the other device, and to verify a challenge received from the other device to mutually authenticate the hardware devices.

Secure coupling of hardware components

NARCIS (Netherlands)

Hoepman, J.H.; Joosten, H.J.M.; Knobbe, J.W.

2011-01-01

A method and a system for securing communication between at least a first and a second hardware components of a mobile device is described. The method includes establishing a first shared secret between the first and the second hardware components during an initialization of the mobile device and,

Reliability of thermal-hydraulic passive safety systems

International Nuclear Information System (INIS)

D'Auria, F.; Araneo, D.; Pierro, F.; Galassi, G.

2014-01-01

The scholar will be informed of reliability concepts applied to passive system adopted for nuclear reactors. Namely, for classical components and systems the failure concept is associated with malfunction of breaking of hardware. In the case of passive systems the failure is associated with phenomena. A method for studying the reliability of passive systems is discussed and is applied. The paper deals with the description of the REPAS (Reliability Evaluation of Passive Safety System) methodology developed by University of Pisa (UNIPI) and with results from its application. The general objective of the REPAS methodology is to characterize the performance of a passive system in order to increase the confidence toward its operation and to compare the performances of active and passive systems and the performances of different passive systems

Re-configurable ATCA Hardware for Plasma Control and Data Acquisition

Energy Technology Data Exchange (ETDEWEB)

Carvalho, B.; Batista, A.; Correia, M.; Fernandes, H.; Sousa, J. [Instituto de Plasmas e Fusao Nuclear - Instituto Superior Tecnico, Lisbon (Portugal)

2009-07-01

The IST/EURATOM Association is developing a new generation of control and data acquisition hardware for fusion experiments based on the ATCA architecture. This emerging open standard offers a significantly higher data throughput over a reliable High Availability (HA) mechanical and electrical platform. One of this ATCA boards, has 32 galvanic isolated ADC channels (18 bit) each mounted on a exchangeable plug-in card, 8 DAC channels (16 bit), 8 digital I/O channels and embeds a high performance XILINX Virtex 4 family field programmable gate array (FPGA). The specific modular hardware design enables adaptable utilization of the board in dissimilar applications. The first configuration, specially developed for tokamak plasma Vertical Stabilization, consists of a Multiple-Input-Multiple-Output (MIMO) controller that is capable of feedback loops faster than 1 ms, using a multitude of input signals fed from different boards communicating through the Aurora point-to-point protocol. Massive parallel algorithms can be implemented inside the FPGA either with programmed digital logic, using a HDL hardware description language, or inside the two included silicon PowerPCs running a full fledged real-time operating system. The second board configuration is dedicated for transient recording of the entire 32 channels at 2 MSamples/s to the built-in 512 MBDDR2 memory. Signal data retrieval is accelerated by a DMA-driven PCI Express-x1 Interface to the ATCA system controller providing an overall throughput in excess of 250 MB/s. This paper illustrates these developments and discusses possible configurations for foreseen applications. (authors)

Influence of Gap Distance on Vacuum Arc Characteristics of Cup Type AMF Electrode in Vacuum Interrupters

International Nuclear Information System (INIS)

Cheng Shaoyong; Xiu Shixin; Wang Jimei; Shen Zhengchao

2006-01-01

The greenhouse effect of SF 6 is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling technique are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device (CCD) video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 mm. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters

Vacuum-assisted delivery

Science.gov (United States)

... medlineplus.gov/ency/patientinstructions/000514.htm Vacuum-assisted delivery To use the sharing features on this page, ... through the birth canal. When is Vacuum-assisted Delivery Needed? Even after your cervix is fully dilated ( ...

The Impact of Flight Hardware Scavenging on Space Logistics

Science.gov (United States)

Oeftering, Richard C.

2011-01-01

For a given fixed launch vehicle capacity the logistics payload delivered to the moon may be only roughly 20 percent of the payload delivered to the International Space Station (ISS). This is compounded by the much lower flight frequency to the moon and thus low availability of spares for maintenance. This implies that lunar hardware is much more scarce and more costly per kilogram than ISS and thus there is much more incentive to preserve hardware. The Constellation Lunar Surface System (LSS) program is considering ways of utilizing hardware scavenged from vehicles including the Altair lunar lander. In general, the hardware will have only had a matter of hours of operation yet there may be years of operational life remaining. By scavenging this hardware the program, in effect, is treating vehicle hardware as part of the payload. Flight hardware may provide logistics spares for system maintenance and reduce the overall logistics footprint. This hardware has a wide array of potential applications including expanding the power infrastructure, and exploiting in-situ resources. Scavenging can also be seen as a way of recovering the value of, literally, billions of dollars worth of hardware that would normally be discarded. Scavenging flight hardware adds operational complexity and steps must be taken to augment the crew s capability with robotics, capabilities embedded in flight hardware itself, and external processes. New embedded technologies are needed to make hardware more serviceable and scavengable. Process technologies are needed to extract hardware, evaluate hardware, reconfigure or repair hardware, and reintegrate it into new applications. This paper also illustrates how scavenging can be used to drive down the cost of the overall program by exploiting the intrinsic value of otherwise discarded flight hardware.

Manufacturing technology development for vacuum vessel and plasma facing components

International Nuclear Information System (INIS)

Laitinen, Arttu; Liimatainen, Jari; Hallila, Pentti

2005-01-01

Vacuum vessel and plasma facing components of the ITER construction including shield modules and primary first wall panels have great impact on the production costs and reliability of the installation. From the manufacturing technology point of view, accuracy of shape, properties of the various austenitic stainless steel/austenitic stainless steel interfaces or CuCrZr/austenitic stainless steel interfaces as well as those of the base materials are crucial for technical reliability of the construction. The current approach in plasma facing components has been utilisation of solid-HIP technology and solid-powder-HIP technology. Due to the large size of especially shield modules shape, control of the internal cavities and cooling channels is extremely demanding. This requires strict control of the raw materials and manufacturing parameters

R and D ERL: Vacuum

International Nuclear Information System (INIS)

Mapes, M.; Smart, L.; Weiss, D.; Steszyn, A.; Todd, R.

2010-01-01

The ERL Vacuum systems are depicted in a figure. ERL has eight vacuum volumes with various sets of requirements. A summary of vacuum related requirements is provided in a table. Five of the eight volumes comprise the electron beamline. They are the 5-cell Superconducting RF Cavity, Superconducting e-gun, injection, loop and beam dump. Two vacuum regions are the individual cryostats insulating the 5-cell Superconducting RF Cavity and the Superconducting e-gun structures. The last ERL vacuum volume not shown in the schematic is the laser transport line. The beamline vacuum regions are separated by electropneumatic gate valves. The beam dump is common with loop beamline but is considered a separate volume due to geometry and requirements. Vacuum in the 5-cell SRF cavity is maintained in the ∼10 -9 torr range at room temperature by two 20 l/s ion pumps and in the e-gun SRF cavity by one 60 l/s ion pump. Vacuum in the SRF cavities operated at 2 o K is reduced to low 10 -11 torr via cryopumping of the cavity walls. The cathode of the e-gun must be protected from poisoning, which can occur if vacuum adjacent to the e-gun in the injection line exceeds 10-11 torr range in the injection warm beamline near the e-gun exit. The vacuum requirements for beam operation in the loop and beam dump are 10-9 torr range. The beamlines are evacuated from atmospheric pressure to high vacuum level with a particulate free, oil free turbomolecular pumping cart. 25 l/s shielded ion pumps distributed throughout the beamlines maintain the vacuum requirement. Due to the more demanding vacuum requirement of the injection beamline proximate to the e-gun, a vacuum bakeout of the injection beamline is required. In addition, two 200 l/s diode ion pumps and supplemental pumping provided by titanium sublimation pumps are installed in the injection line just beyond the exit of the e-gun. Due to expected gas load a similar pumping arrangement is planned for the beam dump. The cryostat vacuum thermally

Constructing Hardware in a Scale Embedded Language

Energy Technology Data Exchange (ETDEWEB)

2014-08-21

Chisel is a new open-source hardware construction language developed at UC Berkeley that supports advanced hardware design using highly parameterized generators and layered domain-specific hardware languages. Chisel is embedded in the Scala programming language, which raises the level of hardware design abstraction by providing concepts including object orientation, functional programming, parameterized types, and type inference. From the same source, Chisel can generate a high-speed C++-based cycle-accurate software simulator, or low-level Verilog designed to pass on to standard ASIC or FPGA tools for synthesis and place and route.

MOV reliability evaluation and periodic verification scheduling

Energy Technology Data Exchange (ETDEWEB)

Bunte, B.D.

1996-12-01

The purpose of this paper is to establish a periodic verification testing schedule based on the expected long term reliability of gate or globe motor operated valves (MOVs). The methodology in this position paper determines the nominal (best estimate) design margin for any MOV based on the best available information pertaining to the MOVs design requirements, design parameters, existing hardware design, and present setup. The uncertainty in this margin is then determined using statistical means. By comparing the nominal margin to the uncertainty, the reliability of the MOV is estimated. The methodology is appropriate for evaluating the reliability of MOVs in the GL 89-10 program. It may be used following periodic testing to evaluate and trend MOV performance and reliability. It may also be used to evaluate the impact of proposed modifications and maintenance activities such as packing adjustments. In addition, it may be used to assess the impact of new information of a generic nature which impacts safety related MOVs.

MOV reliability evaluation and periodic verification scheduling

International Nuclear Information System (INIS)

Bunte, B.D.

1996-01-01

The purpose of this paper is to establish a periodic verification testing schedule based on the expected long term reliability of gate or globe motor operated valves (MOVs). The methodology in this position paper determines the nominal (best estimate) design margin for any MOV based on the best available information pertaining to the MOVs design requirements, design parameters, existing hardware design, and present setup. The uncertainty in this margin is then determined using statistical means. By comparing the nominal margin to the uncertainty, the reliability of the MOV is estimated. The methodology is appropriate for evaluating the reliability of MOVs in the GL 89-10 program. It may be used following periodic testing to evaluate and trend MOV performance and reliability. It may also be used to evaluate the impact of proposed modifications and maintenance activities such as packing adjustments. In addition, it may be used to assess the impact of new information of a generic nature which impacts safety related MOVs

Production of ceramic-metal joints for high-vacuum applications and development of simulation program for discharge tube

Energy Technology Data Exchange (ETDEWEB)

Kang, S. H.; Chung, K. H. [Seoul National University, Seoul (Korea)

2000-04-01

To develop a ceramic-metal jointed tube for high-vacuum applications, metalizing process and active metal brazing were investigated. Active metal brazing was adopted as a joining process to produce a high-vacuum tube which had high joint strength and reliability. A possibility for the development of new composition of Mo-Mn paste was studied. Also, to improve the strength and reliability of active metal brazed joint, TiN coating was introduced as a diffusion barrier. It was revealed that TiN coating could improve the joint strength and reliability. 100mm {phi} tube joint was produced using incusil ABA brazing alloy. The strength and reliability of manufactured tube showed higher value than commercial one. The electric field distribution in ceramic tube under high voltage was analyzed. Two dimensional electric field distribution was investigated under the existence of charged particles. From this result, electric field distribution at the surface of ceramic tube and the location of high electric field was predicted. Finally, Arc discharge was simulated to analyze the effect of arc discharge on the discharge tube wall. The maximum temperature of arc was 12000-13000K. The wall temperature was increased 100-170K by the arc discharge. 45 refs., 57 figs., 4 tabs. (Author)

Hardware Objects for Java

DEFF Research Database (Denmark)

Schoeberl, Martin; Thalinger, Christian; Korsholm, Stephan

2008-01-01

Java, as a safe and platform independent language, avoids access to low-level I/O devices or direct memory access. In standard Java, low-level I/O it not a concern; it is handled by the operating system. However, in the embedded domain resources are scarce and a Java virtual machine (JVM) without...... an underlying middleware is an attractive architecture. When running the JVM on bare metal, we need access to I/O devices from Java; therefore we investigate a safe and efficient mechanism to represent I/O devices as first class Java objects, where device registers are represented by object fields. Access...... to those registers is safe as Java’s type system regulates it. The access is also fast as it is directly performed by the bytecodes getfield and putfield. Hardware objects thus provide an object-oriented abstraction of low-level hardware devices. As a proof of concept, we have implemented hardware objects...

Time response of protection in event of vacuum failure based on Nude ionization gauge controller

Science.gov (United States)

Gao, Hui; Wang, Qiuping; Wang, Weibin; Wu, Qinglin; Chen, Wentong; Sheng, Liusi; Zhang, Yunwu

2001-10-01

This article describes the design and application of fast-response vacuum protection sensor module, based on the Nude ionization gauge and a homemade controller named GH07X. A simulative test indicated that the controller's response time was less than 200 μs when 1 atm air rushed into the vacuum system through a pulsed valve with 0.8 mm orifice nozzle and the emitting current of the Nude gauge was 4 mA. The experiment result showed that the response time mainly depended on the gas density as well as the electron emitting current of the Nude gauge filament. Compared with the vacuum protection sensors based on sputter ion pump and cold-cathode gauge, GH07X is faster and reliable besides, GH07X can be used as an ultrahigh-vacuum slow valve interlock controller with response time of 100 ms, which is faster than other gauge controllers. The widely used field-bus interface CAN and common serial interface RS232/RS485 are embedded in GH07X controller system.

Thermal and Alignment Analysis of the Instrument-Level ATLAS Thermal Vacuum Test

Science.gov (United States)

Bradshaw, Heather

2012-01-01

This paper describes the thermal analysis and test design performed in preparation for the ATLAS thermal vacuum test. NASA's Advanced Topographic Laser Altimeter System (ATLAS) will be flown as the sole instrument aboard the Ice, Cloud, and land Elevation Satellite-2 (ICESat-2). It will be used to take measurements of topography and ice thickness for Arctic and Antarctic regions, providing crucial data used to predict future changes in worldwide sea levels. Due to the precise measurements ATLAS is taking, the laser altimeter has very tight pointing requirements. Therefore, the instrument is very sensitive to temperature-induced thermal distortions. For this reason, it is necessary to perform a Structural, Thermal, Optical Performance (STOP) analysis not only for flight, but also to ensure performance requirements can be operationally met during instrument-level thermal vacuum testing. This paper describes the thermal model created for the chamber setup, which was used to generate inputs for the environmental STOP analysis. This paper also presents the results of the STOP analysis, which indicate that the test predictions adequately replicate the thermal distortions predicted for flight. This is a new application of an existing process, as STOP analyses are generally performed to predict flight behavior only. Another novel aspect of this test is that it presents the opportunity to verify pointing results of a STOP model, which is not generally done. It is possible in this case, however, because the actual pointing will be measured using flight hardware during thermal vacuum testing and can be compared to STOP predictions.

Hardware Development Process for Human Research Facility Applications

Science.gov (United States)

Bauer, Liz

2000-01-01

The simple goal of the Human Research Facility (HRF) is to conduct human research experiments on the International Space Station (ISS) astronauts during long-duration missions. This is accomplished by providing integration and operation of the necessary hardware and software capabilities. A typical hardware development flow consists of five stages: functional inputs and requirements definition, market research, design life cycle through hardware delivery, crew training, and mission support. The purpose of this presentation is to guide the audience through the early hardware development process: requirement definition through selecting a development path. Specific HRF equipment is used to illustrate the hardware development paths. The source of hardware requirements is the science community and HRF program. The HRF Science Working Group, consisting of SCientists from various medical disciplines, defined a basic set of equipment with functional requirements. This established the performance requirements of the hardware. HRF program requirements focus on making the hardware safe and operational in a space environment. This includes structural, thermal, human factors, and material requirements. Science and HRF program requirements are defined in a hardware requirements document which includes verification methods. Once the hardware is fabricated, requirements are verified by inspection, test, analysis, or demonstration. All data is compiled and reviewed to certify the hardware for flight. Obviously, the basis for all hardware development activities is requirement definition. Full and complete requirement definition is ideal prior to initiating the hardware development. However, this is generally not the case, but the hardware team typically has functional inputs as a guide. The first step is for engineers to conduct market research based on the functional inputs provided by scientists. CommerCially available products are evaluated against the science requirements as

Programming languages and compiler design for realistic quantum hardware

Science.gov (United States)

Chong, Frederic T.; Franklin, Diana; Martonosi, Margaret

2017-09-01

Quantum computing sits at an important inflection point. For years, high-level algorithms for quantum computers have shown considerable promise, and recent advances in quantum device fabrication offer hope of utility. A gap still exists, however, between the hardware size and reliability requirements of quantum computing algorithms and the physical machines foreseen within the next ten years. To bridge this gap, quantum computers require appropriate software to translate and optimize applications (toolflows) and abstraction layers. Given the stringent resource constraints in quantum computing, information passed between layers of software and implementations will differ markedly from in classical computing. Quantum toolflows must expose more physical details between layers, so the challenge is to find abstractions that expose key details while hiding enough complexity.

Programming languages and compiler design for realistic quantum hardware.

Science.gov (United States)

Chong, Frederic T; Franklin, Diana; Martonosi, Margaret

2017-09-13

Quantum computing sits at an important inflection point. For years, high-level algorithms for quantum computers have shown considerable promise, and recent advances in quantum device fabrication offer hope of utility. A gap still exists, however, between the hardware size and reliability requirements of quantum computing algorithms and the physical machines foreseen within the next ten years. To bridge this gap, quantum computers require appropriate software to translate and optimize applications (toolflows) and abstraction layers. Given the stringent resource constraints in quantum computing, information passed between layers of software and implementations will differ markedly from in classical computing. Quantum toolflows must expose more physical details between layers, so the challenge is to find abstractions that expose key details while hiding enough complexity.

Techniques to maximize software reliability in radiation fields

International Nuclear Information System (INIS)

Eichhorn, G.; Piercey, R.B.

1986-01-01

Microprocessor system failures due to memory corruption by single event upsets (SEUs) and/or latch-up in RAM or ROM memory are common in environments where there is high radiation flux. Traditional methods to harden microcomputer systems against SEUs and memory latch-up have usually involved expensive large scale hardware redundancy. Such systems offer higher reliability, but they tend to be more complex and non-standard. At the Space Astronomy Laboratory the authors have developed general programming techniques for producing software which is resistant to such memory failures. These techniques, which may be applied to standard off-the-shelf hardware, as well as custom designs, include an implementation of Maximally Redundant Software (MRS) model, error detection algorithms and memory verification and management

IPbus A flexible Ethernet-based control system for xTCA hardware

CERN Document Server

Williams, Thomas Stephen

2014-01-01

The ATCA and uTCA standards include industry-standard data pathway technologies such as Gigabit Ethernet which can be used for control communication, but no specific hardware control protocol is defined. The IPbus suite of software and firmware implements a reliable high-performance control link for particle physics electronics, and has successfully replaced VME control in several large projects. In this paper, we outline the IPbus system architecture, and describe recent developments in the reliability, scalability and performance of IPbus systems, carried out in preparation for deployment of uTCA-based CMS upgrades before the LHC 2015 run. We also discuss plans for future development of the IPbus suite.SUMMARY IPbus will be used for controlling the uTCA electronics in the CMS HCAL, TCDS, Pixel and Level-1 trigger upgrades. IPbus control has already been extensively used in the work of these upgrade projects so far, and final uTCA systems will be deployed in the experiment starting from Autumn 2014. IPbus is...

VEG-01: Veggie Hardware Verification Testing

Science.gov (United States)

Massa, Gioia; Newsham, Gary; Hummerick, Mary; Morrow, Robert; Wheeler, Raymond

2013-01-01

The Veggie plant/vegetable production system is scheduled to fly on ISS at the end of2013. Since much of the technology associated with Veggie has not been previously tested in microgravity, a hardware validation flight was initiated. This test will allow data to be collected about Veggie hardware functionality on ISS, allow crew interactions to be vetted for future improvements, validate the ability of the hardware to grow and sustain plants, and collect data that will be helpful to future Veggie investigators as they develop their payloads. Additionally, food safety data on the lettuce plants grown will be collected to help support the development of a pathway for the crew to safely consume produce grown on orbit. Significant background research has been performed on the Veggie plant growth system, with early tests focusing on the development of the rooting pillow concept, and the selection of fertilizer, rooting medium and plant species. More recent testing has been conducted to integrate the pillow concept into the Veggie hardware and to ensure that adequate water is provided throughout the growth cycle. Seed sanitation protocols have been established for flight, and hardware sanitation between experiments has been studied. Methods for shipping and storage of rooting pillows and the development of crew procedures and crew training videos for plant activities on-orbit have been established. Science verification testing was conducted and lettuce plants were successfully grown in prototype Veggie hardware, microbial samples were taken, plant were harvested, frozen, stored and later analyzed for microbial growth, nutrients, and A TP levels. An additional verification test, prior to the final payload verification testing, is desired to demonstrate similar growth in the flight hardware and also to test a second set of pillows containing zinnia seeds. Issues with root mat water supply are being resolved, with final testing and flight scheduled for later in 2013.

Implementation of Hardware Accelerators on Zynq

DEFF Research Database (Denmark)

Toft, Jakob Kenn

of the ARM Cortex-9 processor featured on the Zynq SoC, with regard to execution time, power dissipation and energy consumption. The implementation of the hardware accelerators were successful. Use of the Monte Carlo processor resulted in a significant increase in performance. The Telco hardware accelerator......In the recent years it has become obvious that the performance of general purpose processors are having trouble meeting the requirements of high performance computing applications of today. This is partly due to the relatively high power consumption, compared to the performance, of general purpose...... processors, which has made hardware accelerators an essential part of several datacentres and the worlds fastest super-computers. In this work, two different hardware accelerators were implemented on a Xilinx Zynq SoC platform mounted on the ZedBoard platform. The two accelerators are based on two different...

Proceedings of the SRESA national conference on reliability and safety engineering

International Nuclear Information System (INIS)

Varde, P.V.; Vaishnavi, P.; Sujatha, S.; Valarmathi, A.

2014-01-01

The objective of this conference was to provide a forum for technical discussions on recent developments in the area of risk based approach and Prognostic Health Management of critical systems in decision making. The reliability and safety engineering methods are concerned with the way which the product fails, and the effects of failure is to understand how a product works and assures acceptable levels of safety. The reliability engineering addresses all the anticipated and possibly unanticipated causes of failure to ensure the occurrence of failure is prevented or minimized. The topics discussed in the conference were: Reliability in Engineering Design, Safety Assessment and Management, Reliability analysis and Assessment , Stochastic Petri nets for reliability Modeling, Dynamic Reliability, Reliability Prediction, Hardware Reliability, Software Reliability in Safety Critical Issues, Probabilistic Safety Assessment, Risk Informed Approach, Dynamic Models for Reliability Analysis, Reliability based Design and Analysis, Prognostics and Health Management, Remaining Useful Life (RUL), Human Reliability Modeling, Risk Based Applications, Hazard and Operability Study (HAZOP), Reliability in Network Security and Quality Assurance and Management etc. The papers relevant to INIS are indexed separately

Reliability analyses of safety systems for WWER-440 nuclear power plants

International Nuclear Information System (INIS)

Dusek, J.; Hojny, V.

1985-01-01

The UJV in Rez near Prague studied the reliability of the system of emergency core cooling and of the system for suppressing pressure in the sealed area of the nuclear power plant in the occurrence of a loss-of-coolant accident. The reliability of the systems was evaluated by failure tree analysis. Simulation and analytical calculation programs were developed and used for the reliability analysis. The results are briefly presented of the reliability analyses of the passive system for the immediate short-term flooding of the reactor core, of the active low-pressure system of emergency core cooling, the spray system, the bubble-vacuum system and the system of emergency supply of the steam generators. (E.S.)

Computer hardware fault administration

Science.gov (United States)

Archer, Charles J.; Megerian, Mark G.; Ratterman, Joseph D.; Smith, Brian E.

2010-09-14

Computer hardware fault administration carried out in a parallel computer, where the parallel computer includes a plurality of compute nodes. The compute nodes are coupled for data communications by at least two independent data communications networks, where each data communications network includes data communications links connected to the compute nodes. Typical embodiments carry out hardware fault administration by identifying a location of a defective link in the first data communications network of the parallel computer and routing communications data around the defective link through the second data communications network of the parallel computer.

Design and reliability analysis of DP-3 dynamic positioning control architecture

Science.gov (United States)

Wang, Fang; Wan, Lei; Jiang, Da-Peng; Xu, Yu-Ru

2011-12-01

As the exploration and exploitation of oil and gas proliferate throughout deepwater area, the requirements on the reliability of dynamic positioning system become increasingly stringent. The control objective ensuring safety operation at deep water will not be met by a single controller for dynamic positioning. In order to increase the availability and reliability of dynamic positioning control system, the triple redundancy hardware and software control architectures were designed and developed according to the safe specifications of DP-3 classification notation for dynamically positioned ships and rigs. The hardware redundant configuration takes the form of triple-redundant hot standby configuration including three identical operator stations and three real-time control computers which connect each other through dual networks. The function of motion control and redundancy management of control computers were implemented by software on the real-time operating system VxWorks. The software realization of task loose synchronization, majority voting and fault detection were presented in details. A hierarchical software architecture was planed during the development of software, consisting of application layer, real-time layer and physical layer. The behavior of the DP-3 dynamic positioning control system was modeled by a Markov model to analyze its reliability. The effects of variation in parameters on the reliability measures were investigated. The time domain dynamic simulation was carried out on a deepwater drilling rig to prove the feasibility of the proposed control architecture.

Vacuum considerations: summary

International Nuclear Information System (INIS)

Blechschmidt, D.; Halama, H.J.

1978-01-01

A summary is given of the efforts of a vacuum systems study group of the workshop on a Heavy Ion Demonstration Experiment (HIDE) for heavy ion fusion. An inadequate knowledge of cross-sections prevents a more concrete vacuum system design. Experiments leading to trustworthy numbers for charge exchange, stripping and capture cross-sections are badly needed and should start as soon as possible. In linacs, beam loss will be almost directly proportional to the pressure inside the tanks. The tanks should, therefore, be built in such a way that they can be baked-out in situ to improve their vacuum, especially if the cross-sections turn out to be higher than anticipated. Using standard UHV techniques and existing pumps, an even lower pressure can be achieved. The vacuum system design for circular machines will be very difficult, and in some cases, beyond the present state-of-the-art

Modern vacuum physics

CERN Document Server

Chambers, Austin

2005-01-01

Modern Vacuum Physics presents the principles and practices of vacuum science and technology along with a number of applications in research and industrial production. The first half of the book builds a foundation in gases and vapors under rarefied conditions, The second half presents examples of the analysis of representative systems and describes some of the exciting developments in which vacuum plays an important role. The final chapter addresses practical matters, such as materials, components, and leak detection. Throughout the book, the author''s explanations are presented in terms of first principles and basic physics, augmented by illustrative worked examples and numerous figures.

Gravitation and vacuum field

International Nuclear Information System (INIS)

Tevikyan, R.V.

1986-01-01

This paper presents equations that describe particles with spins s = 0, 1/2, 1 completely and which also describe 2s + 2 limiting fields as E → ∞. It is shown that the ordinary Hilbert-Einstein action for the gravitation field must be augmented by the action for the Bose vacuum field. This means that one must introduce in the gravitational equations a cosmological term proportional to the square of the strength of the Bose vacuum field. It is shown that the theory of gravitation describes three realities: matter, field, and vacuum field. A new form of matter--the vacuum field--is introduced into field theory

Surge-damping vacuum valve

International Nuclear Information System (INIS)

Bullock, J.C.; Kelley, B.E.

1977-01-01

A valve for damping out flow surges in a vacuum system is described. The surge-damping mechanism consists of a slotted, spring-loaded disk adjacent to the valve's vacuum port (the flow passage to the vacuum roughing pump). Under flow surge conditions, the differential pressure forces the disk into a sealing engagement with the vacuum port, thereby restricting the gas flow path to narrow slots in the disk's periphery. The increased flow damps out the flow surge. When pressure is equalized on both sides of the valve, the spring load moves the disk away from the port to restore full flow conductance through the valve

Comparison of vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification systems.

Science.gov (United States)

Han, Young Keun; Miller, Kevin M

2009-08-01

To compare vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification machines. Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA. The vacuum rise time under normal and enhanced aspiration modes, vacuum limit accuracy, and occlusion break surge of the Infiniti Vision System, Stellaris Vision Enhancement System, and WhiteStar Signature Phacoemulsification System were tested. Vacuum rise time and limit accuracy were measured at limit settings of 400 mm Hg and 600 mm Hg. Surge area was recorded at vacuum limit settings of 200 mm Hg, 300 mm Hg, 400 mm Hg, and 500 mm Hg. The Infiniti had the fastest vacuum rise times under normal and enhanced aspiration modes. At 4 seconds, the vacuum limit accuracy was greatest with the Infiniti at the 400 mm Hg limit and the Signature at the 600 mm Hg limit. The Stellaris did not reach either vacuum target. The Infiniti performed better than the other 2 machines during testing of occlusion break surge at all vacuum limit settings above 200 mm Hg. Under controlled laboratory test conditions, the Infiniti had the fastest vacuum rise time, greatest vacuum limit accuracy at 400 mm Hg, and least occlusion break surge. These results can be explained by the lower compliance of the Infiniti system.

False vacuum decay in quantum mechanics and four dimensional scalar field theory

Science.gov (United States)

Bezuglov, Maxim

2018-04-01

When the Higgs boson was discovered in 2012 it was realized that electroweak vacuum may suffer a possible metastability on the Planck scale and can eventually decay. To understand this problem it is important to have reliable predictions for the vacuum decay rate within the framework of quantum field theory. For now, it can only be done at one loop level, which is apparently is not enough. The aim of this work is to develop a technique for the calculation of two and higher order radiative corrections to the false vacuum decay rate in the framework of four dimensional scalar quantum field theory and then apply it to the case of the Standard Model. To achieve this goal, we first start from the case of d=1 dimensional QFT i.e. quantum mechanics. We show that for some potentials two and three loop corrections can be very important and must be taken into account. Next, we use quantum mechanical example as a template for the general d=4 dimensional theory. In it we are concentrating on the calculations of bounce solution and corresponding Green function in so called thin wall approximation. The obtained Green function is then used as a main ingredient for the calculation of two loop radiative corrections to the false vacuum decay rate.

Vacuum pumping system for the JT-60 radio-frequency heating system

International Nuclear Information System (INIS)

Yokokura, Kenji; Ikeda, Yoshitaka; Imai, Tuyoshi; Suganuma, Kazuaki; Nagashima, Takashi

1988-01-01

The basic design requirements set up for the JT-60 radio-frequency heating system included: (1) rapid pumping of gas released upon application of a radio-frequency power to maintain the pressure in the launchers at 10 -2 - 10 -3 Pa or less, (2) incorporation of a gas analysis system that can operate under a strong field and high pressure (>10 -2 Pa) to permit remote controlled data collection and processing, and (3) low cost, multiple functions and high reliability. The vacuum pumping system, consisting of three units for low hybrid radio-frequency (LHRF) and one unit for ion cyclotron radio-frequency (ICRF), is connected to each launcher provided at the four ports of JT-60. The LHRF unit is composed of a main pump, an alumina joint for electrical insulation from the launcher, a metallic gate valve for isolation from the JT-60 vacuum region, and various vacuum gauges. Only a turbo-molecular pump is used for the ICRF system because a large-scale differential pumping is not required. A gas measuring system is incorporated which consists of a mass filter, personal computer, turbo-molecular pump, and variable flow valve equipped with an APG control. This system is designed to identify and make use of gas impurities released during the launcher aging process. The control system employed consists of a personal computer, interlock control board, data logger and other devices such as vacuum gages. (Nogami, K.)

Task Decomposition in Human Reliability Analysis

Energy Technology Data Exchange (ETDEWEB)

Boring, Ronald Laurids [Idaho National Laboratory; Joe, Jeffrey Clark [Idaho National Laboratory

2014-06-01

In the probabilistic safety assessments (PSAs) used in the nuclear industry, human failure events (HFEs) are determined as a subset of hardware failures, namely those hardware failures that could be triggered by human action or inaction. This approach is top-down, starting with hardware faults and deducing human contributions to those faults. Elsewhere, more traditionally human factors driven approaches would tend to look at opportunities for human errors first in a task analysis and then identify which of those errors is risk significant. The intersection of top-down and bottom-up approaches to defining HFEs has not been carefully studied. Ideally, both approaches should arrive at the same set of HFEs. This question remains central as human reliability analysis (HRA) methods are generalized to new domains like oil and gas. The HFEs used in nuclear PSAs tend to be top-down— defined as a subset of the PSA—whereas the HFEs used in petroleum quantitative risk assessments (QRAs) are more likely to be bottom-up—derived from a task analysis conducted by human factors experts. The marriage of these approaches is necessary in order to ensure that HRA methods developed for top-down HFEs are also sufficient for bottom-up applications.

Control system reliability at Jefferson Lab

International Nuclear Information System (INIS)

White, K.S.; Areti, H.; Garza, O.

1997-01-01

At Thomas Jefferson National Accelerator Facility (Jefferson Lab), the availability of the control system is crucial to the operation of the accelerator for experimental programs. Jefferson Lab's control system, uses 68040 based microprocessors running VxWorks, Unix workstations, and a variety of VME, CAMAC. GPIB, and serial devices. The software consists of control system toolkit software, commercial packages, and over 200 custom and generic applications, some of which are highly complex. The challenge is to keep this highly diverse and still growing system, with over 162,000 control points, operating reliably, while managing changes and upgrades to both the hardware and software. Downtime attributable to the control system includes the time to troubleshoot and repair problems and the time to restore the machine to operation of the scheduled program. This paper describes the availability of the control system during the last year, the heaviest contributors to downtime and the response to problems. Strategies for improving the robustness of the control system am detailed and include changes in hardware, software, procedures and processes. The improvements range from the routine preventive hardware maintenance, to improving their ability to detect, predict and prevent problems. This paper also describes the software tools used to assist in control system troubleshooting, maintenance and failure recovery processes

Vacuum type D initial data

Science.gov (United States)

García-Parrado Gómez-Lobo, Alfonso

2016-09-01

A vacuum type D initial data set is a vacuum initial data set of the Einstein field equations whose data development contains a region where the space–time is of Petrov type D. In this paper we give a systematic characterisation of a vacuum type D initial data set. By systematic we mean that the only quantities involved are those appearing in the vacuum constraints, namely the first fundamental form (Riemannian metric) and the second fundamental form. Our characterisation is a set of conditions consisting of the vacuum constraints and some additional differential equations for the first and second fundamental forms These conditions can be regarded as a system of partial differential equations on a Riemannian manifold and the solutions of the system contain all possible regular vacuum type D initial data sets. As an application we particularise our conditions for the case of vacuum data whose data development is a subset of the Kerr solution. This has applications in the formulation of the nonlinear stability problem of the Kerr black hole.

Server hardware dependability: effect of periodic switching on and off; Auswirkungen von periodischem Ein- und Ausschalten auf die Server-Hardware-Zuverlaessigkeit

Energy Technology Data Exchange (ETDEWEB)

Held, M.

2003-07-01

This final report discusses investigations made on behalf of the Swiss Federal Office of Energy that have shown a large potential for energy savings by switching off servers during idle periods. User concerns such as those concerning the possible effects of intermittent operation on hardware reliability are discussed. On the basis of the RDF 2000 Model evaluated in this project, the predicted failure rates of components of a typical SME (small and medium enterprise) server are presented that were calculated for the three operational modes 'continuous operation', 'on and idle', and 'on and off'. The failure rate model described takes account of the influence of temperature on failure rates as well as thermo-mechanical effects caused by changes in loading and temperature that also have a substantial impact on the failure rates of electronic components.

Vacuum pumping concepts for ETF

International Nuclear Information System (INIS)

Homeyer, W.G.

1980-09-01

The Engineering Test Facility (ETF) poses unique vacuum pumping requirements due to its large size and long burn characteristics. These requirements include torus vacuum pumping initially and between burns and pumping of neutralized gas from divertor collector chambers. It was found that the requirements could be met by compound cryopumps in which molecular sieve 5A is used as the cryosorbent. The pumps, ducts, and vacuum valves required are large but fit with other ETF components and do not require major advances in vacuum pumping technology. Several additional design, analytical, and experimental studies were identified as needed to optimize designs and provide better design definition for the ETF vacuum pumping systems

"Do-It-Yourself" reliable pH-stat device by using open-source software, inexpensive hardware and available laboratory equipment

Science.gov (United States)

Kragic, Rastislav; Kostic, Mirjana

2018-01-01

In this paper, we present the construction of a reliable and inexpensive pH stat device, by using open-source “OpenPhControl” software, inexpensive hardware (a peristaltic and a syringe pump, Arduino, a step motor…), readily available laboratory devices: a pH meter, a computer, a webcam, and some 3D printed parts. We provide a methodology for the design, development and test results of each part of the device, as well as of the entire system. In addition to dosing reagents by means of a low-cost peristaltic pump, we also present carefully controlled dosing of reagents by an open-source syringe pump. The upgrading of the basic open-source syringe pump is given in terms of pump control and application of a larger syringe. In addition to the basic functions of pH stat, i.e. pH value measurement and maintenance, an improvement allowing the device to be used for potentiometric titration has been made as well. We have demonstrated the device’s utility when applied for cellulose fibers oxidation with 2,2,6,6-tetramethylpiperidine-1-oxyl radical, i.e. for TEMPO-mediated oxidation. In support of this, we present the results obtained for the oxidation kinetics, the consumption of added reagent and experimental repeatability. Considering that the open-source scientific tools are available to everyone, and that researchers can construct and adjust the device according to their needs, as well as, that the total cost of the open-source pH stat device, excluding the existing laboratory equipment (pH meter, computer and glossary) was less than 150 EUR, we believe that, at a small fraction of the cost of available commercial offers, our open-source pH stat can significantly improve experimental work where the use of pH stat is necessary. PMID:29509793

"Do-It-Yourself" reliable pH-stat device by using open-source software, inexpensive hardware and available laboratory equipment.

Science.gov (United States)

Milanovic, Jovana Z; Milanovic, Predrag; Kragic, Rastislav; Kostic, Mirjana

2018-01-01

In this paper, we present the construction of a reliable and inexpensive pH stat device, by using open-source "OpenPhControl" software, inexpensive hardware (a peristaltic and a syringe pump, Arduino, a step motor…), readily available laboratory devices: a pH meter, a computer, a webcam, and some 3D printed parts. We provide a methodology for the design, development and test results of each part of the device, as well as of the entire system. In addition to dosing reagents by means of a low-cost peristaltic pump, we also present carefully controlled dosing of reagents by an open-source syringe pump. The upgrading of the basic open-source syringe pump is given in terms of pump control and application of a larger syringe. In addition to the basic functions of pH stat, i.e. pH value measurement and maintenance, an improvement allowing the device to be used for potentiometric titration has been made as well. We have demonstrated the device's utility when applied for cellulose fibers oxidation with 2,2,6,6-tetramethylpiperidine-1-oxyl radical, i.e. for TEMPO-mediated oxidation. In support of this, we present the results obtained for the oxidation kinetics, the consumption of added reagent and experimental repeatability. Considering that the open-source scientific tools are available to everyone, and that researchers can construct and adjust the device according to their needs, as well as, that the total cost of the open-source pH stat device, excluding the existing laboratory equipment (pH meter, computer and glossary) was less than 150 EUR, we believe that, at a small fraction of the cost of available commercial offers, our open-source pH stat can significantly improve experimental work where the use of pH stat is necessary.

Non-fuel bearing hardware melting technology

International Nuclear Information System (INIS)

Newman, D.F.

1993-01-01

Battelle has developed a portable hardware melter concept that would allow spent fuel rod consolidation operations at commercial nuclear power plants to provide significantly more storage space for other spent fuel assemblies in existing pool racks at lower cost. Using low pressure compaction, the non-fuel bearing hardware (NFBH) left over from the removal of spent fuel rods from the stainless steel end fittings and the Zircaloy guide tubes and grid spacers still occupies 1/3 to 2/5 of the volume of the consolidated fuel rod assemblies. Melting the non-fuel bearing hardware reduces its volume by a factor 4 from that achievable with low-pressure compaction. This paper describes: (1) the configuration and design features of Battelle's hardware melter system that permit its portability, (2) the system's throughput capacity, (3) the bases for capital and operating estimates, and (4) the status of NFBH melter demonstration to reduce technical risks for implementation of the concept. Since all NFBH handling and processing operations would be conducted at the reactor site, costs for shipping radioactive hardware to and from a stationary processing facility for volume reduction are avoided. Initial licensing, testing, and installation in the field would follow the successful pattern achieved with rod consolidation technology

Modeling reliability measurement of interface on information system: Towards the forensic of rules

Science.gov (United States)

Nasution, M. K. M.; Sitompul, Darwin; Harahap, Marwan

2018-02-01

Today almost all machines depend on the software. As a software and hardware system depends also on the rules that are the procedures for its use. If the procedure or program can be reliably characterized by involving the concept of graph, logic, and probability, then regulatory strength can also be measured accordingly. Therefore, this paper initiates an enumeration model to measure the reliability of interfaces based on the case of information systems supported by the rules of use by the relevant agencies. An enumeration model is obtained based on software reliability calculation.

Structure of Nonlocal quark vacuum condensate in non-perturbative QCD vacuum

International Nuclear Information System (INIS)

Xiang Qianfei; Ma Weixing; Zhou Lijuan; Jiang Weizhou

2014-01-01

Based on the Dyson-Schwinger Equations (DSEs) with the rainbow truncation, and Operator Product Expansion, the structure of nonlocal quark vacuum condensate in QCD, described by quark self-energy functions A_f and B_f given usually by the solutions of the DSEs of quark propagator, is predicted numerically. We also calculate the local quark vacuum condensate, quark-gluon mixed local vacuum condensate, and quark virtuality. The self-energy functions A_f and B_f are given by the parameterized quark propagator functions σ_v"f (p"2) and σ_s"f (p"2) of Roberts and Williams, instead of the numerical solutions of the DSEs. Our calculated results are in reasonable agreement with those of QCD sum rules, Lattice QCD calculations, and instanton model predictions, although the resulting local quark vacuum condensate for light quarks, u, d, s, are a little bit larger than those of the above theoretical predictions. We think the differences are caused by model dependence. The larger of strange quark vacuum condensate than u, d quark is due to the s quark mass which is more larger than u, d quark masses. Of course, the Roberts-Williams parameterized quark propagator is an empirical formulism, which approximately describes quark propagation. (authors)

A Practical Introduction to HardwareSoftware Codesign

CERN Document Server

Schaumont, Patrick R

2013-01-01

This textbook provides an introduction to embedded systems design, with emphasis on integration of custom hardware components with software. The key problem addressed in the book is the following: how can an embedded systems designer strike a balance between flexibility and efficiency? The book describes how combining hardware design with software design leads to a solution to this important computer engineering problem. The book covers four topics in hardware/software codesign: fundamentals, the design space of custom architectures, the hardware/software interface and application examples. The book comes with an associated design environment that helps the reader to perform experiments in hardware/software codesign. Each chapter also includes exercises and further reading suggestions. Improvements in this second edition include labs and examples using modern FPGA environments from Xilinx and Altera, which make the material applicable to a greater number of courses where these tools are already in use.  Mo...

Comparative Modal Analysis of Sieve Hardware Designs

Science.gov (United States)

Thompson, Nathaniel

2012-01-01

The CMTB Thwacker hardware operates as a testbed analogue for the Flight Thwacker and Sieve components of CHIMRA, a device on the Curiosity Rover. The sieve separates particles with a diameter smaller than 150 microns for delivery to onboard science instruments. The sieving behavior of the testbed hardware should be similar to the Flight hardware for the results to be meaningful. The elastodynamic behavior of both sieves was studied analytically using the Rayleigh Ritz method in conjunction with classical plate theory. Finite element models were used to determine the mode shapes of both designs, and comparisons between the natural frequencies and mode shapes were made. The analysis predicts that the performance of the CMTB Thwacker will closely resemble the performance of the Flight Thwacker within the expected steady state operating regime. Excitations of the testbed hardware that will mimic the flight hardware were recommended, as were those that will improve the efficiency of the sieving process.

Shiva and Argus target diagnostics vacuum systems

International Nuclear Information System (INIS)

Glaros, S.S.; Mayo, S.E.; Campbell, D.; Holeman, D.

1978-09-01

The normal operation of LLL's Argus and Shiva laser irradiation facilities demand a main vacuum system for the target chamber and a separate local vacuum system for each of the larger appendage dianostics. This paper will describe the Argus and Shiva main vacuum systems, their respective auxiliary vacuum systems and the individual diagnostics with their respective special vacuum requirements and subsequent vacuum systems. Our latest approach to automatic computer-controlled vacuum systems will be presented

Remote hardware-reconfigurable robotic camera

Science.gov (United States)

Arias-Estrada, Miguel; Torres-Huitzil, Cesar; Maya-Rueda, Selene E.

2001-10-01

In this work, a camera with integrated image processing capabilities is discussed. The camera is based on an imager coupled to an FPGA device (Field Programmable Gate Array) which contains an architecture for real-time computer vision low-level processing. The architecture can be reprogrammed remotely for application specific purposes. The system is intended for rapid modification and adaptation for inspection and recognition applications, with the flexibility of hardware and software reprogrammability. FPGA reconfiguration allows the same ease of upgrade in hardware as a software upgrade process. The camera is composed of a digital imager coupled to an FPGA device, two memory banks, and a microcontroller. The microcontroller is used for communication tasks and FPGA programming. The system implements a software architecture to handle multiple FPGA architectures in the device, and the possibility to download a software/hardware object from the host computer into its internal context memory. System advantages are: small size, low power consumption, and a library of hardware/software functionalities that can be exchanged during run time. The system has been validated with an edge detection and a motion processing architecture, which will be presented in the paper. Applications targeted are in robotics, mobile robotics, and vision based quality control.

CERN Vacuum-System Activities during the Long Shutdown 1: The LHC Beam Vacuum

CERN Document Server

Baglin, V; Chiggiato, P; Jimenez, JM; Lanza, G

2014-01-01

After the Long Shutdown 1 (LS1) and the consolidation of the magnet bus bars, the CERN Large Hadron Collider (LHC) will operate with nominal beam parameters. Larger beam energy, beam intensities and luminosity are expected. Despite the very good performance of the beam vacuum system during the 2010-12 physics run (Run 1), some particular areas require attention for repair, consolidation and upgrade. Among the main activities, a large campaign aiming at the repair of the RF bridges of some vacuum modules is conducted. Moreover, consolidation of the cryogenic beam vacuum systems with burst disk for safety reasons is implemented. In addition, NEG cartridges, NEG coated inserts and new instruments for the vacuum system upgrade are installed. Besides these activities, repair, consolidation and upgrades of other beam equipment such as collimators, kickers and beam instrumentations are carried out. In this paper, the motivation and the description for such activities, together with the expected beam vacuum performa...

Reliability analysis of diverse safety logic systems of fast breeder reactor

International Nuclear Information System (INIS)

Ravi Kumar, Bh.; Apte, P.R.; Srivani, L.; Ilango Sambasivan, S.; Swaminathan, P.

2006-01-01

Safety Logic for Fast Breeder Reactor (FBR) is designed to initiate safety action against Design Basis Events. Based on the outputs of various processing circuits, Safety logic system drives the control rods of the shutdown system. So, Safety Logic system is classified as safety critical system. Therefore, reliability analysis has to be performed. This paper discusses the Reliability analysis of Diverse Safety logic systems of FBRs. For this literature survey on safety critical systems, system reliability approach and standards to be followed like IEC-61508 are discussed in detail. For Programmable Logic device based systems, Hardware Description Languages (HDL) are used. So this paper also discusses the Verification and Validation for HDLs. Finally a case study for the Reliability analysis of Safety logic is discussed. (author)

The AGS Booster vacuum systems

International Nuclear Information System (INIS)

Hseuh, H.C.

1989-01-01

The AGS Booster is a synchrotron for the acceleration of both protons and heavy ions. The design pressure of low 10 -11 mbar is required to minimize beam loss of the partially stripped heavy ions. To remove contaminants and to reduce outgassing, the vacuum chambers and the components located in them will be chemically cleaned, vacuum fired, baked then treated with nitric oxide. The vacuum sector will be insitu baked to a minimum of 200 degree C and pumped by the combination of sputter ion pumps and titanium sublimation pumps. This paper describes the design and the processing of this ultra high vacuum system, and the performance of some half-cell vacuum chambers. 9 refs., 7 figs

Baking system for vacuum components in INDUS-2

International Nuclear Information System (INIS)

Bhange, Nilesh J.; Bhatnagar, Prateek; Shukla, S.K.

2005-01-01

Optimized bake-out procedures are very important for the overall reliability of vacuum system. In this process the UHV components like Sputter ion pump (SIP), Titanium sublimation pump (TSP) are subjected to temperature rise for sufficiently long period of time. Baking is necessary for obtaining low out gassing rates. In order to provide controlled baking of UHV (Ultra High Vacuum) components for INDUS-II an intelligent ON/OFF control system was needed. For that purpose distributed control system was suitable. For fulfillment of this need modular baking system was developed. This system contains Temperature controller unit (TCU), Pressure Monitoring Unit (PMU), and Temperature control and pressure Monitoring Interface Software (TCPMIS). Each TCU is an eight channel temperature controlling unit. PMU is eight channel pressure monitoring unit to which analog data from gauges like Penning, BA Gauge controllers is given. TCPMIS is a user interface software developed for, controlling up to 5 TCU's. In this way 40 channel temperature control, data logging of 40 channel temperature and logging of eight channel pressures was realized. The present paper describes details about computer controlled baking system. (author)

Transmission delays in hardware clock synchronization

Science.gov (United States)

Shin, Kang G.; Ramanathan, P.

1988-01-01

Various methods, both with software and hardware, have been proposed to synchronize a set of physical clocks in a system. Software methods are very flexible and economical but suffer an excessive time overhead, whereas hardware methods require no time overhead but are unable to handle transmission delays in clock signals. The effects of nonzero transmission delays in synchronization have been studied extensively in the communication area in the absence of malicious or Byzantine faults. The authors show that it is easy to incorporate the ideas from the communication area into the existing hardware clock synchronization algorithms to take into account the presence of both malicious faults and nonzero transmission delays.

The symmetries of the vacuum

International Nuclear Information System (INIS)

Fleming, H.

1985-01-01

The vacuum equation of state required by cosmological inflation is taken seriously as a general property of the cosmological vacuum. This correctly restricts the class of theories which admit inflation. A model of such a vacuum is presented that leads naturally to the cosmological principle. (Author) [pt

Computer hardware description languages - A tutorial

Science.gov (United States)

Shiva, S. G.

1979-01-01

The paper introduces hardware description languages (HDL) as useful tools for hardware design and documentation. The capabilities and limitations of HDLs are discussed along with the guidelines needed in selecting an appropriate HDL. The directions for future work are provided and attention is given to the implementation of HDLs in microcomputers.

Regulating vacuum pump speed with feedback control

International Nuclear Information System (INIS)

Ludington, D.C.; Aneshansley, D.J.; Pellerin, R.; Guo, F.

1992-01-01

Considerable energy is wasted by the vacuum pump/motor on dairy farms. The output capacity (m 3 /min or cfm) of the vacuum pump always exceeds the capacity needed to milk cows and wash pipelines. Vacuum pumps run at full speed and load regardless of actual need for air. Excess air is admitted through a controller. Energy can be saved from electrical demand reduced by regulating vacuum pump speed according to air based on air usage. An adjustable speed drive (ASD) on the motor and controlled based upon air usage, can reduce the energy used by the vacuum pump. However, the ASD unit tested could not maintain vacuum levels within generally accepted guidelines when air usage changed. Adding a high vacuum reserve and a dual vacuum controller between the vacuum pump and the milking pipeline brought vacuum stability within guidelines. The ASD/dual vacuum system can reduce energy consumption and demand by at least 50 percent during milking and provide better vacuum stability than conventional systems. Tests were not run during washing cycles. Using 1990 costs and only the energy saved during milking, the simple payback on investment in new equipment for a 5 hp motor, speed controller and vacuum regulator would be about 5 years

The Source of the Quantum Vacuum

Directory of Open Access Journals (Sweden)

Daywitt W. C.

2009-01-01

Full Text Available The quantum vacuum consists of virtual particles randomly appearing and disappearing in free space. Ordinarily the wavenumber (or frequency spectrum of the zero-point fields for these virtual particles is assumed to be unbounded. The unbounded nature of the spectrum leads in turn to an infinite energy density for the quantum vacuum and an infinite renormalization mass for the free particle. This paper argues that there is a more fundamental vacuum state, the Planck vacuum, from which the quantum vacuum emerges and that the “graininess” of this more fundamental vacuum state truncates the wavenumber spectrum and leads to a finite energy density and a finite renormalization mass.

The Source of the Quantum Vacuum

Directory of Open Access Journals (Sweden)

Daywitt W. C.

2009-01-01

Full Text Available The quantum vacuum consists of virtual particles randomly appearing and disappearing in free space. Ordinarily the wavenumber (or frequency spectrum of the zero-point fields for these virtual particles is assumed to be unbounded. The unbounded nature of the spectrum leads in turn to an infinite energy density for the quantum vacuum and an infinite renormalization mass for the free particle. This paper argues that there is a more fundamental vacuum state, the Planck vacuum, from which the quantum vacuum emerges and that the "graininess" of this more fundamental vacuum state truncates the wavenumber spectrum and leads to a finite energy density and a finite renormalization mass.

Support for NUMA hardware in HelenOS

OpenAIRE

Horký, Vojtěch

2011-01-01

The goal of this master thesis is to extend HelenOS operating system with the support for ccNUMA hardware. The text of the thesis contains a brief introduction to ccNUMA hardware, an overview of NUMA features and relevant features of HelenOS (memory management, scheduling, etc.). The thesis analyses various design decisions of the implementation of NUMA support -- introducing the hardware topology into the kernel data structures, propagating this information to user space, thread affinity to ...

Scroll vacuum pump

Energy Technology Data Exchange (ETDEWEB)

Morishita, Etsuo; Suganami, Takuya; Nishida, Mitsuhiro; Kitora, Yoshihisa; Yamamoto, Sakuei; Fujii, Kosaburo

1988-02-25

An effort is made to apply a scroll machine to development of a vacuum pump. In view of mechanical simplification and load patterns, the vacuum pump uses a rotating mechanism to produce paired vortices rotating around each center. Chip seal and atmospheric pressure are utilized for axial gap sealing while a spring and atmospheric pressure for the radial gap sealing. In both gaps, the sealing direction is stationary relative to the environment during rotation, making it much easier to achieve effective sealing as compared to oscillating pumps. Since the compression ratio is high in vacuum pumps, a zero top clearance form is adopted for the central portion of vortices and an gas release valve is installed in the rotating axis. A compact Oldham coupling with a small inertia force is installed behind the vortices to maintain the required phase relations between the vortices. These improvements result in a vacuum of 1 Pa for dry operation and 10/sup -2/ Pa for oil flooded operation of a single-stage scroll machine at 1800 rpm. (5 figs, 1 tab, 4 refs)

Transparent reliability model for fault-tolerant safety systems

International Nuclear Information System (INIS)

Bodsberg, Lars; Hokstad, Per

1997-01-01

A reliability model is presented which may serve as a tool for identification of cost-effective configurations and operating philosophies of computer-based process safety systems. The main merit of the model is the explicit relationship in the mathematical formulas between failure cause and the means used to improve system reliability such as self-test, redundancy, preventive maintenance and corrective maintenance. A component failure taxonomy has been developed which allows the analyst to treat hardware failures, human failures, and software failures of automatic systems in an integrated manner. Furthermore, the taxonomy distinguishes between failures due to excessive environmental stresses and failures initiated by humans during engineering and operation. Attention has been given to develop a transparent model which provides predictions which are in good agreement with observed system performance, and which is applicable for non-experts in the field of reliability

Cosmology with decaying vacuum energy

International Nuclear Information System (INIS)

Freese, K.; Adams, F.; Frieman, J.; Mottola, E.

1987-09-01

Motivated by recent attempts to solve the cosmological constant problem, we examine the observational consequences of a vacuum energy density which decays in time. For all times later than t ∼ 1 sec, the ratio of the vacuum to the total energy density of the universe must be small. Although the vacuum cannot provide the ''missing mass'' required to close the universe today, its presence earlier in the history of the universe could have important consequences. We discuss restrictions on the vacuum energy arising from primordial nucleosynthesis, the microwave and gamma ray background spectra, and galaxy formation. A small vacuum component at the era of nucleosynthesis, 0.01 5, but in some cases would severely distort the microwave spectrum. 9 refs., 3 figs

Software reliability and safety in nuclear reactor protection systems

Energy Technology Data Exchange (ETDEWEB)

Lawrence, J.D. [Lawrence Livermore National Lab., CA (United States)

1993-11-01

Planning the development, use and regulation of computer systems in nuclear reactor protection systems in such a way as to enhance reliability and safety is a complex issue. This report is one of a series of reports from the Computer Safety and Reliability Group, Lawrence Livermore that investigates different aspects of computer software in reactor National Laboratory, that investigates different aspects of computer software in reactor protection systems. There are two central themes in the report, First, software considerations cannot be fully understood in isolation from computer hardware and application considerations. Second, the process of engineering reliability and safety into a computer system requires activities to be carried out throughout the software life cycle. The report discusses the many activities that can be carried out during the software life cycle to improve the safety and reliability of the resulting product. The viewpoint is primarily that of the assessor, or auditor.

Software reliability and safety in nuclear reactor protection systems

International Nuclear Information System (INIS)

Lawrence, J.D.

1993-11-01

Planning the development, use and regulation of computer systems in nuclear reactor protection systems in such a way as to enhance reliability and safety is a complex issue. This report is one of a series of reports from the Computer Safety and Reliability Group, Lawrence Livermore that investigates different aspects of computer software in reactor National Laboratory, that investigates different aspects of computer software in reactor protection systems. There are two central themes in the report, First, software considerations cannot be fully understood in isolation from computer hardware and application considerations. Second, the process of engineering reliability and safety into a computer system requires activities to be carried out throughout the software life cycle. The report discusses the many activities that can be carried out during the software life cycle to improve the safety and reliability of the resulting product. The viewpoint is primarily that of the assessor, or auditor

Sterilization of space hardware.

Science.gov (United States)

Pflug, I. J.

1971-01-01

Discussion of various techniques of sterilization of space flight hardware using either destructive heating or the action of chemicals. Factors considered in the dry-heat destruction of microorganisms include the effects of microbial water content, temperature, the physicochemical properties of the microorganism and adjacent support, and nature of the surrounding gas atmosphere. Dry-heat destruction rates of microorganisms on the surface, between mated surface areas, or buried in the solid material of space vehicle hardware are reviewed, along with alternative dry-heat sterilization cycles, thermodynamic considerations, and considerations of final sterilization-process design. Discussed sterilization chemicals include ethylene oxide, formaldehyde, methyl bromide, dimethyl sulfoxide, peracetic acid, and beta-propiolactone.

Software for Managing Inventory of Flight Hardware

Science.gov (United States)

Salisbury, John; Savage, Scott; Thomas, Shirman

2003-01-01

The Flight Hardware Support Request System (FHSRS) is a computer program that relieves engineers at Marshall Space Flight Center (MSFC) of most of the non-engineering administrative burden of managing an inventory of flight hardware. The FHSRS can also be adapted to perform similar functions for other organizations. The FHSRS affords a combination of capabilities, including those formerly provided by three separate programs in purchasing, inventorying, and inspecting hardware. The FHSRS provides a Web-based interface with a server computer that supports a relational database of inventory; electronic routing of requests and approvals; and electronic documentation from initial request through implementation of quality criteria, acquisition, receipt, inspection, storage, and final issue of flight materials and components. The database lists both hardware acquired for current projects and residual hardware from previous projects. The increased visibility of residual flight components provided by the FHSRS has dramatically improved the re-utilization of materials in lieu of new procurements, resulting in a cost savings of over $1.7 million. The FHSRS includes subprograms for manipulating the data in the database, informing of the status of a request or an item of hardware, and searching the database on any physical or other technical characteristic of a component or material. The software structure forces normalization of the data to facilitate inquiries and searches for which users have entered mixed or inconsistent values.

Approximated calculation of the vacuum wave function and vacuum energy of the LGT with RPA method

International Nuclear Information System (INIS)

Hui Ping

2004-01-01

The coupled cluster method is improved with the random phase approximation (RPA) to calculate vacuum wave function and vacuum energy of 2 + 1 - D SU(2) lattice gauge theory. In this calculating, the trial wave function composes of single-hollow graphs. The calculated results of vacuum wave functions show very good scaling behaviors at weak coupling region l/g 2 >1.2 from the third order to the sixth order, and the vacuum energy obtained with RPA method is lower than the vacuum energy obtained without RPA method, which means that this method is a more efficient one

Cold Vacuum Drying (CVD) Facility Vacuum Purge System Chilled Water System Design Description. System 47-4

International Nuclear Information System (INIS)

IRWIN, J.J.

2000-01-01

This system design description (SDD) addresses the Vacuum Purge System Chilled Water (VPSCHW) system. The discussion that follows is limited to the VPSCHW system and its interfaces with associated systems. The reader's attention is directed to Drawings H-1-82162, Cold Vacuum Drying Facility Process Equipment Skid PandID Vacuum System, and H-1-82224, Cold Vacuum Drying Facility Mechanical Utilities Process Chilled Water PandID. Figure 1-1 shows the location and equipment arrangement for the VPSCHW system. The VPSCHW system provides chilled water to the Vacuum Purge System (VPS). The chilled water provides the ability to condense water from the multi-canister overpack (MCO) outlet gases during the MCO vacuum and purge cycles. By condensing water from the MCO purge gas, the VPS can assist in drying the contents of the MCO

Targeting multiple heterogeneous hardware platforms with OpenCL

Science.gov (United States)

Fox, Paul A.; Kozacik, Stephen T.; Humphrey, John R.; Paolini, Aaron; Kuller, Aryeh; Kelmelis, Eric J.

2014-06-01

The OpenCL API allows for the abstract expression of parallel, heterogeneous computing, but hardware implementations have substantial implementation differences. The abstractions provided by the OpenCL API are often insufficiently high-level to conceal differences in hardware architecture. Additionally, implementations often do not take advantage of potential performance gains from certain features due to hardware limitations and other factors. These factors make it challenging to produce code that is portable in practice, resulting in much OpenCL code being duplicated for each hardware platform being targeted. This duplication of effort offsets the principal advantage of OpenCL: portability. The use of certain coding practices can mitigate this problem, allowing a common code base to be adapted to perform well across a wide range of hardware platforms. To this end, we explore some general practices for producing performant code that are effective across platforms. Additionally, we explore some ways of modularizing code to enable optional optimizations that take advantage of hardware-specific characteristics. The minimum requirement for portability implies avoiding the use of OpenCL features that are optional, not widely implemented, poorly implemented, or missing in major implementations. Exposing multiple levels of parallelism allows hardware to take advantage of the types of parallelism it supports, from the task level down to explicit vector operations. Static optimizations and branch elimination in device code help the platform compiler to effectively optimize programs. Modularization of some code is important to allow operations to be chosen for performance on target hardware. Optional subroutines exploiting explicit memory locality allow for different memory hierarchies to be exploited for maximum performance. The C preprocessor and JIT compilation using the OpenCL runtime can be used to enable some of these techniques, as well as to factor in hardware

Vacuum leak detector and method

Science.gov (United States)

Edwards, Jr., David

1983-01-01

Apparatus and method for detecting leakage in a vacuum system involves a moisture trap chamber connected to the vacuum system and to a pressure gauge. Moisture in the trap chamber is captured by freezing or by a moisture adsorbent to reduce the residual water vapor pressure therein to a negligible amount. The pressure gauge is then read to determine whether the vacuum system is leaky. By directing a stream of carbon dioxide or helium at potentially leaky parts of the vacuum system, the apparatus can be used with supplemental means to locate leaks.

Reactor fuel reliability constraints on power shape control

International Nuclear Information System (INIS)

Gelhaus, F.; Hallam, J.; Sauar, T.

1977-01-01

The level of reliability of fuel rods operating in commercial nuclear power plants has been less than desired for a number of reasons. Several of these causes have been successfully minimized, but pellet-clad interaction failures persist. Since power and power change are dominant parameters in this failure mode, restrictions on operational maneuvers have been recommended by all U. S. fuel suppliers. Slower-than-design allowable maneuvers decrease the plant capacity factor, which can cost a utility up to $7 million per year per plant. To assist utility engineering and operations personnel in their day-to-day decisions in this regard, the Electric Power Research Institute (EPRI) is initiating a project, designated RP895, to develop a fully computerized Power Shape Monitoring System (PSMS) for core-wide fuel rod reliability prediction. This paper describes the PSMS system and details some of the hardware/software requirements as they are now perceived. Salient results from a just-completed complementary EPRI-funded study, RP509, are described; this effort employed hand data acquisition and many man-machine interfaces that will be fully integrated and automated in the PSMS. The capabilities of the PSMS will derive from the use of modern minicomputer hardware and software and from accurate computational modules that enable near-real-time predictive capability

Technology and equipment to improve reliability of pipeline transport

Science.gov (United States)

Suleimanov, D. F.; Shulayev, N. S.; Bondar, K. E.; Laponov, S. V.; Uzinger, A. A.

2017-10-01

The article is dedicated to development of technology and hardware design of method pipeline transport reliability improving by improving the isolated coating properties modified by microwave radiation. The article describes the technology of the modification process of the coating and instrumentation production, which allows improving operational properties not only in stationary conditions in the manufacture of the insulation coating, but also during its replacement in the field.

Sustainable, Reliable Mission-Systems Architecture

Science.gov (United States)

O'Neil, Graham; Orr, James K.; Watson, Steve

2007-01-01

A mission-systems architecture, based on a highly modular infrastructure utilizing: open-standards hardware and software interfaces as the enabling technology is essential for affordable and sustainable space exploration programs. This mission-systems architecture requires (a) robust communication between heterogeneous system, (b) high reliability, (c) minimal mission-to-mission reconfiguration, (d) affordable development, system integration, and verification of systems, and (e) minimal sustaining engineering. This paper proposes such an architecture. Lessons learned from the Space Shuttle program and Earthbound complex engineered system are applied to define the model. Technology projections reaching out 5 years are mde to refine model details.

A Research Roadmap for Computation-Based Human Reliability Analysis

Energy Technology Data Exchange (ETDEWEB)

Boring, Ronald [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Joe, Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Groth, Katrina [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-08-01

The United States (U.S.) Department of Energy (DOE) is sponsoring research through the Light Water Reactor Sustainability (LWRS) program to extend the life of the currently operating fleet of commercial nuclear power plants. The Risk Informed Safety Margin Characterization (RISMC) research pathway within LWRS looks at ways to maintain and improve the safety margins of these plants. The RISMC pathway includes significant developments in the area of thermalhydraulics code modeling and the development of tools to facilitate dynamic probabilistic risk assessment (PRA). PRA is primarily concerned with the risk of hardware systems at the plant; yet, hardware reliability is often secondary in overall risk significance to human errors that can trigger or compound undesirable events at the plant. This report highlights ongoing efforts to develop a computation-based approach to human reliability analysis (HRA). This computation-based approach differs from existing static and dynamic HRA approaches in that it: (i) interfaces with a dynamic computation engine that includes a full scope plant model, and (ii) interfaces with a PRA software toolset. The computation-based HRA approach presented in this report is called the Human Unimodels for Nuclear Technology to Enhance Reliability (HUNTER) and incorporates in a hybrid fashion elements of existing HRA methods to interface with new computational tools developed under the RISMC pathway. The goal of this research effort is to model human performance more accurately than existing approaches, thereby minimizing modeling uncertainty found in current plant risk models.

A Research Roadmap for Computation-Based Human Reliability Analysis

International Nuclear Information System (INIS)

Boring, Ronald; Mandelli, Diego; Joe, Jeffrey; Smith, Curtis; Groth, Katrina

2015-01-01

The United States (U.S.) Department of Energy (DOE) is sponsoring research through the Light Water Reactor Sustainability (LWRS) program to extend the life of the currently operating fleet of commercial nuclear power plants. The Risk Informed Safety Margin Characterization (RISMC) research pathway within LWRS looks at ways to maintain and improve the safety margins of these plants. The RISMC pathway includes significant developments in the area of thermalhydraulics code modeling and the development of tools to facilitate dynamic probabilistic risk assessment (PRA). PRA is primarily concerned with the risk of hardware systems at the plant; yet, hardware reliability is often secondary in overall risk significance to human errors that can trigger or compound undesirable events at the plant. This report highlights ongoing efforts to develop a computation-based approach to human reliability analysis (HRA). This computation-based approach differs from existing static and dynamic HRA approaches in that it: (i) interfaces with a dynamic computation engine that includes a full scope plant model, and (ii) interfaces with a PRA software toolset. The computation-based HRA approach presented in this report is called the Human Unimodels for Nuclear Technology to Enhance Reliability (HUNTER) and incorporates in a hybrid fashion elements of existing HRA methods to interface with new computational tools developed under the RISMC pathway. The goal of this research effort is to model human performance more accurately than existing approaches, thereby minimizing modeling uncertainty found in current plant risk models.

Improvement of hardware basic testing : Identification and development of a scripted automation tool that will support hardware basic testing

OpenAIRE

Rask, Ulf; Mannestig, Pontus

2002-01-01

In the ever-increasing development pace, circuits and hardware are no exception. Hardware designs grow and circuits gets more complex at the same time as the market pressure lowers the expected time-to-market. In this rush, verification methods often lag behind. Hardware manufacturers must be aware of the importance of total verification if they want to avoid quality flaws and broken deadlines which in the long run will lead to delayed time-to-market, bad publicity and a decreasing market sha...

Real-Time Hardware-in-the-Loop Laboratory Testing for Multisensor Sense and Avoid Systems

Directory of Open Access Journals (Sweden)

Giancarmine Fasano

2013-01-01

Full Text Available This paper focuses on a hardware-in-the-loop facility aimed at real-time testing of architectures and algorithms of multisensor sense and avoid systems. It was developed within a research project aimed at flight demonstration of autonomous non-cooperative collision avoidance for Unmanned Aircraft Systems. In this framework, an optionally piloted Very Light Aircraft was used as experimental platform. The flight system is based on multiple-sensor data integration and it includes a Ka-band radar, four electro-optical sensors, and two dedicated processing units. The laboratory test system was developed with the primary aim of prototype validation before multi-sensor tracking and collision avoidance flight tests. System concept, hardware/software components, and operating modes are described in the paper. The facility has been built with a modular approach including both flight hardware and simulated systems and can work on the basis of experimentally tested or synthetically generated scenarios. Indeed, hybrid operating modes are also foreseen which enable performance assessment also in the case of alternative sensing architectures and flight scenarios that are hardly reproducible during flight tests. Real-time multisensor tracking results based on flight data are reported, which demonstrate reliability of the laboratory simulation while also showing the effectiveness of radar/electro-optical fusion in a non-cooperative collision avoidance architecture.

Evaporation under vacuum condition

International Nuclear Information System (INIS)

Mizuta, Satoshi; Shibata, Yuki; Yuki, Kazuhisa; Hashizume, Hidetoshi; Toda, Saburo; Takase, Kazuyuki; Akimoto, Hajime

2000-01-01

In nuclear fusion reactor design, an event of water coolant ingress into its vacuum vessel is now being considered as one of the most probable accidents. In this report, the evaporation under vacuum condition is evaluated by using the evaporation model we have developed. The results show that shock-wave by the evaporation occurs whose behavior strongly depends on the initial conditions of vacuum. And in the case of lower initial pressure and temperature, the surface temp finally becomes higher than other conditions. (author)

Development of a hardware-in-the-loop-test rig to verify the reliability of oil burner pumps. Application by the use of biocide in domestic heating oil; Entwicklung eines Hardware-in-the-loop Pruefstands zum Nachweis der Betriebssicherheit von Oelbrennerpumpen. Anwendungen bei Einsatz von Biozidadditiven

Energy Technology Data Exchange (ETDEWEB)

Rheinberg, Oliver van; Lukito, Jayadi; Liska, Martin [Oel-Waerme-Institut gGmbH (OWI), Aachen-Herzogenrath (Germany)

2009-09-15

Within this project, a hardware-in-the-loop test rig has been developed to investigate the influence of different fuels on the reliability of oil burner pumps. The test rig is constructed with commercial burner components. One test rig consists of four pump cycles, where the fuel recirculates for max. 2000 h. Low powered electric motors of 90 Watts have been used deliberately, so that the apparatus is more sensitive to failure due to an increase in pump load. A practise relevant intermittent operating mode has been implemented for the simulation of real operation characteristics. The measured variable and evaluation parameters are start-up torque, intake pressure, fuel pump pressure and temperature. Operation failures of oil burner pumps in the field, due to an over-additisation of biocides, have been observed. These failures could be reproducibly simulated on the pump test stands. The results of the project are a redefinition of limits of biocide concentration and the development of new biocides, which are suitable for use in domestic heating oil with a content of up to 20 % Fatty-Acid-Methyl-Ester. (orig.)

Gauge field vacuum structure in geometrical aspect

International Nuclear Information System (INIS)

Konopleva, N.P.

2003-01-01

Vacuum conception is one of the main conceptions of quantum field theory. Its meaning in classical field theory is also very profound. In this case the vacuum conception is closely connected with ideas of the space-time geometry. The global and local geometrical space-time conceptions lead to different vacuum definitions and therefore to different ways of physical theory construction. Some aspects of the gauge field vacuum structure are analyzed. It is shown that in the gauge field theory the vacuum Einstein equation solutions describe the relativistic vacuum as common vacuum of all gauge fields and its sources. Instantons (both usual and hyperbolical) are regarded as nongravitating matter, because they have zero energy-momentum tensors and correspond to vacuum Einstein equations

Vacuum system for the Argonne 6 GeV synchrotron light source

International Nuclear Information System (INIS)

Wehrle, R.; Moenich, J.

1985-01-01

The ANL vacuum system for the 6 GeV light source storage ring features non-evaporable strip getter pumps for uniform pumping around the ring within a gas desorption antechamber, and it also features lumped getter pumping directly under and above crotch radiation absorbers that are positioned after each bending magnet. Based on experiments at ANL in 1980 and by others, the technical and economical advantages have been established for the use of the distributed NeG pumps of non-magnetic strips coated with a non-evaporable Zr Al getter matrix. The NeG strip pump lifetime approaches ten years. The antechamber improves the isolation of the gas desorption process from the main beam chamber and beam. The combination of these vacuum techniques; the NeG strip getter pumps, the gas desorption antechambers, and the lumped ion and lumped getter pumping provide a unique and reliable system for maintaining long beam lifetime

THE THERMOELECTRIC VACUUM CROCK-POT AND THE AUTOMATED WORKPLACE FOR ITS RESEARCH AS A CONTROL OBJECT

Directory of Open Access Journals (Sweden)

S. Hudz

2017-08-01

Full Text Available The technologies of thermal treatment in vacuum are widely used in various fields of production, in particular in the food industry, but their application at farms, hotels or a for domestic purposes is limited because of the big sizes, high cost of processing equipment and complexity of its management at realization of foodstuff processing. Products, made with use of vacuum technologies, keep much more useful substances because they aren't exposed to high-temperature processing and oxidation while preparation. Development and production of the small-sized equipment for realization of heat treatment processes of foodstuff in vacuum would create technical and economic conditions for implementation of temperature processing processes of foodstuff at farms, hotels and even at home that would promote creation of new food, development of new recipes and, in general, development of the new direction in cookery. So the article describes the problem of equipment construction for the process of thermal processing of food in vacuum such as cooking jam, concentration of juices and dairy products, distillation, drying, pickling, and the possibility of building inexpensive compact vacuum unit for the implementation of these processes (crock-pot for use at hotels, farms and even for domestic purposes. The analysis of technological schemes for energy efficient evaporation process in vacuum crock-pot is provided. The developed technological scheme of vacuum crock-pot with thermoelectric converters and principle of its operation are considered. Microprocessor block diagram of a multichannel data acquisition system consisting workstation for investigation of thermoelectric vacuum crock-pot as a control object is presented and control algorithms helping to reduce energy consumption and to increase operational reliability in implementing processes and the quality of ready-made products are provided.

Vacuum metastability with black holes

Energy Technology Data Exchange (ETDEWEB)

Burda, Philipp [Centre for Particle Theory, Durham University,South Road, Durham, DH1 3LE (United Kingdom); Gregory, Ruth [Centre for Particle Theory, Durham University,South Road, Durham, DH1 3LE (United Kingdom); Perimeter Institute, 31 Caroline Street North,Waterloo, ON, N2L 2Y5 (Canada); Moss, Ian G. annd [School of Mathematics and Statistics, Newcastle University,Newcastle Upon Tyne, NE1 7RU (United Kingdom)

2015-08-24

We consider the possibility that small black holes can act as nucleation seeds for the decay of a metastable vacuum, focussing particularly on the Higgs potential. Using a thin-wall bubble approximation for the nucleation process, which is possible when generic quantum gravity corrections are added to the Higgs potential, we show that primordial black holes can stimulate vacuum decay. We demonstrate that for suitable parameter ranges, the vacuum decay process dominates over the Hawking evaporation process. Finally, we comment on the application of these results to vacuum decay seeded by black holes produced in particle collisions.

Vacuum metastability with black holes

International Nuclear Information System (INIS)

Burda, Philipp; Gregory, Ruth; Moss, Ian G. annd

2015-01-01

We consider the possibility that small black holes can act as nucleation seeds for the decay of a metastable vacuum, focussing particularly on the Higgs potential. Using a thin-wall bubble approximation for the nucleation process, which is possible when generic quantum gravity corrections are added to the Higgs potential, we show that primordial black holes can stimulate vacuum decay. We demonstrate that for suitable parameter ranges, the vacuum decay process dominates over the Hawking evaporation process. Finally, we comment on the application of these results to vacuum decay seeded by black holes produced in particle collisions.

The architecture of a reliable software monitoring system for embedded software systems

International Nuclear Information System (INIS)

Munson, J.; Krings, A.; Hiromoto, R.

2006-01-01

We develop the notion of a measurement-based methodology for embedded software systems to ensure properties of reliability, survivability and security, not only under benign faults but under malicious and hazardous conditions as well. The driving force is the need to develop a dynamic run-time monitoring system for use in these embedded mission critical systems. These systems must run reliably, must be secure and they must fail gracefully. That is, they must continue operating in the face of the departures from their nominal operating scenarios, the failure of one or more system components due to normal hardware and software faults, as well as malicious acts. To insure the integrity of embedded software systems, the activity of these systems must be monitored as they operate. For each of these systems, it is possible to establish a very succinct representation of nominal system activity. Furthermore, it is possible to detect departures from the nominal operating scenario in a timely fashion. Such departure may be due to various circumstances, e.g., an assault from an outside agent, thus forcing the system to operate in an off-nominal environment for which it was neither tested nor certified, or a hardware/software component that has ceased to operate in a nominal fashion. A well-designed system will have the property of graceful degradation. It must continue to run even though some of the functionality may have been lost. This involves the intelligent re-mapping of system functions. Those functions that are impacted by the failure of a system component must be identified and isolated. Thus, a system must be designed so that its basic operations may be re-mapped onto system components still operational. That is, the mission objectives of the software must be reassessed in terms of the current operational capabilities of the software system. By integrating the mechanisms to support observation and detection directly into the design methodology, we propose to shift

Vacuum exhaust duct used for thermonuclear device

International Nuclear Information System (INIS)

Tachikawa, Nobuo; Kondo, Mitsuaki; Honda, Tsutomu.

1990-01-01

The present invention concerns a vacuum exhaust duct used for a thermonuclear device. A cylindrical metal liners is lined with a gap to the inside of a vacuum exhaust duct main body. Bellows are connected to both ends of the metal liners and the end of the bellows is welded to the vacuum exhaust duct main body. Futher, a heater is mounted to the metal liner on the side of the vacuum exhaust duct main body, and the metal liner is heated by the heater to conduct baking for the vacuum exhaust duct main body. Accordingly, since there is no requirement for elevating the temperature of the vacuum exhaust duct upon conducting baking, the vacuum exhaust duct scarcely suffers substantial deformation due to heat expansion. Further, there is also no substantial deformation for the bellows disposed between the outer circumference of the vacuum vessel and a portion of a vacuum exhaust duct, so that the durability of the bellows is greatly improved. (I.S.)

Static Scheduling of Periodic Hardware Tasks with Precedence and Deadline Constraints on Reconfigurable Hardware Devices

Directory of Open Access Journals (Sweden)

Ikbel Belaid

2011-01-01

Full Text Available Task graph scheduling for reconfigurable hardware devices can be defined as finding a schedule for a set of periodic tasks with precedence, dependence, and deadline constraints as well as their optimal allocations on the available heterogeneous hardware resources. This paper proposes a new methodology comprising three main stages. Using these three main stages, dynamic partial reconfiguration and mixed integer programming, pipelined scheduling and efficient placement are achieved and enable parallel computing of the task graph on the reconfigurable devices by optimizing placement/scheduling quality. Experiments on an application of heterogeneous hardware tasks demonstrate an improvement of resource utilization of 12.45% of the available reconfigurable resources corresponding to a resource gain of 17.3% compared to a static design. The configuration overhead is reduced to 2% of the total running time. Due to pipelined scheduling, the task graph spanning is minimized by 4% compared to sequential execution of the graph.

Automatic electromagnetic valve for previous vacuum

International Nuclear Information System (INIS)

Granados, C. E.; Martin, F.

1959-01-01

A valve which permits the maintenance of an installation vacuum when electric current fails is described. It also lets the air in the previous vacuum bomb to prevent the oil ascending in the vacuum tubes. (Author)

Development of vacuum brazing furnace

International Nuclear Information System (INIS)

Singh, Rajvir; Yedle, Kamlesh; Jain, A.K.

2005-01-01

In joining of components where welding process is not possible brazing processes are employed. Value added components, high quality RF systems, UHV components of high energy accelerators, carbide tools etc. are produced using different types of brazing methods. Furnace brazing under vacuum atmosphere is the most popular and well accepted method for production of the above mentioned components and systems. For carrying out vacuum brazing successfully it is essential to have a vacuum brazing furnace with latest features of modern vacuum brazing technology. A vacuum brazing furnace has been developed and installed for carrying out brazing of components of copper, stainless steel and components made of dissimilar metals/materials. The above furnace has been designed to accommodate jobs of 700mm diameter x 2000mm long sizes with job weight of 500kgs up to a maximum temperature of 1250 degC at a vacuum of 5 x 10 -5 Torr. Oil diffusion pumping system with a combination of rotary and mechanical booster pump have been employed for obtaining vacuum. Molybdenum heating elements, radiation shield of molybdenum and Stainless Steel Grade 304 have been used. The above furnace is computer controlled with manual over ride facility. PLC and Pentium PC are integrated together to maneuver steps of operation and safety interlocks of the system. Closed loop water supply provides cooling to the system. The installation of the above system is in final stage of completion and it will be ready for use in next few months time. This paper presents insights of design and fabrication of a modern vacuum brazing furnace and its sub-system. (author)

Nuclear computerized library for assessing reactor reliability (NUCLARR): User's guide: Part 3, NUCLARR system description

International Nuclear Information System (INIS)

Gilmore, W.E.; Gentillon, C.D.; Gertman, D.I.; Beers, G.H.; Galyean, W.J.; Gilbert, B.G.

1988-06-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability and hardware component failure data. The NUCLARR system software resides on an IBM (or compatible) personal micro-computer. NUCLARR can be used by the end user to furnish data inputs for both human and hardware reliability analysis in support of a variety of risk assessment activities. The NUCLARR system is documented in a five-volume series of reports. Volume IV of this series is the User's Guide for operating the NUCLARR software and is presented in three parts. This document, Part 3: NUCLARR System Description, provides an in-depth discussion of the design characteristics and special features of the NUCLARR software. Part 3 also presents the organization of the data base structures and techniques used to manipulate the data

Nuclear computerized library for assessing reactor reliability (NUCLARR): Part 2, Guide to operations: User's guide

International Nuclear Information System (INIS)

Gilmore, W.E.; Gentillon, C.D.; Gertman, D.I.; Beers, G.H.; Galyean, W.J.; Gilbert, B.G.

1988-06-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability and hardware component failure data. The NUCLARR system software resides on an IBM (or compatible) personal micro-computer. NUCLARR can be used by the end user to furnish data inputs for both human and hardware reliability analysis in support of a variety of risk assessment activities. The NUCLARR system is documented in a five-volume series of reports. Volume IV of this series is the User's Guide for operating the NUCLARR software and is presented in three parts. This volume, Part 2: Guide to Operations, contains the instructions and basic procedures for using the NUCLARR software. Part 2 provides guidance and information for getting started, performing the desired functions, and making the most efficient use of the system's features

COMPUTER HARDWARE MARKING

CERN Multimedia

Groupe de protection des biens

2000-01-01

As part of the campaign to protect CERN property and for insurance reasons, all computer hardware belonging to the Organization must be marked with the words 'PROPRIETE CERN'.IT Division has recently introduced a new marking system that is both economical and easy to use. From now on all desktop hardware (PCs, Macintoshes, printers) issued by IT Division with a value equal to or exceeding 500 CHF will be marked using this new system.For equipment that is already installed but not yet marked, including UNIX workstations and X terminals, IT Division's Desktop Support Service offers the following services free of charge:Equipment-marking wherever the Service is called out to perform other work (please submit all work requests to the IT Helpdesk on 78888 or helpdesk@cern.ch; for unavoidable operational reasons, the Desktop Support Service will only respond to marking requests when these coincide with requests for other work such as repairs, system upgrades, etc.);Training of personnel designated by Division Leade...

Gases and vacua handbook of vacuum physics

CERN Document Server

Beck, A H

2013-01-01

Handbook of Vacuum Physics, Volume 1: Gases and Vacua provides information on the many aspects of vacuum technology, from material on the quantum theoretical aspects of the complex semi-conductors used for thermionic and photo-electric emission to data on the performance of commercially available pumps, gauges, and high-vacuum materials. The handbook satisfies the need of workers using vacuum apparatuses or works on the diverse applications of high-vacuum technology in research and industry. The book is a compilation of long articles prepared by experts in vacuum technology. Sufficient theoret

Hadron Contribution to Vacuum Polarisation

CERN Document Server

Davier, M; Malaescu, B; Zhang, Z

2016-01-01

Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle–antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e− annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingre...

Helical type vacuum container

International Nuclear Information System (INIS)

Owada, Kimio.

1989-01-01

Helical type vacuum containers in the prior art lack in considerations for thermal expansion stresses to helical coils, and there is a possibility of coil ruptures. The object of the present invention is to avoid the rupture of helical coils wound around the outer surface of a vacuum container against heat expansion if any. That is, bellows or heat expansion absorbing means are disposed to a cross section of a helical type vacuum container. With such a constitution, thermal expansion of helical coils per se due to temperature elevation of the coils during electric supply can be absorbed by expansion of the bellows or absorption of the heat expansion absorbing means. Further, this can be attained by arranging shear pins in the direction perpendicular to the bellows axis so that the bellows are not distorted when the helical coils are wound around the helical type vacuum container. (I.S.)

PDX vacuum vessel stress analysis

International Nuclear Information System (INIS)

Nikodem, Z.D.

1975-01-01

A stress analysis of PDX vacuum vessel is described and the summary of results is presented. The vacuum vessel is treated as a toroidal shell of revolution subjected to an internal vacuum. The critical buckling pressure is calculated. The effects of the geometrical discontinuity at the juncture of toroidal shell head and cylindrical outside wall, and the concavity of the cylindrical wall are examined. An effect of the poloidal field coil supports and the vessel outside supports on the stress distribution in the vacuum vessel is determined. A method evaluating the influence of circular ports in the vessel wall on the stress level in the vessel is outlined

Quark and gluon condensate in vacuum

International Nuclear Information System (INIS)

Vajnshtejn, A.I.; Zakharov, V.I.; Shifman, M.A.

1979-01-01

The mechanism of quark confinement has been reviewed. The fact that coloured particles in a free state cannot be observed is connected with specific properties of vacuum in quantum chromodynamics. The basic hypothesis consists in the existence of vacuum fields, quark and gluon condensates, which affect the coloured objects. The vacuum transparent relative to noncharged ''white'' states serves as a source of the force acting upon the coloured particles. It has been a sucess to examine strictly the action of the vacuum fields on quarks when the distance between them is relatively small and the force of the vacuum fields on quarks is relatively small too. It is shown that the interaction with the vacuum fields manifests itself earlier than the forces connected with the gluon exchange do. It is assumed that the vacuum condensate of quarks and gluons and its relation to properties of resonances and to the bag model exist in reality. The dispersion sum rules are used for calculating masses and lepton widths of resonances

CAS CERN Accelerator School vacuum technology. Proceedings

International Nuclear Information System (INIS)

Turner, S.

1999-01-01

These proceedings present the lectures given at the twelfth specialized course organized by the CERN Accelerator School (CAS), the topic this time being 'Vacuum Technology'. Despite the importance of vacuum technology in the design and operation of particle accelerators at CERN and at the many other accelerators already installed around the world, this was the first time that CAS has organized a course devoted entirely to this topic. Perhaps this reflects the facts that vacuum has become one of the more critical aspects of future accelerators, and that many of the pioneers in the accelerator field are being replaced by new, younger personnel. The lectures start with the basic concepts of the physics and technology of vacuum followed by detailed descriptions of the many different types of gas-pumping devices and methods to measure the pressures achieved. The outgassing characteristics of the different materials used in the construction of vacuum systems and the optimisation of cleaning methods to reduce this outgassing are then explained together with the effects of the residual gases on the particle beams. Then follow chapters on leak detection, materials and vacuum system engineering. Finally, seminars are presented on designing vacuum systems, the history of vacuum devices, the LHC (large hadron collider) vacuum system, vacuum systems for electron storage rings, and quality assurance for vacuum. (orig.)

GOSH! A roadmap for open-source science hardware

CERN Multimedia

Stefania Pandolfi

2016-01-01

The goal of the Gathering for Open Science Hardware (GOSH! 2016), held from 2 to 5 March 2016 at IdeaSquare, was to lay the foundations of the open-source hardware for science movement.   The participants in the GOSH! 2016 meeting gathered in IdeaSquare. (Image: GOSH Community) “Despite advances in technology, many scientific innovations are held back because of a lack of affordable and customisable hardware,” says François Grey, a professor at the University of Geneva and coordinator of Citizen Cyberlab – a partnership between CERN, the UN Institute for Training and Research and the University of Geneva – which co-organised the GOSH! 2016 workshop. “This scarcity of accessible science hardware is particularly obstructive for citizen science groups and humanitarian organisations that don’t have the same economic means as a well-funded institution.” Instead, open sourcing science hardware co...

ULTRARAPID VACUUM-MICROWAVE HISTOPROCESSING

NARCIS (Netherlands)

KOK, LP; BOON, ME

A novel histoprocessing method for paraffin sections is presented in which the combination of vacuum and microwave exposure is the key element. By exploiting the decrease in boiling temperature under vacuum, the liquid molecules in the tissues have been successfully extracted and exchanged at

Hardware Accelerated Simulated Radiography

International Nuclear Information System (INIS)

Laney, D; Callahan, S; Max, N; Silva, C; Langer, S; Frank, R

2005-01-01

We present the application of hardware accelerated volume rendering algorithms to the simulation of radiographs as an aid to scientists designing experiments, validating simulation codes, and understanding experimental data. The techniques presented take advantage of 32 bit floating point texture capabilities to obtain validated solutions to the radiative transport equation for X-rays. An unsorted hexahedron projection algorithm is presented for curvilinear hexahedra that produces simulated radiographs in the absorption-only regime. A sorted tetrahedral projection algorithm is presented that simulates radiographs of emissive materials. We apply the tetrahedral projection algorithm to the simulation of experimental diagnostics for inertial confinement fusion experiments on a laser at the University of Rochester. We show that the hardware accelerated solution is faster than the current technique used by scientists

Selection of vacuum seals for EBT-P

International Nuclear Information System (INIS)

Dillow, C.F.; Adlon, G.L.; Stubblefield, V.E.

1981-01-01

Elmo Bumpy Torus Proof of Principle (EBT-P) is a magnetic fusion RandD facility being constructed by McDonnell Douglas Astronautics Company - St. Louis Division of Oak Ridge National Laboratory (ORNL). EBT-P is a truly unique fusion device requiring careful consideration in selecting both the primary vacuum seals on the toroidal vessel and the secondary vacuum seals in components such as vacuum pumps and and valves. The vacuum seal environment is described and the considerations in vacuum seal selection fully discussed. Methods for protecting vacuum seals in pumps and valves from the microwave environments are also presented

Vacuum transitions in dual models

International Nuclear Information System (INIS)

Pashnev, A.I.; Volkov, D.V.; Zheltukhin, A.A.

1976-01-01

The investigation is continued of the spontaneous vacuum transition problem in the Neview-Schwartz dual model (NSDM). It is shown that vacuum transitions allow disclosing of supplementary degeneration in the resonance state spectrum. The dual amplitudes possess an internal structure corresponding to the presence of an infinite number of quarks with increasing masses and retained charges. The Adler principle holds. Analytic continuation on the constant of induced vacuum transitions makes it possible to establish the existence of spontaneous vacuum transitions in the NSDM. The consequence of this fact is the exact SU(2) symmetry of π, rho meson trajectories and the Higgs mechanism in the model. In this case the ratios of masses of particles leading trajectories are analogous to those obtained in the current algebra. It is shown that in the NSDM there arises chiral SU(2) x SU(2) x U(1) x U(1) x ... symmetry resulting from spontaneous vacuum transitions

Vacuum maintenance in vacuum insulation panels exemplified with a staggered beam VIP

Energy Technology Data Exchange (ETDEWEB)

Kwon, Jae-Sung; Jang, Choong Hyo; Jung, Haeyong; Song, Tae-Ho [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Guseong-dong 373-1, Yuseong-gu, Daejeon (Korea, Republic of)

2010-05-15

Thermal insulation performance of a vacuum insulation panel (VIP) is highly dependent on the inner pressure of the VIP. Long-term vacuum maintenance characteristics are investigated in this study for a VIP with an example of polymer staggered beam structure as the core material. Various gas sources deteriorating the vacuum level in the VIP are investigated based on theoretical models and experiments. Gas permeation occurring through heat-sealed flanges and pinholes in the barrier envelope is the largest gas leakage source. The calculated gas permeation rate is in accordance with the experimental result. To reduce these permeations, a three-side sealing envelope and double enveloping are proposed. Outgassing from the core material and inner surface of the envelope is also critical. It is significantly reduced by a baking pre-treatment in vacuum. When the estimated total gas load exceeds the allowable limit within a few years, a getter material may be applied. Double enveloping structure with a getter is promising as it ensures a lifetime of more than 20 years. (author)

Vacuum guidelines for ISA insertions

International Nuclear Information System (INIS)

Edwards, D. Jr.

1976-01-01

Vacuum requirements place design restrictions on the ISA insertions. The vacuum tube diameter, given a distance L between pumps, is determined by the desorption of molecules from the wall under the impact of ions created by the beam, whereas the thickness of the tube must be sufficient to prevent collapse. In addition, the entire vacuum chamber must be able to be baked out at approximately 200 0 C

Particle contamination in vacuum systems

International Nuclear Information System (INIS)

Martignac, J.; Bonin, B.; Henriot, C.; Poupeau, J.P.; Koltchakian, I.; Kocic, D.; Herbeaux, Ch.; Marx, J.P.

1996-01-01

Many vacuum devices, like RF cavities, are sensitive to particle contamination. This fact has motivated a considerable effort of cleanliness from the SRF community. The present paper reports the first results of a general study trying to identify the most contaminating steps during assembly and vacuum operation of the cavity. The steps investigated here are gasket assembly, evacuation and venting of the vacuum system, and operation of sputter ion pumps. (author)

Particle contamination in vacuum systems

International Nuclear Information System (INIS)

Martignac, J.; Bonin, B.; Henriot, C.; Poupeau, J.P.; Koltchakian, I.; Kocic, D.; Herbeaux, Ch.; Marx, J.P.

1996-01-01

Many vacuum devices, like RF cavities, are sensitive to particle contamination. This fact has motivated a considerable effort of cleanliness from the SRF community. The first results of a general study trying to identify the most contaminating steps during assembly and vacuum operation of the cavity is reported. The steps investigated here are gasket assembly, evacuation and venting of the vacuum system, and operation of sputter ion pumps. (author)

Research on vacuum insulation for cryocables

International Nuclear Information System (INIS)

Graneau, P.

1974-01-01

Vacuum insulation, as compared with solid insulation, simplifies the construction of both resistive or superconducting cryogenic cables. The common vacuum space in the cable can furnish thermal insulation between the environment and the cryogenic coolant, provide electrical insulation between conductors, and establish thermal isolation between go- and return-coolant streams. The differences between solid and vacuum high voltage insulation are discussed, and research on the design, materials selection, and testing of vacuum insulated cryogenic cables is described

Vacuum-insulated catalytic converter

Science.gov (United States)

Benson, David K.

2001-01-01

A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

Software Reliability Issues Concerning Large and Safety Critical Software Systems

Science.gov (United States)

Kamel, Khaled; Brown, Barbara

1996-01-01

This research was undertaken to provide NASA with a survey of state-of-the-art techniques using in industrial and academia to provide safe, reliable, and maintainable software to drive large systems. Such systems must match the complexity and strict safety requirements of NASA's shuttle system. In particular, the Launch Processing System (LPS) is being considered for replacement. The LPS is responsible for monitoring and commanding the shuttle during test, repair, and launch phases. NASA built this system in the 1970's using mostly hardware techniques to provide for increased reliability, but it did so often using custom-built equipment, which has not been able to keep up with current technologies. This report surveys the major techniques used in industry and academia to ensure reliability in large and critical computer systems.

Spent nuclear fuel project cold vacuum drying facility vacuum and purge system design description

Energy Technology Data Exchange (ETDEWEB)

IRWIN, J.J.

1998-11-30

This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Vacuum and Purge System (VPS) . The SDD was developed in conjunction with HNF-SD-SNF-SAR-O02, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), The HNF-SD-SNF-DRD-002, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the VPS equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SDD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

Spent nuclear fuel project cold vacuum drying facility vacuum and purge system design description

International Nuclear Information System (INIS)

IRWIN, J.J.

1998-01-01

This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Vacuum and Purge System (VPS) . The SDD was developed in conjunction with HNF-SD-SNF-SAR-O02, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), The HNF-SD-SNF-DRD-002, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the VPS equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SDD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved

Color-magnetic permeability of QCD vacuum

Energy Technology Data Exchange (ETDEWEB)

Saito, T [Kyoto Prefectural Univ. of Medicine (Japan); Shigemoto, K

1980-03-01

In the very strong background gauge field the QCD true vacuum has been shown to have lower energy than the ''perturbative vacuum.'' The color-magnetic permeability of the QCD true vacuum is then calculated to be 1/2 within the quark-one-loop approximation.

Vacuum vessel for thermonuclear device

International Nuclear Information System (INIS)

Kikuchi, Mitsuru; Kurita, Gen-ichi; Onozuka, Masaki; Suzuki, Masaru.

1997-01-01

Heat of inner walls of a vacuum vessel that receive radiation heat from plasmas by way of first walls is removed by a cooling medium flowing in channels for cooling the inner walls. Nuclear heat generation of constitutional materials of the vacuum vessel caused by fast neutrons and γ rays is removed by a cooling medium flowing in cooling channels disposed in the vacuum vessel. Since the heat from plasmas and the nuclear heat generation are removed separately, the amount of the cooling medium flowing in the channels for cooling inner walls is increased for cooling a great amount of heat from plasmas while the amount of the cooling medium flowing in the channels for cooling the inside of the vacuum vessel is reduced for cooling the small amount of nuclear heat generation. Since the amount of the cooling medium can thus be optimized, the capacity of the facilities for circulating the cooling medium can be reduced. In addition, since the channels for cooling the inner walls and the channels of cooling medium formed in the vacuum vessel are disposed to the inner walls of the vacuum vessel on the side opposite to plasmas, integrity of the channels relative to leakage of the cooling medium can be ensured. (N.H.)

Vacuum vessel for thermonuclear device

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, Mitsuru; Kurita, Gen-ichi [Japan Atomic Energy Research Inst., Tokyo (Japan); Onozuka, Masaki; Suzuki, Masaru

1997-07-31

Heat of inner walls of a vacuum vessel that receive radiation heat from plasmas by way of first walls is removed by a cooling medium flowing in channels for cooling the inner walls. Nuclear heat generation of constitutional materials of the vacuum vessel caused by fast neutrons and {gamma} rays is removed by a cooling medium flowing in cooling channels disposed in the vacuum vessel. Since the heat from plasmas and the nuclear heat generation are removed separately, the amount of the cooling medium flowing in the channels for cooling inner walls is increased for cooling a great amount of heat from plasmas while the amount of the cooling medium flowing in the channels for cooling the inside of the vacuum vessel is reduced for cooling the small amount of nuclear heat generation. Since the amount of the cooling medium can thus be optimized, the capacity of the facilities for circulating the cooling medium can be reduced. In addition, since the channels for cooling the inner walls and the channels of cooling medium formed in the vacuum vessel are disposed to the inner walls of the vacuum vessel on the side opposite to plasmas, integrity of the channels relative to leakage of the cooling medium can be ensured. (N.H.)

Ultra high vacuum systems for accelerators

International Nuclear Information System (INIS)

Loefgren, P.

2001-01-01

Full text: In order to perform controlled, stable, and reproducible experiments, several research areas today require very low pressures. Maybe the most important example is the research that is performed in storage rings and accelerators where the lifetime and stability of particle beams depends critically on the vacuum conditions. Although the vacuum requirements ultimately depend on the kind of experiments that is performed, the studies of more and more rare and exotic species in storage rings and accelerators today pushes the demands on the vacuum conditions towards lower and lower pressures. The final pressure obtained in the vacuum system can often be the key factor for the outcome of an experiment. Pioneering work in vacuum technology has therefore often been performed at storage rings and accelerator facilities around the world. In order to reach pressures in the low UHV regime and lower (below 10 -11 mbar), several aspects have to be considered which implies choosing the proper materials, pumps and vacuum gauges. In the absence of gases inleaking from the outside, the rate of gas entering a vacuum system is determined by the release of molecules adsorbed on the surfaces and the outgassing from the bulk of the vacuum chamber walls. This means that the choice of material and, equally important, the pre treatment of the material, must be such that these rates are minimised. Today the most widely used material for vacuum applications are stainless steel. Besides its many mechanical advantages, it is resistant to corrosion and oxidation. If treated correctly the major gas source in a stainless steel chamber is hydrogen outgassing from the chamber walls. The hydrogen outgassing can be decreased by vacuum firing at 950 deg. C under vacuum. In addition to choosing the right materials the choice of vacuum pumps is important for the final pressure. Since no vacuum pump is capable of taking care of all kinds of gases found in the rest gas at pressures below 10 -11

Wireless Integrated Microelectronic Vacuum Sensor System

Science.gov (United States)

Krug, Eric; Philpot, Brian; Trott, Aaron; Lawrence, Shaun

2013-01-01

NASA Stennis Space Center's (SSC's) large rocket engine test facility requires the use of liquid propellants, including the use of cryogenic fluids like liquid hydrogen as fuel, and liquid oxygen as an oxidizer (gases which have been liquefied at very low temperatures). These fluids require special handling, storage, and transfer technology. The biggest problem associated with transferring cryogenic liquids is product loss due to heat transfer. Vacuum jacketed piping is specifically designed to maintain high thermal efficiency so that cryogenic liquids can be transferred with minimal heat transfer. A vacuum jacketed pipe is essentially two pipes in one. There is an inner carrier pipe, in which the cryogenic liquid is actually transferred, and an outer jacket pipe that supports and seals the vacuum insulation, forming the "vacuum jacket." The integrity of the vacuum jacketed transmission lines that transfer the cryogenic fluid from delivery barges to the test stand must be maintained prior to and during engine testing. To monitor the vacuum in these vacuum jacketed transmission lines, vacuum gauge readings are used. At SSC, vacuum gauge measurements are done on a manual rotation basis with two technicians, each using a handheld instrument. Manual collection of vacuum data is labor intensive and uses valuable personnel time. Additionally, there are times when personnel cannot collect the data in a timely fashion (i.e., when a leak is detected, measurements must be taken more often). Additionally, distribution of this data to all interested parties can be cumbersome. To simplify the vacuum-gauge data collection process, automate the data collection, and decrease the labor costs associated with acquiring these measurements, an automated system that monitors the existing gauges was developed by Invocon, Inc. For this project, Invocon developed a Wireless Integrated Microelectronic Vacuum Sensor System (WIMVSS) that provides the ability to gather vacuum

Baking results of KSTAR vacuum vessel

International Nuclear Information System (INIS)

Kim, S. T.; Kim, Y. J.; Kim, K. M.; Im, D. S.; Joung, N. Y.; Yang, H. L.; Kim, Y. S.; Kwon, M.

2009-01-01

The Korea Superconducting Tokamak Advanced Research (KSTAR) is an advanced superconducting tokamak designed to establish a scientific and technological basis for an attractive fusion reactor. The fusion energy in the tokamak device is released through fusion reactions of light atoms such as deuterium or helium in hot plasma state, of which temperature reaches several hundreds of millions Celsius. The high temperature plasma is created in the vacuum vessel that provides ultra high vacuum status. Accordingly, it is most important for the vacuum condition to keep clean not only inner space but also surface of the vacuum vessel to make high quality plasma. There are two methods planned to clean the wall surface of the KSTAR vacuum vessel. One is surface baking and the other is glow discharge cleaning (GDC). To bake the vacuum vessel, De-Ionized (DI) water is heated to 130 .deg. C and circulated in the passage between double walls of the vacuum vessel (VV) in order to bake the surface. The GDC operation uses hydrogen and inert gas discharges. In this paper, general configuration and brief introduction of the baking result will be reported

Baking results of KSTAR vacuum vessel

Energy Technology Data Exchange (ETDEWEB)

Kim, S. T.; Kim, Y. J.; Kim, K. M.; Im, D. S.; Joung, N. Y.; Yang, H. L.; Kim, Y. S.; Kwon, M. [National Fusion Research Institute, Daejeon (Korea, Republic of)

2009-05-15

The Korea Superconducting Tokamak Advanced Research (KSTAR) is an advanced superconducting tokamak designed to establish a scientific and technological basis for an attractive fusion reactor. The fusion energy in the tokamak device is released through fusion reactions of light atoms such as deuterium or helium in hot plasma state, of which temperature reaches several hundreds of millions Celsius. The high temperature plasma is created in the vacuum vessel that provides ultra high vacuum status. Accordingly, it is most important for the vacuum condition to keep clean not only inner space but also surface of the vacuum vessel to make high quality plasma. There are two methods planned to clean the wall surface of the KSTAR vacuum vessel. One is surface baking and the other is glow discharge cleaning (GDC). To bake the vacuum vessel, De-Ionized (DI) water is heated to 130 .deg. C and circulated in the passage between double walls of the vacuum vessel (VV) in order to bake the surface. The GDC operation uses hydrogen and inert gas discharges. In this paper, general configuration and brief introduction of the baking result will be reported.

Software coding for reliable data communication in a reactor safety system

International Nuclear Information System (INIS)

Maghsoodi, R.

1978-01-01

A software coding method is proposed to improve the communication reliability of a microprocessor based fast-reactor safety system. This method which replaces the conventional coding circuitry, applies a program to code the data which is communicated between the processors via their data memories. The system requirements are studied and the suitable codes are suggested. The problems associated with hardware coders, and the advantages of software coding methods are discussed. The product code which proves a faster coding time over the cyclic code is chosen as the final code. Then the improvement of the communication reliability is derived for a processor and its data memory. The result is used to calculate the reliability improvement of the processing channel as the basic unit for the safety system. (author)

Hardware device to physical structure binding and authentication

Science.gov (United States)

Hamlet, Jason R.; Stein, David J.; Bauer, Todd M.

2013-08-20

Detection and deterrence of device tampering and subversion may be achieved by including a cryptographic fingerprint unit within a hardware device for authenticating a binding of the hardware device and a physical structure. The cryptographic fingerprint unit includes an internal physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generate an internal PUF value. Binding logic is coupled to receive the internal PUF value, as well as an external PUF value associated with the physical structure, and generates a binding PUF value, which represents the binding of the hardware device and the physical structure. The cryptographic fingerprint unit also includes a cryptographic unit that uses the binding PUF value to allow a challenger to authenticate the binding.

Raspberry Pi hardware projects 1

CERN Document Server

Robinson, Andrew

2013-01-01

Learn how to take full advantage of all of Raspberry Pi's amazing features and functions-and have a blast doing it! Congratulations on becoming a proud owner of a Raspberry Pi, the credit-card-sized computer! If you're ready to dive in and start finding out what this amazing little gizmo is really capable of, this ebook is for you. Taken from the forthcoming Raspberry Pi Projects, Raspberry Pi Hardware Projects 1 contains three cool hardware projects that let you have fun with the Raspberry Pi while developing your Raspberry Pi skills. The authors - PiFace inventor, Andrew Robinson and Rasp

A Hardware Abstraction Layer in Java

DEFF Research Database (Denmark)

Schoeberl, Martin; Korsholm, Stephan; Kalibera, Tomas

2011-01-01

Embedded systems use specialized hardware devices to interact with their environment, and since they have to be dependable, it is attractive to use a modern, type-safe programming language like Java to develop programs for them. Standard Java, as a platform-independent language, delegates access...... to devices, direct memory access, and interrupt handling to some underlying operating system or kernel, but in the embedded systems domain resources are scarce and a Java Virtual Machine (JVM) without an underlying middleware is an attractive architecture. The contribution of this article is a proposal...... for Java packages with hardware objects and interrupt handlers that interface to such a JVM. We provide implementations of the proposal directly in hardware, as extensions of standard interpreters, and finally with an operating system middleware. The latter solution is mainly seen as a migration path...

Designing Secure Systems on Reconfigurable Hardware

OpenAIRE

Huffmire, Ted; Brotherton, Brett; Callegari, Nick; Valamehr, Jonathan; White, Jeff; Kastner, Ryan; Sherwood, Ted

2008-01-01

The extremely high cost of custom ASIC fabrication makes FPGAs an attractive alternative for deployment of custom hardware. Embedded systems based on reconfigurable hardware integrate many functions onto a single device. Since embedded designers often have no choice but to use soft IP cores obtained from third parties, the cores operate at different trust levels, resulting in mixed trust designs. The goal of this project is to evaluate recently proposed security primitives for reconfigurab...

Vacuum system of SST-1 Tokamak

International Nuclear Information System (INIS)

Khan, Ziauddin; Pathan, Firozkhan; George, Siju; Semwal, Pratibha; Dhanani, Kalpesh; Paravastu, Yuvakiran; Thankey, Prashant; Ramesh, Gattu; Himabindu, Manthena; Pradhan, Subrata

2013-01-01

Highlights: ► Air leaks developed during ongoing SST-1 cooldown campaign were detected online using RGA. ► The presence of N 2 and O 2 gases with the ratio of their partial pressures with ∼3.81:1 confirmed the air leaks. ► Baking of SST-1 was done efficiently by flowing hot N 2 gas in C-channels welded on inner surfaces without any problem. ► In-house fabricated demountable bull nose couplers were demonstrated for high temperature and pressure applications. ► Cryopumping effect was observed when liquid helium cooled superconducting magnets reached below 63 K. -- Abstract: Vacuum chambers of Steady State Superconducting (SST-1) Tokamak comprises of the vacuum vessel and the cryostat. The plasma will be confined inside the vacuum vessel while the cryostat houses the superconducting magnet systems (TF and PF coils), LN 2 cooled thermal shields and hydraulics for these circuits. The vacuum vessel is an ultra-high (UHV) vacuum chamber while the cryostat is a high-vacuum (HV) chamber. In order to achieve UHV inside the vacuum vessel, it would be baked at 150 °C for longer duration. For this purpose, U-shaped baking channels are welded inside the vacuum vessel. The baking will be carried out by flowing hot nitrogen gas through these channels at 250 °C at 4.5 bar gauge pressure. During plasma operation, the pressure inside the vacuum vessel will be raised between 1.0 × 10 −4 mbar and 1.0 × 10 −5 mbar using piezoelectric valves and control system. An ultimate pressure of 4.78 × 10 −6 mbar is achieved inside the vacuum vessel after 100 h of pumping. The limitation is due to the development of few leaks of the order of 10 −5 mbar l/s at the critical locations of the vacuum vessel during baking which was confirmed with the presence of nitrogen gas and oxygen gas with the ratio of ∼3.81:1 indicating air leak. Similarly an ultimate vacuum of 2.24 × 10 −5 mbar is achieved inside the cryostat. Baking of the vacuum vessel up to 110 °C with ±10 �

Hardware-Accelerated Simulated Radiography

International Nuclear Information System (INIS)

Laney, D; Callahan, S; Max, N; Silva, C; Langer, S.; Frank, R

2005-01-01

We present the application of hardware accelerated volume rendering algorithms to the simulation of radiographs as an aid to scientists designing experiments, validating simulation codes, and understanding experimental data. The techniques presented take advantage of 32-bit floating point texture capabilities to obtain solutions to the radiative transport equation for X-rays. The hardware accelerated solutions are accurate enough to enable scientists to explore the experimental design space with greater efficiency than the methods currently in use. An unsorted hexahedron projection algorithm is presented for curvilinear hexahedral meshes that produces simulated radiographs in the absorption-only regime. A sorted tetrahedral projection algorithm is presented that simulates radiographs of emissive materials. We apply the tetrahedral projection algorithm to the simulation of experimental diagnostics for inertial confinement fusion experiments on a laser at the University of Rochester

Treatment of hardware infection after osteosynthesis of lower leg using negative pressure wound therapy and transforming powder dressing.

Science.gov (United States)

Marinović, Marin; Ivandcić, Aldo; Spanjol, Josip; Pina, Maja; Bakota, Bore; Bandalović, Ante; Cukeljs, Fabijan

2014-12-01

Fractures of the distal part of the lower leg are more common in everyday practice and traumatology. In young and active patients these injuries are mainly caused by high energy trauma. They are treated with external fixator in first step, and in second step, after sanation of the soft tissue, with open reduction and internal fixation (ORIF). It is very safe and effective method of treatment. Treatment of the infections that occur in the early postoperative period after open reduction and internal fixation represents a great problem and challenge for surgeons. It is widely accepted that the presence of deep infection can't be cured in the presence of hardware. However, removal of hardware in the presence of unhealed fractures significantly complicates sanation of infection and fracture itself We have decided to present a 35-years-old patient with a hardware infection with present chronic wound with hardware exposed eight months after the first operation and six months after second operation. The wound measured one centimeter in diameter with cell detritus and bad granulations tissue inside the wound. Hardwre was exposed in the depth of the wound.The secretion was minimal. Negative Pressure Wound Therapy (NPWT) was applicated after debridemet and lavage performed in ambulatory conditions. The starting therapy was continuously -125 mm Hg of vacuum. After five days of NPWT the defect was partially filled with granula- tion tissue. For another five days we continue with NPWT with the same values of-125 mm Hg pressure but in the inter- mitent mode. After that period we used transforming powder dressing for covering and protection of the wound with was filled with granulation tissue. Five days later, wound was completely healed with epithelisation. After four months of patient follow-up, we found the wound is completely repaired. The patient denies pain and has continued orderly flow of fracture healing, with no signs of infection.

Evacuation of the NET vacuum chamber

International Nuclear Information System (INIS)

Muller, R.A.

1987-01-01

Parametric calculations of the evacuation process were carried out for the NET-vacuum chamber involving two blanket designs. The results show that with an acceptable vacuum pumping capacity the required start vacuum conditions can be realized within reasonable time. The two blanket concepts do not differ remarkably in their evacuation behaviour. The remaining large pressure differences between the different locations of the vacuum chamber can be reduced if approximately 30% of the total gas flow is extracted from the heads of the blanket replacement ports

Evacuation of the NET vacuum chamber

International Nuclear Information System (INIS)

Mueller, R.

1986-01-01

Parametric calculations of the evacuation process were carried out for the NET-vacuum chamber involving two blanket designs. The results show that with an acceptable vacuum pumping capacity the required start vacuum conditions can be realized within reasonable time. The two blanket concepts do not differ remarkably in their evacuation behaviour. The remaining large pressure differences between the different locations of the vacuum chamber can be reduced if approximately 30% of the total gas flow is extracted from the heads of the blanket replacement ports. (author)

Big Bang or vacuum fluctuation

International Nuclear Information System (INIS)

Zel'dovich, Ya.B.

1980-01-01

Some general properties of vacuum fluctuations in quantum field theory are described. The connection between the ''energy dominance'' of the energy density of vacuum fluctuations in curved space-time and the presence of singularity is discussed. It is pointed out that a de-Sitter space-time (with the energy density of the vacuum fluctuations in the Einstein equations) that matches the expanding Friedman solution may describe the history of the Universe before the Big Bang. (P.L.)

Hardware descriptions of the I and C systems for NPP

International Nuclear Information System (INIS)

Lee, Cheol Kwon; Oh, In Suk; Park, Joo Hyun; Kim, Dong Hoon; Han, Jae Bok; Shin, Jae Whal; Kim, Young Bak

2003-09-01

The hardware specifications for I and C Systems of SNPP(Standard Nuclear Power Plant) are reviewed in order to acquire the hardware requirement and specification of KNICS (Korea Nuclear Instrumentation and Control System). In the study, we investigated hardware requirements, hardware configuration, hardware specifications, man-machine hardware requirements, interface requirements with the other system, and data communication requirements that are applicable to SNP. We reviewed those things of control systems, protection systems, monitoring systems, information systems, and process instrumentation systems. Through the study, we described the requirements and specifications of digital systems focusing on a microprocessor and a communication interface, and repeated it for analog systems focusing on the manufacturing companies. It is expected that the experience acquired from this research will provide vital input for the development of the KNICS

Vacuum vessel for thermonuclear device

International Nuclear Information System (INIS)

Kikuchi, Mitsuru; Nagashima, Keisuke; Suzuki, Masaru; Onozuka, Masaki.

1997-01-01

A vacuum vessel main body and structural members at the inside and the outside of the vacuum vessel main body are constituted by structural materials activated by irradiation of neutrons from plasmas such as stainless steels. Shielding members comprising tungsten or molybdenum are disposed on the surface of the vacuum vessel main body and the structural members of the inside and the outside of the main body. The shielding members have a function also as first walls or a seat member for the first walls. Armor tiles may be disposed to the shielding members. The shielding members and the armor tiles are secured to a securing seat member disposed, for example, to an inner plate of the vacuum vessel main body by bolts. Since the shielding members are disposed, it is not necessary to constitute the vacuum vessel main body and the structural members at the inside and the outside thereof by using a low activation material which is less activated, such as a titanium alloy. (I.N.)

Vacuum vessel for thermonuclear device

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, Mitsuru; Nagashima, Keisuke [Japan Atomic Energy Research Inst., Tokyo (Japan); Suzuki, Masaru; Onozuka, Masaki

1997-07-11

A vacuum vessel main body and structural members at the inside and the outside of the vacuum vessel main body are constituted by structural materials activated by irradiation of neutrons from plasmas such as stainless steels. Shielding members comprising tungsten or molybdenum are disposed on the surface of the vacuum vessel main body and the structural members of the inside and the outside of the main body. The shielding members have a function also as first walls or a seat member for the first walls. Armor tiles may be disposed to the shielding members. The shielding members and the armor tiles are secured to a securing seat member disposed, for example, to an inner plate of the vacuum vessel main body by bolts. Since the shielding members are disposed, it is not necessary to constitute the vacuum vessel main body and the structural members at the inside and the outside thereof by using a low activation material which is less activated, such as a titanium alloy. (I.N.)

Design consideration on the synchrotron ultrahigh vacuum system

International Nuclear Information System (INIS)

Tsujikawa, H.; Chida, K.; Mizobuchi, A.; Miyahara, A.

1982-01-01

Ultrahigh vacuum production for the high-energy heavy-ion accelerator poses special problems concerning beam-gas molecule and beam-wall interactions. In this paper, summary of the TARN ultrahigh vacuum system and design criteria of the synchrotron ultrahigh vacuum system are presented. On-beam pressure of 4 x 10 -11 Torr is achieved in the TARN ultrahigh vacuum system, of which experiences through the construction and the operation are described and discussed. With emphasis on the application of newly developed technique in the fabrication of vacuum chamber and ultrahigh vacuum pump for the synchrotron ultrahigh vacuum system. (author)

Vacuum status-display and sector-conditioning programs

International Nuclear Information System (INIS)

Skelly, J.; Yen, S.

1989-01-01

Two programs have been developed for observation and control of the AGS vacuum system, which include these notable features: they incorporate a graphical user interface, and they are driven by a relational database which describes the vacuum system. The vacuum system comprises some 440 devices organized into 28 vacuum sectors. The Status Display Program invites menu selection of a sector, interrogates the relational database for relevant vacuum devices, acquires live readbacks, and posts a graphical display of their status. The Sector Conditioning Program likewise invites sector selection, produces the same status display, and also implements process control logic on the sector devices to pump the sector down from atmospheric pressure to high vacuum over a period extending for several hours. As additional devices are installed in the vacuum system, the devices are likewise added to the relational database; these programs then automatically include the new devices. 2 refs., 1 fig

Dynamical effects of QCD vacuum structure

International Nuclear Information System (INIS)

Ferreira, Erasmo

1994-01-01

The role of the QCD vacuum structure in the determination of the properties of states and processes occurring in the confinement regime of QCD is reviewed. The finite range of the vacuum correlations is discussed, and an analytical form is suggested for the correlation functions. The role of the vacuum quantum numbers in the phenomenology of high-energy scattering is reviewed. The vacuum correlation model of non-perturbative QCD is mentioned as a bridge between the fundamental theory and the description of the experiments. (author). 13 refs., 1 fig

Vacuum technology in the chemical industry

CERN Document Server

Jorisch, Wolfgang

2015-01-01

Based on the very successful German edition and a seminar held by the German Engineers` Association (VDI) on a regular basis for years now, this English edition has been thoroughly updated and revised to reflect the latest developments. It supplies in particular the special aspects of vacuum technology, applied vacuum pump types and vacuum engineering in the chemical, pharmaceutical and process industry application-segments. The text includes chapters dedicated to latest European regulations for operating in hazardous zones with vacuum systems, methods for process pressure control and regulati

Running vacuum cosmological models: linear scalar perturbations

Energy Technology Data Exchange (ETDEWEB)

Perico, E.L.D. [Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, CEP 05508-090, São Paulo, SP (Brazil); Tamayo, D.A., E-mail: elduartep@usp.br, E-mail: tamayo@if.usp.br [Departamento de Astronomia, Universidade de São Paulo, Rua do Matão 1226, CEP 05508-900, São Paulo, SP (Brazil)

2017-08-01

In cosmology, phenomenologically motivated expressions for running vacuum are commonly parameterized as linear functions typically denoted by Λ( H {sup 2}) or Λ( R ). Such models assume an equation of state for the vacuum given by P-bar {sub Λ} = - ρ-bar {sub Λ}, relating its background pressure P-bar {sub Λ} with its mean energy density ρ-bar {sub Λ} ≡ Λ/8π G . This equation of state suggests that the vacuum dynamics is due to an interaction with the matter content of the universe. Most of the approaches studying the observational impact of these models only consider the interaction between the vacuum and the transient dominant matter component of the universe. We extend such models by assuming that the running vacuum is the sum of independent contributions, namely ρ-bar {sub Λ} = Σ {sub i} ρ-bar {sub Λ} {sub i} . Each Λ i vacuum component is associated and interacting with one of the i matter components in both the background and perturbation levels. We derive the evolution equations for the linear scalar vacuum and matter perturbations in those two scenarios, and identify the running vacuum imprints on the cosmic microwave background anisotropies as well as on the matter power spectrum. In the Λ( H {sup 2}) scenario the vacuum is coupled with every matter component, whereas the Λ( R ) description only leads to a coupling between vacuum and non-relativistic matter, producing different effects on the matter power spectrum.

Avoiding vacuum arcs in high gradient normal conducting RF structures

CERN Document Server

Sjøbæk, Kyrre Ness; Adli, Erik; Grudiev, Alexej; Wuensch, Walter

In order to build the Compact LInear Collider (CLIC), accelerating structures reaching extremely high accelerating gradients are needed. Such structures have been built and tested using normal-conducting copper, powered by X-band RF power and reaching gradients of 100 MV/m and above. One phenomenon that must be avoided in order to reliably reach such gradients, is vacuum arcs or “breakdowns”. This can be accomplished by carefully designing the structure geometry such that high surface fields and large local power flows are avoided. The research presented in this thesis presents a method for optimizing the geometry of accelerating structures so that these breakdowns are made less likely, allowing the structure to operate reliably at high gradients. This was done primarily based on a phenomenological scaling model, which predicted the maximum gradient as a function of the break down rate, pulse length, and field distribution in the structure. The model is written in such a way that it allows direct comparis...

46 CFR 154.804 - Vacuum protection.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Vacuum protection. 154.804 Section 154.804 Shipping... Systems § 154.804 Vacuum protection. (a) Except as allowed under paragraph (b) of this section, each cargo tank must have a vacuum protection system meeting paragraph (a)(1) of this section and either paragraph...

Vacuum Mechatronics And Insvection For Self-Contained Manufacturing

Science.gov (United States)

Belinski, Steve E.; Shirazi, Majid; Seidel, Thomas E.; Hackwood, Susan

1990-02-01

The vacuum environment is increasingly being used in manufacturing operations, especially in the semiconductor industry. Shrinking linewidths and feature sizes dictate that cleanliness standards become continually more strict. Studies at the Center for Robotic Systems in Microelectronics (CRSM) indicate that a controlled vacuum enclosure can provide a superior clean environment. In addition, since many microelectronic fabrication steps are already carried out under vacuum, self-contained multichamber processing systems are being developed at a rapid pace. CRSM support of these systems includes the development of a research system, the Self-contained Automated Robotic Factory (SCARF), a vacuum-compatible robot, and investigations of particulate characterization in vacuum and inspection for multichamber systems. Successful development of complex and expensive multichamber systems is, to a great extent, dependent upon the discipline called vacuum mechatronics, which includes the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. Here the constituents of the vacuum mechatronics discipline are defined and reviewed in the context of the importance to self-contained in-vacuum manufacturing.

Vacuum system for HIMAC synchrotrons

International Nuclear Information System (INIS)

Kanazawa, M.; Sudou, M.; Sato, K.

1994-01-01

HIMAC synchrotrons are now under construction, which require vacuum chambers of large aperture and high vacuum of about 10 -9 torr. Wide thin wall vacuum chamber of 0.3 mm thickness reinforced with ribs has been developed as the chamber at dipole magnet. We have just now started to evacuate the lower ring. The obtained average value was about 5x10 -8 torr with turbo-molecular and sputter ion pumps, and 1.1x10 -9 torr after baking. (author)

Vacuum vessel for thermonuclear device

International Nuclear Information System (INIS)

Hagiwara, Koji; Imura, Yasuya.

1979-01-01

Purpose: To provide constituted method for easily performing baking of vacuum vessel, using short-circuiting segments. Constitution: At the time of baking, one turn circuit is formed by the vacuum vessel and short-circuiting segments, and current transformer converting the one turn circuit into a secondary circuit by the primary coil and iron core is formed, and the vacuum vessel is Joule heated by an induction current from the primary coil. After completion of baking, the short-circuiting segments are removed. (Kamimura, M.)

ITER diagnostic system: Vacuum interface

Energy Technology Data Exchange (ETDEWEB)

Patel, K.M., E-mail: Kaushal.Patel@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Udintsev, V.S.; Hughes, S.; Walker, C.I.; Andrew, P.; Barnsley, R.; Bertalot, L. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Drevon, J.M. [Bertin Technologies, BP 22, 13762 Aix-en Provence cedex 3 (France); Encheva, A. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Kashchuk, Y. [Institution “PROJECT CENTER ITER”, 1, Akademika Kurchatova pl., Moscow (Russian Federation); Maquet, Ph. [Bertin Technologies, BP 22, 13762 Aix-en Provence cedex 3 (France); Pearce, R.; Taylor, N.; Vayakis, G.; Walsh, M.J. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France)

2013-10-15

Diagnostics play an essential role for the successful operation of the ITER tokamak. They provide the means to observe control and to measure plasma during the operation of ITER tokamak. The components of the diagnostic system in the ITER tokamak will be installed in the vacuum vessel, in the cryostat, in the upper, equatorial and divertor ports, in the divertor cassettes and racks, as well as in various buildings. Diagnostic components that are placed in a high radiation environment are expected to operate for the life of ITER. There are approx. 45 diagnostic systems located on ITER. Some diagnostics incorporate direct or independently pumped extensions to maintain their necessary vacuum conditions. They require a base pressure less than 10{sup −7} Pa, irrespective of plasma operation, and a leak rate of less than 10{sup −10} Pa m{sup 3} s{sup −1}. In all the cases it is essential to maintain the ITER closed fuel cycle. These directly coupled diagnostic systems are an integral part of the ITER vacuum containment and are therefore subject to the same design requirements for tritium and active gas confinement, for all normal and accidental conditions. All the diagnostics, whether or not pumped, incorporate penetration of the vacuum boundary (i.e. window assembly, vacuum feedthrough etc.) and demountable joints. Monitored guard volumes are provided for all elements of the vacuum boundary that are judged to be vulnerable by virtue of their construction, material, load specification etc. Standard arrangements are made for their construction and for the monitoring, evacuating and leak testing of these volumes. Diagnostic systems are incorporated at more than 20 ports on ITER. This paper will describe typical and particular arrangements of pumped diagnostic and monitored guard volume. The status of the diagnostic vacuum systems, which are at the start of their detailed design, will be outlined and the specific features of the vacuum systems in ports and extensions

ITER diagnostic system: Vacuum interface

International Nuclear Information System (INIS)

Patel, K.M.; Udintsev, V.S.; Hughes, S.; Walker, C.I.; Andrew, P.; Barnsley, R.; Bertalot, L.; Drevon, J.M.; Encheva, A.; Kashchuk, Y.; Maquet, Ph.; Pearce, R.; Taylor, N.; Vayakis, G.; Walsh, M.J.

2013-01-01

Diagnostics play an essential role for the successful operation of the ITER tokamak. They provide the means to observe control and to measure plasma during the operation of ITER tokamak. The components of the diagnostic system in the ITER tokamak will be installed in the vacuum vessel, in the cryostat, in the upper, equatorial and divertor ports, in the divertor cassettes and racks, as well as in various buildings. Diagnostic components that are placed in a high radiation environment are expected to operate for the life of ITER. There are approx. 45 diagnostic systems located on ITER. Some diagnostics incorporate direct or independently pumped extensions to maintain their necessary vacuum conditions. They require a base pressure less than 10 −7 Pa, irrespective of plasma operation, and a leak rate of less than 10 −10 Pa m 3 s −1 . In all the cases it is essential to maintain the ITER closed fuel cycle. These directly coupled diagnostic systems are an integral part of the ITER vacuum containment and are therefore subject to the same design requirements for tritium and active gas confinement, for all normal and accidental conditions. All the diagnostics, whether or not pumped, incorporate penetration of the vacuum boundary (i.e. window assembly, vacuum feedthrough etc.) and demountable joints. Monitored guard volumes are provided for all elements of the vacuum boundary that are judged to be vulnerable by virtue of their construction, material, load specification etc. Standard arrangements are made for their construction and for the monitoring, evacuating and leak testing of these volumes. Diagnostic systems are incorporated at more than 20 ports on ITER. This paper will describe typical and particular arrangements of pumped diagnostic and monitored guard volume. The status of the diagnostic vacuum systems, which are at the start of their detailed design, will be outlined and the specific features of the vacuum systems in ports and extensions will be described

Software-Controlled Dynamically Swappable Hardware Design in Partially Reconfigurable Systems

Directory of Open Access Journals (Sweden)

Huang Chun-Hsian

2008-01-01

Full Text Available Abstract We propose two basic wrapper designs and an enhanced wrapper design for arbitrary digital hardware circuit designs such that they can be enhanced with the capability for dynamic swapping controlled by software. A hardware design with either of the proposed wrappers can thus be swapped out of the partially reconfigurable logic at runtime in some intermediate state of computation and then swapped in when required to continue from that state. The context data is saved to a buffer in the wrapper at interruptible states, and then the wrapper takes care of saving the hardware context to communication memory through a peripheral bus, and later restoring the hardware context after the design is swapped in. The overheads of the hardware standardization and the wrapper in terms of additional reconfigurable logic resources and the time for context switching are small and generally acceptable. With the capability for dynamic swapping, high priority hardware tasks can interrupt low-priority tasks in real-time embedded systems so that the utilization of hardware space per unit time is increased.

Vacuum system of SST-1 Tokamak

Energy Technology Data Exchange (ETDEWEB)

Khan, Ziauddin, E-mail: ziauddin@ipr.res.in [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382 428 (India); Pathan, Firozkhan; George, Siju; Semwal, Pratibha; Dhanani, Kalpesh; Paravastu, Yuvakiran; Thankey, Prashant; Ramesh, Gattu; Himabindu, Manthena; Pradhan, Subrata [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382 428 (India)

2013-10-15

Highlights: ► Air leaks developed during ongoing SST-1 cooldown campaign were detected online using RGA. ► The presence of N{sub 2} and O{sub 2} gases with the ratio of their partial pressures with ∼3.81:1 confirmed the air leaks. ► Baking of SST-1 was done efficiently by flowing hot N{sub 2} gas in C-channels welded on inner surfaces without any problem. ► In-house fabricated demountable bull nose couplers were demonstrated for high temperature and pressure applications. ► Cryopumping effect was observed when liquid helium cooled superconducting magnets reached below 63 K. -- Abstract: Vacuum chambers of Steady State Superconducting (SST-1) Tokamak comprises of the vacuum vessel and the cryostat. The plasma will be confined inside the vacuum vessel while the cryostat houses the superconducting magnet systems (TF and PF coils), LN{sub 2} cooled thermal shields and hydraulics for these circuits. The vacuum vessel is an ultra-high (UHV) vacuum chamber while the cryostat is a high-vacuum (HV) chamber. In order to achieve UHV inside the vacuum vessel, it would be baked at 150 °C for longer duration. For this purpose, U-shaped baking channels are welded inside the vacuum vessel. The baking will be carried out by flowing hot nitrogen gas through these channels at 250 °C at 4.5 bar gauge pressure. During plasma operation, the pressure inside the vacuum vessel will be raised between 1.0 × 10{sup −4} mbar and 1.0 × 10{sup −5} mbar using piezoelectric valves and control system. An ultimate pressure of 4.78 × 10{sup −6} mbar is achieved inside the vacuum vessel after 100 h of pumping. The limitation is due to the development of few leaks of the order of 10{sup −5} mbar l/s at the critical locations of the vacuum vessel during baking which was confirmed with the presence of nitrogen gas and oxygen gas with the ratio of ∼3.81:1 indicating air leak. Similarly an ultimate vacuum of 2.24 × 10{sup −5} mbar is achieved inside the cryostat. Baking of the

Coil-On-Plug Ignition for LOX/Methane Liquid Rocket Engines in Thermal Vacuum Environments

Science.gov (United States)

Melcher, John C.; Atwell, Matthew J.; Morehead, Robert L.; Hurlbert, Eric A.; Bugarin, Luz; Chaidez, Mariana

2017-01-01

A coil-on-plug ignition system has been developed and tested for Liquid Oxygen (LOX) / liquid methane rocket engines operating in thermal vacuum conditions. The igniters were developed and tested as part of the Integrated Cryogenic Propulsion Test Article (ICPTA), previously tested as part of the Project Morpheus test vehicle. The ICPTA uses an integrated, pressure-fed, cryogenic LOX/methane propulsion system including a reaction control system (RCS) and a main engine. The ICPTA was tested at NASA Glenn Research Center's Plum Brook Station in the Spacecraft Propulsion Research Facility (B-2) under vacuum and thermal vacuum conditions. In order to successfully demonstrate ignition reliability in the vacuum conditions and eliminate corona discharge issues, a coil-on-plug ignition system has been developed. The ICPTA uses spark-plug ignition for both the main engine igniter and the RCS. The coil-on-plug configuration eliminates the conventional high-voltage spark plug cable by combining the coil and the spark-plug into a single component. Prior to ICPTA testing at Plum Brook, component-level reaction control engine (RCE) and main engine igniter testing was conducted at NASA Johnson Space Center (JSC), which demonstrated successful hot-fire ignition using the coil-on-plug from sea-level ambient conditions down to 10(exp.-2) torr. Integrated vehicle hot-fire testing at JSC demonstrated electrical and command/data system performance. Lastly, Plum Brook testing demonstrated successful ignitions at simulated altitude conditions at 30 torr and cold thermal-vacuum conditions at 6 torr. The test campaign successfully proved that coil-on-plug technology will enable integrated LOX/methane propulsion systems in future spacecraft.

Rotary bayonets for cryogenic and vacuum service

International Nuclear Information System (INIS)

Rucinski, R.A.; Dixon, K.D.; Krasa, R.; Krempetz, K.J.; Mulholland, G.T.; Trotter, G.R.; Urbin, J.B.

1993-07-01

Rotary bayonets were designed, tested, and installed for liquid nitrogen, liquid argon, and vacuum service. This paper will present the design, testing, and service record for two sizes of vacuum jacketed cryogenic rotary bayonets and two sizes of vacuum service rotary bayonets. Materials used in construction provide electrical isolation across the bayonet joint. The joint permits 360 degrees of rotation between the male and female pipe sections while maintaining integrity of service. Assemblies using three such joints were built to allow end connection points to be translated through at least 1 meter of horizontal travel while kept in service. Vacuum jacketed sizes built in-house at Fermi National Accelerator Laboratory are 1-1/2 in. inner pipe size, 3 in. vacuum jacket, and 4 in. inner pipe size, 6 in. vacuum jacket The single wall vacuum service bayonets are in 4 in. and 6 in. pipe sizes. The bayonets have successfully been in active service for over one year

Rotary bayonets for cryogenic and vacuum service

International Nuclear Information System (INIS)

Rucinski, R.A.; Dixon, K.D.; Krasa, R.; Krempetz, K.J.; Mulholland, G.T.; Trotter, G.R.; Urbin, J.B.

1994-01-01

Rotary bayonets were designed, tested, and installed for liquid nitrogen, liquid argon, and vacuum service. This paper will present the design, testing, and service record for two sizes of vacuum jacketed cryogenic rotary bayonets and two sizes of vacuum service rotary bayonets. Materials used in construction provide electrical isolation across the bayonet joint. The joint permits 360 degrees of rotation between the male and female pipe sections while maintaining integrity of service. Assemblies using three such joints were built to allow end connection points to be translated through at least 1 meter of horizontal travel while kept in service. Vacuum jacketed sizes built in-house at Fermi National Accelerator Laboratory are 1 1/2 inches inner pipe size, 3 inches vacuum jacket, and 4 inches inner pipe size, 6 inches vacuum jacket. The single wall vacuum service bayonets are in 4 inch and 6 inch pipe sizes. The bayonets have successfully been in active service for over one year

TPX vacuum vessel transient thermal and stress conditions

International Nuclear Information System (INIS)

Feldshteyn, Y.; Dinkevich, S.; Feng, T.; Majumder, D.

1995-01-01

The TPX vacuum vessel provides the vacuum boundary for the plasma and the mechanical support for the internal components. Another function of the vacuum vessel is to contain neutron shielding water in the double wall space during normal operation. This double wall space serves as a heat reservoir for the entire vacuum vessel during bakeout. The vacuum vessel and the internal components are subjected to thermal stresses induced by a nonuniform temperature distribution within the structure during bakeout. A successful Conceptual Design Review in March 1993 has established superheated steam as the heating source of the vacuum vessel. A transient bakeout mode of the vacuum vessel and in-vessel components has been analyzed to evaluate transient period duration, proper temperature level, actual thermal stresses and performance of the steam equipment. Thermally, the vacuum vessel structure may be considered as an adiabatic system because it is perfectly insulated by the strong surrounding vacuum and multiple layers of superinsulation. Important aspects of the analysis are described herein

On Improving Reliability of SRAM-Based Physically Unclonable Functions

Directory of Open Access Journals (Sweden)

Arunkumar Vijayakumar

2017-01-01

Full Text Available Physically unclonable functions (PUFs have been touted for their inherent resistance to invasive attacks and low cost in providing a hardware root of trust for various security applications. SRAM PUFs in particular are popular in industry for key/ID generation. Due to intrinsic process variations, SRAM cells, ideally, tend to have the same start-up behavior. SRAM PUFs exploit this start-up behavior. Unfortunately, not all SRAM cells exhibit reliable start-up behavior due to noise susceptibility. Hence, design enhancements are needed for improving reliability. Some of the proposed enhancements in literature include fuzzy extraction, error-correcting codes and voting mechanisms. All enhancements involve a trade-off between area/power/performance overhead and PUF reliability. This paper presents a design enhancement technique for reliability that improves upon previous solutions. We present simulation results to quantify improvement in SRAM PUF reliability and efficiency. The proposed technique is shown to generate a 128-bit key in ≤0.2 μ s at an area estimate of 4538 μ m 2 with error rate as low as 10 − 6 for intrinsic error probability of 15%.

Generation of Embedded Hardware/Software from SystemC

Directory of Open Access Journals (Sweden)

Dominique Houzet

2006-08-01

Full Text Available Designers increasingly rely on reusing intellectual property (IP and on raising the level of abstraction to respect system-on-chip (SoC market characteristics. However, most hardware and embedded software codes are recoded manually from system level. This recoding step often results in new coding errors that must be identified and debugged. Thus, shorter time-to-market requires automation of the system synthesis from high-level specifications. In this paper, we propose a design flow intended to reduce the SoC design cost. This design flow unifies hardware and software using a single high-level language. It integrates hardware/software (HW/SW generation tools and an automatic interface synthesis through a custom library of adapters. We have validated our interface synthesis approach on a hardware producer/consumer case study and on the design of a given software radiocommunication application.

Generation of Embedded Hardware/Software from SystemC

Directory of Open Access Journals (Sweden)

Ouadjaout Salim

2006-01-01

Full Text Available Designers increasingly rely on reusing intellectual property (IP and on raising the level of abstraction to respect system-on-chip (SoC market characteristics. However, most hardware and embedded software codes are recoded manually from system level. This recoding step often results in new coding errors that must be identified and debugged. Thus, shorter time-to-market requires automation of the system synthesis from high-level specifications. In this paper, we propose a design flow intended to reduce the SoC design cost. This design flow unifies hardware and software using a single high-level language. It integrates hardware/software (HW/SW generation tools and an automatic interface synthesis through a custom library of adapters. We have validated our interface synthesis approach on a hardware producer/consumer case study and on the design of a given software radiocommunication application.

Consolidation of simulated nuclear metallic waste by vacuum coreless induction melting

International Nuclear Information System (INIS)

Montgomery, D.R.

1984-10-01

Vacuum coreless induction melting with bottom pouring has exceeded expectations for simplicity, reliability, and versatility when melting the zirconium and iron eutectic alloy. The melting tests have established that: the eutectic mixture of oxidized Zircaloy 4 hulls mixed with Type 316 stainless steel hulls can be melted at 41 kg/h at 40 kW with a power consumption of 1.03 kWh/kg and a melting temperature of 1260 0 C; the life of a graphite crucible can be expected to be longer by a factor of 4 than was previously projected; the bottom-pour water-cooled copper freeze plug was 100% reliable; a 24-in.-tall stainless steel canister with 1/4-in.-thick walls (6-in. inside diameter) was satisfactory in every respect; an ingot formed from 4 consecutive heats poured into a stainless steel canister appeared to be approx. 99% dense after sectioning; preplaced scrap in the canister can be encapsulated with molten metal to about 99% density; large pieces of Zircaloy 4 and stainless steel scrap can be melted, but have differing melting parameters; the pouring nozzle requires further development to prevent solidified drops from forming at the hole exit after a pour. It is recommended that a large-scale cold mock-up facility be established to refine and test a full-scale vacuum coreless induction melting system. Other options might include further scaled-down experiments to test other alloys and crucible materials under different atmospheric conditions (i.e., air melting). 1 reference, 18 figures, 1 table

Design foundation of vacuum system for electron beam machine

International Nuclear Information System (INIS)

Darsono; Suprapto; Djasiman

1999-01-01

Vacuum system is a main part of electron beam Machine because (EBM) the electron can not be produced without this vacuum. Vacuum system consists of vacuum pump, connecting pipe, valve, and vacuum gauge. The design vacuum system of EBM, basis knowledge and technology of vacuum is needed. The paper describes types of vacuum pump, calculation of pipe conductance and pumping time of vacuum system then there are used as consideration of criteria to choose vacuum pump for EBM. From the result of study, it is concluded that for EBM of 500 keV/10 mA which is going to use for wood coating and with consideration of economic and technic factor it is better to use diffusion pump. (author)

Cooperative communications hardware, channel and PHY

CERN Document Server

Dohler, Mischa

2010-01-01

Facilitating Cooperation for Wireless Systems Cooperative Communications: Hardware, Channel & PHY focuses on issues pertaining to the PHY layer of wireless communication networks, offering a rigorous taxonomy of this dispersed field, along with a range of application scenarios for cooperative and distributed schemes, demonstrating how these techniques can be employed. The authors discuss hardware, complexity and power consumption issues, which are vital for understanding what can be realized at the PHY layer, showing how wireless channel models differ from more traditional

IDD Archival Hardware Architecture and Workflow

Energy Technology Data Exchange (ETDEWEB)

Mendonsa, D; Nekoogar, F; Martz, H

2008-10-09

This document describes the functionality of every component in the DHS/IDD archival and storage hardware system shown in Fig. 1. The document describes steps by step process of image data being received at LLNL then being processed and made available to authorized personnel and collaborators. Throughout this document references will be made to one of two figures, Fig. 1 describing the elements of the architecture and the Fig. 2 describing the workflow and how the project utilizes the available hardware.

Latent fingermark development using low-vacuum vaporization of ninhydrin.

Science.gov (United States)

Chen, Chun-Chieh; Yang, Chao-Kai; Liao, Jeh-Shane; Wang, Sheng-Meng

2015-12-01

The vacuum technique is a method of vaporizing a solid material to its gas phase, helping deposit reagents gently on target surfaces to develop latent fingermarks. However, this application is rarely reported in the literature. In this study, a homemade fume hood with a built-in vacuum control system and programmable heating system designed by the Taiwan Criminal Investigation Bureau is introduced. Factors that affect the instrument's performance in developing fingermarks are discussed, including the quantity of chemicals for vaporization, heating program arrangement, and paper of different materials. The results show that fingermarks are effectively developed by vaporizing solid ninhydrin. This would be an alternative application in selecting a solvent-free method for protecting the environment and reducing health hazards in the lab. In terms of the heating program, the result indicates that under a low-vacuum condition (50 mTorr), 80-90 °C is a suitable temperature range for ninhydrin vaporization, allowing ninhydrin to be vaporized without bumping and waste. In terms of the performance on different material papers, this instrument demonstrates its capacity by developing latent fingermarks on thermal paper without discoloration or damaging the original writing, and the same results are also observed on Taiwan and United States banknotes. However, a coherent result could be hardly obtained using the same vaporization setting because different banknotes have their own surface features and water absorption ability or other unique factors may influence the effect of ninhydrin deposition. This study provides a reliable application for developing latent fingermarks without using solvents, and it is also expected to contribute to environmental protection along with the trend of green chemistry technology. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Development of a vacuum superinsulation panel

Energy Technology Data Exchange (ETDEWEB)

Timm, H; Seefeldt, D; Nitze, C

1983-05-01

After completion of the investigations the vacuum-insulated panel is available as prototype. The aim of the investigations was to optimize and to finalize the vacuum superinsulation system with regard to a pressure-resistant, temperature-resistant thermal insulation of high efficiency. In this connection, particularly investigations with regard to vacuum-tight sealing, compression and evacuation of powder filling as well as special material investigations were performed. The application-specific utilization of the vacuum-insulated panel and the adjustment to special operational conditions can now be started. Application possibilities are at present seen in coverings or linings with high temperature and/or pressure requirements.

Aspects of system modelling in Hardware/Software partitioning

DEFF Research Database (Denmark)

Knudsen, Peter Voigt; Madsen, Jan

1996-01-01

This paper addresses fundamental aspects of system modelling and partitioning algorithms in the area of Hardware/Software Codesign. Three basic system models for partitioning are presented and the consequences of partitioning according to each of these are analyzed. The analysis shows...... the importance of making a clear distinction between the model used for partitioning and the model used for evaluation It also illustrates the importance of having a realistic hardware model such that hardware sharing can be taken into account. Finally, the importance of integrating scheduling and allocation...

Vacuum phonon tunneling.

Science.gov (United States)

Altfeder, Igor; Voevodin, Andrey A; Roy, Ajit K

2010-10-15

Field-induced phonon tunneling, a previously unknown mechanism of interfacial thermal transport, has been revealed by ultrahigh vacuum inelastic scanning tunneling microscopy (STM). Using thermally broadened Fermi-Dirac distribution in the STM tip as in situ atomic-scale thermometer we found that thermal vibrations of the last tip atom are effectively transmitted to sample surface despite few angstroms wide vacuum gap. We show that phonon tunneling is driven by interfacial electric field and thermally vibrating image charges, and its rate is enhanced by surface electron-phonon interaction.

Vacuum and ultravacuum physics and technology

CERN Document Server

Bello, Igor

2018-01-01

Vacuum technology has enormous impact on human life in many aspects and fields, such as metallurgy, material development and production, food and electronic industry, microelectronics, device fabrication, physics, materials science, space science, engineering, chemistry, technology of low temperature, pharmaceutical industry, and biology. All decorative coatings used in jewelries and various daily products—including shiny decorative papers, the surface finish of watches, and light fixtures—are made using vacuum technological processes. Vacuum analytical techniques and vacuum technologies are pillars of the technological processes, material synthesis, deposition, and material analyses—all of which are used in the development of novel materials, increasing the value of industrial products, controlling the technological processes, and ensuring the high product quality. Based on physical models and calculated examples, the book provides a deeper look inside the vacuum physics and technology.

Comprehending the structure of a vacuum vessel and in-vessel components of fusion machines. 1. Comprehending the vacuum vessel structure

International Nuclear Information System (INIS)

Onozuka, Masanori; Nakahira, Masataka

2006-01-01

The functions, conditions and structure of vacuum vessel using tokamak fusion machines are explained. The structural standard and code of vacuum vessel, process of vacuum vessel design, and design of ITER vacuum vessel are described. Production and maintenance of ultra high vacuum, confinement of radioactive materials, support of machines in vessel and electromagnetic force, radiation shield, plasma vertical stability, one-turn electric resistance, high temperature baking heat and remove of nuclear heat, reduce of troidal ripple, structural standard, features of safety of nuclear fusion machines, subjects of structural standard of fusion vacuum vessel, design flow of vacuum vessel, establishment of radial build, selections of materials, baking and cooling method, basic structure, structure of special parts, shield structure, and of support structure, and example of design of structure, ITER, are stated. (S.Y.)

Hardware Acceleration of Adaptive Neural Algorithms.

Energy Technology Data Exchange (ETDEWEB)

James, Conrad D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-11-01

As tradit ional numerical computing has faced challenges, researchers have turned towards alternative computing approaches to reduce power - per - computation metrics and improve algorithm performance. Here, we describe an approach towards non - conventional computing that strengthens the connection between machine learning and neuroscience concepts. The Hardware Acceleration of Adaptive Neural Algorithms (HAANA) project ha s develop ed neural machine learning algorithms and hardware for applications in image processing and cybersecurity. While machine learning methods are effective at extracting relevant features from many types of data, the effectiveness of these algorithms degrades when subjected to real - world conditions. Our team has generated novel neural - inspired approa ches to improve the resiliency and adaptability of machine learning algorithms. In addition, we have also designed and fabricated hardware architectures and microelectronic devices specifically tuned towards the training and inference operations of neural - inspired algorithms. Finally, our multi - scale simulation framework allows us to assess the impact of microelectronic device properties on algorithm performance.

Vacuum Acceptance Tests for the UHV Room Temperature Vacuum System of the LHC during LS1

CERN Document Server

Cattenoz, G; Bregliozzi, G; Calegari, D; Gallagher, J; Marraffa, A; Chiggiato, P

2014-01-01

During the CERN Large Hadron Collider (LHC) first long shut down (LS1), a large number of vacuum tests are carried out on consolidated or newly fabricated devices. In such a way, the vacuum compatibility is assessed before installation in the UHV system of the LHC. According to the equipment’s nature, the vacuum acceptance tests consist in functional checks, leak test, outgassing rate measurements, evaluation of contaminants by Residual Gas Analysis (RGA), pumping speed measurements and qualification of the H2 sticking probability of Non-Evaporable-Getter (NEG) coating. In this paper, the methods used for the tests and the acceptance criteria are described. A summary of the measured vacuum characteristics for the tested components is also given.

The reliability of the software of the digital control system Nuclear Advantage

International Nuclear Information System (INIS)

Graae, T.; Engdahl, L.

1996-01-01

The ABB nuclear power control system Nuclear Advantage is a truly integrated control system. The integration of process control and safety control aims at achieving a common operator interface in order to simplify and thus improve control room ergonomics. The challenge is to design an integrated control system and at the same time ensure the functional separation between the independent safety subsystems as well as between the safety and the conventional sections. Software reliability is discussed and illustrated by statistical test results. It has proved to be a hundred times better than the reliability of the high-quality hardware. (orig.) [de

Complexity optimization and high-throughput low-latency hardware implementation of a multi-electrode spike-sorting algorithm.

Science.gov (United States)

Dragas, Jelena; Jackel, David; Hierlemann, Andreas; Franke, Felix

2015-03-01

Reliable real-time low-latency spike sorting with large data throughput is essential for studies of neural network dynamics and for brain-machine interfaces (BMIs), in which the stimulation of neural networks is based on the networks' most recent activity. However, the majority of existing multi-electrode spike-sorting algorithms are unsuited for processing high quantities of simultaneously recorded data. Recording from large neuronal networks using large high-density electrode sets (thousands of electrodes) imposes high demands on the data-processing hardware regarding computational complexity and data transmission bandwidth; this, in turn, entails demanding requirements in terms of chip area, memory resources and processing latency. This paper presents computational complexity optimization techniques, which facilitate the use of spike-sorting algorithms in large multi-electrode-based recording systems. The techniques are then applied to a previously published algorithm, on its own, unsuited for large electrode set recordings. Further, a real-time low-latency high-performance VLSI hardware architecture of the modified algorithm is presented, featuring a folded structure capable of processing the activity of hundreds of neurons simultaneously. The hardware is reconfigurable “on-the-fly” and adaptable to the nonstationarities of neuronal recordings. By transmitting exclusively spike time stamps and/or spike waveforms, its real-time processing offers the possibility of data bandwidth and data storage reduction.

Vacuum anti-shielding of monopoles

International Nuclear Information System (INIS)

Goebel, D.J.

1984-01-01

This chapter examines the difficulties in calculating the vacuum polarization, or magnetization, induced in the vacuum by a monopole. The usual Lagrangian formalism and consequent Feynman rules do not apply. Another problem is that the interaction strength between the monopole and a charge is not small (unless it vanishes exactly) because it is quantized to half integer values. Perturbation theory is therefore not applicable. The discussed problems are solved by using the old fashioned method of calculating a vacuum expectation value as a sum over single particle modes

High current vacuum closing switch

International Nuclear Information System (INIS)

Dolgachev, G.I.; Maslennikov, D.D.; Romanov, A.S.; Ushakov, A.G.

2005-01-01

The paper proposes a powerful pulsed closing vacuum switch for high current commutation consisting of series of the vacuum diodes with near 1 mm gaps having closing time determined by the gaps shortening with the near-electrode plasmas [ru

Hardware/software virtualization for the reconfigurable multicore platform.

NARCIS (Netherlands)

Ferger, M.; Al Kadi, M.; Hübner, M.; Koedam, M.L.P.J.; Sinha, S.S.; Goossens, K.G.W.; Marchesan Almeida, Gabriel; Rodrigo Azambuja, J.; Becker, Juergen

2012-01-01

This paper presents the Flex Tiles approach for the virtualization of hardware and software for a reconfigurable multicore architecture. The approach enables the virtualization of a dynamic tile-based hardware architecture consisting of processing tiles connected via a network-on-chip and a

Vacuum considerations summary

International Nuclear Information System (INIS)

1977-01-01

The vacuum system for Heavy Ion Fusion machines can be divided according to pressure into 4 parts: (a) Ion Sources; (b) Linear Accelerators; (c) Circular Accelerators, Accumulators and Storage Rings; and (d) Reactors. Since ion sources will need rather conventional pumping arrangements and reactors will operate with greater pressures, depending on their mode of operation, only items b and c will be treated in this report. In particular, the vacuum system design will be suggested for the machines proposed by various scenarios arrived at during the workshop. High mass numbers will be assumed

Vacuum systems for the ILC helical undulator

CERN Document Server

Malyshev, O B; Clarke, J A; Bailey, I R; Dainton, J B; Malysheva, L I; Barber, D P; Cooke, P; Baynham, E; Bradshaw, T; Brummitt, A; Carr, S; Ivanyushenkov, Y; Rochford, J; Moortgat-Pick, G A

2007-01-01

The International Linear Collider (ILC) positron source uses a helical undulator to generate polarized photons of ∼10MeV∼10MeV at the first harmonic. Unlike many undulators used in synchrotron radiation sources, the ILC helical undulator vacuum chamber will be bombarded by photons, generated by the undulator, with energies mostly below that of the first harmonic. Achieving the vacuum specification of ∼100nTorr∼100nTorr in a narrow chamber of 4–6mm4–6mm inner diameter, with a long length of 100–200m100–200m, makes the design of the vacuum system challenging. This article describes the vacuum specifications and calculations of the flux and energy of photons irradiating the undulator vacuum chamber and considers possible vacuum system design solutions for two cases: cryogenic and room temperature.

Hardware upgrade for A2 data acquisition

Energy Technology Data Exchange (ETDEWEB)

Ostrick, Michael; Gradl, Wolfgang; Otte, Peter-Bernd; Neiser, Andreas; Steffen, Oliver; Wolfes, Martin; Koerner, Tito [Institut fuer Kernphysik, Mainz (Germany); Collaboration: A2-Collaboration

2014-07-01

The A2 Collaboration uses an energy tagged photon beam which is produced via bremsstrahlung off the MAMI electron beam. The detector system consists of Crystal Ball and TAPS and covers almost the whole solid angle. A frozen-spin polarized target allows to perform high precision measurements of polarization observables in meson photo-production. During the last summer, a major upgrade of the data acquisition system was performed, both on the hardware and the software side. The goal of this upgrade was increased reliability of the system and an improvement in the data rate to disk. By doubling the number of readout CPUs and employing special VME crates with a split backplane, the number of bus accesses per readout cycle and crate was cut by a factor of two, giving almost a factor of two gain in the readout rate. In the course of the upgrade, we also switched most of the detector control system to using the distributed control system EPICS. For the upgraded control system, some new tools were developed to make full use of the capabilities of this decentralised slow control and monitoring system. The poster presents some of the major contributions to this project.

PERANCANGAN APLIKASI SISTEM PAKAR DIAGNOSA KERUSAKAN HARDWARE KOMPUTER METODE FORWARD CHAINING

Directory of Open Access Journals (Sweden)

Ali Akbar Rismayadi

2016-09-01

Full Text Available Abstract Damage to computer hardware, not a big disaster, because not all damage to computer hardware can not be repaired, nearly all computer users, whether public or institutions often suffer various kinds of damage that occurred in the computer hardware it has, and the damage can be caused by various factors that are basically as the user does not know the cause of what makes the computer hardware used damaged. Therefore, it is necessary to build an application that can help users to mendiganosa damage to computer hardware. So that everyone can diagnose the type of hardware damage his computer. Development of expert system diagnosis of damage to computer hardware uses forward chaining method by promoting alisisis descriptive of various damage data obtained from several experts and other sources of literature to reach a conclusion on the diagnosis of damage. As well as using the waterfall model as a model system development, starting from the analysis stage to stage software needs support. This application is built using a programming language tools Eclipse ADT as well as SQLite as its database. diagnosis expert system damage computer hardware is expected to be used as a tool to help find the causes of damage to computer hardware independently without the help of a computer technician.

ATLAS TileCal LVPS Upgrade Hardware and Testing

CERN Document Server

Hibbard, Michael James; The ATLAS collaboration; Hadavand, Haleh Khani

2018-01-01

UTA (University of Texas at Arlington) has been designing and producing new testing stations to ensure the reliability and quality of new TileLVPS (Low Voltage Power Supplies), also produced at UTA, which will power the next generation of upgraded hardware in the TileCal (Tile Calorimeter) system of ATLAS at CERN. UTA has produced two new types of testing stations, which build upon the previous generation of testing stations used in the initial production of the TileCal system. The first station is the Initial Test Station, and quickly quantifies a multitude of performance metrics of a LVPS. We have developed our own PC based program which graphically display and records onto file these metrics. A few notable metrics we are measuring are the system clock and its jitter. Excessive clock jitter in LVPS can affect system stability and derate the working range of the system duty cycle. This station also verifies protection circuitry of LVPS, which protects it from over temperature, current and voltage. The second...

Flight Hardware Virtualization for On-Board Science Data Processing

Data.gov (United States)

National Aeronautics and Space Administration — Utilize Hardware Virtualization technology to benefit on-board science data processing by investigating new real time embedded Hardware Virtualization solutions and...

Speed challenge: a case for hardware implementation in soft-computing

Science.gov (United States)

Daud, T.; Stoica, A.; Duong, T.; Keymeulen, D.; Zebulum, R.; Thomas, T.; Thakoor, A.

2000-01-01

For over a decade, JPL has been actively involved in soft computing research on theory, architecture, applications, and electronics hardware. The driving force in all our research activities, in addition to the potential enabling technology promise, has been creation of a niche that imparts orders of magnitude speed advantage by implementation in parallel processing hardware with algorithms made especially suitable for hardware implementation. We review our work on neural networks, fuzzy logic, and evolvable hardware with selected application examples requiring real time response capabilities.

Computer hardware for radiologists: Part I

International Nuclear Information System (INIS)

Indrajit, IK; Alam, A

2010-01-01

Computers are an integral part of modern radiology practice. They are used in different radiology modalities to acquire, process, and postprocess imaging data. They have had a dramatic influence on contemporary radiology practice. Their impact has extended further with the emergence of Digital Imaging and Communications in Medicine (DICOM), Picture Archiving and Communication System (PACS), Radiology information system (RIS) technology, and Teleradiology. A basic overview of computer hardware relevant to radiology practice is presented here. The key hardware components in a computer are the motherboard, central processor unit (CPU), the chipset, the random access memory (RAM), the memory modules, bus, storage drives, and ports. The personnel computer (PC) has a rectangular case that contains important components called hardware, many of which are integrated circuits (ICs). The fiberglass motherboard is the main printed circuit board and has a variety of important hardware mounted on it, which are connected by electrical pathways called “buses”. The CPU is the largest IC on the motherboard and contains millions of transistors. Its principal function is to execute “programs”. A Pentium ® 4 CPU has transistors that execute a billion instructions per second. The chipset is completely different from the CPU in design and function; it controls data and interaction of buses between the motherboard and the CPU. Memory (RAM) is fundamentally semiconductor chips storing data and instructions for access by a CPU. RAM is classified by storage capacity, access speed, data rate, and configuration

Computer hardware for radiologists: Part I

Directory of Open Access Journals (Sweden)

Indrajit I

2010-01-01

Full Text Available Computers are an integral part of modern radiology practice. They are used in different radiology modalities to acquire, process, and postprocess imaging data. They have had a dramatic influence on contemporary radiology practice. Their impact has extended further with the emergence of Digital Imaging and Communications in Medicine (DICOM, Picture Archiving and Communication System (PACS, Radiology information system (RIS technology, and Teleradiology. A basic overview of computer hardware relevant to radiology practice is presented here. The key hardware components in a computer are the motherboard, central processor unit (CPU, the chipset, the random access memory (RAM, the memory modules, bus, storage drives, and ports. The personnel computer (PC has a rectangular case that contains important components called hardware, many of which are integrated circuits (ICs. The fiberglass motherboard is the main printed circuit board and has a variety of important hardware mounted on it, which are connected by electrical pathways called "buses". The CPU is the largest IC on the motherboard and contains millions of transistors. Its principal function is to execute "programs". A Pentium® 4 CPU has transistors that execute a billion instructions per second. The chipset is completely different from the CPU in design and function; it controls data and interaction of buses between the motherboard and the CPU. Memory (RAM is fundamentally semiconductor chips storing data and instructions for access by a CPU. RAM is classified by storage capacity, access speed, data rate, and configuration.

DC photogun vacuum characterization through photocathode lifetime studies

International Nuclear Information System (INIS)

Marcy Stutzman; Joseph Grames; Matt Poelker; Kenneth Surles-Law; Philip Adderley

2007-01-01

Excellent vacuum is essential for long photocathode lifetimes in DC high voltage photoelectron guns. Vacuum Research at Thomas Jefferson National Accelerator Facility has focused on characterizing the existing vacuum systems at the CEBAF polarized photoinjector and on quantifying improvements for new systems. Vacuum chamber preprocessing, full activation of NEG pumps and NEG coating the chamber walls should improve the vacuum within the electron gun, however, pressure measurement is difficult at pressures approaching the extreme-high-vacuum (XHV) region and extractor gauge readings are not significantly different between the improved and original systems. The ultimate test of vacuum in a DC high voltage photogun is the photocathode lifetime, which is limited by the ionization and back-bombardment of residual gasses. Discussion will include our new load-locked gun design as well as lifetime measurements in both our operational and new photo-guns, and the correlations between measured vacuum and lifetimes will be investigated

Hardware malware

CERN Document Server

Krieg, Christian

2013-01-01

In our digital world, integrated circuits are present in nearly every moment of our daily life. Even when using the coffee machine in the morning, or driving our car to work, we interact with integrated circuits. The increasing spread of information technology in virtually all areas of life in the industrialized world offers a broad range of attack vectors. So far, mainly software-based attacks have been considered and investigated, while hardware-based attacks have attracted comparatively little interest. The design and production process of integrated circuits is mostly decentralized due to

The importance of the reliability study for the safety operation of chemical plants. Application in heavy water plants

International Nuclear Information System (INIS)

Dumitrescu, Maria; Lazar, Roxana Elena; Preda, Irina Aida; Stefanescu, Ioan

1999-01-01

Heavy water production in Romania is based on H 2 O-H 2 S isotopic exchange process followed by vacuum isotopic distillation. The heavy water plant are complex chemical systems, characterized by an ensemble of static and dynamic equipment, AMC components, enclosures. Such equipment must have a high degree of reliability, a maximum safety in technological operation and a high availability index. Safety, reliable and economical operation heavy water plants need to maintain the systems and the components at adequate levels of reliability. The paper is a synthesis of the qualitative and quantitative assessment reliability studies for heavy water plants. The operation analysis on subsystems, each subsystems being a well-defined unit, is required by the plant complexity. For each component the reliability indicators were estimated by parametric and non-parametric methods based on the plant operation data. Also, the reliability qualitative and quantitative assessment was done using the fault tree technique. For the dual temperature isotopic exchange plants the results indicate an increase of the MTBF after the first years of operation, illustrating both the operation experience increasing and maintenance improvement. Also a high degree of availability was illustrated by the reliability studies of the vacuum distillation plant. The establishment of the reliability characteristics for heavy water plant represents an important step, a guide for highlighting the elements and process liable to failure being at the same time a planning modality to correlate the control times with the maintenance operations. This is the way to minimise maintenance, control and costs. The main purpose of the reliability study was the safety increase of the plant operation and the support for decision making. (authors)

Effect of system workload on operating system reliability - A study on IBM 3081

Science.gov (United States)

Iyer, R. K.; Rossetti, D. J.

1985-01-01

This paper presents an analysis of operating system failures on an IBM 3081 running VM/SP. Three broad categories of software failures are found: error handling, program control or logic, and hardware related; it is found that more than 25 percent of software failures occur in the hardware/software interface. Measurements show that results on software reliability cannot be considered representative unless the system workload is taken into account. The overall CPU execution rate, although measured to be close to 100 percent most of the time, is not found to correlate strongly with the occurrence of failures. Possible reasons for the observed workload failure dependency, based on detailed investigations of the failure data, are discussed.

Troubleshooting vacuum systems steam turbine surface condensers and refinery vacuum towers

CERN Document Server

Lieberman, Norman P

2012-01-01

Vacuum systems are in wide spread use in the petrochemical plants, petroleum refineries and power generation plants. The existing texts on this subject are theoretical in nature and only deal with how the equipment functions when in good mechanical conditions, from the viewpoint of the equipment vendor.  In this much-anticipated volume, one of the most well-respected and prolific process engineers in the world takes on troubleshooting vacuum systems, and especially steam ejectors, an extremely complex and difficult subject that greatly effects the profitability of the majority of the world'

Hardware Accelerated Sequence Alignment with Traceback

Directory of Open Access Journals (Sweden)

Scott Lloyd

2009-01-01

in a timely manner. Known methods to accelerate alignment on reconfigurable hardware only address sequence comparison, limit the sequence length, or exhibit memory and I/O bottlenecks. A space-efficient, global sequence alignment algorithm and architecture is presented that accelerates the forward scan and traceback in hardware without memory and I/O limitations. With 256 processing elements in FPGA technology, a performance gain over 300 times that of a desktop computer is demonstrated on sequence lengths of 16000. For greater performance, the architecture is scalable to more processing elements.

Vacuum arc anode phenomena

International Nuclear Information System (INIS)

Miller, H.C.

1976-01-01

A brief review of anode phenomena in vacuum arcs is presented. Discussed in succession are: the transition of the arc into the anode spot mode; the temperature of the anode before, during and after the anode spot forms; and anode ions. Characteristically the anode spot has a temperature of the order of the atmospheric boiling point of the anode material and is a copious source of vapor and energetic ions. The dominant mechanism controlling the transition of the vacuum arc into the anode spot mode appears to depend upon the electrode geometry, the electrode material, and the current waveform of the particular vacuum arc being considered. Either magnetic constriction in the gap plasma or gross anode melting can trigger the transition; indeed, a combination of the two is a common cause of anode spot formation

Hardware-in-the-Loop Testing

Data.gov (United States)

Federal Laboratory Consortium — RTC has a suite of Hardware-in-the Loop facilities that include three operational facilities that provide performance assessment and production acceptance testing of...

MYRRHA cryogenic system study on performances and reliability requirements

International Nuclear Information System (INIS)

Junquera, T.; Chevalier, N.R.; Thermeau, J.P.; Medeiros Romao, L.; Vandeplassche, D.

2015-01-01

A precise evaluation of the cryogenic requirements for accelerator-driven system such as the MYRRHA project has been performed. In particular, operation temperature, thermal losses, and required cryogenic power have been evaluated. A preliminary architecture of the cryogenic system including all its major components, as well as the principles for the cryogenic fluids distribution has been proposed. A detailed study on the reliability aspects has also been initiated. This study is based on the reliability of large cryogenic systems used for accelerators like HERA, LHC or SNS Linac. The requirements to guarantee good cryogenic system availability can be summarised as follows: 1) Mean Time Between Maintenance (MTBM) should be > 8 000 hours; 2) Valves, heat exchangers and turbines are particularly sensitive elements to impurities (dust, oil, gases), improvements are necessary to keep a minimal level in these components; 3) Redundancy studies for all elements containing moving/vibrating parts (turbines, compressors, including their respective bearings and seal shafts) are necessary; 4) Periodic maintenance is mandatory: oil checks, control of screw compressors every 10.000-15.000 hours, vibration surveillance programme, etc; 5) Special control and maintenance of utilities equipment (supply of cooling water, compressed air and electrical supply) is necessary; 6) Periodic vacuum checks to identify leakage appearance such as insulation vacuum of transfer lines and distribution boxes are necessary; 7) Easily exchangeable cold compressors are required

Desenvolvimento de software e hardware para irrigação de precisão usando pivô central Development of software and hardware for precision irrigation using the center pivot

Directory of Open Access Journals (Sweden)

Tadeu M. de Queiroz

2008-03-01

the Basic Step software was developed in Tbasic language. The hardware was constituted by two electronic circuits. The first circuit was developed as an interface to the computer and the second one for the management and transmission of tensiometers readings through radio frequency Evaluations of range and efficiency of the radio modules and performance of data transmission, of the software and hardware operations were carried out. The results showed that the circuits and the developed software operated satisfactorily. The reliable communication range of the radios is 50 meters maximum. In conclusion, the developed system presented great potential used in precision irrigation for center pivot systems, since the range of the radio communication could be increased.

Resistor cooling in a vacuum

International Nuclear Information System (INIS)

Crittenden, R.; Krider, J.

1987-01-01

This note describes thermal measurements which were done on a resistor operating both in air at one atmosphere pressure and in a vacuum of a few milliTorr. The motivation for this measurement was our interest in operating a BGO crystal-photomultiplier tube-base assembly in a vacuum, as a synchrotron radiation detector to tag electrons in the MT beam. We wished to determine what fraction of the total resistor power was dissipated by convection in air, in order to know whether there would be excessive heating of the detector assembly in a vacuum. 3 figs

Structural design of shield-integrated thin-wall vacuum vessel and manufacturing qualification tests for International Thermonuclear Experimental Reactor (ITER)

International Nuclear Information System (INIS)

Shimizu, Katsusuke; Shibui, Masanao; Koizumi, Koichi; Kanamori, Naokazu; Nishio, Satoshi; Sasaki, Takashi; Tada, Eisuke

1992-09-01

Conceptual design of shield-integrated thin-wall vacuum vessel has been done for ITER (International Thermonuclear Experimental Reactor). The vacuum vessel concept is based on a thin-double-wall structure, which consists of inner and outer plates and rib stiffeners. Internal shielding structures, which provide neutron irradiation shielding to protect TF coils, are set up between the inner plate and the outer plate of the vessel to avoid complexity of machine systems such as supporting systems of blanket modules. The vacuum vessel is assembled/disassembled by remote handling, so that welding joints are chosen as on-site joint method from reliability of mechanical strength. From a view point of assembling TF coils, the vacuum vessel is separated at the side of port, and is divided into 32 segments similar to the ITER-CDA reference design. Separatrix sweeping coils are located in the vacuum vessel to reduce heat fluxes onto divertor plates. Here, the coil structure and attachment to the vacuum vessel have been investigated. A sectorized saddle-loop coil is available for assembling and disassembling the coil. To support electromagnetic loads on the coils, they are attached to the groove in the vacuum vessel by welding. Flexible multi-plate supporting structure (compression-type gravity support), which was designed during CDA, is optimized by investigating buckling and frequency response properties, and concept on manufacturing and fabrication of the gravity support are proposed. Partial model of the vacuum vessel is manufactured for trial, so that fundamental data on welding and fabrication are obtained. From mechanical property tests of weldment and partial models, mechanical intensity and behaviors of the weldment are obtained. Informations on FEM-modeling are obtained by comparing analysis results with experimental results. (author)

Evaluation of a Prototype Hybrid Vacuum Pump to Provide Vacuum-Assisted Suspension for Above-Knee Prostheses.

Science.gov (United States)

Major, Matthew J; Caldwell, Ryan; Fatone, Stefania

2015-12-01

Vacuum-assisted suspension (VAS) of prosthetic sockets utilizes a pump to evacuate air from between the prosthetic liner and socket, and are available as mechanical or electric systems. This technical note describes a hybrid pump that benefits from the advantages of mechanical and electric systems, and evaluates a prototype as proof-of-concept. Cyclical bench testing of the hybrid pump mechanical system was performed using a materials testing system to assess the relationship between compression cycles and vacuum pressure. Phase 1 in vivo testing of the hybrid pump was performed by an able-bodied individual using prosthesis simulator boots walking on a treadmill, and phase 2 involved an above-knee prosthesis user walking with the hybrid pump and a commercial electric pump for comparison. Bench testing of 300 compression cycles produced a maximum vacuum of 24 in-Hg. In vivo testing demonstrated that the hybrid pump continued to pull vacuum during walking, and as opposed to the commercial electric pump, did not require reactivation of the electric system during phase 2 testing. The novelty of the hybrid pump is that while the electric system provides rapid, initial vacuum suspension, the mechanical system provides continuous air evacuation while walking to maintain suspension without reactivation of the electric system, thereby allowing battery power to be reserved for monitoring vacuum levels.

Cyber Security Vulnerability Impact on I and C Reliability

International Nuclear Information System (INIS)

Hadley, Mark D.; McBride, Justin B.

2006-01-01

We present a discussion of the cyber security vulnerability impact on instrument and control reliability. In the discussion we demonstrate the likely vector of attack and vulnerabilities associated with commodity hardware, protocols and communication media. The current fleet of nuclear power plants in the United States utilizes aging analog instrument and control systems which are more frequently suffering from obsolescence and failure. The commodity equipment available now and in the near future incorporates features from information technology systems which compound cyber vulnerabilities

NMR and Chemometric Characterization of Vacuum Residues and Vacuum Gas Oils from Crude Oils of Different Origin

Directory of Open Access Journals (Sweden)

Jelena Parlov Vuković

2015-03-01

Full Text Available NMR spectroscopy in combination with statistical methods was used to study vacuum residues and vacuum gas oils from 32 crude oils of different origin. Two chemometric metodes were applied. Firstly, principal component analysis on complete spectra was used to perform classification of samples and clear distinction between vacuum residues and vacuum light and heavy gas oils were obtained. To quantitatively predict the composition of asphaltenes, principal component regression models using areas of resonance signals spaned by 11 frequency bins of the 1H NMR spectra were build. The first 5 principal components accounted for more than 94 % of variations in the input data set and coefficient of determination for correlation between measured and predicted values was R2 = 0.7421. Although this value is not significant, it shows the underlying linear dependence in the data. Pseudo two-dimensional DOSY NMR experiments were used to assess the composition and structural properties of asphaltenes in a selected crude oil and its vacuum residue on the basis of their different hydrodynamic behavior and translational diffusion coefficients. DOSY spectra showed the presence of several asphaltene aggregates differing in size and interactions they formed. The obtained results have shown that NMR techniques in combination with chemometrics are very useful to analyze vacuum residues and vacuum gas oils. Furthermore, we expect that our ongoing investigation of asphaltenes from crude oils of different origin will elucidate in more details composition, structure and properties of these complex molecular systems.

Topology of classical vacuum space-time

International Nuclear Information System (INIS)

Cho, Y.M.

2007-04-01

We present a topological classification of classical vacuum space-time. Assuming the 3-dimensional space allows a global chart, we show that the static vacuum space-time of Einstein's theory can be classified by the knot topology π 3 (S 3 ) = π 3 (S 2 ). Viewing Einstein's theory as a gauge theory of Lorentz group and identifying the gravitational connection as the gauge potential of Lorentz group, we construct all possible vacuum gravitational connections which give a vanishing curvature tensor. With this we show that the vacuum connection has the knot topology, the same topology which describes the multiple vacua of SU(2) gauge theory. We discuss the physical implications of our result in quantum gravity. (author)

Gravitational collapse and the vacuum energy

International Nuclear Information System (INIS)

Campos, M

2014-01-01

To explain the accelerated expansion of the universe, models with interacting dark components (dark energy and dark matter) have been considered recently in the literature. Generally, the dark energy component is physically interpreted as the vacuum energy of the all fields that fill the universe. As the other side of the same coin, the influence of the vacuum energy on the gravitational collapse is of great interest. We study such collapse adopting different parameterizations for the evolution of the vacuum energy. We discuss the homogeneous collapsing star fluid, that interacts with a vacuum energy component, using the stiff matter case as example. We conclude this work with a discussion of the Cahill-McVittie mass for the collapsed object.

Pseudo-absolute quantitative analysis using gas chromatography – Vacuum ultraviolet spectroscopy – A tutorial

Energy Technology Data Exchange (ETDEWEB)

Bai, Ling [Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX (United States); Smuts, Jonathan; Walsh, Phillip [VUV Analytics, Inc., Cedar Park, TX (United States); Qiu, Changling [Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX (United States); McNair, Harold M. [Department of Chemistry, Virginia Tech, Blacksburg, VA (United States); Schug, Kevin A., E-mail: kschug@uta.edu [Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX (United States)

2017-02-08

The vacuum ultraviolet detector (VUV) is a new non-destructive mass sensitive detector for gas chromatography that continuously and rapidly collects full wavelength range absorption between 120 and 240 nm. In addition to conventional methods of quantification (internal and external standard), gas chromatography - vacuum ultraviolet spectroscopy has the potential for pseudo-absolute quantification of analytes based on pre-recorded cross sections (well-defined absorptivity across the 120–240 nm wavelength range recorded by the detector) without the need for traditional calibration. The pseudo-absolute method was used in this research to experimentally evaluate the sources of sample loss and gain associated with sample introduction into a typical gas chromatograph. Standard samples of benzene and natural gas were used to assess precision and accuracy for the analysis of liquid and gaseous samples, respectively, based on the amount of analyte loaded on-column. Results indicate that injection volume, split ratio, and sampling times for splitless analysis can all contribute to inaccurate, yet precise sample introduction. For instance, an autosampler can very reproducibly inject a designated volume, but there are significant systematic errors (here, a consistently larger volume than that designated) in the actual volume introduced. The pseudo-absolute quantification capability of the vacuum ultraviolet detector provides a new means for carrying out system performance checks and potentially for solving challenging quantitative analytical problems. For practical purposes, an internal standardized approach to normalize systematic errors can be used to perform quantitative analysis with the pseudo-absolute method. - Highlights: • Gas chromatography diagnostics and quantification using VUV detector. • Absorption cross-sections for molecules enable pseudo-absolute quantitation. • Injection diagnostics reveal systematic errors in hardware settings. • Internal

Pseudo-absolute quantitative analysis using gas chromatography – Vacuum ultraviolet spectroscopy – A tutorial

International Nuclear Information System (INIS)

Bai, Ling; Smuts, Jonathan; Walsh, Phillip; Qiu, Changling; McNair, Harold M.; Schug, Kevin A.

2017-01-01

The vacuum ultraviolet detector (VUV) is a new non-destructive mass sensitive detector for gas chromatography that continuously and rapidly collects full wavelength range absorption between 120 and 240 nm. In addition to conventional methods of quantification (internal and external standard), gas chromatography - vacuum ultraviolet spectroscopy has the potential for pseudo-absolute quantification of analytes based on pre-recorded cross sections (well-defined absorptivity across the 120–240 nm wavelength range recorded by the detector) without the need for traditional calibration. The pseudo-absolute method was used in this research to experimentally evaluate the sources of sample loss and gain associated with sample introduction into a typical gas chromatograph. Standard samples of benzene and natural gas were used to assess precision and accuracy for the analysis of liquid and gaseous samples, respectively, based on the amount of analyte loaded on-column. Results indicate that injection volume, split ratio, and sampling times for splitless analysis can all contribute to inaccurate, yet precise sample introduction. For instance, an autosampler can very reproducibly inject a designated volume, but there are significant systematic errors (here, a consistently larger volume than that designated) in the actual volume introduced. The pseudo-absolute quantification capability of the vacuum ultraviolet detector provides a new means for carrying out system performance checks and potentially for solving challenging quantitative analytical problems. For practical purposes, an internal standardized approach to normalize systematic errors can be used to perform quantitative analysis with the pseudo-absolute method. - Highlights: • Gas chromatography diagnostics and quantification using VUV detector. • Absorption cross-sections for molecules enable pseudo-absolute quantitation. • Injection diagnostics reveal systematic errors in hardware settings. • Internal

Numerical study on the performance of vacuum cooler and evaporation-boiling phenomena during vacuum cooling of cooked meat

International Nuclear Information System (INIS)

Jin, T.X.; Xu, L.

2006-01-01

The vacuum cooling of cooked meats is described in this paper. Based on the energy and mass balance, a modified mathematical model based on a previous model is developed to analyze the performance of the vacuum cooler and the evaporation-boiling phenomena during vacuum cooling of cooked meat. Validation experimentation is performed in the designed vacuum cooler. Boiling occurs inside the cooked meat. There is a boiling front, and the boiling front moves toward the center of the cooked meat as the vacuum cooling proceeds. The experimental data are compared with the simulation results. It is found that the differences of the temperature between the simulation and the experimentation are within 5 deg. C, and the deviation of weight loss between the simulation and the experimentation is within 4%. The simulation results agree with the experimental data well. The modified model can be used to predict the variation of the vacuum pressure in the chamber, the temperature and pressure distributions and the weight loss profiles of cylindrical cooked meats

Learning Machines Implemented on Non-Deterministic Hardware

OpenAIRE

Gupta, Suyog; Sindhwani, Vikas; Gopalakrishnan, Kailash

2014-01-01

This paper highlights new opportunities for designing large-scale machine learning systems as a consequence of blurring traditional boundaries that have allowed algorithm designers and application-level practitioners to stay -- for the most part -- oblivious to the details of the underlying hardware-level implementations. The hardware/software co-design methodology advocated here hinges on the deployment of compute-intensive machine learning kernels onto compute platforms that trade-off deter...

The HIE-ISOLDE Vacuum System

CERN Document Server

Vandoni, G; Radwan, K; Chiggiato, P

2014-01-01

The High Intensity and Energy Isolde (HIE-Isolde) project aims at increasing the energy and intensity of the radioactive ion beams (RIB) delivered by the present Rex-Isolde facility. Energy up to 10MeV/amu will be reached by a new post-accelerating, superconducting (SC) linac. Beam will be delivered via a HEBT to three experimental stations for nuclear physics. To keep the SC linac compact and avoid cold-warm transitions, the cryomodules feature a common beam and insulation vacuum. Radioactive ion beams require a hermetically sealed vacuum, with transfer of the effluents to the nuclear ventilation chimney. Hermetically sealed, dry, gas transfer vacuum pumps are preferred to gas binding pumps, for an optimized management of radioactive contamination risk during maintenance and intervention. The vacuum system of the SC-linac is isolated by two fast valves, triggered by fast reacting cold cathode gauges installed on the warm linac, the HEBT and the experimental stations. Rough pumping is distributed, while the H...

Particle creation during vacuum decay

International Nuclear Information System (INIS)

Rubakov, V.A.

1984-01-01

The hamiltonian approach is developed with regard to the problem of particle creation during the tunneling process, leading to the decay of the false vacuum in quantum field theory. It is shown that, to the lowest order in (h/2π), the particle creation is described by the euclidean Schroedinger equation in an external field of a bounce. A technique for solving this equation is developed in an analogy to the Bogoliubov transformation technique, in the theory of particle creation in the presence of classical background fields. The technique is illustrated by two examples, namely, the particle creation during homogeneous vacuum decay and during the tunneling process leading to the materialization of the thin-wall bubble of a new vacuum in the metastable one. The curious phenomenon of intensive particle annihilation during vacuum decay is discussed and explicitly illustrated within the former example. The non-unitary extension of the Bogoliubov u, v transformations is described in the appendix. (orig.)

Hardware Middleware for Person Tracking on Embedded Distributed Smart Cameras

Directory of Open Access Journals (Sweden)

Ali Akbar Zarezadeh

2012-01-01

Full Text Available Tracking individuals is a prominent application in such domains like surveillance or smart environments. This paper provides a development of a multiple camera setup with jointed view that observes moving persons in a site. It focuses on a geometry-based approach to establish correspondence among different views. The expensive computational parts of the tracker are hardware accelerated via a novel system-on-chip (SoC design. In conjunction with this vision application, a hardware object request broker (ORB middleware is presented as the underlying communication system. The hardware ORB provides a hardware/software architecture to achieve real-time intercommunication among multiple smart cameras. Via a probing mechanism, a performance analysis is performed to measure network latencies, that is, time traversing the TCP/IP stack, in both software and hardware ORB approaches on the same smart camera platform. The empirical results show that using the proposed hardware ORB as client and server in separate smart camera nodes will considerably reduce the network latency up to 100 times compared to the software ORB.

Programming time-multiplexed reconfigurable hardware using a scalable neuromorphic compiler.

Science.gov (United States)

Minkovich, Kirill; Srinivasa, Narayan; Cruz-Albrecht, Jose M; Cho, Youngkwan; Nogin, Aleksey

2012-06-01

Scalability and connectivity are two key challenges in designing neuromorphic hardware that can match biological levels. In this paper, we describe a neuromorphic system architecture design that addresses an approach to meet these challenges using traditional complementary metal-oxide-semiconductor (CMOS) hardware. A key requirement in realizing such neural architectures in hardware is the ability to automatically configure the hardware to emulate any neural architecture or model. The focus for this paper is to describe the details of such a programmable front-end. This programmable front-end is composed of a neuromorphic compiler and a digital memory, and is designed based on the concept of synaptic time-multiplexing (STM). The neuromorphic compiler automatically translates any given neural architecture to hardware switch states and these states are stored in digital memory to enable desired neural architectures. STM enables our proposed architecture to address scalability and connectivity using traditional CMOS hardware. We describe the details of the proposed design and the programmable front-end, and provide examples to illustrate its capabilities. We also provide perspectives for future extensions and potential applications.

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Part 1, Overview of NUCLARR data retrieval: User's guide

International Nuclear Information System (INIS)

Gilmore, W.E.; Gentillon, C.D.; Gertman, D.I.; Beers, G.H.; Galyean, W.J.; Gilbert, B.G.

1988-06-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability and hardware component failure data. The NUCLARR system software resides on an IBM (or compatible) personal micro-computer. NUCLARR can be used by the end user to furnish data inputs for both human and hardware reliability analysis in support of a variety of risk assessment activities. The NUCLARR system is documented in a five-volume series of reports. Volume IV of this series is the User's Guide for operating the NUCLARR software and is presented in three parts. This document, Part 1: Overview of NUCLARR Data Retrieval provides an introductory overview to the system's capabilities and procedures for data retrieval. The methods and criteria for selection of data sources and entering them into the NUCLARR system are also described in this document

P3-approximation for gaseous media and vacuum

International Nuclear Information System (INIS)

Raevskaya, V.E.

1986-01-01

The problems connected with calculation of neutron field in a fuel assembly (FA) of a gas cooled reactor are discussed. The problem of P 3 -approximation applicability for the description of neutron fields in closed vacuum and gas volumes is considered. Under the assumption of the field azimuthal symmetry derived are the formulas for determination of the field in cylindrical vacuum layer of multizone FA as well as the solution for the cluster central zone, where the rods with vacuum between them are placed. Because of the finiteness of voids surrounded by medium it is possible to use the condition of neutron flux density continuity as the boundary conditions for the interface with vacuum. For representation of boundary conditions for rod surfaces and the cluster central zone with vacuum the addition theorems for the field in vacuum between the roads are derived. The formulas for mean neutron fluxes in vacuum cylindrical layer and in vacuum between rods are derived. The numerical calculations performed according to various programs confirmed the validity of the derived formulas

Progress in vacuum metal extraction, refining and consolidation

International Nuclear Information System (INIS)

Sundaram, C.V.; Mukherjee, T.K.; Sharma, B.P.

1973-01-01

The unique achievements in the process metallurgy of rare metals in the past quarter century should largely be attributed to advances in vacuum technology. New standards for high purity, increasing demand for pure metals and alloys for established applications, and steady improvement in sophistication and capacity of vacuum furnaces have provided the stimulus for developing and expanding vacuum metal extraction processes, and also exploring totally new processes. The paper discusses the thermochemistry of vacuum metallurgy, carbothermic and metallothermic reduction reactions, consolidation and refining by vacuum arc melting, electron beam melting and high temperature high vacuum sintering, and ultrapurification, with special reference to the reactive and refractory metals of Group IV to VI. (author)

Proof-Carrying Hardware: Concept and Prototype Tool Flow for Online Verification

OpenAIRE

Drzevitzky, Stephanie; Kastens, Uwe; Platzner, Marco

2010-01-01

Dynamically reconfigurable hardware combines hardware performance with software-like flexibility and finds increasing use in networked systems. The capability to load hardware modules at runtime provides these systems with an unparalleled degree of adaptivity but at the same time poses new challenges for security and safety. In this paper, we elaborate on the presentation of proof carrying hardware (PCH) as a novel approach to reconfigurable system security. PCH takes ...

Vacuum Energy and Inflation: 4. An Inflationary Universe

Science.gov (United States)

Huggins, Elisha

2013-01-01

This is the fourth paper in a series of four. The first paper in the series, "Vacuum Energy and Inflation: 1. A Liter of Vacuum Energy" [EJ1024183] discusses an example of vacuum energy. Vacuum energy is explained as an energy with a negative pressure whose energy density remains constant in an expanding space. Paper 2, "Vacuum…

At Home in Service Discovery

OpenAIRE

Sundramoorthy, V.

2006-01-01

Modern computer systems (since 1950s) evolved from being bulky, unreliable and expensive, to being tiny, reliable, cheaper and faster. Improvements in size, expense and performance was due to the evolution in computer hardware; from vacuum tubes, magnetic tapes, integrated circuits, to very large-scale integration (VLSI) of thousands of transistors and other circuit elements onto a single chip. The drop in cost and size led to the introduction of personal computers (PCs) for use in office, sc...

21 CFR 884.5070 - Vacuum abortion system.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vacuum abortion system. 884.5070 Section 884.5070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... § 884.5070 Vacuum abortion system. (a) Identification. A vacuum abortion system is a device designed to...

Vacuum compatibility of 3D-printed materials

OpenAIRE

Povilus, AP; Wurden, CJ; Vendeiro, Z; Baquero-Ruiz, M; Fajans, J

2014-01-01

The fabrication fidelity and vacuum properties are tested for currently available 3D-printed materials including polyamide, glass, acrylic, and sterling silver. The silver was the only material found to be suitable to ultrahigh vacuum environments due to outgassing and sublimation observed in other materials. © 2014 American Vacuum Society.

Ultra high vacuum technology

CERN Multimedia

CERN. Geneva

2001-01-01

A short introduction for some basic facts and equations. Subsquently, discussion about: Building blocks of an ultrahigh vacuum system - Various types of pumps required to reach uhv and methods to reduce these effects - Outgassing phenomena induced by the presence of a particle beam and the most common methods to reduce these effects It will be given some practical examples from existing CERN accelerators and discuss the novel features of the future LHC vacuum system.

A Planck Vacuum Cosmology

Directory of Open Access Journals (Sweden)

Daywitt W. C.

2009-04-01

Full Text Available Both the big-bang and the quasi-steady-state cosmologies originate in some type of Planck state. This paper presents a new cosmological theory based on the Planck- vacuum negative-energy state, a state consisting of a degenerate collection of negative- energy Planck particles. A heuristic look at the Einstein field equation provides a con- vincing argument that such a vacuum state could provide a theoretical explanation for the visible universe.

The localized quantum vacuum field

International Nuclear Information System (INIS)

Dragoman, D

2008-01-01

A model for the localized quantum vacuum is proposed in which the zero-point energy (ZPE) of the quantum electromagnetic field originates in energy- and momentum-conserving transitions of material systems from their ground state to an unstable state with negative energy. These transitions are accompanied by emissions and re-absorptions of real photons, which generate a localized quantum vacuum in the neighborhood of material systems. The model could help resolve the cosmological paradox associated with the ZPE of electromagnetic fields, while reclaiming quantum effects associated with quantum vacuum such as the Casimir effect and the Lamb shift. It also offers a new insight into the Zitterbewegung of material particles

The localized quantum vacuum field

Energy Technology Data Exchange (ETDEWEB)

Dragoman, D [Physics Department, University of Bucharest, PO Box MG-11, 077125 Bucharest (Romania)], E-mail: danieladragoman@yahoo.com

2008-03-15

A model for the localized quantum vacuum is proposed in which the zero-point energy (ZPE) of the quantum electromagnetic field originates in energy- and momentum-conserving transitions of material systems from their ground state to an unstable state with negative energy. These transitions are accompanied by emissions and re-absorptions of real photons, which generate a localized quantum vacuum in the neighborhood of material systems. The model could help resolve the cosmological paradox associated with the ZPE of electromagnetic fields, while reclaiming quantum effects associated with quantum vacuum such as the Casimir effect and the Lamb shift. It also offers a new insight into the Zitterbewegung of material particles.

Experimental tests of vacuum energy

CERN Multimedia

CERN. Geneva

2015-01-01

While the current vacuum energy of the Universe is very small, in our standard cosmological picture it has been much larger at earlier epochs. We try to address the question of what are possible ways to try to experimentally verify this. One direction is to look for systems where vacuum energy constitutes a non-negligible fraction of the total energy, and study the properties of those. Another possibility is to focus on the epochs around cosmic phase transitions, when the vacuum energy is of the same order as the total energy. Along these lines we investigate properties of neutron stars and the imprint of phase transitions on primordial gravitational waves.

Vacuum Technology for Superconducting Devices

Energy Technology Data Exchange (ETDEWEB)

Chiggiato, P [European Organization for Nuclear Research, Geneva (Switzerland)

2014-07-01

The basic notions of vacuum technology for superconducting applications are presented, with an emphasis on mass and heat transport in free molecular regimes. The working principles and practical details of turbomolecular pumps and cryopumps are introduced. The specific case of the Large Hadron Collider’s cryogenic vacuum system is briefly reviewed.

Highly reliable electro-hydraulic control system

International Nuclear Information System (INIS)

Mande, Morima; Hiyama, Hiroshi; Takahashi, Makoto

1984-01-01

The unscheduled shutdown of nuclear power stations disturbs power system, and exerts large influence on power generation cost due to the lowering of capacity ratio; therefore, high reliability is required for the control system of nuclear power stations. Toshiba Corp. has exerted effort to improve the reliability of the control system of power stations, and in this report, the electro-hydraulic control system for the turbines of nuclear power stations is described. The main functions of the electro-hydraulic control system are the control of main steam pressure with steam regulation valves and turbine bypass valves, the control of turbine speed and load, the prevention of turbine overspeed, the protection of turbines and so on. The system is composed of pressure sensors and a speed sensor, the control board containing the electronic circuits for control computation and protective sequence, the oil cylinders, servo valves and opening detectors of the valves for control, a high pressure oil hydraulic machine and piping, the operating panel and so on. The main features are the adoption of tripling intermediate value selection method, the multiplying of protection sensors and the adoption of 2 out of 3 trip logic, the multiplying of power sources, the improvement of the reliability of electronic circuit hardware and oil hydraulic system. (Kako, I.)

Compressed Air/Vacuum Transportation Techniques

Science.gov (United States)

Guha, Shyamal

2011-03-01

General theory of compressed air/vacuum transportation will be presented. In this transportation, a vehicle (such as an automobile or a rail car) is powered either by compressed air or by air at near vacuum pressure. Four version of such transportation is feasible. In all versions, a ``c-shaped'' plastic or ceramic pipe lies buried a few inches under the ground surface. This pipe carries compressed air or air at near vacuum pressure. In type I transportation, a vehicle draws compressed air (or vacuum) from this buried pipe. Using turbine or reciprocating air cylinder, mechanical power is generated from compressed air (or from vacuum). This mechanical power transferred to the wheels of an automobile (or a rail car) drives the vehicle. In type II-IV transportation techniques, a horizontal force is generated inside the plastic (or ceramic) pipe. A set of vertical and horizontal steel bars is used to transmit this force to the automobile on the road (or to a rail car on rail track). The proposed transportation system has following merits: virtually accident free; highly energy efficient; pollution free and it will not contribute to carbon dioxide emission. Some developmental work on this transportation will be needed before it can be used by the traveling public. The entire transportation system could be computer controlled.

Rising hopes for vacuum tube collectors

Energy Technology Data Exchange (ETDEWEB)

Godolphin, D.

1982-06-01

The performance, feasibility and use of vacuum tube solar collectors for domestic hot water (DHW) systems are discussed. An introduction to the design of vacuum tube collectors is presented and comparisons are made with flat plate collectors in terms of effectiveness in DHW applications and cost. The use of vacuum tube collectors is well established for high temperature use such as process heat and absorption cooling applications; there is considerable debate concerning their use in DHW and these arguments are presented. It is pointed out that the accepted standardized comparison test (ASHRAE 93-77) is apparently biased towards the flat plate collectors in direct comparisons of collector efficiencies. Recent developments among manufacturers with regard to vacuum tube collectors and their thinking (pro and con) are discussed in some detail. Breakage and other problems are pointed out although advocates look ahead to lower costs, higher efficiencies, and broader markets (particularly in DHW). It is concluded by some that flat plate collector technology has reached its peak and that vacuum tube collectors will be very prominent in the future. (MJJ)

Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers

Science.gov (United States)

Kim, Jae-Woo; Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

2014-02-01

Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10 000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm-2. The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices.

The VMTG Hardware Description

CERN Document Server

Puccio, B

1998-01-01

The document describes the hardware features of the CERN Master Timing Generator. This board is the common platform for the transmission of General Timing Machine required by the CERN accelerators. In addition, the paper shows the various jumper options to customise the card which is compliant to the VMEbus standard.

Investigating reliability attributes of silicon photovoltaic cells - An overview

Science.gov (United States)

Royal, E. L.

1982-01-01

Reliability attributes are being developed on a wide variety of advanced single-crystal silicon solar cells. Two separate investigations: cell-contact integrity (metal-to-silicon adherence), and cracked cells identified with fracture-strength-reducing flaws are discussed. In the cell-contact-integrity investigation, analysis of contact pull-strength data shows that cell types made with different metallization technologies, i.e., vacuum, plated, screen-printed and soldered, have appreciably different reliability attributes. In the second investigation, fracture strength was measured using Czochralski wafers and cells taken at various stages of processing and differences were noted. Fracture strength, which is believed to be governed by flaws introduced during wafer sawing, was observed to improve (increase) after chemical polishing and other process steps that tend to remove surface and edge flaws.

Dynamically-Loaded Hardware Libraries (HLL) Technology for Audio Applications

DEFF Research Database (Denmark)

Esposito, A.; Lomuscio, A.; Nunzio, L. Di

2016-01-01

In this work, we apply hardware acceleration to embedded systems running audio applications. We present a new framework, Dynamically-Loaded Hardware Libraries or HLL, to dynamically load hardware libraries on reconfigurable platforms (FPGAs). Provided a library of application-specific processors......, we load on-the-fly the specific processor in the FPGA, and we transfer the execution from the CPU to the FPGA-based accelerator. The proposed architecture provides excellent flexibility with respect to the different audio applications implemented, high quality audio, and an energy efficient solution....

[Ambulant treatment of wounds by vacuum sealing].

Science.gov (United States)

Ziegler, U E; Schmidt, K; Breithaupt, B; Menig, R; Debus, E S; Thiede, A

2000-01-01

The treatment of chronic wounds by vacuum sealing as an outpatient procedure is a new method of wound conditioning before closing the defect. The quality of life for the patient in his usual surrounding is maintained. Financial aspects also play a role in this treatment since costs for the health care system can be reduced. Various vacuum pumps, drainages and polymere foams are available and suitable for the outpatient treatment. The most important condition is to regularly check the vacuum. This can performed by the patient, the relatives or nursing staff. The main complication consists in loss of vacuum but technical and local or systemic complications can also appear. Individually applied vacuum dressings (polyvinyl foam, drainage tube and polymere foil) are practical. The ideal pump systems for the outpatient treatment are still not trial.

Vacuum chamber-free centrifuge with magnetic bearings.

Science.gov (United States)

Park, Cheol Hoon; Kim, Soohyun; Kim, Kyung-Soo

2013-09-01

Centrifuges are devices that separate particles of different densities and sizes through the application of a centrifugal force. If a centrifuge could be operated under atmospheric conditions, all vacuum-related components such as the vacuum chamber, vacuum pump, diffusion pump, and sealing could be removed from a conventional centrifuge system. The design and manufacturing procedure for centrifuges could then be greatly simplified to facilitate the production of lightweight centrifuge systems of smaller volume. Furthermore, the maintenance costs incurred owing to wear and tear due to conventional ball bearings would be eliminated. In this study, we describe a novel vacuum chamber-free centrifuge supported by magnetic bearings. We demonstrate the feasibility of the vacuum chamber-free centrifuge by presenting experimental results that verify its high-speed support capability and motoring power capacity.

Manufacture of superhigh vacuum testing tank

International Nuclear Information System (INIS)

Sakai, Kusuo; Suzui, Koichi; Horigome, Toshio

1981-01-01

This apparatus is one of the preliminary experiment equipments for the vacuum system of a UVSOR, and the main objective is to obtain the clean vacuum below 10 - 10 Torr. From the viewpoint of manufacture, there is no problem, but all the works from the design through manufacture, assembling and adjustment of the apparatus, to the obtaining of required vacuum were carried out by the authors themselves. The design and its points, and manufacture are described. In order to obtain clean vacuum and maintain it for long period, the surface cleaning of vacuum tanks is very important. Therefore the method of electrolytic polishing was adopted for the purpose, and its effectiveness was examined. After the surface treatment by two methods, the evacuation test was carried out, and the attained pressure was compared. Electrolytic polishing seemed to be effective. As the method of suppressing surface degasification, there is argon bombardment method. It was attempted to improve the pressure attained by baking only further by this method. By baking at 250 deg C for 30 hr only, the final pressure attained was 1.7 x 10 - 10 Torr, and by making argon bombardment twice during baking, it was 0.9 x 10 - 10 Torr, thus slight improvement was obtained. The main objective to obtain vacuum below 10 - 10 Torr was accomplished, but surface treatment requires more experience. (Kako, I.)

Vacuum strings in FRW models

Energy Technology Data Exchange (ETDEWEB)

Dyer, C C; Oattes, L M; Starkman, G D

1988-01-01

The authors find that vacuum string solutions cannot be embedded in an FRW model in the spirit of the swiss cheese model for inhomogeneities. Since all standard lensing calculations rely implicitly on the Swiss Cheese model, this result indicates that the previous lensing results for the vacuum string may be in error.

Procurement specification high vacuum test chamber and pumping system

International Nuclear Information System (INIS)

1976-01-01

The specification establishes requirements for a high-vacuum test chamber, associated vacuum pumps, valves, controls, and instrumentation that shall be designed and fabricated for use as a test chamber for testing a closed loop Brayton Isotope Power System (BIPS) Ground Demonstration System (GDS). The vacuum system shall include all instrumentation required for pressure measurement and control of the vacuum pumping system. A general outline of the BIPS-GDS in the vacuum chamber and the preliminary piping and instrumentation interface to the vacuum chamber are shown

Hardware Approach for Real Time Machine Stereo Vision

Directory of Open Access Journals (Sweden)

Michael Tornow

2006-02-01

Full Text Available Image processing is an effective tool for the analysis of optical sensor information for driver assistance systems and controlling of autonomous robots. Algorithms for image processing are often very complex and costly in terms of computation. In robotics and driver assistance systems, real-time processing is necessary. Signal processing algorithms must often be drastically modified so they can be implemented in the hardware. This task is especially difficult for continuous real-time processing at high speeds. This article describes a hardware-software co-design for a multi-object position sensor based on a stereophotogrammetric measuring method. In order to cover a large measuring area, an optimized algorithm based on an image pyramid is implemented in an FPGA as a parallel hardware solution for depth map calculation. Object recognition and tracking are then executed in real-time in a processor with help of software. For this task a statistical cluster method is used. Stabilization of the tracking is realized through use of a Kalman filter. Keywords: stereophotogrammetry, hardware-software co-design, FPGA, 3-d image analysis, real-time, clustering and tracking.

Hardware implementation of a GFSR pseudo-random number generator

Science.gov (United States)

Aiello, G. R.; Budinich, M.; Milotti, E.

1989-12-01

We describe the hardware implementation of a pseudo-random number generator of the "Generalized Feedback Shift Register" (GFSR) type. After brief theoretical considerations we describe two versions of the hardware, the tests done and the performances achieved.

ELETTRA vacuum system

International Nuclear Information System (INIS)

Bernardini, M.; Daclon, F.; Giacuzzo, F.; Miertusova, J.; Pradal, F.; Kersevan, R.

1993-01-01

Elettra is a third-generation synchrotron light source which is being built especially for the use of high brilliance radiation from insertion devices and bending magnets. The UHV conditions in a storage ring lead to a longer beam lifetime - one of the most important criterion. The Elettra vacuum system presents some pecularities which cannot be found in any already existing machine. The final version of bending magnet vacuum chamber is presented. After chemical and thermal conditioning the specific outgassing rate of about 1.5e-12 Torr. liters sec -1 cm -2 was obtained. A microprocessor-controlled system has been developed to perform bake-out at the uniform temperature. The etched-foil type heaters are glued to the chamber and Microtherm insulation is used. UHV pumps based on standard triode sputter-ion pumps were modified with ST 707 NEG (Non Evaporable Getter) modules. A special installation enables the resistive activation of getters and significantly increases pumping speed for hydrogen and other residual gases (except methane and argon). All these technological innovations improve vacuum conditions in Elettra storage ring and consequently also the other parameters of the light source

Performance evaluation on vacuum pumps using nanolubricants

Energy Technology Data Exchange (ETDEWEB)

Lue, Yeou Feng; Hsu, Yu Chun; Teng, Tun Ping [Dept. of Industrial EducationNational Taiwan Normal University, Taiwan (China)

2016-09-15

This study produced alumina (Al{sub 2}O{sub 3}) nanovacuum-pump lubricants (NVALs) by involving the dispersion of Al{sub 2}O{sub 3} nanoparticles in a vacuum-pump lubricant (VAL) with oleic as a dispersant. Experiments were conducted to evaluate the suspension performance, thermal conductivity, viscosity, specific heat, tribological performance and vacuum-pump performance of the NVALs. The experimental results obtained from the vacuum-pump performance tests show that the NVALs with Al{sub 2}O{sub 3} concentration of 0.2 wt.% and oleic concentration of 0.025 wt.% yielded the lowest electricity consumption, conserving 2.39% of electricity compared with the VAL. No marked difference was observed between the temperatures of the vacuum pump using VAL and NVAL. Furthermore, evacuation (i.e., the minimal pressure of -99.5 kPa) was reached faster by the vacuum pump with the NVALs, and the evacuation time could be reduced by 4.91% under optimal conditions. In addition, the vacuum pump with the NVALs exhibited superior overall effectiveness under relatively lower ambient temperatures.

Vacuum leak test technique of JT-60

International Nuclear Information System (INIS)

Kaminaga, Atsushi; Arai, Takashi; Kodama, Kozo; Sasaki, Noboru; Saidoh, Masahiro

1998-01-01

Since a vacuum vessel of JT-60 is very large (167 m 3 ) and is combined with many components, such as magnetic coils, neutral beam injection systems and RF heating systems, etc., the position of leak testing exceeds 700. The two kind of techniques for vacuum leak test used in JT-60 has been described. Firstly the probe helium gas can be fed remotely in the three-dimensionally sectioned 54 regions of the JT-60 torus. The leak test was very rapidly performed by using this method. Secondly the helium detector system has been modified by the additional installation of the cryopump, which reduced the background level of the deuterium gas. The sensitivity of vacuum leak test with the cryopump was two orders of magnitude larger than that of without it. The examples of the performed vacuum leak test are stated. The vacuum leaks during experiments were 9 times. They were caused by thermal strain and plasma discharge. The vacuum leaks just after maintenance are 36 times which mainly caused by mis-installation. (author)

Hardware Realization of Chaos Based Symmetric Image Encryption

KAUST Repository

Barakat, Mohamed L.

2012-06-01

This thesis presents a novel work on hardware realization of symmetric image encryption utilizing chaos based continuous systems as pseudo random number generators. Digital implementation of chaotic systems results in serious degradations in the dynamics of the system. Such defects are illuminated through a new technique of generalized post proceeding with very low hardware cost. The thesis further discusses two encryption algorithms designed and implemented as a block cipher and a stream cipher. The security of both systems is thoroughly analyzed and the performance is compared with other reported systems showing a superior results. Both systems are realized on Xilinx Vetrix-4 FPGA with a hardware and throughput performance surpassing known encryption systems.

Desenvolvimento de hardware reconfigurável de criptografia assimétrica

Directory of Open Access Journals (Sweden)

Otávio Souza Martins Gomes

2015-01-01

Full Text Available Este artigo apresenta o resultado parcial do desenvolvimento de uma interface de hardware reconfigurável para criptografia assimétrica que permite a troca segura de dados. Hardwares reconfiguráveis permitem o desenvolvimento deste tipo de dispositivo com segurança e flexibilidade e possibilitam a mudança de características no projeto com baixo custo e de forma rápida.Palavras-chave: Criptografia. Hardware. ElGamal. FPGA. Segurança. Development of an asymmetric cryptography reconfigurable harwadre ABSTRACTThis paper presents some conclusions and choices about the development of an asymmetric cryptography reconfigurable hardware interface to allow a safe data communication. Reconfigurable hardwares allows the development of this kind of device with safety and flexibility, and offer the possibility to change some features with low cost and in a fast way.Keywords: Cryptography. Hardware. ElGamal. FPGAs. Security.

MRI monitoring of focused ultrasound sonications near metallic hardware.

Science.gov (United States)

Weber, Hans; Ghanouni, Pejman; Pascal-Tenorio, Aurea; Pauly, Kim Butts; Hargreaves, Brian A

2018-07-01

To explore the temperature-induced signal change in two-dimensional multi-spectral imaging (2DMSI) for fast thermometry near metallic hardware to enable MR-guided focused ultrasound surgery (MRgFUS) in patients with implanted metallic hardware. 2DMSI was optimized for temperature sensitivity and applied to monitor focus ultrasound surgery (FUS) sonications near metallic hardware in phantoms and ex vivo porcine muscle tissue. Further, we evaluated its temperature sensitivity for in vivo muscle in patients without metallic hardware. In addition, we performed a comparison of temperature sensitivity between 2DMSI and conventional proton-resonance-frequency-shift (PRFS) thermometry at different distances from metal devices and different signal-to-noise ratios (SNR). 2DMSI thermometry enabled visualization of short ultrasound sonications near metallic hardware. Calibration using in vivo muscle yielded a constant temperature sensitivity for temperatures below 43 °C. For an off-resonance coverage of ± 6 kHz, we achieved a temperature sensitivity of 1.45%/K, resulting in a minimum detectable temperature change of ∼2.5 K for an SNR of 100 with a temporal resolution of 6 s per frame. The proposed 2DMSI thermometry has the potential to allow MR-guided FUS treatments of patients with metallic hardware and therefore expand its reach to a larger patient population. Magn Reson Med 80:259-271, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Vacuum Exhaust Process in Pilot-Scale Vacuum Pressure Swing Adsorption for Coal Mine Ventilation Air Methane Enrichment

Directory of Open Access Journals (Sweden)

Xiong Yang

2018-04-01

Full Text Available Recovery and treatment of methane from coal mine ventilation air methane (VAM with cost-effective technologies have been an ongoing challenge due to low methane concentrations. In this study, a type of coconut shell-based active carbon was employed to enrich VAM with a three-bed vacuum pressure swing adsorption unit. A new vacuum exhaust step for the VPSA process was introduced. The results show that the vacuum exhaust step can increase the methane concentration of the product without changing adsorption and desorption pressure. Under laboratory conditions, the concentration of product increased from 0.4% to 0.69% as the vacuum exhaust ratio increased from 0 to 3.1 when the feed gas concentration was 0.2%. A 500 m³/h pilot-scale test system for VAM enrichment was built rendering good correlation with the laboratory results in terms of the vacuum exhaust step. By using a two-stage three-bed separation unit, the VAM was enriched from 0.2% to over 1.2%.

Design of the ZTH vacuum liner

International Nuclear Information System (INIS)

Prince, P.P.; Dike, R.S.

1987-01-01

The current status of the ZTh vacuum liner design is covered by this report. ZTH will be the first experiment to be installed in the CPRF (Confinement Physics Research Facility) at the Los Alamos National Laboratory and is scheduled to be operational at the rated current of 4 MA in 1992. The vacuum vessel has a 2.4m major radius and a 40 cm minor radius. Operating parameters which drive the vacuum vessel mechanical design include a 300 C bakeout temperature, an armour support system capable of withstanding 25 kV, a high toroidal resistance, 1250 kPa magnetic loading, a 10 minute cycle time, and high positional accuracy with respect to the conducting shell. The vacuum vessel design features which satisfy the operating parameters are defined

Vacuum Alignment with more Flavors

DEFF Research Database (Denmark)

Ryttov, Thomas

2014-01-01

We study the alignment of the vacuum in gauge theories with $N_f$ Dirac fermions transforming according to a complex representation of the gauge group. The alignment of the vacuum is produced by adding a small mass perturbation to the theory. We study in detail the $N_f=2,3$ and $4$ case. For $N_...

Filling the vacuum at LHCb

CERN Multimedia

Katarina Anthony

2013-01-01

Last month, the Vacuum, Surfaces and Coatings (VSC) group was tasked with an unusually delicate operation in the LHCb experiment cavern: removing the LHC beam pipe while keeping the sensitive Vertex Locator vacuum vessel (VELO) completely isolated from the action.   The VSC group seal off the VELO beam pipe with a flange. Image: Gloria Corti. LHCb’s VELO detector is one of the crown jewels of the experiment. With detector elements surrounded by a vacuum, it gets as close as 5 cm from the beam. Fantastic for physics, but difficult for all-important access. “Because of the sensitivity of the VELO detector and its proximity to the beam, the collaboration decided not to bake (see box) its portion of the beam pipe,” says Giulia Lanza (TE-VSC-LBV), the expert in charge of the beam vacuum operation. “Our group was therefore asked to remove the rest of the LHC beam pipe while keeping the VELO portion of the pipe completely isolated. This work...

Engineering, maintenance, and new initiatives to improve LAMPF beam availability and system reliability

International Nuclear Information System (INIS)

Harris, H.W.; DeHaven, R.A.; Hart, V.E.; Parsons, W.M.; Sturrock, J.C.

1992-01-01

Two different requirements are driving engineering studies and hardware development to improve LAMPF. The first is concerned with component and system improvements to increase beam availability during the LAMPF production cycle. Hardware changes in RF, power supplies, and magnets are being implemented to increase mean time between failure and reduce time to replace or repair failed units. A joint LAMPF-Industry project is on-going to improve reliability of RF components. A component test stand is being refurbished to include significant development capability. The second approach includes several changes that will increase the duty factor of the existing accelerator. Major changes are being evaluated for replacing the front end of the accelerator. Other changes improving high brightness capability could result in a new performance plateau for LAMPF

Vacuum gauges

International Nuclear Information System (INIS)

Power, B.D.; Priestland, C.R.D.

1978-01-01

This invention relates to vacuum gauges, particularly of the type known as Penning gauges, which are cold cathode ionisation gauges, in which a magnetic field is used to lengthen the electron path and thereby increase the number of ions produced. (author)

Engineering, maintenance, and initiatives to improve LAMPF beam availability and system reliability

International Nuclear Information System (INIS)

Harris, H.W.; DeHaven, R.A.; Hart, V.E.; Parsons, W.M.; Sturrock, J.C.

1992-01-01

Two different requirements are driving engineering studies and hardware development to improve LAMPF. The first is concerned with component and system improvements to increase beam availability during the LAMPF production cycle. Hardware changes in RF, power supplies, and magnets are being implemented to increase mean time between failure and reduce time to replace or repair failed units. A joint LAMPF-Industry project is on-going to improve reliability of RF components. A component test stand is being refurbished to include significant development capability. The second approach includes several changes that will increase the duty factor of the existing accelerator. Major changes are being evaluated for replacing the front end of the accelerator. Other changes improving the high brightness capability could result in a new performance plateau for LAMPF. 2 refs., 2 figs

Maxwell electrodynamics subjected to quantum vacuum fluctuations

International Nuclear Information System (INIS)

Gevorkyan, A. S.; Gevorkyan, A. A.

2011-01-01

The propagation of electromagnetic waves in the vacuum is considered taking into account quantum fluctuations in the limits of Maxwell-Langevin (ML) equations. For a model of “white noise” fluctuations, using ML equations, a second order partial differential equation is found which describes the quantum distribution of virtual particles in vacuum. It is proved that in order to satisfy observed facts, the Lamb Shift etc, the virtual particles should be quantized in unperturbed vacuum. It is shown that the quantized virtual particles in toto (approximately 86 percent) are condensed on the “ground state” energy level. It is proved that the extension of Maxwell electrodynamics with inclusion of the vacuum quantum field fluctuations may be constructed on a 6D space-time continuum with a 2D compactified subspace. Their influence on the refraction indexes of vacuum is studied.

A new vacuum for loop quantum gravity

International Nuclear Information System (INIS)

Dittrich, Bianca; Geiller, Marc

2015-01-01

We construct a new vacuum and representation for loop quantum gravity. Because the new vacuum is based on BF theory, it is physical for (2+1)-dimensional gravity, and much closer to the spirit of spin foam quantization in general. To construct this new vacuum and the associated representation of quantum observables, we introduce a modified holonomy–flux algebra that is cylindrically consistent with respect to the notion of refinement by time evolution suggested in Dittrich and Steinhaus (2013 arXiv:1311.7565). This supports the proposal for a construction of the physical vacuum made in Dittrich and Steinhaus (2013 arXiv:1311.7565) and Dittrich (2012 New J. Phys. 14 123004), and for (3+1)-dimensional gravity. We expect that the vacuum introduced here will facilitate the extraction of large scale physics and cosmological predictions from loop quantum gravity. (fast track communication)

Detecting leaks in vacuum bags

Science.gov (United States)

Carlstrom, E. E.

1980-01-01

Small leaks in vacuum bag can be readily detected by eye, using simple chemical reaction: combination of ammonia and acetic acid vapors to produce cloudy white smoke. Technique has been successfully used to test seam integrity and to identify minute pinholes in vacuum bag used in assembly of ceramic-tile heat shield for Space Shuttle Orbiter.

Vacuum Technology for Ion Sources

International Nuclear Information System (INIS)

Chiggiato, P

2013-01-01

The basic notions of vacuum technology for ion sources are presented, with emphasis on pressure profile calculation and choice of pumping technique. A Monte Carlo code (Molflow+) for the evaluation of conductances and the vacuum-electrical analogy for the calculation of time-dependent pressure variations are introduced. The specific case of the Linac4 H - source is reviewed. (author)

The realm of the vacuum

International Nuclear Information System (INIS)

Buchholz, D.; Wanzenberg, R.

1992-01-01

The spacelike asymptotic structure of physical states in local quantum theory is analysed. It is shown that this structure can be described in terms of a vacuum state if the theory satisfies a condition of timelike asymptotic abelianess. Theories which violate this condition can have an involved asymptotic vacuum structure as is illustrated by a simple example. (orig.)

Trends in computer hardware and software.

Science.gov (United States)

Frankenfeld, F M

1993-04-01

Previously identified and current trends in the development of computer systems and in the use of computers for health care applications are reviewed. Trends identified in a 1982 article were increasing miniaturization and archival ability, increasing software costs, increasing software independence, user empowerment through new software technologies, shorter computer-system life cycles, and more rapid development and support of pharmaceutical services. Most of these trends continue today. Current trends in hardware and software include the increasing use of reduced instruction-set computing, migration to the UNIX operating system, the development of large software libraries, microprocessor-based smart terminals that allow remote validation of data, speech synthesis and recognition, application generators, fourth-generation languages, computer-aided software engineering, object-oriented technologies, and artificial intelligence. Current trends specific to pharmacy and hospitals are the withdrawal of vendors of hospital information systems from the pharmacy market, improved linkage of information systems within hospitals, and increased regulation by government. The computer industry and its products continue to undergo dynamic change. Software development continues to lag behind hardware, and its high cost is offsetting the savings provided by hardware.

An Embedded System for Safe, Secure and Reliable Execution of High Consequence Software

Energy Technology Data Exchange (ETDEWEB)

MCCOY,JAMES A.

2000-08-29

As more complex and functionally diverse requirements are placed on high consequence embedded applications, ensuring safe and secure operation requires an execution environment that is ultra reliable from a system viewpoint. In many cases the safety and security of the system depends upon the reliable cooperation between the hardware and the software to meet real-time system throughput requirements. The selection of a microprocessor and its associated development environment for an embedded application has the most far-reaching effects on the development and production of the system than any other element in the design. The effects of this choice ripple through the remainder of the hardware design and profoundly affect the entire software development process. While state-of-the-art software engineering principles indicate that an object oriented (OO) methodology provides a superior development environment, traditional programming languages available for microprocessors targeted for deeply embedded applications do not directly support OO techniques. Furthermore, the microprocessors themselves do not typically support nor do they enforce an OO environment. This paper describes a system level approach for the design of a microprocessor intended for use in deeply embedded high consequence applications that both supports and enforces an OO execution environment.

RELATION BETWEEN FUNCTION AND FORM IN VACUUM CLEANERS DESIGN

Directory of Open Access Journals (Sweden)

RADU Ștefan

2015-11-01

Full Text Available The paper analyses how robotic vacuum cleaner works, describing their cleaning capabilities and additional features. The paper illustrates advantages of using robotic vacuum cleaners that have intelligent programming and a vacuum cleaning system, the components of a robotic vacuum cleaner. The paper develops aspects concerning to create 2D scale models for the evaluation of specific features of the new components for a prototype robotic vacuum cleaner.

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Data manual. Part 2: Human error probability (HEP) data; Volume 5, Revision 4

Energy Technology Data Exchange (ETDEWEB)

Reece, W.J.; Gilbert, B.G.; Richards, R.E. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

1994-09-01

This data manual contains a hard copy of the information in the Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) Version 3.5 database, which is sponsored by the US Nuclear Regulatory Commission. NUCLARR was designed as a tool for risk analysis. Many of the nuclear reactors in the US and several outside the US are represented in the NUCLARR database. NUCLARR includes both human error probability estimates for workers at the plants and hardware failure data for nuclear reactor equipment. Aggregations of these data yield valuable reliability estimates for probabilistic risk assessments and human reliability analyses. The data manual is organized to permit manual searches of the information if the computerized version is not available. Originally, the manual was published in three parts. In this revision the introductory material located in the original Part 1 has been incorporated into the text of Parts 2 and 3. The user can now find introductory material either in the original Part 1, or in Parts 2 and 3 as revised. Part 2 contains the human error probability data, and Part 3, the hardware component reliability data.

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Data manual. Part 2: Human error probability (HEP) data; Volume 5, Revision 4

International Nuclear Information System (INIS)

Reece, W.J.; Gilbert, B.G.; Richards, R.E.

1994-09-01

This data manual contains a hard copy of the information in the Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) Version 3.5 database, which is sponsored by the US Nuclear Regulatory Commission. NUCLARR was designed as a tool for risk analysis. Many of the nuclear reactors in the US and several outside the US are represented in the NUCLARR database. NUCLARR includes both human error probability estimates for workers at the plants and hardware failure data for nuclear reactor equipment. Aggregations of these data yield valuable reliability estimates for probabilistic risk assessments and human reliability analyses. The data manual is organized to permit manual searches of the information if the computerized version is not available. Originally, the manual was published in three parts. In this revision the introductory material located in the original Part 1 has been incorporated into the text of Parts 2 and 3. The user can now find introductory material either in the original Part 1, or in Parts 2 and 3 as revised. Part 2 contains the human error probability data, and Part 3, the hardware component reliability data