Data of evolutionary structure change: 1AKMC-9ATCA [Confc[Archive

Lifescience Database Archive (English)

Full Text Available 1AKMC-9ATCA 1AKM 9ATC C A -SGFYHKHFLKLLDFTPAELNSLLQLAAKLKADKKSGKEEAKLTGKNIALIFEKDSTRTRCSFEVAAYDQGARVTYLG--PSGSQIGHKESIK... 9ATC A 9ATCA... 9ATC A 9ATCA LAKFDG...del> 2 9ATC A 9ATCA...>A 9ATCA QETQG--RLDNL

Development of high-availability ATCA/PCIe data acquisition instrumentation

Energy Technology Data Exchange (ETDEWEB)

Correia, Miguel; Sousa, Jorge; Batista, Antonio J.N.; Combo, Alvaro; Santos, Bruno; Rodrigues, Antonio P.; Carvalho, Paulo F.; Goncalves, Bruno [Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, 1049- 001 Lisboa (Portugal); Correia, Carlos M.B.A. [Centro de Instrumentacao, Dept. de Fisica, Universidade de Coimbra, 3004-516 Coimbra (Portugal)

2015-07-01

Latest Fusion energy experiments envision a quasi-continuous operation regime. In consequence, the largest experimental devices, currently in development, specify high-availability (HA) requirements for the whole plant infrastructure. HA features enable the whole facility to perform seamlessly in the case of failure of any of its components, coping with the increasing duration of plasma discharges (steady-state) and assuring safety of equipment, people, environment and investment. IPFN developed a control and data acquisition system, aiming for fast control of advanced Fusion devices, which is thus required to provide such HA features. The system is based on in-house developed Advanced Telecommunication Computing Architecture (ATCA) instrumentation modules - IO blades and data switch blades, establishing a PCIe network on the ATCA shelf's back-plane. The data switch communicates to an external host computer through a PCIe data network. At the hardware management level, the system architecture takes advantage of ATCA native redundancy and hot swap specifications to implement fail-over substitution of IO or data switch blades. A redundant host scheme is also supported by the ATCA/PCIe platform. At the software level, PCIe provides implementation of hot plug services, which translate the hardware changes to the corresponding software/operating system devices. The paper presents how the ATCA and PCIe based system can be setup to perform with the desired degree of HA, thus being suitable for advanced Fusion control and data acquisition systems. (authors)

Development of high-availability ATCA/PCIe data acquisition instrumentation

International Nuclear Information System (INIS)

Correia, Miguel; Sousa, Jorge; Batista, Antonio J.N.; Combo, Alvaro; Santos, Bruno; Rodrigues, Antonio P.; Carvalho, Paulo F.; Goncalves, Bruno; Correia, Carlos M.B.A.

2015-01-01

Latest Fusion energy experiments envision a quasi-continuous operation regime. In consequence, the largest experimental devices, currently in development, specify high-availability (HA) requirements for the whole plant infrastructure. HA features enable the whole facility to perform seamlessly in the case of failure of any of its components, coping with the increasing duration of plasma discharges (steady-state) and assuring safety of equipment, people, environment and investment. IPFN developed a control and data acquisition system, aiming for fast control of advanced Fusion devices, which is thus required to provide such HA features. The system is based on in-house developed Advanced Telecommunication Computing Architecture (ATCA) instrumentation modules - IO blades and data switch blades, establishing a PCIe network on the ATCA shelf's back-plane. The data switch communicates to an external host computer through a PCIe data network. At the hardware management level, the system architecture takes advantage of ATCA native redundancy and hot swap specifications to implement fail-over substitution of IO or data switch blades. A redundant host scheme is also supported by the ATCA/PCIe platform. At the software level, PCIe provides implementation of hot plug services, which translate the hardware changes to the corresponding software/operating system devices. The paper presents how the ATCA and PCIe based system can be setup to perform with the desired degree of HA, thus being suitable for advanced Fusion control and data acquisition systems. (authors)

Development of prototype digital LLRF system at RRCAT

International Nuclear Information System (INIS)

Tiwari, Nitesh; Bagduwal, Pritam S.; Sharma, Dheeraj; Chakraborty, Shoubhik; Lad, Mahendra; Hannurkar, P.R.

2013-01-01

RF field is used in accelerator to accelerate the charge particles. The beam parameters depend highly on the stability of the RF field. Due to dynamic beam loading conditions the variations in RF parameters of accelerating structures needs to be controlled precisely, hence low level RF feedback control system plays vital role. Considering revolutionary development in the field of digital electronics and inherent advantages of digital systems, digital LLRF control system work was taken up. The digital LLRF system consists of two major units namely RF processing and digital processing. RF processing unit uses I/Q modulator for amplitude and phase control. This unit provides synchronized clock using ÷16 pre-scalar and also performs up conversion and down conversion for synchronized LO and IF generation respectively, along with required amplification and filtering. Digital processing unit takes down converted IF signal with appropriate sampling rate for I/Q detection. To extract the amplitude and phase information I/Q data is digitally filtered and processed using CORDIC algorithm in FPGA. I/Q modulator is used for controlling the amplitude and phase of RF field. Prototype development of digital LLRF control system for 325 MHz, 650 MHz is in progress. Digital LLRF system at 505 MHz has been installed in one RF station of Indus-2 RF system. In this paper development of prototype Digital LLRF system at RFSD, Raja Ramanna Centre for Advanced Technology and results are presented. (author)

13 CFR 120.847 - Requirements for the Loan Loss Reserve Fund (LLRF).

Science.gov (United States)

2010-01-01

... Requirements for the Loan Loss Reserve Fund (LLRF). (a) General. PCLP CDCs must establish and maintain a LLRF... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Requirements for the Loan Loss Reserve Fund (LLRF). 120.847 Section 120.847 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION...

Design and development progress of a LLRF control system for a 500 MHz superconducting cavity

Science.gov (United States)

Lee, Y. S.; Kim, H. W.; Song, H. S.; Lee, J. H.; Park, K. H.; Yu, I. H.; Chai, J. S.

2012-07-01

The LLRF (low-level radio-frequency) control system which regulates the amplitude and the phase of the accelerating voltage inside a RF cavity is essential to ensure the stable operation of charged particle accelerators. Recent advances in digital signal processors and data acquisition systems have allowed the LLRF control system to be implemented in digitally and have made it possible to meet the higher demands associated with the performance of LLRF control systems, such as stability, accuracy, etc. For this reason, many accelerator laboratories have completed or are completing the developments of digital LLRF control systems. The digital LLRF control system has advantages related with flexibility and fast reconfiguration. This paper describes the design of the FPGA (field programmable gate array) based LLRF control system and the status of development for this system. The proposed LLRF control system includes an analog front-end, a digital board (ADC (analog to digital converter), DAC (digital to analog converter), FPGA, etc.) and a RF & clock generation system. The control algorithms will be implemented by using the VHDL (VHSIC (very high speed integrated circuits) hardware description language), and the EPICS (experiment physics and industrial control system) will be ported to the host computer for the communication. In addition, the purpose of this system is to control a 500 MHz RF cavity, so the system will be applied to the superconducting cavity to be installed in the PLS storage ring, and its performance will be tested.

Commissioning and performance of the BNL EBIS LLRF system

International Nuclear Information System (INIS)

Yuan, S.; Smith, K.S.; Hayes, T.; Severino, F.; Harvey, M.; Narayan, G.; Zaltsman, A.

2011-01-01

The Electron Beam Ion Source (EBIS) LLRF system utilizes the RHIC LLRF upgrade platform to achieve the required functionality and flexibility. The LLRF system provides drive to the EBIS high-level RF system, employs I-Q feedback to provide required amplitude and phase stability, and implements a cavity resonance control scheme. The embedded system provides the interface to the existing Controls System, making remote system control and diagnostics possible. The flexibility of the system allows us to reuse VHDL codes, develop new functionalities, improve current designs, and implement new features with relative ease. In this paper, we will discuss the commissioning process, issues encountered, and performance of the system.

Commissioning and performance of the BNL EBIS LLRF system

Energy Technology Data Exchange (ETDEWEB)

Yuan, S.; Smith, K.S.; Hayes, T.; Severino, F.; Harvey, M.; Narayan, G.; Zaltsman, A.

2011-03-28

The Electron Beam Ion Source (EBIS) LLRF system utilizes the RHIC LLRF upgrade platform to achieve the required functionality and flexibility. The LLRF system provides drive to the EBIS high-level RF system, employs I-Q feedback to provide required amplitude and phase stability, and implements a cavity resonance control scheme. The embedded system provides the interface to the existing Controls System, making remote system control and diagnostics possible. The flexibility of the system allows us to reuse VHDL codes, develop new functionalities, improve current designs, and implement new features with relative ease. In this paper, we will discuss the commissioning process, issues encountered, and performance of the system.

Development of an ATCA IPMI controller mezzanine board to be used in the ATCA developments for the ATLAS Liquid Argon upgrade

CERN Document Server

Dumont Dayot, N

2012-01-01

In the context of the LHC upgrades, a new Read-Out Driver (ROD) board for the ATLAS LAr calorimeter is being developed. xTCA (Advanced/Micro Telecom Computing Architecture) is becoming a standard in high energy physics and is a serious candidate for future readout systems. We will present our current developments to master ATCA and to integrate a large number of very high speed links (96 links/8.5 Gbps) on a ROD Evaluator ATCA board. To manage our ROD Evaluator, we have developed a versatile ATCA IPMI controller for ATCA boards which is FPGA Mezzanine Card (FMC) compliant.

Development of an ATCA IPMI Controller Mezzanine Board to be used in the ATCA developments for the ATLAS Liquid Argon upgrade

CERN Document Server

"LETENDRE, N; The ATLAS collaboration

2011-01-01

In the context of the LHC upgrades, a new Read-Out Driver (ROD) board for the ATLAS LAr calorimeter is being developed. xTCA (Advanced/Micro Telecom Computing Architecture) is becoming a standard in high energy physics and is a serious candidate for future readout systems. We will present our current developments to master ATCA and to integrate a large number of very high speed links (96 links/8.5 Gbps) on a ROD Evaluator ATCA board. To manage our ROD Evaluator, we have developed a versatile ATCA IPMI controller for ATCA boards which is FPGA Mezzanine Card (FMC) compliant.

CERN's PS Booster LLRF renovation : plans and initial beam tests

CERN Document Server

Angoletta, ME; Butterworth, A; Findlay, A; Leinonen, PM; Molendijk, JC; Pedersen, F; Sanchez-Quesada, J; Schokker, M

2010-01-01

In 2008 a project was started to renovate the CERN's PS Booster (PSB) low-level RF (LLRF). Required LLRF capabilities include frequency program, beam phase, radial and synchronization loops. The new LLRF will control the signals feeding the three RF cavities present in each ring; it will also shape the beam in a dual harmonic mode, operate a bunch splitting and create a longitudinal blow-up. The main benefits of this new LLRF are its full remote and cycle-to-cycle controllability, built-in observation capability and flexibility. The overall aim is to improve the robustness, maintainability and reliability of the PSB operation and to make it compatible with the injection from the future Linac4. This paper outlines the main characteristics of the software and hardware building blocks. Initial beam test results and hints on the main milestones and future work are also given.

Data of evolutionary structure change: 1AKMA-2ATCA [Confc[Archive

Lifescience Database Archive (English)

Full Text Available 1AKMA-2ATCA 1AKM 2ATC A A -SGFYHKHFLKLLDFTPAELNSLLQLAAKLKADKKSGKEEAKLTGKNIALIFEKDSTRTRCSFEVAAYDQGARVTYLGPSG--SQIGHKESIK.../line> HIS CA 158 2ATC A 2ATCA...>2ATC A 2ATCA A 2ATCA GDLKYGRTVHS ARG CA 481 2ATC A

A hardware overview of the RHIC LLRF platform

International Nuclear Information System (INIS)

Hayes, T.; Smith, K.S.

2011-01-01

The RHIC Low Level RF (LLRF) platform is a flexible, modular system designed around a carrier board with six XMC daughter sites. The carrier board features a Xilinx FPGA with an embedded, hard core Power PC that is remotely reconfigurable. It serves as a front end computer (FEC) that interfaces with the RHIC control system. The carrier provides high speed serial data paths to each daughter site and between daughter sites as well as four generic external fiber optic links. It also distributes low noise clocks and serial data links to all daughter sites and monitors temperature, voltage and current. To date, two XMC cards have been designed: a four channel high speed ADC and a four channel high speed DAC. The new LLRF hardware was used to replace the old RHIC LLRF system for the 2009 run. For the 2010 run, the RHIC RF system operation was dramatically changed with the introduction of accelerating both beams in a new, common cavity instead of each ring having independent cavities. The flexibility of the new system was beneficial in allowing the low level system to be adapted to support this new configuration. This hardware was also used in 2009 to provide LLRF for the newly commissioned Electron Beam Ion Source.

Development of an ATCA IPMI Controller Mezzanine Board and its usage on an ATCA ROD Evaluator board for the ATLAS LAr upgrade

CERN Document Server

"DUMONT DAYOT, N; The ATLAS collaboration; "CAP, S; "DUMONT DAYOT, N; "FOURNIER, L; "LETENDRE, N; "PERROT, G; "Wingerter, I

2011-01-01

In the context of the LHC upgrades, a new Read-Out Driver (ROD) board for the ATLAS LAr calorimeter is being developed. xTCA (Advanced/Micro Telecom Computing Architecture) is becoming a standard in high energy physics and is a serious candidate for future readout systems. We will present our current developments to master ATCA and to integrate a large number of very high speed links (96 links/8.5 Gbps) on a ROD Evaluator ATCA board. To manage our ROD Evaluator, we have developed a versatile ATCA IPMI controller for ATCA boards which is FPGA Mezzanine Card (FMC) compliant.

Digital control in LLRF system for CYCIAE-100 cyclotron

Energy Technology Data Exchange (ETDEWEB)

Yin, Zhiguo, E-mail: bitbearAT@hotmail.com; Fu, Xiaoliang; Ji, Bin; Zhang, Tianjue; Wang, Chuan

2016-05-21

As a driven accelerator, the CYCIAE-100 cyclotron is designed by China Institute of Atomic Energy for the Beijing Radio Ion-beam Facility project. The cyclotron RF system is designed to use two RF power sources of 100 kW to drive two half-wavelength cavities respectively. Two Dee accelerating electrodes are kept separately from each other inside the cyclotron, while their accelerating voltages are maintained in phase by the efforts of LLRF control. An analog–digital hybrid LLRF system has been developed to achieve cavity tuning control, dee voltage amplitude and phase stabilization etc. The analog subsystems designs are focused on RF signal up/down conversion, tuning control, and dee voltage regulation. The digital system provides an RF signal source, aligns the cavity phases and maintains a Finite State Machine. The digital parts combine with the analog functions to provide the LLRF control. A brief system hardware introduction will be given in this paper, followed by the review of several major characteristics of the digital control in the 100 MeV cyclotron LLRF system. The commissioning is also introduced, and most of the optimization during the process was done by changing the digital parts.

The ITER Fast Plant System Controller ATCA prototype Real-Time Software Architecture

International Nuclear Information System (INIS)

Carvalho, B.B.; Santos, B.; Carvalho, P.F.; Neto, A.; Boncagni, L.; Batista, A.J.N.; Correia, M.; Sousa, J.; Gonçalves, B.

2013-01-01

Highlights: ► High performance ATCA systems for fast control and data acquisition. ► IEEE1588 timing system and synchronization. ► Plasma control algorithms. ► Real-time control software frameworks. ► Targeted for nuclear fusion experiments with long duration discharges. -- Abstract: IPFN is developing a prototype Fast Plant System Controller (FPSC) based in ATCA embedded technologies dedicated to ITER CODAC data acquisition and control tasks in the sub-millisecond range. The main goal is to demonstrate the usability of the ATCA standard and its enhanced specifications for the high speed, very high density parallel data acquisition needs of the most demanding ITER tokamak plasma Instrumentation and Control (I and C) systems. This effort included the in-house development of a new family of high performance ATCA I/O and timing boards. The standard ITER software system CODAC Core System (CCS) v3.1, with the control based in the EPICS system does not cover yet the real-time requirements fulfilled by this hardware, so a new set of software components was developed for this specific platform, attempting to integrate and leverage the new features in CSS, for example the Multithreaded Application Real Time executor (MARTe) software framework, the new Data Archiving Network (DAN) solution, an ATCA IEEE-1588-2008 timing interface, and the Intelligent Platform Management Interface (IPMI) for system monitoring and remote management. This paper presents the overall software architecture for the ATCA FPSC, as well a discussion on the ITER constrains and design choices and finally a detailed description of the software components already developed

The ITER Fast Plant System Controller ATCA prototype Real-Time Software Architecture

Energy Technology Data Exchange (ETDEWEB)

Carvalho, B.B., E-mail: bernardo@ipfn.ist.utl.pt [Associacao EURATOM/IST Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, P-1049-001 Lisboa (Portugal); Santos, B.; Carvalho, P.F.; Neto, A. [Associacao EURATOM/IST Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, P-1049-001 Lisboa (Portugal); Boncagni, L. [Associazione Euratom-ENEA sulla Fusione, Frascati Research Centre, Division of Fusion Physics, Frascati, Rome (Italy); Batista, A.J.N.; Correia, M.; Sousa, J.; Gonçalves, B. [Associacao EURATOM/IST Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, P-1049-001 Lisboa (Portugal)

2013-10-15

Highlights: ► High performance ATCA systems for fast control and data acquisition. ► IEEE1588 timing system and synchronization. ► Plasma control algorithms. ► Real-time control software frameworks. ► Targeted for nuclear fusion experiments with long duration discharges. -- Abstract: IPFN is developing a prototype Fast Plant System Controller (FPSC) based in ATCA embedded technologies dedicated to ITER CODAC data acquisition and control tasks in the sub-millisecond range. The main goal is to demonstrate the usability of the ATCA standard and its enhanced specifications for the high speed, very high density parallel data acquisition needs of the most demanding ITER tokamak plasma Instrumentation and Control (I and C) systems. This effort included the in-house development of a new family of high performance ATCA I/O and timing boards. The standard ITER software system CODAC Core System (CCS) v3.1, with the control based in the EPICS system does not cover yet the real-time requirements fulfilled by this hardware, so a new set of software components was developed for this specific platform, attempting to integrate and leverage the new features in CSS, for example the Multithreaded Application Real Time executor (MARTe) software framework, the new Data Archiving Network (DAN) solution, an ATCA IEEE-1588-2008 timing interface, and the Intelligent Platform Management Interface (IPMI) for system monitoring and remote management. This paper presents the overall software architecture for the ATCA FPSC, as well a discussion on the ITER constrains and design choices and finally a detailed description of the software components already developed.

Data of evolutionary structure change: 1A1SA-2ATCA [Confc[Archive

Lifescience Database Archive (English)

Full Text Available 1A1SA-2ATCA 1A1S 2ATC A A VVSLAGRDLLCLQDYTAEEIWTILETAKMFKIWQKIGKP...entryChain> 2ATC A 2ATCA TEFSGNVP...entryChain> 2ATC A 2ATCA MVGDLKYG...ntryChain> 2ATC A 2ATCA ALAKFDGNR...VID> 3 2ATC A 2ATCA

APT LLRF control system functionality and architecture

International Nuclear Information System (INIS)

Regan, A.H.; Rohlev, A.S.; Ziomek, C.D.

1996-01-01

The low-level RF (LLRF) control system for the Accelerator Production of Tritium (APT) will perform various functions. Foremost is the feedback control of the accelerating fields within the cavity in order to maintain field stability within ± 1% amplitude and 1 degree phase. The feedback control system requires a phase-stable RF reference subsystem signal to correctly phase each cavity. Also, instead of a single klystron RF source for individual accelerating cavities, multiple klystrons will drive a string of resonantly coupled cavities, based on input from a single LLRF feedback control system. To achieve maximum source efficiency, we will be employing single fast feedback controls around individual klystrons such that the gain and phase characteristics of each will be 'identical'. In addition, the resonance condition of the cavities is monitored and maintained. To quickly respond to RF shutdowns, and hence rapid accelerating cavity cool-down, due to RF fault conditions, drive frequency agility in the main feedback control subsystem will also be incorporated. Top level block diagrams will be presented and described as they will first be developed and demonstrated on the Low Energy Demonstrator Accelerator (LEDA). (author)

EPICS device support module as ATCA system manager for the ITER fast plant system controller

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Paulo F., E-mail: pricardofc@ipfn.ist.utl.pt [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico – Universidade Técnica de Lisboa, Lisboa (Portugal); Santos, Bruno; Gonçalves, Bruno; Carvalho, Bernardo B.; Sousa, Jorge; Rodrigues, A.P.; Batista, António J.N.; Correia, Miguel; Combo, Álvaro [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico – Universidade Técnica de Lisboa, Lisboa (Portugal); Correia, Carlos M.B.A. [Centro de Instrumentação, Departamento de Física, Universidade de Coimbra, Coimbra (Portugal); Varandas, Carlos A.F. [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico – Universidade Técnica de Lisboa, Lisboa (Portugal)

2013-10-15

Highlights: ► In Nuclear Fusion, demanding security and high-availability requirements call for redundancy to be available. ► ATCA based Nuclear Fusion Systems are composed by several electronic and mechanical component. ► Control and monitoring of ATCA electronic systems are recommended. ► ITER Fast Plant System Controller Project CODAC system prototype. ► EPICS device support module as External ATCA system manager solution. -- Abstract: This paper presents an Enhanced Physics and Industrial Control System (EPICS) device support module for the International Thermonuclear Experimental Reactor (ITER) Fast Plant System Controller (FPSC) project based in Advanced Telecommunications Computing Architecture (ATCA) specification. The developed EPICS device support module provides an External System Manager (ESM) solution for monitoring and control the ITER FPSC ATCA shelf system and data acquisition boards in order to take proper action and report problems to a control room operator or high level management unit in case of any system failure occurrence. EPICS device support module acts as a Channel Access (CA) server to report problems and publish ATCA system data information to the control room operator, high level management unit or other CA network clients such as Control System Studio Operator Interfaces (CSS OPIs), Best Ever Alarm System Toolkit (BEAST), Best Ever Archive Utility (BEAUTY) or other CA client applications. EPICS device support module communicates with the ATCA Shelf manager (ShM) using HTTP protocol to send and receive commands through POST method in order to get and set system and shelf components properties such as fan speeds measurements, temperatures readings, module status and ATCA boards acquisition and configuration parameters. All system properties, states, commands and parameters are available through the EPICS device support module CA server in EPICS Process Variables (PV) and signals format. ATCA ShM receives the HTTP protocol

ATCA - thermal management study for the ATLAS phase II upgrades

OpenAIRE

Bortolin, Claudio; Dyngosz, Damian; Kalinowski, Michal; Koziol, Piotr; Mendez, Julian; Walerianczyk, Jan; Zwalinski, Lukasz

2017-01-01

The AdvancedTCA (ATCA) telecom industry standard has been selected as the hardware platform for the “Phase-II Upgrade” of ATLAS at the Large Hadron Collider (LHC) at CERN. In November 2014 a project dedicated to the study of the impact of the ATCA integration in the actual counting rooms was launched analysing the impact on the cooling infrastructures. A spare rack equipped with two ATCA shelves, high power dissipating load blades, temperature and air velocity sensors were installed in a lab....

ATCA digital controller hardware for vertical stabilization of plasmas in tokamaks

International Nuclear Information System (INIS)

Batista, A. J. N.; Sousa, J.; Varandas, C. A. F.

2006-01-01

The efficient vertical stabilization (VS) of plasmas in tokamaks requires a fast reaction of the VS controller, for example, after detection of edge localized modes (ELM). For controlling the effects of very large ELMs a new digital control hardware, based on the Advanced Telecommunications Computing Architecture trade mark sign (ATCA), is being developed aiming to reduce the VS digital control loop cycle (down to an optimal value of 10 μs) and improve the algorithm performance. The system has 1 ATCA trade mark sign processor module and up to 12 ATCA trade mark sign control modules, each one with 32 analog input channels (12 bit resolution), 4 analog output channels (12 bit resolution), and 8 digital input/output channels. The Aurora trade mark sign and PCI Express trade mark sign communication protocols will be used for data transport, between modules, with expected latencies below 2 μs. Control algorithms are implemented on a ix86 based processor with 6 Gflops and on field programmable gate arrays with 80 GMACS, interconnected by serial gigabit links in a full mesh topology

Communication system of LLRF based on SOPC of Nios Ⅱ softcore: design and performance

International Nuclear Information System (INIS)

Zhang He; Wang Fang; Qiu Feng; Wang Qunyao; Sha Peng

2011-01-01

DC-SC photocathode injector at Peking University and 9 cell superconducting cavity at Institute of High Energy Physics have both adopted digital LLRF control system, in which communication system based on STRATIX Ⅳ series FPGA development Kit. Through the System-on-a-Programmable-Chip (SOPC) technology and the development environment provided by NIOS Ⅱ IDE, It realized communication function with Tri-State Ethernet. The interface created by Labview has been used to set the parameters and get data. After repeating tests, the communication system has been running well all through. (authors)

LHC and CLIC LLRF final reports

CERN Document Server

Dexter, A; Woolley, B; Ambattu, P; Tahir, I; Syratchev, Igor; Wuensch, Walter

2013-01-01

Crab cavities rotate bunches from opposing beams to achieve effective head-on collision in CLIC or collisions at an adjustable angle in LHC. Without crab cavities 90% of achievable luminosity at CLIC would be lost. In the LHC, the crab cavities allow the same or larger integrated luminosity while reducing significantly the requested dynamic range of physics detectors. The focus for CLIC is accurate phase synchronisation of the cavities, adequate damping of wakefields and modest amplitude stability. For the LHC, the main LLRF issues are related to imperfections: beam offsets in cavities, RF noise, measurement noise in feedback loops, failure modes and mitigations. This report develops issues associated with synchronising the CLIC cavities. It defines an RF system and experiments to validate the approach. It reports on the development of hardware for measuring the phase performance of the RF distributions system and cavities. For the LHC, the hardware being very close to the existing LLRF, the report focuses on...

N + 1 redundancy on ATCA instrumentation for Nuclear Fusion

Energy Technology Data Exchange (ETDEWEB)

Correia, Miguel, E-mail: miguelfc@ipfn.ist.utl.pt [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico – Universidade Técnica de Lisboa, Lisboa (Portugal); Sousa, Jorge; Rodrigues, António P.; Batista, António J.N.; Combo, Álvaro; Carvalho, Bernardo B.; Santos, Bruno; Carvalho, Paulo F.; Gonçalves, Bruno [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico – Universidade Técnica de Lisboa, Lisboa (Portugal); Correia, Carlos M.B.A. [Centro de Instrumentação, Departamento de Física, Universidade de Coimbra, Coimbra (Portugal); Varandas, Carlos A.F. [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico – Universidade Técnica de Lisboa, Lisboa (Portugal)

2013-10-15

Highlights: ► In Nuclear Fusion, demanding security and high-availability requirements call for redundancy to be available. ► ATCA standard features desirable redundancy features for Fusion instrumentation. ► The developed control and data acquisition hardware modules support additional redundancy schemes. ► Implementation of N + 1 redundancy of host processor and I/O data modules. -- Abstract: The role of redundancy on control and data acquisition systems has gained a significant importance in the case of Nuclear Fusion, as demanding security and high-availability requirements call for redundancy to be available. IPFN's control and data acquisition system hardware is based on an Advanced Telecommunications Computing Architecture (ATCA) set of I/O (DAC/ADC endpoints) and data/timing switch modules, which handle data and timing from all I/O endpoints. Modules communicate through Peripheral Component Interconnect Express (PCIe), established over the ATCA backplane and controlled by one or more external hosts. The developed hardware modules were designed to take advantage of ATCA specification's redundancy features, namely at the hardware management level, including support of: (i) multiple host operation with N + 1 redundancy – in which a designated failover host takes over data previously assigned to a suddenly malfunctioning host and (ii) N + 1 redundancy of I/O and data/timing switch modules. This paper briefly describes IPFN's control and data acquisition system, which is being developed for ITER fast plant system controller (FPSC), and analyses the hardware implementation of its supported redundancy features.

A Full Mesh ATCA-based General Purpose Data Processing Board (Pulsar II)

CERN Document Server

Ajuha, S; Costa de Paiva, Thiago; Das, Souvik; Eusebi, Ricardo; Finotti Ferreira, Vitor; Hahn, Kristian; Hu, Zhen; Jindariani, Sergo; Konigsberg, Jacobo; Liu, Tiehui Ted; Low, Jia Fu; Okumura, Yasuyuki; Olsen, Jamieson; Arruda Ramalho, Lucas; Rossin, Roberto; Ristori, Luciano; Akira Shinoda, Ailton; Tran, Nhan; Trovato, Marco; Ulmer, Keith; Vaz, Mario; Wen, Xianshan; Wu, Jin-Yuan; Xu, Zijun; Yin, Han; Zorzetti, Silvia

2017-01-01

The Pulsar II is a custom ATCA full mesh enabled FPGA-based processor board which has been designed with the goal of creating a scalable architecture abundant in flexible, non-blocking, high bandwidth interconnections. The design has been motivated by silicon-based tracking trigger needs for LHC experiments. In this technical memo we describe the Pulsar II hardware and its performance, such as the performance test results with full mesh backplanes from di↵erent vendors, how the backplane is used for the development of low-latency time-multiplexed data transfer schemes and how the inter-shelf and intra-shelf synchronization works.

A Full Mesh ATCA-based General Purpose Data Processing Board (Pulsar II)

Energy Technology Data Exchange (ETDEWEB)

Ajuha, S. [Univ. of Sao Paulo (Brazil); et al.

2017-06-29

The Pulsar II is a custom ATCA full mesh enabled FPGA-based processor board which has been designed with the goal of creating a scalable architecture abundant in flexible, non-blocking, high bandwidth interconnections. The design has been motivated by silicon-based tracking trigger needs for LHC experiments. In this technical memo we describe the Pulsar II hardware and its performance, such as the performance test results with full mesh backplanes from different vendors, how the backplane is used for the development of low-latency time-multiplexed data transfer schemes and how the inter-shelf and intra-shelf synchronization works.

Precision Time Protocol support hardware for ATCA control and data acquisition system

Energy Technology Data Exchange (ETDEWEB)

Correia, Miguel, E-mail: miguelfc@ipfn.ist.utl.pt [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Sousa, Jorge; Carvalho, Bernardo B.; Santos, Bruno; Carvalho, Paulo F.; Rodrigues, António P.; Combo, Álvaro M.; Pereira, Rita C. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Correia, Carlos M.B.A. [Centro de Instrumentação, Departamento de Física, Universidade de Coimbra, 3004-516 Coimbra (Portugal); Gonçalves, Bruno [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal)

2015-10-15

Highlights: • ATCA based control and data acquisition subsystem has been developed at IPFN. • PTP and time stamping were implemented with VHDL and PTP daemon (PTPd) codes. • The RTM (…) provides PTP synchronization with an external GMC. • The main advantage is that timestamps are generated closer to the Physical Layer at the GMII. • IPFN's upgrade consistently exhibited jitter values below 25 ns RMS. - Abstract: An in-house, Advanced Telecom Computing Architecture (ATCA) based control and data acquisition (C&DAQ) subsystem has been developed at Instituto de Plasmas e Fusão Nuclear (IPFN), aiming for compliance with the ITER Fast Plant System Controller (FPSC). Timing and synchronization for the ATCA modules connects to ITER Control, Data Access and Communication (CODAC) through the Timing Communication Network (TCN), which uses IEEE 1588-2008 Precision Time Protocol (PTP) to synchronize devices to a Grand Master Clock (GMC). The TCN infrastructure was tested for an RMS jitter under the limit of 50 ns. Therefore, IPFN's hardware, namely the ATCA-PTSW-AMC4 hub-module, which is in charge of timing and synchronization distribution for all subsystem endpoints, shall also perform within this jitter limit. This paper describes a relevant upgrade, applied to the ATCA-PTSW-AMC4 hardware, to comply with these requirements – in particular, the integration of an add-on module “RMC-TMG-1588” on its Rear Transition Module (RTM). This add-on is based on a commercial FPGA-based module from Trenz Electronic, using the ZHAW “PTP VHDL code for timestamping unit and clock”, which features clock offset and drift correction and hardware-assisted time stamping. The main advantage is that timestamps are generated closer to the Physical Layer, at the Gigabit Ethernet Media Independent Interface (GMII), avoiding the timing uncertainties accumulated through the upper layers. PTP code and user software run in a MicroBlaze™ soft-core CPU with Linux in the

Precision Time Protocol support hardware for ATCA control and data acquisition system

International Nuclear Information System (INIS)

Correia, Miguel; Sousa, Jorge; Carvalho, Bernardo B.; Santos, Bruno; Carvalho, Paulo F.; Rodrigues, António P.; Combo, Álvaro M.; Pereira, Rita C.; Correia, Carlos M.B.A.; Gonçalves, Bruno

2015-01-01

Highlights: • ATCA based control and data acquisition subsystem has been developed at IPFN. • PTP and time stamping were implemented with VHDL and PTP daemon (PTPd) codes. • The RTM (…) provides PTP synchronization with an external GMC. • The main advantage is that timestamps are generated closer to the Physical Layer at the GMII. • IPFN's upgrade consistently exhibited jitter values below 25 ns RMS. - Abstract: An in-house, Advanced Telecom Computing Architecture (ATCA) based control and data acquisition (C&DAQ) subsystem has been developed at Instituto de Plasmas e Fusão Nuclear (IPFN), aiming for compliance with the ITER Fast Plant System Controller (FPSC). Timing and synchronization for the ATCA modules connects to ITER Control, Data Access and Communication (CODAC) through the Timing Communication Network (TCN), which uses IEEE 1588-2008 Precision Time Protocol (PTP) to synchronize devices to a Grand Master Clock (GMC). The TCN infrastructure was tested for an RMS jitter under the limit of 50 ns. Therefore, IPFN's hardware, namely the ATCA-PTSW-AMC4 hub-module, which is in charge of timing and synchronization distribution for all subsystem endpoints, shall also perform within this jitter limit. This paper describes a relevant upgrade, applied to the ATCA-PTSW-AMC4 hardware, to comply with these requirements – in particular, the integration of an add-on module “RMC-TMG-1588” on its Rear Transition Module (RTM). This add-on is based on a commercial FPGA-based module from Trenz Electronic, using the ZHAW “PTP VHDL code for timestamping unit and clock”, which features clock offset and drift correction and hardware-assisted time stamping. The main advantage is that timestamps are generated closer to the Physical Layer, at the Gigabit Ethernet Media Independent Interface (GMII), avoiding the timing uncertainties accumulated through the upper layers. PTP code and user software run in a MicroBlaze™ soft-core CPU with Linux in the same FPGA

ATCA - thermal management study for the ATLAS phase II upgrades

CERN Document Server

Bortolin, Claudio; Kalinowski, Michal; Koziol, Piotr; Mendez, Julian; Walerianczyk, Jan; Zwalinski, Lukasz

2017-01-01

The AdvancedTCA (ATCA) telecom industry standard has been selected as the hardware platform for the “Phase-II Upgrade” of ATLAS at the Large Hadron Collider (LHC) at CERN. In November 2014 a project dedicated to the study of the impact of the ATCA integration in the actual counting rooms was launched analysing the impact on the cooling infrastructures. A spare rack equipped with two ATCA shelves, high power dissipating load blades, temperature and air velocity sensors were installed in a lab. Vertical and horizontal cooling performance were checked and some crtitical aspects identified.

APT LLRF control system functionality and architecture

International Nuclear Information System (INIS)

Regan, A.H.; Rohlev, A.S.; Ziomek, C.D.

1996-01-01

1% amplitude and l degree phase. The feedback control system requires a phase-stable RF reference subsystem signal to correctly phase each cavity. Also, instead of a single klystron RF source for individual accelerating cavities, multiple klystrons will drive a string of resonantly coupled cavities, based on input from a single LLRF feedback control system. To achieve maximum source efficiency, we will be employing single fast feedback controls around individual klystrons such that the gain and phase characteristics of each will be ''identical.'' In addition, resonance control is performed by providing a proper drive signal to structure cooling water valves in order to keep the cavity resonant during operation. To quickly respond to RF shutdowns, and hence rapid accelerating cavity cool- down, due to RF fault conditions, drive frequency agility in the main feedback control subsystem will also be incorporated. Top level block diagrams will be presented and described for each of the aforementioned subsystems as they will first be developed and demonstrated on the Low Energy Demonstrator Accelerator (LEDA) The low-level RF (LLRF) control system for the Accelerator Production of Tritium (APT) will perform various functions. Foremost is the feedback control of the accelerating fields within the cavity in order to maintain field stability within

ATCA for Machines-- Advanced Telecommunications Computing Architecture

Energy Technology Data Exchange (ETDEWEB)

Larsen, R.S.; /SLAC

2008-04-22

The Advanced Telecommunications Computing Architecture is a new industry open standard for electronics instrument modules and shelves being evaluated for the International Linear Collider (ILC). It is the first industrial standard designed for High Availability (HA). ILC availability simulations have shown clearly that the capabilities of ATCA are needed in order to achieve acceptable integrated luminosity. The ATCA architecture looks attractive for beam instruments and detector applications as well. This paper provides an overview of ongoing R&D including application of HA principles to power electronics systems.

ATCA for Machines-- Advanced Telecommunications Computing Architecture

International Nuclear Information System (INIS)

Larsen, R

2008-01-01

The Advanced Telecommunications Computing Architecture is a new industry open standard for electronics instrument modules and shelves being evaluated for the International Linear Collider (ILC). It is the first industrial standard designed for High Availability (HA). ILC availability simulations have shown clearly that the capabilities of ATCA are needed in order to achieve acceptable integrated luminosity. The ATCA architecture looks attractive for beam instruments and detector applications as well. This paper provides an overview of ongoing R and D including application of HA principles to power electronics systems

FPGA-based multichannel optical concentrator SIMCON 4.0 for TESLA cavities LLRF control system

Science.gov (United States)

Perkuszewski, Karol; Pozniak, Krzysztof T.; Jalmuzna, Wojciech; Koprek, Waldemar; Szewinski, Jaroslaw; Romaniuk, Ryszard S.; Simrock, Stefan

2006-10-01

The paper presents an idea, design and realization of a gigabit, optoelectronic synchronous massive data concentrator for the LLRF control system for FLASH and XFEL superconducting accelerators and lasers. The design bases on a central, large, programmable FPGA VirtexIIPro circuit by Xilinx and on eight commercial optoelectronic transceivers. There were implemented peripheral devices for embedded PowerPC block like: memory and Ethernet. The SIMCON 4.0 module was realized as a single, standard EURO-6HE board with VXI/VME-bus. Hardware implementation was described for the most important functional blocks. Construction solutions were presented.

FPGA based multichannel optical concentrator SIMCON 4.0 for TESLA cavities LLRF control system

International Nuclear Information System (INIS)

Perkuszewski, K.; Pozniak, K.T.; Jalmuzna, W.; Koprek, W.; Szewinski, J.; Romaniuk, R.S.

2006-01-01

The paper presents an idea, design and realization of a gigabit, optoelectronic synchronous massive data concentrator for the LLRF control system for FLASH and XFEL superconducting accelerators and lasers. The design bases on a central, large, programmable FPGA VirtexIIPro circuit by Xilinx and on eight commercial optoelectronic transceivers. There were implemented peripheral devices for embedded PowerPC block like: memory and Ethernet. The SIMCON 4.0 module was realized as a single, standard EURO-6HE board with VXI/VME-bus. Hardware implementation was described for the most important functional blocks. Construction solutions were presented. (orig.)

FPGA based multichannel optical concentrator SIMCON 4.0 for TESLA cavities LLRF control system

Energy Technology Data Exchange (ETDEWEB)

Perkuszewski, K.; Pozniak, K.T.; Jalmuzna, W.; Koprek, W.; Szewinski, J.; Romaniuk, R.S. [Warsaw Univ. of Technology (Poland). Inst. of Electronic Systems; Simrock, S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2006-07-01

The paper presents an idea, design and realization of a gigabit, optoelectronic synchronous massive data concentrator for the LLRF control system for FLASH and XFEL superconducting accelerators and lasers. The design bases on a central, large, programmable FPGA VirtexIIPro circuit by Xilinx and on eight commercial optoelectronic transceivers. There were implemented peripheral devices for embedded PowerPC block like: memory and Ethernet. The SIMCON 4.0 module was realized as a single, standard EURO-6HE board with VXI/VME-bus. Hardware implementation was described for the most important functional blocks. Construction solutions were presented. (orig.)

Implementation of IEEE-1588 timing and synchronization for ATCA control and data acquisition systems

International Nuclear Information System (INIS)

Correia, Miguel; Sousa, Jorge; Combo, Álvaro; Rodrigues, António P.; Carvalho, Bernardo B.; Batista, António J.N.; Gonçalves, Bruno; Correia, Carlos M.B.A.; Varandas, Carlos A.F.

2012-01-01

Highlights: ► IEEE-1588 over Ethernet protocol is implemented for the synchronization of all clock signals of an ATCA AMC carrier module. ► The ATCA hardware consists of an AMC quad-carrier main-board with PCI Express switching. ► IEEE-1588 is to be implemented on a Virtex-6 FPGA. ► Timing signals on the ATX-AMC4-PTP are managed and routed by a crosspoint-switch implemented on a Virtex-6 FPGA. ► Each clock signal source may be independently located (on each of the AMC cards, RTM or ATCA backplane). - Abstract: Control and data acquisition (C and DA) systems for Fusion experiments are required to provide accurate timing and synchronization (T and S) signals to all of its components. IPFN adopted PICMG's Advanced Telecommunications Computing Architecture (ATCA) industry standard to develop C and DA instrumentation. ATCA was chosen not only for its high throughput characteristics but also for its high availability (HA) features which become of greater importance in steady-state operation scenarios. However, the specified ATCA clock and synchronization interface may be too limited for the timing and synchronization needs in advanced Physics experiments. Upcoming specification extensions, developed by the “xTCA for Physics” workgroups, will contemplate, among others, a complementary timing specification, developed by the PICMG xTCA for Physics IO, Timing and Synchronization Technical Committee. The IEEE-1588 Precision Time Protocol (PTP) over Ethernet is one of the protocols, proposed by the Committee, aiming for precise synchronization of clocks in measurement and control systems, based on low jitter and slave-to-slave skew criteria. The paper presents an implementation of IEEE-1588 over Ethernet, in an ATCA hardware platform. The ATCA hardware consists of an Advanced Mezzanine Card (AMC) quad-carrier front board with PCI Express switching. IEEE-1588 is to be implemented on a Virtex-6 FPGA. Ethernet connectivity with the remote master clock is located on

ATCA/AXIe compatible board for fast control and data acquisition in nuclear fusion experiments

International Nuclear Information System (INIS)

Batista, A.J.N.; Leong, C.; Bexiga, V.; Rodrigues, A.P.; Combo, A.; Carvalho, B.B.; Fortunato, J.; Correia, M.; Teixeira, J.P.; Teixeira, I.C.; Sousa, J.; Gonçalves, B.; Varandas, C.A.F.

2012-01-01

Platform Management Controller (IPMC), two PCI Express x4 (generation 2) ATCA Fabric channels (dual-star topology), eleven Xilinx Aurora x1 (or other ATCA compatible communications protocol) ATCA fabric channels (full-mesh topology) and two Fast Ethernet (Precision Time Protocol – PTP IEEE1588-V2 and Lan eXtensions for Instrumentation – LXI compatible) ATCA base channels (dual-star topology).

LEDA LLRF control system characterization

International Nuclear Information System (INIS)

Regan, A.H.; Balleyguier, P.; Ziomek, C.D.

1998-01-01

The Low Energy Demonstration Accelerator (LEDA) for the Accelerator for the Production of Tritium (APT) project will be built at Los Alamos National Laboratory. The low-level RF (LLRF) control system portion of this accelerator must perform many functions, of which the primary one is controlling the RF fields in the accelerating cavities. Plans have been made to provide for on-line characterization of the LLRF control system and the complete RF system through use of stimulus and response buffers, and a digital signal processor built into the field control system electronics. The purpose of this circuitry is to characterize the behavior of the entire RF system (klystron, waveguides, high power splitters, accelerator cavity, etc.). This characterization feature can be used to measure the performance of the closed loop system with respect to the open loop system, to provide an automated way to set loop parameters, to determine the cavity Q-curve, and to detect any abnormal behavior in the RF chain. The types of measurements include frequency and time-domain responses to given perturbations, amplitude modulations, etc. This paper will discuss types of algorithms that can be implemented and present a description and block diagram of the electronics to be used

FPGA based, DSP board for LLRF 8-Channel SIMCON 3.0 Part I: Hardware

Science.gov (United States)

Giergusiewicz, Wojciech; Koprek, Waldemar; Jalmuzna, Wojciech; Pozniak, Krzysztof T.; Romaniuk, Ryszard S.

2005-09-01

The paper describes design, construction and initial measurements of an eight channel electronic LLRF device predicted for building of the control system for the VUV-FEL accelerator at DESY (Hamburg). The device, referred in the paper to as the SIMCON 3.0 (from the SC cavity simulator and controller) consists of a 16 layers, VME size, PCB, a large FPGA chip (VirtexII-4000 by Xilinx), eight fast ADCs and four DACs (by Analog Devices). To our knowledge, the proposed device is the first of this kind for the accelerator technology in which there was achieved (the FPGA based) DSP latency below 200 ns. With the optimized data transmission system, the overall LLRF system latency can be as low as 500 ns. The SIMCON 3.0 sub-system was applied for initial tests with the ACC1 module of the VUV FEL accelerator (eight channels) and with the CHECHIA test stand (single channel), both at the DESY. The promising results with the SIMCON 3.0 encouraged us to enter the design of SIMCON 3.1 possessing 10 measurement and control channels and some additional features to be reported in the next technical note. SIMCON 3.0 is a modular solution, while SIMCON 3.1 will be an integrated board of the all-in-one type. Two design approaches - modular and all-in-one, after branching off in this version of the SIMCON, will be continued.

IFMIF LLRF control system architecture based on EPICS

International Nuclear Information System (INIS)

Calvo, J.; Ibarra, A.; Miguel Angel Patricio; Rivers, M.

2012-01-01

The IFMIF-EVEDA (International Fusion Materials Irradiation Facility - Engineering Validation and Engineering Design Activity) linear accelerator will be a 9 MeV, 125 mA CW (Continuous Wave) deuteron accelerator prototype to validate the technical options of the accelerator design for IFMIF. The primary mission of such facility is to test and verify materials performance when subjected to extensive neutron irradiation of the type encountered in a fusion reactor. The RF (Radio Frequency) power system of IFMIF-EVEDA consists of 18 RF chains working at 175 MHz with three amplification stages each. The LLRF (Low-Level Radio Frequency) controls the amplitude and phase of the signal to be synchronized with the beam and it also controls the resonance frequency of the cavities. The system is based on a commercial cPCI (Compact Peripheral Component Interconnect) FPGA (Field Programmable Gate Array) board provided by Lyrtech and controlled by a Windows Host PC. For this purpose, it is mandatory to communicate the cPCI FPGA Board with an EPICS Channel Access, building an IOC (Input Output Controller). A new software architecture to design a device support, using AsynPortDriver class and CSS as a GUI (Graphical User Interface), is also presented. (authors)

PFGA based, full-duplex, multi-channel, optical gigabit, synchronous data transceiver for TESLA technology LLRF control system

Energy Technology Data Exchange (ETDEWEB)

Pozniak, K.T.; Romaniuk, R.S.; Jalmuzna, W.; Olowski, K.; Perkuszewski, K.; Zielinski, J. [Warsaw Univ. of Technology (Poland). Inst. of Electronic Systems; Kierzkowski, K. [Warsaw Univ. (Poland). Inst. of Experimental Physics

2005-07-01

It may be predicted now, even assuming very conservative approach, that the next generation of the Low Level RF control systems for future accelerators will use extensively such technologies like: very fast programmable circuits equipped with DSP, embedded PC and optical communication I/O functionalities, as well as multi-gigabit optical transmission of measurement data and control signals. The paper presents the idea and realization of a gigabit synchronous data distributor designed to work in the LLRF control system of TESLA technology based X-ray FEL. The design bases on a relatively simple and cheap FPGA chip Cyclone. Commercially available SERDES (serializer/deserializer) and optical transceiver chips were applied. The optoelectronic module is embedded on the main LLRF BMB (backbone mother board). The MB provides communication with the outside computer control system, programmable chip configuration, integration with other functional modules and power supply. The hardware implementation is here described and the used software for BER (bit-error-rate) testing of the multi-gigabit optical link. The measurement results are presented. The appendix contains a comparison between the available protocols of serial data transmission for FPGA technology. This TESLA Technology Report is a partial contribution to the next version of the SIMCON system which is expected to be released this year. The SIMCON, ver 3. will contain 8 channels and multi-gigabit optical transmission capability. (orig.)

Design and development of Low Level RF (LLRF) control system

International Nuclear Information System (INIS)

Mandi, T.K.; Suman, S.; Pandey, H.K.; Bandyopadhyay, A.

2015-01-01

All the linear accelerator cavities of Radioactive Ion Beam have separate RF power amplifiers. In these accelerators, high stabilities of the order of ± 0.5% in amplitude and ± 0.5° in phase of RF signal inside the cavities are required for proper and efficient acceleration of RIB. For this purpose, a low level RF (LLRF) control system is being designed which includes amplitude and phase controllers to ensure efficient and stable operation of the RF accelerators. The RF output of the LLRF system is finally amplified and fed to the accelerator cavities. The LLRF system is based on IQ (In-phase and Quadrature) modulation-demodulation technique in which an IQ modulator and a demodulator has been used to control the amplitude and phase of the RF carrier signal. The HigH-speed DAC and ADC have been used for processing the in-phase (I) and quadrature-phase (Q) components of the RF signal. This system is a closed-loop feedback control system. The feedback signal is obtained from the pick-up of accelerator cavity. PID control method is used to regulate the amplitude and phase of the RF signal to the desired/set value. The control system is optimized for minimum response time with satisfactory performance. The transfer function of the PID controller and the RF cavity is compared with the transfer function of a first order system and the values of proportional gain (Kp), integral gain (Ti) and derivative gain (Td) are obtained from Matlab- Simulink Simulation. The PID controller has been implemented into a high speed microcontroller (LPC2478) for fast operation. A GUI has been developed in NI LabView software to monitor the Amplitude and Phase of the RF signal and control manually if required. The detailed design and development of the control system will be discussed in this paper. (author)

A deterministic, gigabit serial timing, synchronization and data link for the RHIC LLRF

International Nuclear Information System (INIS)

Hayes, T.; Smith, K.S.; Severino, F.

2011-01-01

A critical capability of the new RHIC low level rf (LLRF) system is the ability to synchronize signals across multiple locations. The 'Update Link' provides this functionality. The 'Update Link' is a deterministic serial data link based on the Xilinx RocketIO protocol that is broadcast over fiber optic cable at 1 gigabit per second (Gbps). The link provides timing events and data packets as well as time stamp information for synchronizing diagnostic data from multiple sources. The new RHIC LLRF was designed to be a flexible, modular system. The system is constructed of numerous independent RF Controller chassis. To provide synchronization among all of these chassis, the Update Link system was designed. The Update Link system provides a low latency, deterministic data path to broadcast information to all receivers in the system. The Update Link system is based on a central hub, the Update Link Master (ULM), which generates the data stream that is distributed via fiber optic links. Downstream chassis have non-deterministic connections back to the ULM that allow any chassis to provide data that is broadcast globally.

A New ATLAS Muon CSC Readout System with System on Chip Technology on ATCA Platform

CERN Document Server

AUTHOR|(SzGeCERN)664042

2016-01-01

The ATLAS muon Cathode Strip Chamber (CSC) back-end readout system has been upgraded during the LHC 2013-2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run 2 luminosity. The readout design is based on the Reconfiguration Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the ATCA platform. The RCE design is based on the new System on Chip Xilinx Zynq series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources together with auxiliary memories to form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the Zynq for G-link, S-link and TTC allowed the full system of 320 G-links from the 32 chambers to be processed by 6 COBs in one ATCA shelf thr...

A New ATLAS Muon CSC Readout System with System on Chip Technology on ATCA Platform

CERN Document Server

Claus, Richard; The ATLAS collaboration

2015-01-01

The ATLAS muon Cathode Strip Chamber (CSC) backend readout system has been upgraded during the LHC 2013-2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run 2 luminosity. The readout design is based on the Reconfiguration Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the ATCA platform. The RCE design is based on the new System on Chip XILINX ZYNQ series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources together with auxiliary memories to form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the ZYNQ for G-link, S-link and TTC allowed the full system of 320 G-links from the 32 chambers to be processed by 6 COBs in one ATCA shelf thro...

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.

Modular and reconfigurable common PCB-platform of FPGA based LLRF control system for TESLA test facility

Energy Technology Data Exchange (ETDEWEB)

Pozniak, K.T.; Romaniuk, R.S. [Institute of Electronic Systems, Warsaw (Poland); Kierzkowski, K. [Institute of Experimental Physics, Warsaw (Poland)

2005-07-01

The paper includes a description of predicted functionalities to be implemented in a universal motherboard (MB) for the next generation of LLRF control system for TESLA. The motherboard bases on a number of quasi-autonomous embedded executive modules. The modules are implemented in a few FPGA chips featured by the MB. The paper presents a practical design of the MB. The initial (basic) solution of the MB has the Cyclone as the chip where the board management is embedded. The board features communication modules - VME and micro, single chip PC with Ethernet. The board provides power supply for the FPGA chips. The board has fast internal communication between particular modules. (orig.)

Modular and reconfigurable common PCB-platform of FPGA based LLRF control system for TESLA test facility

International Nuclear Information System (INIS)

Pozniak, K.T.; Romaniuk, R.S.; Kierzkowski, K.

2005-01-01

The paper includes a description of predicted functionalities to be implemented in a universal motherboard (MB) for the next generation of LLRF control system for TESLA. The motherboard bases on a number of quasi-autonomous embedded executive modules. The modules are implemented in a few FPGA chips featured by the MB. The paper presents a practical design of the MB. The initial (basic) solution of the MB has the Cyclone as the chip where the board management is embedded. The board features communication modules - VME and micro, single chip PC with Ethernet. The board provides power supply for the FPGA chips. The board has fast internal communication between particular modules. (orig.)

A high performance DAC/DDS daughter module for the RHIC LLRF platform

International Nuclear Information System (INIS)

Hayes, T.; Harvey, M.; Narayan, G.; Severino, F.; Smith, K.S.; Yuan, S.

2011-01-01

The RHIC LLRF upgrade is a flexible, modular system. Output signals are generated by a custom designed XMC card with 4 high speed digital to analog (DAC) converters interfaced to a high performance field programmable gate array (FPGA). This paper discusses the hardware details of the XMC DAC board as well as the implementation of a low noise rf synthesizer with digital IQ modulation. This synthesizer also provides injection phase cogging and frequency hop rebucketing capabilities. A new modular RHIC LLRF system was recently designed and commissioned based on custom designed XMC cards. As part of that effort a high speed, four channel DAC board was designed. The board uses Maxim MAX5891 16 bit DACs with a maximum update rate of 600 Msps. Since this module is intended to be used for many different systems throughout the Collider Accelerator complex, it was designed to be as generic as possible. One major application of this DAC card is to implement digital synthesizers to provide drive signals to the various cavities at RHIC. Since RHIC is a storage ring with stores that typically last many hours, extremely low RF noise is a critical requirement. Synchrotron frequencies at RHIC range from a few hertz to several hundred hertz depending on the species and point in the acceleration cycle so close in phase noise is a major concern. The RHIC LLRF system uses the Update Link, a deterministic, high speed data link that broadcasts the revolution frequency and the synchronous phase angle. The digital synthesizers use this data to generate a properly phased analog drive signal. The synthesizers must also provide smooth phase shifts for cogging and support frequency shift rebucketing. One additional feature implemented in the FPGA is a digital waveform generator (WFG) that generates I and Q data pairs based on a user selected amplitude and phase profile as a function of time.

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)

Design of the SLAC RCE Platform: A General Purpose ATCA Based Data Acquisition System

International Nuclear Information System (INIS)

Herbst, R.; Claus, R.; Freytag, M.; Haller, G.; Huffer, M.; Maldonado, S.; Nishimura, K.; O'Grady, C.; Panetta, J.; Perazzo, A.; Reese, B.; Ruckman, L.; Thayer, J.G.; Weaver, M.

2015-01-01

The SLAC RCE platform is a general purpose clustered data acquisition system implemented on a custom ATCA compliant blade, called the Cluster On Board (COB). The core of the system is the Reconfigurable Cluster Element (RCE), which is a system-on-chip design based upon the Xilinx Zynq family of FPGAs, mounted on custom COB daughter-boards. The Zynq architecture couples a dual core ARM Cortex A9 based processor with a high performance 28nm FPGA. The RCE has 12 external general purpose bi-directional high speed links, each supporting serial rates of up to 12Gbps. 8 RCE nodes are included on a COB, each with a 10Gbps connection to an on-board 24-port Ethernet switch integrated circuit. The COB is designed to be used with a standard full-mesh ATCA backplane allowing multiple RCE nodes to be tightly interconnected with minimal interconnect latency. Multiple shelves can be clustered using the front panel 10-gbps connections. The COB also supports local and inter-blade timing and trigger distribution. An experiment specific Rear Transition Module adapts the 96 high speed serial links to specific experiments and allows an experiment-specific timing and busy feedback connection. This coupling of processors with a high performance FPGA fabric in a low latency, multiple node cluster allows high speed data processing that can be easily adapted to any physics experiment. RTEMS and Linux are both ported to the module. The RCE has been used or is the baseline for several current and proposed experiments (LCLS, HPS, LSST, ATLAS-CSC, LBNE, DarkSide, ILC-SiD, etc).

Nominal Device Support for ATCA Shelf Manager

Energy Technology Data Exchange (ETDEWEB)

Santos, Bruno; Carvalho, Paulo F.; Rodrigues, A.P.; Carvalho, Bernardo B.; Sousa, Jorge; Batista, Antonio J.N.; Combo, Alvaro M.; Cruz, Nuno; Correia, Carlos M.B.A.; Goncalves, Bruno [Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Correia, Miguel [Centro de Instrumentacao, Departamento de Fisica, Universidade de Coimbra, 3004-516 Coimbra (Portugal)

2015-07-01

The ATCA standard specifies a mandatory Shelf Manager (ShM) unit which is a key element for the system operation. It includes the Intelligent Platform Management Controller (IPMC) which monitors the system health, retrieves inventory information and controls the Field Replaceable Units (FRUs). These elements enable the intelligent health monitoring, providing high-availability and safety operation, ensuring the correct system operation. For critical systems like ones of tokamak ITER these features are mandatory to support the long pulse operation. The Nominal Device Support (NDS) was designed and developed for the ITER CODAC Core System (CCS), which will be the responsible for plant Instrumentation and Control (I and C), supervising and monitoring on ITER. It generalizes the Enhanced Physics and Industrial Control System (EPICS) device support interface for Data Acquisition (DAQ) and timing devices. However the support for health management features and ATCA ShM are not yet provided. This paper presents the implementation and test of a NDS for the ATCA ShM, using the ITER Fast Plant System Controller (FPSC) prototype environment. This prototype is fully compatible with the ITER CCS and uses the EPICS Channel Access (CA) protocol as the interface with the Plant Operation Network (PON). The implemented solution running in an EPICS Input / Output Controller (IOC) provides Process Variables (PV) to the PON network with the system information. These PVs can be used for control and monitoring by all CA clients, such as EPICS user interface clients and alarm systems. The results are presented, demonstrating the fully integration and the usability of this solution. (authors)

A Full Mesh ATCA-based General Purpose Data Processing Board: Pulsar II

CERN Document Server

Olsen, J; Okumura, Y

2014-01-01

High luminosity conditions at the LHC pose many unique challenges for potential silicon based track trigger systems. Among those challenges is data formatting, where hits from thousands of silicon modules must first be shared and organized into overlapping trigger towers. Other challenges exist for Level-1 track triggers, where many parallel data paths may be used for 5 high speed time multiplexed data transfers. Communication between processing nodes requires high bandwidth, low latency, and flexible real time data sharing, for which a full mesh backplane is a natural fit. A custom full mesh enabled ATCA board called the Pulsar II has been designed with the goal of creating a scalable architecture abundant in flexible, non-blocking, high bandwidth board- to-board communication channels while keeping the design as simple as possible.

Prototype Control System for Compensation of Superconducting Cavities Detuning Using Piezoelectric Actuators

Science.gov (United States)

Przygoda, K.; Piotrowski, A.; Jablonski, G.; Makowski, D.; Pozniak, T.; Napieralski, A.

2009-08-01

Pulsed operation of high gradient superconducting radio frequency (SCRF) cavities results in dynamic Lorentz force detuning (LFD) approaching or exceeding the bandwidth of the cavity of order of a few hundreds of Hz. The resulting modulation of the resonance frequency of the cavity is leading to a perturbation of the amplitude and phase of the accelerating field, which can be controlled only at the expense of RF power. Presently, at various labs, a piezoelectric fast tuner based on an active compensation scheme for the resonance frequency control of the cavity is under study. The tests already performed in the Free Electron Laser in Hamburg (FLASH), proved the possibility of Lorentz force detuning compensation by the means of the piezo element excited with the single period of sine wave prior to the RF pulse. The X-Ray Free Electron Laser (X-FEL) accelerator, which is now under development in Deutsche Elektronen-Synchrotron (DESY), will consists of around 800 cavities with a fast tuner fixture including the actuator/sensor configuration. Therefore, it is necessary to design a distributed control system which would be able to supervise around 25 RF stations, each one comprised of 32 cavities. The Advanced Telecomunications Computing Architecture (ATCA) was chosen to design, develop, and build a Low Level Radio Frequency (LLRF) controller for X-FEL. The prototype control system for Lorentz force detuning compensation was designed and developed. The control applications applied in the system were fitted to the main framework of interfaces and communication protocols proposed for the ATCA-based LLRF control system. The paper presents the general view of a designed control system and shows the first experimental results from the tests carried out in FLASH facility. Moreover, the possibilities for integration of the piezo control system to the ATCA standards are discussed.

Next generation ATCA control infrastructure for the CMS Phase-2 upgrades

CERN Document Server

Smith, Wesley; Svetek, Aleš; Tikalsky, Jes; Fobes, Robert; Dasu, Sridhara; Smith, Wesley; Vicente, Marcelo

2017-01-01

A next generation control infrastructure to be used in Advanced TCA (ATCA) blades at CMS experiment is being designed and tested. Several ATCA systems are being prepared for the High-Luminosity LHC (HL-LHC) and will be installed at CMS during technical stops. The next generation control infrastructure will provide all the necessary hardware, firmware and software required in these systems, decreasing development time and increasing flexibility. The complete infrastructure includes an Intelligent Platform Management Controller (IPMC), a Module Management Controller (MMC) and an Embedded Linux Mezzanine (ELM) processing card.

ATCA Shelf Manager EPICS device support for ITER CODAC Core System

Energy Technology Data Exchange (ETDEWEB)

Santos, Bruno, E-mail: bsantos@ipfn.ist.utl.pt [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Carvalho, Paulo F.; Rodrigues, A.P.; Carvalho, Bernardo B.; Sousa, Jorge; Batista, António J.N.; Correia, Miguel; Combo, Álvaro M.; Cruz, Nuno [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Correia, Carlos M.B.A. [Centro de Instrumentação, Departamento de Física, Universidade de Coimbra, 3004-516 Coimbra (Portugal); Gonçalves, Bruno [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal)

2015-10-15

Highlights: • This architecture targets the health management integration into the NDS. • The developed solution supports the ShM redundancy features, specified by ATCA. • The average RTT was around 59 ms and in 99.9% of the cases was less than 130 ms. • Without losing any update cycle, can monitor a system shelf with approximately 400 sensors. • This solution enables the user to configure the entire system in DB files and st.cmd. - Abstract: The ITER CODAC Core System (CCS) is responsible for plant Instrumentation and Control (I&C) supervising and monitoring. This system uses the Enhanced Physics and Industrial Control System (EPICS) Channel Access (CA) protocol as the interface with the Plant Operation Network (PON). This paper presents a generic EPICS device support developed for the integration of the ATCA Shelf Manager (ShM) into the ITER CCS, providing scalability and easy configuration. The device support uses the available HTTP interface on Shelf Manager in the communication layer. Both HTTP server and sensors/actuators definitions can be configured using the EPICS database file and the Input/Output Controller (IOC) initialization file. A proposal based on this device is also presented, targeting the Nominal Device Support (NDS) for health management. The EPICS device support running in an IOC provides Process Variables (PV) to the PON network with the system information and these PVs can be used by all CA clients, such as EPICS user interface clients, alarm systems and archive systems. Operation with redundant ATCA ShMs and device support scalability tests were performed and the results are presented.

Design of eight-channel ADC card for GHz signal conversion

CERN Document Server

Habib, Samer Bou; Jalmuzna, Wojciech; Jezynski, Tomasz

2011-01-01

This paper describes the design of an eight-channel ATCA card suited for direct analog-to-digital conversion of 1.3 GHz signals with a maximum ADC clock frequency of 500 MHz. The undersampling operation is used for signal conversion. This card was designed for the needs of the LLRF system of the FLASH and XFEL accelerators. The designed module consists of a main ATCA board with eight ADCs, FPGA unit, memory, power supply and diagnostic circuits. The main ATCA card allows connecting a daughter board with IPMI, CPU and fast interfaces for communication purposes. This paper describes such issues as system organization allowing acquisition of data at such high data rates, circuit synchronization by high-quality clock signals, CPU and connectivity features, 20-layer PCB design and techniques used for high-frequency signals transmission and matching.

A new ATLAS muon CSC readout system with system on chip technology on ATCA platform

Science.gov (United States)

Claus, R.; ATLAS Collaboration

2016-07-01

The ATLAS muon Cathode Strip Chamber (CSC) back-end readout system has been upgraded during the LHC 2013-2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run 2 luminosity. The readout design is based on the Reconfiguration Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the ATCA platform. The RCE design is based on the new System on Chip Xilinx Zynq series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources together with auxiliary memories to form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the Zynq for G-link, S-link and TTC allowed the full system of 320 G-links from the 32 chambers to be processed by 6 COBs in one ATCA shelf through software waveform feature extraction to output 32 S-links. The full system was installed in Sept. 2014. We will present the RCE/COB design concept, the firmware and software processing architecture, and the experience from the intense commissioning towards LHC Run 2.

A new ATLAS muon CSC readout system with system on chip technology on ATCA platform

International Nuclear Information System (INIS)

Claus, R.

2016-01-01

The ATLAS muon Cathode Strip Chamber (CSC) back-end readout system has been upgraded during the LHC 2013–2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run 2 luminosity. The readout design is based on the Reconfiguration Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the ATCA platform. The RCE design is based on the new System on Chip Xilinx Zynq series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources together with auxiliary memories to form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the Zynq for G-link, S-link and TTC allowed the full system of 320 G-links from the 32 chambers to be processed by 6 COBs in one ATCA shelf through software waveform feature extraction to output 32 S-links. The full system was installed in Sept. 2014. We will present the RCE/COB design concept, the firmware and software processing architecture, and the experience from the intense commissioning towards LHC Run 2.

A new ATLAS muon CSC readout system with system on chip technology on ATCA platform

Science.gov (United States)

Bartoldus, R.; Claus, R.; Garelli, N.; Herbst, R. T.; Huffer, M.; Iakovidis, G.; Iordanidou, K.; Kwan, K.; Kocian, M.; Lankford, A. J.; Moschovakos, P.; Nelson, A.; Ntekas, K.; Ruckman, L.; Russell, J.; Schernau, M.; Schlenker, S.; Su, D.; Valderanis, C.; Wittgen, M.; Yildiz, S. C.

2016-01-01

The ATLAS muon Cathode Strip Chamber (CSC) backend readout system has been upgraded during the LHC 2013-2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run-2 luminosity. The readout design is based on the Reconfigurable Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the Advanced Telecommunication Computing Architecture (ATCA) platform. The RCE design is based on the new System on Chip XILINX ZYNQ series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources. Together with auxiliary memories, all these components form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the ZYNQ for high speed input and output fiberoptic links and TTC allowed the full system of 320 input links from the 32 chambers to be processed by 6 COBs in one ATCA shelf. The full system was installed in September 2014. We will present the RCE/COB design concept, the firmware and software processing architecture, and the experience from the intense commissioning for LHC Run 2.

A new ATLAS muon CSC readout system with system on chip technology on ATCA platform

International Nuclear Information System (INIS)

Bartoldus, R.; Claus, R.; Garelli, N.; Herbst, R.T.; Huffer, M.; Kocian, M.; Ruckman, L.; Russell, J.; Su, D.; Wittgen, M.; Iakovidis, G.; Iordanidou, K.; Moschovakos, P.; Ntekas, K.; Kwan, K.; Lankford, A.J.; Nelson, A.; Schernau, M.; Schlenker, S.; Valderanis, C.

2016-01-01

The ATLAS muon Cathode Strip Chamber (CSC) backend readout system has been upgraded during the LHC 2013-2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run-2 luminosity. The readout design is based on the Reconfigurable Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the Advanced Telecommunication Computing Architecture (ATCA) platform. The RCE design is based on the new System on Chip XILINX ZYNQ series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources. Together with auxiliary memories, all these components form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the ZYNQ for high speed input and output fiberoptic links and TTC allowed the full system of 320 input links from the 32 chambers to be processed by 6 COBs in one ATCA shelf. The full system was installed in September 2014. We will present the RCE/COB design concept, the firmware and software processing architecture, and the experience from the intense commissioning for LHC Run 2

A new ATLAS muon CSC readout system with system on chip technology on ATCA platform

Energy Technology Data Exchange (ETDEWEB)

Claus, R., E-mail: claus@slac.stanford.edu

2016-07-11

The ATLAS muon Cathode Strip Chamber (CSC) back-end readout system has been upgraded during the LHC 2013–2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run 2 luminosity. The readout design is based on the Reconfiguration Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the ATCA platform. The RCE design is based on the new System on Chip Xilinx Zynq series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources together with auxiliary memories to form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the Zynq for G-link, S-link and TTC allowed the full system of 320 G-links from the 32 chambers to be processed by 6 COBs in one ATCA shelf through software waveform feature extraction to output 32 S-links. The full system was installed in Sept. 2014. We will present the RCE/COB design concept, the firmware and software processing architecture, and the experience from the intense commissioning towards LHC Run 2.

Development of RF non-IQ sampling module for Helium RFQ LLRF system

Energy Technology Data Exchange (ETDEWEB)

Jeong, Hae-Seong; Ahn, Tae-Sung; Kim, Seong-Gu; Kwon, Hyeok-Jung; Kim, Han-Sung; Song, Young-Gi; Seol, Kyung-Tae; Cho, Yong-Sub [KOMAC, Gyeongju (Korea, Republic of)

2015-05-15

KOMAC (Korea Multi-purpose Accelerator Complex) has a plan to develop the helium irradiation system. This system includes the Ion source, LEBT, RFQ, MEBT systems to transport helium particles to the target. Especially, the RFQ (Radio Frequency Quadrupole) system should receive the 200MHz RF within 1% amplitude error stability. For supplying stable 200MHz RF to the RFQ, the low-level radio frequency (LLRF) should be controlled by control system. The helium RFQ LLRF control system adopted non- IQ sampling method to sample the analog input RF. Sampled input data will be calculated to get the I, Q values. These I, Q values will be used to monitor the amplitude and phase of the RF signal. In this paper, non-IQ sampling logic and amplitude and phase calculating logic of the FPGA will be introduced. Using Xilinx ISE design suite which is tool for developing the FPGA logic module, non-IQ sampling module and amplitude and phase computing module developed. In the future, PI gain module and frequency error computing module will be developed.

Simulation of the Direct Digital Synthesis module for Helium RFQ LLRF system

Energy Technology Data Exchange (ETDEWEB)

Jeong, Hae-Seong; Ahn, Tae-Sung; Kim, Seong-Gu; Kwon, Hyeok-Jung; Kim, Han-Sung; Song, Young-Gi; Seol, Kyung-Tae; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of)

2015-10-15

In this paper, the DDS module in the FPGA simulated and the analysis result will be introduced. Using Xilinx ISE design suite which is tool for developing the FPGA logic module, DDS module simulated. KOMAC (Korea Multi-purpose Accelerator Complex) has a plan to develop the helium irradiation system. This system includes the Ion source, LEBT, RFQ, MEBT systems to transport helium particles to the target. Especially, the RFQ (Radio Frequency Quadrupole) system should receive the 200 MHz RF within 1% amplitude error stability. For supplying stable 200 MHz RF to the RFQ, the LLRF (low-level radio frequency) should be controlled by control system. This helium RFQ LLRF control system have a concept to track the cavity resonance frequency. For tracking the cavity resonance frequency, the FPGA (Field Programmable Gate Array) in the digital board will tune the frequency of the output sinusoidal signal. In order to implement this frequency tracking concept, the DDS (Direct Digital Synthesis) module should be implemented in the FPGA. In the future, frequency tracking system will be tested using test cavity.

A New ATLAS Muon CSC Readout System with System on Chip Technology on ATCA Platform

CERN Document Server

AUTHOR|(SzGeCERN)696050; Garelli, N.; Herbst, R.T.; Huffer, M.; Iakovidis, G.; Iordanidou, K.; Kwan, K.; Kocian, M.; Lankford, A.J.; Moschovakos, P.; Nelson, A.; Ntekas, K.; Ruckman, L.; Russell, J.; Schernau, M.; Schlenker, S.; Su, D.; Valderanis, C.; Wittgen, M.; Bartoldus, R.

2016-01-01

The ATLAS muon Cathode Strip Chamber (CSC) backend readout system has been upgraded during the LHC 2013-2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run 2 luminosity. The readout design is based on the Reconfigurable Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the Advanced Telecommunication Computing Architecture (ATCA) platform. The RCE design is based on the new System on Chip XILINX ZYNQ series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources together with auxiliary memories to form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the ZYNQ for G-link, S-link and TTC allowed the full system of 320 G-links from the 32 chambe...

A New ATLAS Muon CSC Readout System with System on Chip Technology on ATCA Platform

CERN Document Server

ATLAS CSC Collaboration; The ATLAS collaboration

2016-01-01

The ATLAS muon Cathode Strip Chamber (CSC) backend readout system has been upgrade during the LHC 2013-2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run 2 luminosity. The readout design is based on the Reconfigurable Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the Advanced Telecommunication Computing Architecture (ATCA) platform. The RCE design is based on the new System on Chip XILINX ZYNQ series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources together with auxiliary memories to form a versatile DAQ building block that can host applications tapping into both software and firmware resources. The Cluster on Board (COB) ATCA carrier hosts RCE mezzanines and an embedded Fulcrum network switch to form an online DAQ processing cluster. More compact firmware solutions on the ZYNQ for G-link, S-link and TTC allowed the full system of 320 G-links from the 32 chamber...

MatLab script to C code converter for embedded processors of FLASH LLRF control system

Science.gov (United States)

Bujnowski, K.; Siemionczyk, A.; Pucyk, P.; Szewiński, J.; Pożniak, K. T.; Romaniuk, R. S.

2008-01-01

The low level RF control system (LLRF) of FEL serves for stabilization of the electromagnetic (EM) field in the superconducting niobium, resonant, microwave cavities and for controlling high power (MW) klystron. LLRF system of FLASH accelerator bases on FPGA technology and embedded microprocessors. Basic and auxiliary functions of the systems are listed as well as used algorithms for superconductive cavity parameters identification. These algorithms were prepared originally in Matlab. The main part of the paper presents implementation of the cavity parameters identification algorithm in a PowerPC processor embedded in the FPGA circuit VirtexIIPro. A construction of a very compact Matlab script converter to C code was presented, referred to as M2C. The application is designed specifically for embedded systems of very confined resources. The generated code is optimized for the weight. The code should be transferable between different hardware platforms. The converter generates a code for Linux and for stand-alone applications. Functional structure of the program was described and the way it is acting. FLEX and BIZON tools were used for construction of the converter. The paper concludes with an example of the M2C application to convert a complex identification algorithm for superconductive cavities in FLASH laser.

Data transmission optical link for LLRF TESLA project part I: hardware structure of OPT0 module

Science.gov (United States)

Pozniak, Krzysztof T.; Romaniuk, Ryszard S.; Jalmuzna, Wojciech; Olowski, Krzysztof; Perkuszewski, Karol; Zielinski, Jerzy; Kierzkowski, Krzysztof

2006-03-01

It may be predicted now, even assuming a very conservative approach, that the next generation of the Low Level RF control systems for future accelerators will use extensively such technologies like: very fast programmable circuits equipped with DSP, embedded PC and optical communication I/O functionalities, as well as multi-gigabit optical transmission of measurement data and control signals. The paper presents the idea and realization of a gigabit synchronous data distributor designed to work in the LLRF control system of TESLA technology based X-ray FEL. The design bases on a relatively simple and cheap FPGA chip Cyclone. Commercially available SERDES (serializer/deserializer) and optical transceiver chips were applied. The optoelectronic module is embedded on the main LLRF BMB (backbone mother board). The MB provides communication with the outside computer control system, programmable chip configuration, integration with other functional modules and power supply. The hardware implementation is here described and the used software for BER (bit-error-rate) testing of the multi-gigabit optical link. The measurement results are presented. The appendix contains a comparison between the available protocols of serial data transmission for FPGA technology. This paper is a partial contribution to the next version of the SIMCON system which is expected to be released this year. The SIMCON, ver 3.0 will contain 8 channels and multi-gigabit optical transmission capability. It will be a fully modular construction.

Modular version of SIMCON, FPGA based, DSP integrated, LLRF control system for TESLA FEL part II: measurement of SIMCON 3.0 DSP daughterboard

Science.gov (United States)

Giergusiewicz, Wojciech; Koprek, Waldemar; Jalmuzna, Wojciech; Pozniak, Krzysztof T.; Romaniuk, Ryszard S.

2006-02-01

The paper describes design, construction and initial measurements of an eight channel electronic LLRF device predicted for building of the control system for the W-FEL accelerator at DESY (Hamburg). The device, referred in the paper to as the SIMCON 3.0 (from the SC cavity simulator and controller) consists of a 16 layer, VME size, PCB, a large FPGA chip (VirtexII-4000 by Xilinx), eight fast ADCs and four DACs (by Analog Devices). To our knowledge, the proposed device is the first of this kind for the accelerator technology in which there was achieved (the FPGA based) DSP latency below 200 ns. With the optimized data transmission system, the overall LLRF system latency can be as low as 500 ns. The SIMCON 3.0 sub-system was applied for initial tests with the ACCl module of the VUV FEL accelerator (eight channels) and with the CHECHIA test stand (single channel), both at the DESY. The promising results with the SIMCON 3.0. encouraged us to enter the design of SIMCON 3.1. possessing 10 measurement and control channels and some additional features to be reported in the next technical note. SIMCON 3.0. is a modular solution, while SIMCON 3.1. will be an integrated board of the all-in-one type. Two design approaches - modular and all-in-one - after branching off in this version of the Simcon, will be continued.

An Integration Framework Tool for ATCA Chassis in the ATLAS Detector Control System

International Nuclear Information System (INIS)

Reed, Robert Graham

2015-01-01

The Large Hadron Collider at CERN is scheduled to undergo a major upgrade in 2022. The ATLAS collaboration will do major modifications to the detector to account for the increased luminosity. More specifically, a large proportion of the current front-end electronics, on the Tile Calorimeter sub-detector, will be upgraded and relocated to the backend. A Demonstrator program has been established as a proof of principle. A new system will be required to house, manage and connect this new hardware. The proposed solution will be an Advanced Telecommunication Computing Architecture (ATCA) which will not only house but also allow advanced management features and control at a hardware level by integrating the ATCA chassis into the Detector Control System. (paper)

R and D of an LLRF control system for a 162.5 MHz radio frequency system

International Nuclear Information System (INIS)

Wen Lianghua; Wu Xianwu; He Yuan; Zhang Ruifeng; Zhang Shenghu; Zhu Zhenglong; Li Chunlong; Shi Longbo; Zhang Rui; Chang Wei

2013-01-01

This paper describes a low level radio frequency control system that was developed by the Institute of Modern Physics Chinese Academy of Sciences, and will be used in Injector Ⅱ of the China-ADS project. The LLRF control system consists of an RF modulated front end, fast analog-to-digital converter (ADC) modules, and a digital signal processing board based on a field programmable gate array. The system has been tested on a room temperature cavity with 12-hr, and the results illustrate that the stability of amplitude and phase achieved ±0.32% and ±0.35 degrees, respectively. (authors)

PSB LLRF: new features for machine studies and operation in the PSB 2016 run

CERN Document Server

Angoletta, M E

2017-01-01

A new digital Low-Level RF (LLRF) system has beensuccessfully deployed on the four PS Booster (PSB) ringsin June 2014, after the Long-Shutdown 1 (LS1). Althoughonly recently deployed, several new features for machinestudies and operation have already been required and im-plemented. This note provides an overview of the main fea-tures deployed for the 2016 PSB run and of their results

CERN's LEIR Digital LLRF : system overview and operational experience

CERN Document Server

Angoletta, ME; Blas, A; Bracke, E; Butterworth, A; Dubouchet, F; Findlay, A; Pedersen, F; Sanchez-Quesada, J

2010-01-01

The Low Energy Ion Ring (LEIR) is an accumulation and acceleration ring in the Large Hadron Collider (LHC) ion injector chain. After its successful start in 2005, it has been running in three operational campaigns. The LEIR low-level RF (LLRF) system is the first all-digital system to operate in a CERN circular machine. Its capabilities include beam control tasks as well as dual-harmonic cavity voltage/phase servoing. All the system’s control parameters are fully configurable, remotely and in-between cycles; extensive built-in observation capabilities and diagnostics are available. The system is flexible, powerful and extremely reliable. This paper outlines the main building blocks and operational features, along with results obtained during the first years of operation.

Participants of the LLRF05 : Workshop on Low Level RF, CERN 10-13 October 2005

CERN Multimedia

Maximilien Brice

2005-01-01

Sophisticated Low Level RF systems are needed in modern particle accelerators to deal with the characteristics of state-of-the-art RF accelerating structures and their power sources, and to meet unprecedented levels of performance. The goal of the LLRF05 workshop is to share experience between linac and synchrotron projects (SNS, J-PARC, ILC, LHC etc.) and to discuss the best engineering practice.

Control and data acquisition ATCA/AXIe board designed for high system availability and reliability of nuclear fusion experiments

International Nuclear Information System (INIS)

Batista, A.J.N.; Leong, C.; Bexiga, V.; Rodrigues, A.P.; Combo, A.; Carvalho, B.B.; Carvalho, P.F.; Fortunato, J.; Santos, B.; Carvalho, P.; Correia, M.; Teixeira, J.P.; Teixeira, I.C.; Sousa, J.; Gonçalves, B.; Varandas, C.A.F.

2013-01-01

This paper describes the implementation and test of a control and data acquisition board designed to be integrated on systems demanding high availability and reliability, foreseen for future experiments like ITER or other long operation fusion devices. The Advanced Telecommunications Computing Architecture (ATCA) standard (PICMG 3.0 and 3.4) was selected for board implementation, which has support for the desired system robustness and performance. Some board features such as rear Input/Output (IO) signals connectivity (passive, copper tracks only), cable-less hot-swap maintenance, Intelligent Platform Management Controller (IPMC) and redundancy on timing signals, communications links and power supplies are significant board improvements, relatively to previous control and data acquisition boards, allowing the development of more reliable system architectures. Moreover, the developed board is also compatible with the emerging ATCA eXtensions for Instrumentation (AXIe) specifications, which provides additional timing and synchronization signals on the backplane. ATCA full-mesh, multi-gigabit, full-duplex, point-to-point communication links between Field Programmable Gate Arrays (FPGA), of peer boards inside the shelf, allow the implementation of distributed algorithms and development of Multi-Input Multi-Output (MIMO) systems. Up to 48 analog input channels, simultaneously digitized (2 MSPS @ 18-bits), are filtered/decimated by the board FPGA and sent to the ATCA/AXIe host through Peripheral Component Interconnect express (PCIe) using Direct Memory Access (DMA). In real-time, the host can update up to 48 analog output channels (1 MSPS @ 18-bits), per board, through PCIe. Further board characteristics comprise analog IO channels with galvanic isolation and an optional signal chopper mode, for offset compensation over time on digital integration of magnetic signals. Board time synchronization is attained by means of the Inter-Range Instrumentation Group (IRIG) time-code

Real-time cavity simulator-based low-level radio-frequency test bench and applications for accelerators

Science.gov (United States)

Qiu, Feng; Michizono, Shinichiro; Miura, Takako; Matsumoto, Toshihiro; Liu, Na; Wibowo, Sigit Basuki

2018-03-01

A Low-level radio-frequency (LLRF) control systems is required to regulate the rf field in the rf cavity used for beam acceleration. As the LLRF system is usually complex, testing of the basic functions or control algorithms of this system in real time and in advance of beam commissioning is strongly recommended. However, the equipment necessary to test the LLRF system, such as superconducting cavities and high-power rf sources, is very expensive; therefore, we have developed a field-programmable gate array (FPGA)-based cavity simulator as a substitute for real rf cavities. Digital models of the cavity and other rf systems are implemented in the FPGA. The main components include cavity baseband models for the fundamental and parasitic modes, a mechanical model of the Lorentz force detuning, and a model of the beam current. Furthermore, in our simulator, the disturbance model used to simulate the power-supply ripples and microphonics is also carefully considered. Based on the presented cavity simulator, we have established an LLRF system test bench that can be applied to different cavity operational conditions. The simulator performance has been verified by comparison with real cavities in KEK accelerators. In this paper, the development and implementation of this cavity simulator is presented first, and the LLRF test bench based on the presented simulator is constructed. The results are then compared with those for KEK accelerators. Finally, several LLRF applications of the cavity simulator are illustrated.

Real-time cavity simulator-based low-level radio-frequency test bench and applications for accelerators

Directory of Open Access Journals (Sweden)

Feng Qiu

2018-03-01

Full Text Available A Low-level radio-frequency (LLRF control systems is required to regulate the rf field in the rf cavity used for beam acceleration. As the LLRF system is usually complex, testing of the basic functions or control algorithms of this system in real time and in advance of beam commissioning is strongly recommended. However, the equipment necessary to test the LLRF system, such as superconducting cavities and high-power rf sources, is very expensive; therefore, we have developed a field-programmable gate array (FPGA-based cavity simulator as a substitute for real rf cavities. Digital models of the cavity and other rf systems are implemented in the FPGA. The main components include cavity baseband models for the fundamental and parasitic modes, a mechanical model of the Lorentz force detuning, and a model of the beam current. Furthermore, in our simulator, the disturbance model used to simulate the power-supply ripples and microphonics is also carefully considered. Based on the presented cavity simulator, we have established an LLRF system test bench that can be applied to different cavity operational conditions. The simulator performance has been verified by comparison with real cavities in KEK accelerators. In this paper, the development and implementation of this cavity simulator is presented first, and the LLRF test bench based on the presented simulator is constructed. The results are then compared with those for KEK accelerators. Finally, several LLRF applications of the cavity simulator are illustrated.

Synchronic, optical transmission data link integrated with FPGA circuits (for TESLA LLRF control system)

Energy Technology Data Exchange (ETDEWEB)

Zielinski, J.S.

2006-07-15

The X-ray free-electron laser X-FEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new possibilities for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated to the LLRF1 system in VUV FEL experiment It is being developed by the ELHEP2 group in the Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller to stabilize the vector sum of fields in cavities of one cryo-module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. The synchronic, optical link project was made for the accelerator X-FEL laser TESLA, the LLRF control system experiment at DESY, Hamburg. The control and diagnostic data is transmitted up to 2.5Gbit/s through a plastic fiber in a distance up to a few hundred meters. The link is synchronized once after power up, and never resynchronized when data is transmitted with maximum speed. The one way link bit error rate is less then 10{sup -15}. The transceiver component written in VHDL that works in the dedicated Altera registered Stratix registered GX FPGA circuit. During the work in the PERG laboratory a 2,5Gbit/s serial link with the long vector parallel interface transceiver was created. Long-Data-Vector transceiver transmits 16bit vector each 8ns with 120ns latency. (orig.)

Synchronic, optical transmission data link integrated with FPGA circuits (for TESLA LLRF control system)

International Nuclear Information System (INIS)

Zielinski, J.S.

2006-05-01

The X-ray free-electron laser X-FEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new possibilities for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated to the LLRF1 system in VUV FEL experiment It is being developed by the ELHEP2 group in the Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller to stabilize the vector sum of fields in cavities of one cryo-module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. The synchronic, optical link project was made for the accelerator X-FEL laser TESLA, the LLRF control system experiment at DESY, Hamburg. The control and diagnostic data is transmitted up to 2.5Gbit/s through a plastic fiber in a distance up to a few hundred meters. The link is synchronized once after power up, and never resynchronized when data is transmitted with maximum speed. The one way link bit error rate is less then 10 -15 . The transceiver component written in VHDL that works in the dedicated Altera registered Stratix registered GX FPGA circuit. During the work in the PERG laboratory a 2,5Gbit/s serial link with the long vector parallel interface transceiver was created. Long-Data-Vector transceiver transmits 16bit vector each 8ns with 120ns latency. (orig.)

LLRF beam results on the first year of ELENA’s commissioning with beam

CERN Document Server

Angoletta, Maria Elena; Molendijk, John; Sanchez Quesada, Jorge; CERN. Geneva. ATS Department

2018-01-01

CERN’s Extra Low ENergy Antiproton (ELENA) ring’s commissioning with beam started in earnest in March 2017. Ions from an H- source were injected in ELENA at low energy, although in a degraded way (lower voltage and intensity than planned) and with not constant reproducibility of the injection. From August 2017 onwards antiprotons from the AD were also injected in ELENA at high energy for up to three, weekly MD session. The 2017 ELENA commissioning run stopped on December 1st to allow the installation of the electron cooler. This note gives an overview of the successful operation carried out by the ELENA Low-Level RF (LLRF) during the first year of ELENA commissioning and of the main beam results obtained. Operation with H- ions and with antiprotons are considered, together with different operational settings and problems encountered. Hints on future deployment and commissioning steps are also provided.

A 96 channel receiver for the ILCTA LLRF system at Fermilab

International Nuclear Information System (INIS)

Mavric, Uros; Chase, Brian; Branlard, Julien; Cullerton, Ed; Klepec, Dan; Fermilab

2007-01-01

The present configuration of an ILC main LINAC RF station has 26 nine cell cavities driven from one klystron. With the addition of waveguide power coupler monitors, 96 RF signals will be down-converted and processed. A down-converter chassis is being developed that contains 12 eight channel analog modules and a single upconverter module. This chassis will first be deployed for testing a cryomodule composed of eight cavities located at New Muon Laboratory (NML) - Fermilab. Critical parts of the design for LLRF applications are identified and a detailed description of the circuit with various characteristic measurements is presented. The board is composed of an input band-pass filter centered at 1.3GHz, followed by a mixer, which down-converts the cavity probe signal to a proposed 13 MHz intermediate frequency. Cables with 8 channels per connector and good isolation between channels are being used to interconnect each down-converter module with a digital board. As mixers, amplifiers and power splitters are the most sensitive parts for noise, nonlinearities and crosstalk issues, special attention is given to these parts in the design of the LO port multiplication and distribution

LLRF Control of High Loaded-Q Cavities for the LCLS-II

Energy Technology Data Exchange (ETDEWEB)

Serrano, Carlos [LBNL, Berkeley; Babel, Sandeep [SLAC; Bachimanchi, Ramakrishna [Jefferson Lab; Boyes, Matt [SLAC; Chase, Brian [Fermilab; Cullerton, Ed [Fermilab; Doolittle, Lawrence [LBNL, Berkeley; Einstein, Joshua [Fermilab; Hong, Bo [SLAC; Hovater, Curt [Jefferson Lab; Huang, Gang [LBNL, Berkeley; Ratti, Alessandro [LBNL, Berkeley

2016-06-01

The SLAC National Accelerator Laboratory is planning an upgrade (LCLS-II) to the Linear Coherent Light Source with a 4 GeV CW Superconducting Radio Frequency (SCRF) linac. The nature of the machine places stringent requirements in the Low-Level RF (LLRF) system, expected to control the cavity fields within 0.01 degrees in phase and 0.01% in amplitude, which is equivalent to a longitudinal motion of the cavity structure in the nanometer range. This stability has been achieved in the past but never for hundreds of superconducting cavities in Continuous-Wave (CW) operation. The difficulty resides in providing the ability to reject disturbances from the cryomodule, which is incompletely known as it depends on the cryomodule structure itself (currently under development at JLab and Fermilab) and the harsh accelerator environment. Previous experience in the field and an extrapolation to the cavity design parameters (relatively high Q_{L}c≈ 4×10⁷ , implying a half-bandwidth of around 16 Hz) suggest the use of strong RF feedback to reject the projected noise disturbances, which in turn demands careful engineering of the entire system.

High accuracy amplitude and phase measurements based on a double heterodyne architecture

International Nuclear Information System (INIS)

Zhao Danyang; Wang Guangwei; Pan Weimin

2015-01-01

In the digital low level RF (LLRF) system of a circular (particle) accelerator, the RF field signal is usually down converted to a fixed intermediate frequency (IF). The ratio of IF and sampling frequency determines the processing required, and differs in various LLRF systems. It is generally desirable to design a universally compatible architecture for different IFs with no change to the sampling frequency and algorithm. A new RF detection method based on a double heterodyne architecture for wide IF range has been developed, which achieves the high accuracy requirement of modern LLRF. In this paper, the relation of IF and phase error is systematically analyzed for the first time and verified by experiments. The effects of temperature drift for 16 h IF detection are inhibited by the amplitude and phase calibrations. (authors)

Spectral and morphological analysis of the remnant of supernova 1987A with ALMA and ATCA

Energy Technology Data Exchange (ETDEWEB)

Zanardo, Giovanna; Staveley-Smith, Lister [International Centre for Radio Astronomy Research (ICRAR), M468, University of Western Australia, Crawley, WA 6009 (Australia); Indebetouw, Remy; Chevalier, Roger A. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Matsuura, Mikako; Barlow, Michael J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Gaensler, Bryan M. [Australian Research Council, Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Fransson, Claes; Lundqvist, Peter [Department of Astronomy, Oskar Klein Center, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Manchester, Richard N. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Baes, Maarten [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Kamenetzky, Julia R. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States); Lakićević, Maša [Institute for the Environment, Physical Sciences and Applied Mathematics, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Marcaide, Jon M. [Departamento de Astronomía, Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Martí-Vidal, Ivan [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Meixner, Margaret [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ng, C.-Y. [Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong (China); Park, Sangwook, E-mail: giovanna.zanardo@gmail.com [Department of Physics, University of Texas at Arlington, 108 Science Hall, Box 19059, Arlington, TX 76019 (United States); and others

2014-12-01

We present a comprehensive spectral and morphological analysis of the remnant of supernova (SN) 1987A with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The non-thermal and thermal components of the radio emission are investigated in images from 94 to 672 GHz (λ 3.2 mm to 450 μm), with the assistance of a high-resolution 44 GHz synchrotron template from the ATCA, and a dust template from ALMA observations at 672 GHz. An analysis of the emission distribution over the equatorial ring in images from 44 to 345 GHz highlights a gradual decrease of the east-to-west asymmetry ratio with frequency. We attribute this to the shorter synchrotron lifetime at high frequencies. Across the transition from radio to far infrared, both the synchrotron/dust-subtracted images and the spectral energy distribution (SED) suggest additional emission beside the main synchrotron component (S {sub ν}∝ν{sup –0.73}) and the thermal component originating from dust grains at T ∼ 22 K. This excess could be due to free-free flux or emission from grains of colder dust. However, a second flat-spectrum synchrotron component appears to better fit the SED, implying that the emission could be attributed to a pulsar wind nebula (PWN). The residual emission is mainly localized west of the SN site, as the spectral analysis yields –0.4 ≲ α ≲ –0.1 across the western regions, with α ∼ 0 around the central region. If there is a PWN in the remnant interior, these data suggest that the pulsar may be offset westward from the SN position.

Performance of Ferrite Vector Modulators in the LLRF System of the Fermilab HINS 6-Cavity Test

Energy Technology Data Exchange (ETDEWEB)

Varghese, Philip [Fermilab; Barnes, Barry [Fermilab; Chase, Brian [Fermilab; Cullerton, Ed [Fermilab; Tan, Cong [Fermilab

2013-04-01

The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton Hsup>- linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

Development of digital low level rf system

International Nuclear Information System (INIS)

Michizono, Shinichiro; Anami, Shozo; Katagiri, Hiroaki; Fang, Zhigao; Matsumoto, Toshihiro; Miura, Takako; Yano, Yoshiharu; Yamaguchi, Seiya; Kobayashi, Tetsuya

2008-01-01

One of the biggest advantages of the digital low level rf (LLRF) system is its flexibility. Owing to the recent rapid progress in digital devices (such as ADCs and DACs) and telecommunication devices (mixers and IQ modulators), digital LLRF system becomes popular in these 10 years. The J-PARC linac LLRF system adopted cPCI crates and FPGA based digital feedback system. Since the LLRF control of the normal conducting cavities are more difficult than super conducting cavities due to its lower Q values, fast processing using the FPGA was the essential to the feedback control. After the successful operation of J-PARC linac LLRF system, we developed the STF (ILC test facility in KEK) LLRF system. Since the klystron drives eight cavities in STF phase 1, we modified the FPGA board. Basic configuration and the performances of these systems are summarized. The future R and D projects (ILC and ERL) is also described from the viewpoints of LLRF. (author)

Effect Analysis of Early Warning for Abandoned Object on Highway Based on Internet-of-Vehicles CA Model

Directory of Open Access Journals (Sweden)

Juan Bao

2018-01-01

Full Text Available An early warning on the highway will effectively reduce traffic accidents. Considering the influence of an abandoned object on driving behavior, a Visual-based Asymmetric Two-lane Cellular Automata model with Abandoned Object (V-ATCA-AO and an Internet-of-Vehicles-based Asymmetric Two-lane Cellular Automata model with Abandoned Object (IoV-ATCA-AO are proposed. Based on the two models, two types of traffic accidents caused by an abandoned object are analyzed: rear-end collision caused by the abandoned object ahead and collision of the vehicle with the abandoned object. Simulation results show the following: (1 the accidents occur when the road density is smaller, while the accidents will not occur when the density is larger. The results are different from the rear-end collision rate curve without abandoned object in a single lane. (2 Compared with the visual-based avoidance pattern in V-ATCA-AO, the Internet-of-Vehicles-based avoidance pattern in IoV-ATCA-AO can create an early warning for the abandoned object and tell the vehicle to make an earlier lane change and decelerate in advance, thereby significantly reducing the accident rate. (3 Spatiotemporal characteristics in front of the abandoned object directly affect the accident rate: the less the “stability” of a traffic jam in front of the abandoned object, the higher the accident rate.

Architecture design of the application software for the low-level RF control system of the free-electron laser at Hamburg

International Nuclear Information System (INIS)

Geng, Z.; Ayvazyan, V.; Simrock, S.

2012-01-01

The superconducting linear accelerator of the Free-Electron Laser at Hamburg (FLASH) provides high performance electron beams to the lasing system to generate synchrotron radiation to various users. The Low-Level RF (LLRF) system is used to maintain the beam stabilities by stabilizing the RF field in the superconducting cavities with feedback and feed forward algorithms. The LLRF applications are sets of software to perform RF system model identification, control parameters optimization, exception detection and handling, so as to improve the precision, robustness and operability of the LLRF system. In order to implement the LLRF applications in the hardware with multiple distributed processors, an optimized architecture of the software is required for good understandability, maintainability and extendibility. This paper presents the design of the LLRF application software architecture based on the software engineering approach for FLASH. (authors)

Research of high speed data readout and pre-processing system based on xTCA for silicon pixel detector

International Nuclear Information System (INIS)

Zhao Jingzhou; Lin Haichuan; Guo Fang; Liu Zhen'an; Xu Hao; Gong Wenxuan; Liu Zhao

2012-01-01

As the development of the detector, Silicon pixel detectors have been widely used in high energy physics experiments. It needs data processing system with high speed, high bandwidth and high availability to read data from silicon pixel detectors which generate more large data. The same question occurs on Belle II Pixel Detector which is a new style silicon pixel detector used in SuperKEKB accelerator with high luminance. The paper describes the research of High speed data readout and pre-processing system based on xTCA for silicon pixel detector. The system consists of High Performance Computer Node (HPCN) based on xTCA and ATCA frame. The HPCN consists of 4XFPs based on AMC, 1 AMC Carrier ATCA Board (ACAB) and 1 Rear Transmission Module. It characterized by 5 high performance FPGAs, 16 fiber links based on RocketIO, 5 Gbit Ethernet ports and DDR2 with capacity up to 18GB. In a ATCA frame, 14 HPCNs make up a system using the high speed backplane to achieve the function of data pre-processing and trigger. This system will be used on the trigger and data acquisition system of Belle II Pixel detector. (authors)

Development of EPICS Input Output Controller and User Interface for the PEFP Low Level RF Control System

International Nuclear Information System (INIS)

Song, Young Gi; Kim, Han Sung; Seol, Kyung Tae; Kwon, Hyeok Jung; Cho, Yong Sub

2010-01-01

The Low-Level RF (LLRF) control system of the Proton Engineering Frontier Project (PEFP) was developed for handling the driving frequency for Quadrupole (RFQ) and the Draft Tube Linac (DTL) cavities in 2006. The RF amplitude and phase of the accelerating field were controlled within 1% and 1 degree by stability requirements, respectively. Operators have been using the LLRF control system under the windows based text console mode as an operator interface. The LLRF control system could not be integrated with Experimental Physics Industrial Control System (EPICS) Input Output Controllers (IOC) for each subsection of PEFP facility. The main objective of this study is to supply operators of the LLRF control system with user friendly and convenient operating environment. The new LLRF control system is composed of a Verse Module Eurocard (VME) baseboard, a PCI Mezzanine Card (PMC), Board Support Package (BSP), EPICS software tool and a Real-Time Operating System (RTOS) VxWorks. A test with a dummy cavity of the new LLRF control system shows that operators can control and monitor operation parameters for a desired feedback action by using EPICS Channel Access (CA).

Development of EPICS Input Output Controller and User Interface for the PEFP Low Level RF Control System

Energy Technology Data Exchange (ETDEWEB)

Song, Young Gi; Kim, Han Sung; Seol, Kyung Tae; Kwon, Hyeok Jung; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-05-15

The Low-Level RF (LLRF) control system of the Proton Engineering Frontier Project (PEFP) was developed for handling the driving frequency for Quadrupole (RFQ) and the Draft Tube Linac (DTL) cavities in 2006. The RF amplitude and phase of the accelerating field were controlled within 1% and 1 degree by stability requirements, respectively. Operators have been using the LLRF control system under the windows based text console mode as an operator interface. The LLRF control system could not be integrated with Experimental Physics Industrial Control System (EPICS) Input Output Controllers (IOC) for each subsection of PEFP facility. The main objective of this study is to supply operators of the LLRF control system with user friendly and convenient operating environment. The new LLRF control system is composed of a Verse Module Eurocard (VME) baseboard, a PCI Mezzanine Card (PMC), Board Support Package (BSP), EPICS software tool and a Real-Time Operating System (RTOS) VxWorks. A test with a dummy cavity of the new LLRF control system shows that operators can control and monitor operation parameters for a desired feedback action by using EPICS Channel Access (CA).

Real-Time IPMI Protocol Analyzer

CERN Document Server

Kozak, T; Makowski, D

2011-01-01

The Advanced Telecommunications Computing Ar- chitecture (ATCA) is a modern platform, which gains popularity, not only in telecommunication, but also in others fields like High Energy Physics (HEP) experiments. Computing systems based on ATCA provide high performance and efficiency and are char- acterized by significant reliability, availability and serviceability. ATCA offers these features because of an integrated manage- ment system realized by the Intelligent Platform Management Interface (IPMI) implemented on dedicated Intelligent Platform Management Controller (IPMC). IPMC is required on each ATCA board to fulfill the ATCA standard and is responsible for many vital procedures performed to support proper operation of ATCA system. It covers, among others, activation and deactivations of modules, monitoring of actual parameters or controlling fans. The commercially available IPMI implementations are expensive and often not suited to demands of specific ATCA applications and available hardware. Thus, many r...

Low Level RF Control System of J-PARC Synchrotrons

CERN Document Server

Tamura, Fumihiko; Ezura, Eizi; Hara, Keigo; Nomura, Masahiro; Ohmori, Chihiro; Schnase, Alexander; Takagi, Akira; Yamamoto, Masanobu; Yoshii, Masahito

2005-01-01

We present the concept and the design of the low level RF (LLRF) control system of the J-PARC synchrotrons. The J-PARC synchrotrons are the rapid cycling 3-GeV synchrotron (RCS) and the 50-GeV main ring (MR) which require very precise and stable LLRF control systems to accelerate the ultra-high proton beam current. The LLRF system of the synchrotron is a full-digital system based on the direct digital synthesis (DDS). The functions of the system are (1) the multi-harmonic RF generation for the acceleration and the longitudinal bunch shaping, (2) the feedbacks for stabilizing the beam, (3) the feedforward for compensating the heavy beam loading, and (4) other miscellaneous functions such as the synchronization and chopper timing. The LLRF system of the RCS is now under construction. We present the details of the system. Also, we show preliminary results of performance tests of the control modules.

FPGA remote update for nuclear environments

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Ana; Pereira, Rita C.; Sousa, Jorge; Carvalho, Paulo F.; Correia, Miguel; Rodrigues, Antonio P.; Carvalho, Bernardo B.; Goncalves, Bruno [Instituto de Plasmasbe Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, 1049-001 Lisboa, (Portugal); Correia, Carlos M.B.A. [Centro de Instrumentacao, Dept. de Fisica, Universidade de Coimbra, 3004-516 Coimbra, (Portugal)

2015-07-01

The Instituto de Plasmas e Fusao Nuclear (IPFN) has developed dedicated re-configurable modules based on field programmable gate array (FPGA) devices for several nuclear fusion machines worldwide. Moreover, new Advanced Telecommunication Computing Architecture (ATCA) based modules developed by IPFN are already included in the ITER catalogue. One of the requirements for re-configurable modules operating in future nuclear environments including ITER is the remote update capability. Accordingly, this work presents an alternative method for FPGA remote programing to be implemented in new ATCA based re-configurable modules. FPGAs are volatile devices and their programming code is usually stored in dedicated flash memories for properly configuration during module power-on. The presented method is capable to store new FPGA codes in Serial Peripheral Interface (SPI) flash memories using the PCIexpress (PCIe) network established on the ATCA back-plane, linking data acquisition endpoints and the data switch blades. The method is based on the Xilinx Quick Boot application note, adapted to PCIe protocol and ATCA based modules. (authors)

Local Group dSph radio survey with ATCA (I): observations and background sources

Science.gov (United States)

Regis, Marco; Richter, Laura; Colafrancesco, Sergio; Massardi, Marcella; de Blok, W. J. G.; Profumo, Stefano; Orford, Nicola

2015-04-01

Dwarf spheroidal (dSph) galaxies are key objects in near-field cosmology, especially in connection to the study of galaxy formation and evolution at small scales. In addition, dSphs are optimal targets to investigate the nature of dark matter. However, while we begin to have deep optical photometric observations of the stellar population in these objects, little is known so far about their diffuse emission at any observing frequency, and hence on thermal and non-thermal plasma possibly residing within dSphs. In this paper, we present deep radio observations of six local dSphs performed with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength. We mosaicked a region of radius of about 1 deg around three `classical' dSphs, Carina, Fornax, and Sculptor, and of about half of degree around three `ultrafaint' dSphs, BootesII, Segue2, and Hercules. The rms noise level is below 0.05 mJy for all the maps. The restoring beams full width at half-maximum ranged from 4.2 arcsec × 2.5 arcsec to 30.0 arcsec × 2.1 arcsec in the most elongated case. A catalogue including the 1392 sources detected in the six dSph fields is reported. The main properties of the background sources are discussed, with positions and fluxes of brightest objects compared with the FIRST, NVSS, and SUMSS observations of the same fields. The observed population of radio emitters in these fields is dominated by synchrotron sources. We compute the associated source number counts at 2 GHz down to fluxes of 0.25 mJy, which prove to be in agreement with AGN count models.

Capture cavity II results at FNAL

Energy Technology Data Exchange (ETDEWEB)

Branlard, Julien; Chase, Brian; Cancelo, G.; Carcagno, R.; Edwards, H.; Fliller, R.; Hanna, B.; Harms, Elvan; Hocker, A.; Koeth, T.; Kucera, M.; /Fermilab

2007-06-01

As part of the research and development towards the International Linear Collider (ILC), several test facilities have been developed at Fermilab. This paper presents the latest Low Level RF (LLRF) results obtained with Capture Cavity II (CCII) at the ILC Test Accelerator (ILCTA) test facility. The main focus will be on controls and RF operations using the SIMCON based LLRF system developed in DESY [1]. Details about hardware upgrades and future work will be discussed.

The upgrade for the data acquisition system of the KOTO detector

Energy Technology Data Exchange (ETDEWEB)

Tecchio, M., E-mail: tecchio@umich.edu [University of Michigan, Ann Arbor, MI (United States); Beechert, J.; Campbell, M. [University of Michigan, Ann Arbor, MI (United States); Huff, M. [Kenyon College, Gambier, OH (United States); Micallef, J.; Rymph, C.; Schamis, H.; Su, S. [University of Michigan, Ann Arbor, MI (United States); Xu, J. [Apple Inc., Cupertino, CA (United States)

2016-07-11

A major upgrade to the KOTO detector data acquisition system based on the ATCA standard is being considered. The ATCA standard provides a natural solution to the current KOTO constraints, including communication between boards and higher input and output bandwidth.

The upgrade for the data acquisition system of the KOTO detector

International Nuclear Information System (INIS)

Tecchio, M.; Beechert, J.; Campbell, M.; Huff, M.; Micallef, J.; Rymph, C.; Schamis, H.; Su, S.; Xu, J.

2016-01-01

A major upgrade to the KOTO detector data acquisition system based on the ATCA standard is being considered. The ATCA standard provides a natural solution to the current KOTO constraints, including communication between boards and higher input and output bandwidth.

DOOCS based control system for FPGA based cavity simulator and controller in VUV FEL

International Nuclear Information System (INIS)

Pucyk, P.

2005-09-01

The X-ray free-electron laser XFEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new perspectives for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated for LLRF 1 system in VUV FEL experiment It is being developed by ELHEP 2 group in Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller for stabilizing the vector sum of fields in cavities of one cryo module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. Ths paper describes the concept, implementation and tests of the DOOCS based control system for SIMCON. The designed system is based the concept of autonomic and extendable modules connected by well defined, unified interfaces. The communication module controls the access to the hardware. It is crucial, that all modules (this presented in thesis and developed in the future) use this interface. Direct access to the control tables let the engineers to perform algorithm development or diagnostic measurements of the LLRF system. Default control tables generator makes the whole SIMCON an autonomic device, which can start immediately the operation without any additional tools. (orig.)

DOOCS based control system for FPGA based cavity simulator and controller in VUV FEL

International Nuclear Information System (INIS)

Pucyk, P.D.

2006-03-01

The X-ray free-electron laser XFEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new perspectives for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated for LLRF 1 system in VUV FEL experiment It is being developed by ELHEP 2 group in Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller for stabilizing the vector sum of fields in cavities of one cryo module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. This paper describes the concept, implementation and tests of the DOOCS based control system for SIMCON. The designed system is based the concept of autonomic and extendable modules connected by well defined, unified interfaces. The communication module controls the access to the hardware. It is crucial, that all modules (this presented in thesis and developed in the future) use this interface. Direct access to the control tables let the engineers to perform algorithm development or diagnostic measurements of the LLRF system. Default control tables generator makes the whole SIMCON an autonomic device, which can start immediately the operation without any additional tools. (Orig.)

Simulation experiment on low-level RF control for dual-harmonic acceleration at CSNS RCS

International Nuclear Information System (INIS)

Shen Sirong; Li Xiao; Zhang Chunlin; Sun Hong; Tang Jingyu

2013-01-01

The design and test of the low-level RF (LLRF) control system for the dual-harmonic acceleration at the rapid cycling synchrotron (RCS) of China Spallation Neutron Source (CSNS) at phase Ⅰ is introduced. In order to implement the mode switch from the second harmonic to the fundamental during the acceleration cycle for one of the eight RF cavities, the LLRF system for the cavity has been designed differently from the others. Several technical measures such as the opening of the control loops during the mode switch and the reclosing of two tuning circuits of the RF amplifier at different moments, have been taken. The experimental results on the testing platform based on an RF prototype show good dynamic performance of the LLRF system and prove the feasibility of dual-harmonic operation. (authors)

Local Group dSph radio survey with ATCA (III): constraints on particle dark matter

International Nuclear Information System (INIS)

Regis, Marco; Colafrancesco, Sergio; Profumo, Stefano; De Blok, W.J.G.; Massardi, Marcella; Richter, Laura

2014-01-01

We performed a deep search for radio synchrotron emissions induced by weakly interacting massive particles (WIMPs) annihilation or decay in six dwarf spheroidal (dSph) galaxies of the Local Group. Observations were conducted with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength, with an rms sensitivity better than 0.05 mJy/beam in each field. In this work, we first discuss the uncertainties associated with the modeling of the expected signal, such as the shape of the dark matter (DM) profile and the dSph magnetic properties. We then investigate the possibility that point-sources detected in the proximity of the dSph optical center might be due to the emission from a DM cuspy profile. No evidence for an extended emission over a size of few arcmin (which is the DM halo size) has been detected. We present the associated bounds on the WIMP parameter space for different annihilation/decay final states and for different astrophysical assumptions. If the confinement of electrons and positrons in the dSph is such that the majority of their power is radiated within the dSph region, we obtain constraints on the WIMP annihilation rate which are well below the thermal value for masses up to few TeV. On the other hand, for conservative assumptions on the dSph magnetic properties, the bounds can be dramatically relaxed. We show however that, within the next 10 years and regardless of the astrophysical assumptions, it will be possible to progressively close in on the full parameter space of WIMPs by searching for radio signals in dSphs with SKA and its precursors

Local Group dSph radio survey with ATCA (III): constraints on particle dark matter

Energy Technology Data Exchange (ETDEWEB)

Regis, Marco [Dipartimento di Fisica, Università di Torino, via P. Giuria 1, I-10125 Torino (Italy); Colafrancesco, Sergio [School of Physics, University of the Witwatersrand, Johannesburg (South Africa); Profumo, Stefano [Department of Physics, University of California, 1156 High St., Santa Cruz, CA 95064 (United States); De Blok, W.J.G. [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Massardi, Marcella [INAF—Istituto di Radioastronomia, Via Gobetti 101, I-40129, Bologna (Italy); Richter, Laura, E-mail: regis@to.infn.it, E-mail: sergio.colafrancesco@wits.ac.za, E-mail: profumo@ucsc.edu, E-mail: blok@astron.nl, E-mail: massardi@ira.inaf.it, E-mail: laura@ska.ac.za [SKA South Africa, 3rd Floor, The Park, Park Road, Pinelands, 7405 (South Africa)

2014-10-01

We performed a deep search for radio synchrotron emissions induced by weakly interacting massive particles (WIMPs) annihilation or decay in six dwarf spheroidal (dSph) galaxies of the Local Group. Observations were conducted with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength, with an rms sensitivity better than 0.05 mJy/beam in each field. In this work, we first discuss the uncertainties associated with the modeling of the expected signal, such as the shape of the dark matter (DM) profile and the dSph magnetic properties. We then investigate the possibility that point-sources detected in the proximity of the dSph optical center might be due to the emission from a DM cuspy profile. No evidence for an extended emission over a size of few arcmin (which is the DM halo size) has been detected. We present the associated bounds on the WIMP parameter space for different annihilation/decay final states and for different astrophysical assumptions. If the confinement of electrons and positrons in the dSph is such that the majority of their power is radiated within the dSph region, we obtain constraints on the WIMP annihilation rate which are well below the thermal value for masses up to few TeV. On the other hand, for conservative assumptions on the dSph magnetic properties, the bounds can be dramatically relaxed. We show however that, within the next 10 years and regardless of the astrophysical assumptions, it will be possible to progressively close in on the full parameter space of WIMPs by searching for radio signals in dSphs with SKA and its precursors.

Digital low level rf control system with four different intermediate frequencies for the International Linear Collider

Science.gov (United States)

Wibowo, Sigit Basuki; Matsumoto, Toshihiro; Michizono, Shinichiro; Miura, Takako; Qiu, Feng; Liu, Na

2017-09-01

A field programmable gate array-based digital low level rf (LLRF) control system will be used in the International Linear Collider (ILC) in order to satisfy the rf stability requirements. The digital LLRF control system with four different intermediate frequencies has been developed to decrease the required number of analog-to-digital converters in this system. The proof of concept of this technique was demonstrated at the Superconducting RF Test Facility in the High Energy Accelerator Research Organization, Japan. The amplitude and phase stability has fulfilled the ILC requirements.

Embedded system in FPGA-based LLRF controller for FLASH

Science.gov (United States)

Szewinski, Jaroslaw; Pucyk, Piotr; Jalmuzna, Wojciech; Fafara, Przemyslaw; Pieciukiewicz, Marcin; Romaniuk, Ryszard; Pozniak, Krzysztof T.

2006-10-01

FPGA devices are often used in High Energy Physics and accelerator technology experiments, where the highest technologies are needed. To make FPGA based systems more flexible, common technique is to provide SoC (System on a Chip) solution in the FPGA, which is in most cases a CPU unit. Such a combination gives possibility to balance between hardware and software implementation of particular task. SoC solution on FPGA can be very flexible, because in simplest cases no additional hardware is needed to run programs on CPU, and when system has such devices like UART, SDRAM memory, mass storage and network interface, it can handle full featured operating system such as Linux or VxWorks. Embedded process can be set up in different configurations, depending on the available resources on board, so every user can adjust system to his own needs. Embedded systems can be also used to perform partial self-reconfiguration of FPGA logic of the chip, on which the system is running. This paper will also present some results on SoC implementations in a Low Level RF system under design for the VUV Free Electron Laser, FLASH, DESY, Hamburg.

8-channel, FPGA based, DSP integrated cavity simulator and controller for VUV-FEL. SIMCON 3.0 Ver. 3.0. rev. 1, 06.2005 - Hardware manual

International Nuclear Information System (INIS)

Pozniak, K.T.; Czarski, T.; Koprek, W.; Giergusiewicz, W.; Romaniuk, R.S.

2005-01-01

The note describes integrated, eight channel system of hardware controller and simulator of the resonant superconducting, narrowband niobium cavity, originally considered for the TTF and TESLA in DESY, Hamburg (now tested for the VUV FEL and developed for X-Ray FEL). The controller bases on a programmable circuit Xilinx VirtexII V4000. The solution uses DSP EMBEDDED BOARD module positioned on a Modular LLRF Control Platform. The algorithm and FPGA circuit configuration was done in the VHDL language. The internal hardware multiplication components, present in Virtex II chips, were used, to improve the floating point calculation efficiency. The implementation was achieved of a device working in the real time, according to the demands of the LLRF control system for the TESLA Test Facility (now associated with the VUV FEL machine). The device under consideration will be referred to as superconducting cavity (SCCav) SIMCON throughout this work. The manual describes hardware features of SIMCON, ver. 3.0 in modular solution. The following components are described here in detail: functional layer, parameter programming, foundations of control of particular blocks and monitoring of the real time processes. This note is accompanied by the one describing the multichannel DOOCS interface for the described hardware system. The interface was prepared in DOOCS for Solaris and in Windows. The hardware and software of 8-channel SIMCON was tested in CHECIA and ACC1 module of VUV FEL linac. The measurements results are presented. While giving all necessary technical details required to understand the work of the integrated hardware controller and simulator and to enable its practical copying, this document is a unity with other TESLA technical notes published by the same team on the subject. Thus, some modeling and other subjects were omitted, as they were addressed in detail in the quoted references. Keywords: Super conducting cavity, cavity simulator, CAVITIES CONTROLLER, SIMCON

Operational experience with the new LEIR digital low-level RF System

CERN Document Server

Angoletta, ME

2010-01-01

The LEIR Low-Level (LLRF) system is the first all-digital low LLRF system that has been put into operation in a CERN circular machine. It is a very compact system, composed of one VME64x crate and of few NIM modules. System capabilities include typical beam control tasks, such as frequency program, beam phase, radial and extraction synchronization feedback loops, as well as cavity voltage/phase feedback loops. The system is also capable of coping with the large variation of the revolution frequency during an acceleration cycle as well as with the high dynamic range required by the LEIR cavities operation. Extensive diagnostics and observation capabilities are built-in and the system’s control parameters are fully configurable remotely and in-between cycles. Over the various LEIR runs, the LLRF system has proven to be reliable and reproducible as well as extremely flexible and powerful. These characteristics are essential for a LLRF system and LEIR is already profiting from them. Moreover, high beam availabi...

Fundamental cavity impedance and longitudinal coupled-bunch instabilities at the High Luminosity Large Hadron Collider

Directory of Open Access Journals (Sweden)

P. Baudrenghien

2017-01-01

Full Text Available The interaction between beam dynamics and the radio frequency (rf station in circular colliders is complex and can lead to longitudinal coupled-bunch instabilities at high beam currents. The excitation of the cavity higher order modes is traditionally damped using passive devices. But the wakefield developed at the cavity fundamental frequency falls in the frequency range of the rf power system and can, in theory, be compensated by modulating the generator drive. Such a regulation is the responsibility of the low-level rf (llrf system that measures the cavity field (or beam current and generates the rf power drive. The Large Hadron Collider (LHC rf was designed for the nominal LHC parameter of 0.55 A DC beam current. At 7 TeV the synchrotron radiation damping time is 13 hours. Damping of the instability growth rates due to the cavity fundamental (400.789 MHz can only come from the synchrotron tune spread (Landau damping and will be very small (time constant in the order of 0.1 s. In this work, the ability of the present llrf compensation to prevent coupled-bunch instabilities with the planned high luminosity LHC (HiLumi LHC doubling of the beam current to 1.1 A DC is investigated. The paper conclusions are based on the measured performances of the present llrf system. Models of the rf and llrf systems were developed at the LHC start-up. Following comparisons with measurements, the system was parametrized using these models. The parametric model then provides a more realistic estimation of the instability growth rates than an ideal model of the rf blocks. With this modeling approach, the key rf settings can be varied around their set value allowing for a sensitivity analysis (growth rate sensitivity to rf and llrf parameters. Finally, preliminary measurements from the LHC at 0.44 A DC are presented to support the conclusions of this work.

Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators

Energy Technology Data Exchange (ETDEWEB)

Mastoridis, Themistoklis [Stanford Univ., CA (United States)

2010-08-01

The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accelerator currents and energies. Stability of the RF loop and the beam are necessary conditions for reliable machine operation. This dissertation describes theoretical formalisms and models that determine the longitudinal beam dynamics based on the LLRF implementation, time domain simulations that capture the dynamic behavior of the RF station-beam interaction, and measurements from the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC) that validate the models and simulations. These models and simulations are structured to capture the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They also provide the opportunity to study diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Coupled-bunch instabilities and RF station power were the performance limiting effects for PEP-II. The sensitivity of the instabilities to individual LLRF parameters, the effectiveness of alternative operational algorithms, and the possible tradeoffs between RF loop and beam stability were studied. New algorithms were implemented, with significant performance improvement leading to a world record current during the last PEP-II run of 3212 mA for the Low Energy Ring. Longitudinal beam emittance growth due to RF noise is a major concern for LHC

FPGA based, DSP integrated, 8-channel SIMCON, ver. 3.0. Initial results for 8-channel algorithm

Energy Technology Data Exchange (ETDEWEB)

Giergusiewicz, W.; Koprek, W.; Jalmuzna, W.; Pozniak, K.T.; Romaniuk, R.S. [Warsaw Univ. of Technology (Poland). Inst. of Electronic Systems

2005-07-01

The paper describes design, construction and initial measurements of an eight channel electronic LLRF device predicted for building of the control system for the VUV-FEL accelerator at DESY (Hamburg). The device, referred in the paper to as the SIMCON 3.0 (from the SC cavity simulator and controller) consists of a 16 layer, VME size, PCB, a large FPGA chip (VirtexII-4000 by Xilinx), eight fast ADCs and four DACs (by Analog Devices). To our knowledge, the proposed device is the first of this kind for the accelerator technology in which there was achieved (the FPGA based) DSP latency below 200 ns. With the optimized data transmission system, the overall LLRF system latency can be as low as 500 ns. The SIMCON 3.0 sub-system was applied for initial tests with the ACC1 module of the VUV FEL accelerator (eight channels) and with the CHECHIA test stand (single channel), both at the DESY. The promising results with the SIMCON 3.0. encouraged us to enter the design of SIMCON 3.1. possessing 10 measurement and control channels and some additional features to be reported in the next technical note. SIMCON 3.0. is a modular solution, while SIMCON 3.1. will be an integrated board of the all-in-one type. Two design approaches - modular and all-in-one, after branching off in this version of the Simcon, will be continued. (orig.)

FPGA-based 10-Gbit Ethernet Data Acquisition Interface for the Upgraded Electronics of the ATLAS Liquid Argon Calorimeters

CERN Document Server

Grohs, J P; The ATLAS collaboration

2013-01-01

The readout of the trigger signals of the ATLAS Liquid Argon (LAr) calorimeters is foreseen to be upgraded in order to prepare for operation during the first high-luminosity phase of the Large Hadron Collider (LHC). Signals with improved spatial granularity are planned to be received from the detector by a Digitial Processing System (DPS) in ATCA technology and will be sent in real-time to the ATLAS trigger system using custom optical links. These data are also sampled by the DPS for monitoring and will be read out by the regular Data Acquisition (DAQ) system of ATLAS which is a network-based PC-farm. The bandwidth between DPS module and DAQ system is expected to be in the order of 10 Gbit/s per module and a standard Ethernet protocol is foreseen to be used. DSP data will be prepared and sent by a modern FPGA either through a switch or directly to a Read-Out System (ROS) PC serving as buffer interface of the ATLAS DAQ. In a prototype setup, an ATCA blade equipped with a Xilinx Virtex-5 FPGA is used to send da...

EPICS based low-level radio frequency control system in LIPAc

Energy Technology Data Exchange (ETDEWEB)

Calvo, Julio, E-mail: julio.calvo@ciemat.es [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Ciemat (Spain); Rivers, Mark L. [Department of Geophysical Sciences and Center for Advanced Radiation Sources, The University of Chicago (United States); Patricio, Miguel A. [Departamento de Informatica, Universidad Carlos III de Madrid (Spain); Ibarra, Angel [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Ciemat (Spain)

2012-11-15

Highlights: Black-Right-Pointing-Pointer The system proposed can control amplitude and phase of each cavity. Black-Right-Pointing-Pointer Rapid diagnostics are refreshed in milliseconds. Black-Right-Pointing-Pointer Increasing control parameters will not increase consumed time neither complexity. Black-Right-Pointing-Pointer IQ demodulation can be achieved thanks to the transformed values at driver level. - Abstract: The IFMIF-EVEDA (International Fusion Materials Irradiation Facility - Engineering Validation and Engineering Design Activity) linear accelerator, known as Linear IFMIF Prototype Accelerator (LIPAc), will be a 9 MeV, 125 mA continuous wave (CW) deuteron accelerator prototype to validate the technical options of the accelerator design for IFMIF. The primary mission of such facility is to test and verify materials performance when subjected to extensive neutron irradiation of the type encountered in a fusion reactor to prepare for the design, construction, licensing and safe operation of a fusion demonstration reactor (DEMO). The radio frequency (RF) power system of IFMIF-EVEDA consists of 18 RF chains working at 175 MHz with three amplification stages each. The low-level radio frequency (LLRF) controls the amplitude and phase of the signal to be synchronized with the beam and it also controls the resonance frequency of the cavities. The system is based on a commercial compact peripheral component interconnect (cPCI) field programmable gate array (FPGA) board, provided by Lyrtech and controlled by a Windows host PC. For this purpose, it is mandatory to communicate the cPCI FPGA board from EPICS Channel Access [1]. A software architecture on EPICS framework in order to control and monitor the LLRF system is presented.

Lessons learned from positron-electron project low level rf and longitudinal feedback

Directory of Open Access Journals (Sweden)

J. Fox

2010-05-01

Full Text Available The Positron-Electron Project II (PEP-II B Factory collider ended the final phase of operation at nearly twice the design current and 4X the design luminosity. In the ultimate operation state, eight 1.2 MW radio-frequency (rf klystrons and 12 accelerating cavities were added beyond the original implementation, and the two storage rings were operating with longitudinal instability growth rates roughly 5X in excess of the original design estimates. From initial commissioning there has been continual adaptation of the low level rf (LLRF control strategies, configuration tools, and some new hardware in response to unanticipated technical challenges. This paper offers a perspective on the original LLRF and longitudinal instability control design, and highlights via two examples the system evolution from the original design estimates through to the final machine with 1.2×10^{34} luminosity. The impact of unanticipated signals in the coupled-bunch longitudinal feedback and the significance of nonlinear processing elements in the LLRF systems are presented. We present valuable “lessons learned” which are of interest to designers of next generation feedback and impedance controlled LLRF systems.

Hardware trigger processor for the MDT system

CERN Document Server

AUTHOR|(SzGeCERN)757787; The ATLAS collaboration; Hazen, Eric; Butler, John; Black, Kevin; Gastler, Daniel Edward; Ntekas, Konstantinos; Taffard, Anyes; Martinez Outschoorn, Verena; Ishino, Masaya; Okumura, Yasuyuki

2017-01-01

We are developing a low-latency hardware trigger processor for the Monitored Drift Tube system in the Muon spectrometer. The processor will fit candidate Muon tracks in the drift tubes in real time, improving significantly the momentum resolution provided by the dedicated trigger chambers. We present a novel pure-FPGA implementation of a Legendre transform segment finder, an associative-memory alternative implementation, an ARM (Zynq) processor-based track fitter, and compact ATCA carrier board architecture. The ATCA architecture is designed to allow a modular, staged approach to deployment of the system and exploration of alternative technologies.

The correct estimate of the probability of false detection of the matched filter in weak-signal detection problems . II. Further results with application to a set of ALMA and ATCA data

Science.gov (United States)

Vio, R.; Vergès, C.; Andreani, P.

2017-08-01

The matched filter (MF) is one of the most popular and reliable techniques to the detect signals of known structure and amplitude smaller than the level of the contaminating noise. Under the assumption of stationary Gaussian noise, MF maximizes the probability of detection subject to a constant probability of false detection or false alarm (PFA). This property relies upon a priori knowledge of the position of the searched signals, which is usually not available. Recently, it has been shown that when applied in its standard form, MF may severely underestimate the PFA. As a consequence the statistical significance of features that belong to noise is overestimated and the resulting detections are actually spurious. For this reason, an alternative method of computing the PFA has been proposed that is based on the probability density function (PDF) of the peaks of an isotropic Gaussian random field. In this paper we further develop this method. In particular, we discuss the statistical meaning of the PFA and show that, although useful as a preliminary step in a detection procedure, it is not able to quantify the actual reliability of a specific detection. For this reason, a new quantity is introduced called the specific probability of false alarm (SPFA), which is able to carry out this computation. We show how this method works in targeted simulations and apply it to a few interferometric maps taken with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Australia Telescope Compact Array (ATCA). We select a few potential new point sources and assign an accurate detection reliability to these sources.

RF control hardware design for CYCIAE-100 cyclotron

Energy Technology Data Exchange (ETDEWEB)

Yin, Zhiguo, E-mail: bitbearAT@hotmail.com; Fu, Xiaoliang; Ji, Bin; Zhao, Zhenlu; Zhang, Tianjue; Li, Pengzhan; Wei, Junyi; Xing, Jiansheng; Wang, Chuan

2015-11-21

The Beijing Radioactive Ion-beam Facility project is being constructed by BRIF division of China Institute of Atomic Energy. In this project, a 100 MeV high intensity compact proton cyclotron is built for multiple applications. The first successful beam extraction of CYCIAE-100 cyclotron was done in the middle of 2014. The extracted proton beam energy is 100 MeV and the beam current is more than 20 μA. The RF system of the CYCIAE-100 cyclotron includes two half-wavelength cavities, two 100 kW tetrode amplifiers and power transmission line systems (all above are independent from each other) and two sets of Low Level RF control crates. Each set of LLRF control includes an amplitude control unit, a tuning control unit, a phase control unit, a local Digital Signal Process control unit and an Advanced RISC Machines based EPICS IOC unit. These two identical LLRF control crates share one common reference clock and take advantages of modern digital technologies (e.g. DSP and Direct Digital Synthesizer) to achieve closed loop voltage and phase regulations of the dee-voltage. In the beam commission, the measured dee-voltage stability of RF system is better than 0.1% and phase stability is better than 0.03°. The hardware design of the LLRF system will be reviewed in this paper.

Development of Low Level RF Control Systems for Superconducting Heavy Ion Linear Accelerators, Electron Synchrotrons and Storage Rings

CERN Document Server

Aminov, Bachtior; Kolesov, Sergej; Pekeler, Michael; Piel, Christian; Piel, Helmut

2005-01-01

Since 2001 ACCEL Instruments is supplying low level RF control systems together with turn key cavity systems. The early LLRF systems used the well established technology based on discrete analogue amplitude and phase detectors and modulators. Today analogue LLRF systems can make use of advanced vector demodulators and modulators combined with a fast computer controlled analogue feed back loop. Feed forward control is implemented to operate the RF cavity in an open loop mode or to compensate for predictable perturbations. The paper will introduce the general design philosophy and show how it can be adapted to different tasks as controlling a synchrotron booster nc RF system at 500 MHz, or superconducting storage ring RF cavities, as well as a linear accelerator at 176 MHz formed by a chain of individually driven and controlled superconducting λ/2 cavities.

Overview of the Spallation Neutron Source Linac Low-Level RF Control System

CERN Document Server

Champion, Mark; Doolittle, Lawrence; Kasemir, Kay-Uwe; Ma, Hengjie; Piller, Maurice; Ratti, Alessandro

2005-01-01

The design and production of the Spallation Neutron Source Linac Low-Level RF control system is complete, and installation will be finished in Spring 2005. The warm linac beam commissioning run in Fall 2004 was the most extensive test to date of the LLRF control system, with fourteen (of an eventual 96) systems operating simultaneously. In this paper we present an overview of the LLRF control system, the experience in designing, building and installing the system, and operational results.

Pseudo-variables method to calculate HMA relaxation modulus through low-temperature induced stress and strain

International Nuclear Information System (INIS)

Canestrari, Francesco; Stimilli, Arianna; Bahia, Hussain U.; Virgili, Amedeo

2015-01-01

Highlights: • Proposal of a new method to analyze low-temperature cracking of bituminous mixtures. • Reliability of the relaxation modulus master curve modeling through Prony series. • Suitability of the pseudo-variables approach for a close form solution. - Abstract: Thermal cracking is a critical failure mode for asphalt pavements. Relaxation modulus is the major viscoelastic property that controls the development of thermally induced tensile stresses. Therefore, accurate determination of the relaxation modulus is fundamental for designing long lasting pavements. This paper proposes a reliable analytical solution for constructing the relaxation modulus master curve by measuring stress and strain thermally induced in asphalt mixtures. The solution, based on Boltzmann’s Superposition Principle and pseudo-variables concepts, accounts for time and temperature dependency of bituminous materials modulus, avoiding complex integral transformations. The applicability of the solution is demonstrated by testing a reference mixture using the Asphalt Thermal Cracking Analyzer (ATCA) device. By applying thermal loadings on restrained and unrestrained asphalt beams, ATCA allows the determination of several parameters, but is still unable to provide reliable estimations of relaxation properties. Without them the measurements from ATCA cannot be used in modeling of pavement behavior. Thus, the proposed solution successfully integrates ATCA experimental data. The same methodology can be applied to all test methods that concurrently measure stress and strain. The statistical parameters used to evaluate the goodness of fit show optimum correlation between theoretical and experimental results, demonstrating the accuracy of this mathematical approach

An Update on ConSys Including a New LabVIEW FPGA Based LLRF System

DEFF Research Database (Denmark)

Worm, Torben; Nielsen, Jørgen S.

. This system use a National Instruments NI-PCIe7852R DAQ card, which includes an on-board FPGA and are hosted in a standard PC. The fast (50 kHz) amplitude loop has been implemented on the FPGA, whereas the slower tuning and phase loops are implemented in the real-time system. An operator interface including......ConSys, the Windows based control system for ASTRID and ASTRID2, is now a mature system, having been in operation for more than 15 years. All the standard programs (Console, plots, data logging, control setting store/restore etc.) are fully general and are configured through a database or file. Con......Sys is a standard publisher/subscriber system, where all nodes can act both as client and server. One very strong feature is the easy ability to make virtual devices (devices which do not depend on hardware directly, but combine hardware parameters.) For ASTRID2 a new LabVIEW based Low-Level RF system has been made...

Modeling and Simulation of Longitudinal Dynamics for Low Energy Ring-High Energy Ring at the Positron-Electron Project

International Nuclear Information System (INIS)

Rivetta, Claudio; Mastorides, T.; Fox, J.D.; Teytelman, D.; Van Winkle, D.

2007-01-01

A time domain dynamic modeling and simulation tool for beam-cavity interactions in the Low Energy Ring (LER) and High Energy Ring (HER) at the Positron-Electron Project (PEP-II) is presented. Dynamic simulation results for PEP-II are compared to measurements of the actual machine. The motivation for this tool is to explore the stability margins and performance limits of PEP-II radio-frequency (RF) systems at future higher currents and upgraded RF configurations. It also serves as a test bed for new control algorithms and can define the ultimate limits of the low-level RF (LLRF) architecture. The time domain program captures the dynamic behavior of the beam-cavity-LLRF interaction based on a reduced model. The ring current is represented by macrobunches. Multiple RF stations in the ring are represented via one or two macrocavities. Each macrocavity captures the overall behavior of all the 2 or 4 cavity RF stations. Station models include nonlinear elements in the klystron and signal processing. This enables modeling the principal longitudinal impedance control loops interacting via the longitudinal beam model. The dynamics of the simulation model are validated by comparing the measured growth rates for the LER with simulation results. The simulated behavior of the LER at increased operation currents is presented via low-mode instability growth rates. Different control strategies are compared and the effects of both the imperfections in the LLRF signal processing and the nonlinear drivers and klystrons are explored

THE Low-level Radio Frequency System for the superconducting cavities of National Synchrotron Light Source II

International Nuclear Information System (INIS)

Ma, H.; Rose, J.; Holub, B.; Cupolo, J.; Oliva, J.; Sikora, R.; Yeddulla, M.

2011-01-01

A digital low-level radio frequency (LLRF) field controller has been developed for the storage ring of The National Synchrotron Light Source-II (NSLS-II). The primary performance goal for the LLRF is to support the required RF operation of the superconducting cavities with a beam current of 500mA and a 0.14 degree or better RF phase stability. The digital field controller is FPGA-based, in a standard format 19-inch/I-U chassis. It has an option of high-level control support with MATLAB running on a local host computer through a USB2.0 port. The field controller has been field tested with the high-power superconducting RF (SRF) at Canadian light Source, and successfully stored a high beam current of 250 mA. The test results show that required specifications for the cavity RF field stability are met. This digital field controller is also currently being used as a development platform for other functional modules in the NSLS-II RF systems.

FPGA based compute nodes for high level triggering in PANDA

International Nuclear Information System (INIS)

Kuehn, W; Gilardi, C; Kirschner, D; Lang, J; Lange, S; Liu, M; Perez, T; Yang, S; Schmitt, L; Jin, D; Li, L; Liu, Z; Lu, Y; Wang, Q; Wei, S; Xu, H; Zhao, D; Korcyl, K; Otwinowski, J T; Salabura, P

2008-01-01

PANDA is a new universal detector for antiproton physics at the HESR facility at FAIR/GSI. The PANDA data acquisition system has to handle interaction rates of the order of 10 7 /s and data rates of several 100 Gb/s. FPGA based compute nodes with multi-Gb/s bandwidth capability using the ATCA architecture are designed to handle tasks such as event building, feature extraction and high level trigger processing. Data connectivity is provided via optical links as well as multiple Gb Ethernet ports. The boards will support trigger algorithms such us pattern recognition for RICH detectors, EM shower analysis, fast tracking algorithms and global event characterization. Besides VHDL, high level C-like hardware description languages will be considered to implement the firmware

New digital low-level rf system for heavy-ion synchrotrons

Directory of Open Access Journals (Sweden)

Harald Klingbeil

2011-10-01

Full Text Available In the scope of the Facility for Antiproton and Ion Research (FAIR project, several new synchrotrons and storage rings will be built. The existing heavy-ion synchrotron SIS18 has to be upgraded to serve as an injector for the FAIR accelerators. All this imposes new requirements on the low-level rf (LLRF systems. These requirements include fast ramping modes, arbitrary ion species, and complex beam manipulations such as dual-harmonic operation, bunch merging/splitting, barrier bucket operation, or bunch compression. In order to fulfill these tasks, a completely new and unique system architecture has been developed since 2002, and the system is now used in SIS18 operation. The presentation of this novel system architecture is the purpose of this paper. We first describe the requirements and the design of the LLRF system. Afterwards, some key components and key interfaces of the system are summarized followed by a discussion of technological aspects. Finally, we present some beam experiment results that were obtained using the new LLRF system.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Using 1.4 GHz ATCA & VLA images with 5.5 GHz ATCA data, we present a sample of 12 bent-tailed galaxies over the 4 deg2 area of the Chandra Deep Field South (CDFS). We find 10 new sources, one of which is possibly the highest red-shift bent-tailed galaxy detected at ∼ 2.

Building highly available control system applications with Advanced Telecom Computing Architecture and open standards

International Nuclear Information System (INIS)

Kazakov, Artem; Furukawa, Kazuro

2010-01-01

Requirements for modern and future control systems for large projects like International Linear Collider demand high availability for control system components. Recently telecom industry came up with a great open hardware specification - Advanced Telecom Computing Architecture (ATCA). This specification is aimed for better reliability, availability and serviceability. Since its first market appearance in 2004, ATCA platform has shown tremendous growth and proved to be stable and well represented by a number of vendors. ATCA is an industry standard for highly available systems. On the other hand Service Availability Forum, a consortium of leading communications and computing companies, describes interaction between hardware and software. SAF defines a set of specifications such as Hardware Platform Interface, Application Interface Specification. SAF specifications provide extensive description of highly available systems, services and their interfaces. Originally aimed for telecom applications, these specifications can be used for accelerator controls software as well. This study describes benefits of using these specifications and their possible adoption to accelerator control systems. It is demonstrated how EPICS Redundant IOC was extended using Hardware Platform Interface specification, which made it possible to utilize benefits of the ATCA platform.

Network Communication for Low Level RF Control

International Nuclear Information System (INIS)

Liu Weiqing; Yin Chengke; Zhang Tongxuan; Fu Zechuan; Liu Jianfei

2009-01-01

Low Level RF (LLRF) control system for storage ring of Shanghai Synchrotron Radiation Facility (SSRF) has been built by digital technology. The settings of parameters and the feedback loop status are carried out through the network communication interface, and the local oscillation and clock, which is the important component of the digital LLRF control system, are also configured through network communication. NIOS II processor was employed as a core to build the embedded system with a real-time operating system MicroC/OS-II, finally Lightweight TCP/IP (LwIP) was used to achieve the communication interface. The communication network is stable after a long-term operation. (authors)

M10.6.6: Designed and manufactured Frequency Synthesizer Board (AMC)

CERN Document Server

Czuba, K

2011-01-01

The LLRF system require generation of highly stable clock and trigger signals for high precision data processing and synchronous system operation. This deliverable provides an updated AMC module designed to fulfill the LLRF system timing synchronization needs. The module contains three independent clock synthesizers that are able to generate LVDS clock signals in the range of 10 MHz to 100 MHz. The clock synthesizers can be synchronized either by an internal quartz oscillator or an external phase reference signal provided to the board from the FLASH Master Oscillator. Besides clock synthesizers the AMC card contains also an optical receiver suited to convert and decode FLASH timing signals.

Development of the accelerating system

Energy Technology Data Exchange (ETDEWEB)

Jang, Jiho; Kwon, H. J.; Kim, D. I.; Kim, H. S.; Ryu, J. Y.; Park, B. S.; Seol, K. T.; Yun, S. P.; Song, Y. G.; Cho, Y. S.

2013-02-15

One of the main purposes of the 'Development of the Accelerating System' is developing a 100-MeV proton linac which accelerate proton beams from 20 MeV to 100 MeV by using 7 DTL (drift tube linac) tanks. Two of them were finished in the 2-nd stage of the project. The remaining part was also successfully fabricated and installed at Gyeongju site of KAERI. The MEBT is an essential component to extract and supply 20-MeV proton beams to users, and to match proton beams to the next accelerating structure for 100-MeV acceleration. The development of the MEBT has successfully finished. The project also developed the digital LLRF (low level RF) system which control the accelerating field within 1% in magnitude and 1 degree in phase. This system has been successfully tested in the 20-MeV linac operation at Daejeon site of KAERI. The modified version of the digital LLRF system will be used in the 100-MeV linac operation. The project also developed the beam diagnostic system. They are the strip-line type beam position monitor (BPM), the beam current monitor (CT), the beam loss monitor (BLM), and the emittance measurement system. They are used to measure the characteristics of the 20-MeV proton beams. The project also developed the EPIC-based control system. It is used to monitor the status of the accelerator and components, and to remotely control accelerator components. It has been used and modified in the 20-MeV linac operation. The modified version of the LLRF, diagnostics and control systems will be used in 100-MeV linac operation.

Prototype performance studies of a Full Mesh ATCA-based General Purpose Data Processing Board

CERN Document Server

Okumura, Yasuyuki; Liu, Tiehui Ted; Yin, Hang

2013-01-01

High luminosity conditions at the LHC pose many unique challenges for potential silicon based track trigger systems. One of the major challenges is data formatting, where hits from thousands of silicon modules must first be shared and organized into overlapping eta-phi trigger towers. Communication between nodes requires high bandwidth, low latency, and flexible real time data sharing, for which a full mesh backplane is a natural solution. A custom Advanced Telecommunications Computing Architecture data processing board is designed with the goal of creating a scalable architecture abundant in flexible, non-blocking, high bandwidth board to board communication channels while keeping the design as simple as possible. We have performed the first prototype board testing and our first attempt at designing the prototype system has proven to be successful. Leveraging the experience we gained through designing, building and testing the prototype board system we are in the final stages of laying out the next generatio...

RF System description for the ground test accelerator radio-frequency quadrupole

International Nuclear Information System (INIS)

Regan, A.H.; Brittain, D.; Rees, D.E.; Ziomek, D.

1992-01-01

This paper describes the RF system being used to provide RF power and to control the cavity field for the ground test accelerator (GTA) radio-frequency quadrupole (RFQ). The RF system consists of a low-level RF (LLRF) control system, and RF Reference generation subsystem, and a tetrode as a high-power amplifier (HPA) that can deliver up to 300 kW of peak power to the RFQ cavity at a 2% duty factor. The LLRF control system implements in-phase and quadrature (I and Q) control to maintain the cavity field within tolerances of 0.5% in amplitude and 0.5 degrees in phase in the presence of beam-induced instabilities

Optical network and FPGA/DSP based control system for free electron laser

International Nuclear Information System (INIS)

Romaniuk, R.S.; Pozniak, K.T.; Czarski, T.; Czuba, K.; Giergusiewicz, W.; Kasprowicz, G.; Koprek, W.

2005-01-01

The work presents a structural and functional model of a distributed low level radio frequency (LLRF) control, diagnostic and telemetric system for a large industrial object. An example of system implementation is the European TESLA-XFEL accelerator. The free electron laser is expected to work in the VUV region now and in the range of X-rays in the future. The design of a system based on the FPGA circuits and multi-gigabit optical network is discussed. The system design approach is fully parametric. The major emphasis is put on the methods of the functional and hardware concentration to use fully both: a very big transmission capacity of the optical fiber telemetric channels and very big processing power of the latest series of DSP/PC enhanced and optical I/O equipped, FPGA chips. The subject of the work is the design of a universal, laboratory module of the LLRF sub-system. The current parameters of the system model, under the design, are presented. The considerations are shown on the background of the system application in the hostile industrial environment. The work is a digest of a few development threads of the hybrid, optoelectronic, telemetric networks (HOTN). In particular, the outline of construction theory of HOTN node was presented as well as the technology of complex, modular, multilayer HOTN system PCBs. The PCBs contain critical sub-systems of the node and the network. The presented exemplary sub-systems are: fast optical data transmission of 2.5 Gbit/s, 3.125 Gbit/s and 10 Gbit/s; fast A/C and C/A multichannel data conversion managed by FPGA chip (40 MHz, 65 MHz, 105 MHz), data and functionality concentration, integration of floating point calculations in the DSP units of FPGA circuit, using now discrete and next integrated PC chip with embedded OS; optical distributed timing system of phase reference; and 1GbEth video interface (over UTP or FX) for CCD telemetry and monitoring. The data and functions concentration in the HOTN node is necessary to

Design and Calibration of an RF Actuator for Low-Level RF Systems

Science.gov (United States)

Geng, Zheqiao; Hong, Bo

2016-02-01

X-ray free electron laser (FEL) machines like the Linac Coherent Light Source (LCLS) at SLAC require high-quality electron beams to generate X-ray lasers for various experiments. Digital low-level RF (LLRF) systems are widely used to control the high-power RF klystrons to provide a highly stable RF field in accelerator structures for beam acceleration. Feedback and feedforward controllers are implemented in LLRF systems to stabilize or adjust the phase and amplitude of the RF field. To achieve the RF stability and the accuracy of the phase and amplitude adjustment, low-noise and highly linear RF actuators are required. Aiming for the upgrade of the S-band Linac at SLAC, an RF actuator is designed with an I/Qmodulator driven by two digital-to-analog converters (DAC) for the digital LLRF systems. A direct upconversion scheme is selected for RF actuation, and an on-line calibration algorithm is developed to compensate the RF reference leakage and the imbalance errors in the I/Q modulator, which may cause significant phase and amplitude actuation errors. This paper presents the requirements on the RF actuator, the design of the hardware, the calibration algorithm, and the implementation in firmware and software and the test results at LCLS.

Low-level RF LabVIEW reg-sign control software user's manual: Version 1.0

International Nuclear Information System (INIS)

1992-06-01

This document details information on the low-level radio frequency (LLRF) software control package. The chapters in this manual cover the following topics: Chapter one describes the general operating principles of the LabVIEW software package, and also discusses the high-level menu panels which allow access to the individual control panels. Chapter two covers the control panels used for conditioning the cavity, and for controlling the accelerator under normal operating conditions. Chapter three provides information on the resonance detection and reflectometer calibration function, including the setup and status panels for each. Chapter four contain instructions on the use of those panels dedicated to controlling the cavity RF field. Chapter five discusses the control panels that provide setup and status information on the diagnostic monitor subsystem. Chapter six outlines those panels used to control the timing functions provided by the LLRF system. Finally, chapter seven describes the control panels used to monitor and adjust the alarm and limit functions of the system. Throughout the document, it is assumed that the reader has a general working knowledge of accelerators, high-power amplifier equipment, and low-level RF (LLRF) control systems. References are listed as footnotes as they occur in the text

Timing and low-level rf system for an x-ray laser

Directory of Open Access Journals (Sweden)

Yuji Otake

2016-02-01

Full Text Available An x-ray free-electron laser (XFEL, SACLA, designed to open up new science, was constructed for generating coherent x rays with a peak power of more than 10 GW and a very short pulse of below 30 fs. This feature demands a very highly short-term temporal stability of less than 50 fs to the acceleration rf field of SACLA. For this reason, we developed a timing and low-level rf (LLRF system for SACLA based on that of the SPring8 compact SASE source (SCSS test accelerator for verifying the feasibility of an XFEL. The performance of the system using the in-phase and quadrature rf manipulation method was improved from SCSS’s system. Since the facility length of SACLA is 700 m, which is 10 times longer than that of the SCSS test accelerator, a phase-stabilized optical-fiber system designed to transmit time standard rf signals with low loss was also developed and deployed. This optical-fiber system equips fiber optical-length feedback control in order to mitigate environmental effects, such as temperature and humidity changes. On the other hand, the demanded maximum rf temporal stability is less than 50 fs, which is almost 10 times smaller than that of the SCSS test accelerator. Hence, reducing electric noise and increasing the temperature stability around timing and LLRF instruments were necessary and realized with a very low-noise power supply and a hemathermal 19-inch enclosure. The short-term temporal performance of the timing LLRF system finally attained a temporal stability of less than 13.6 fs in rms measured by a beam arrival-time measurement. This stability greatly helps to achieve the stable x-ray lasing of SACLA for routine operation during user experiments.

Cyanide toxicokinetics: the behavior of cyanide, thiocyanate and 2-amino-2-thiazoline-4-carboxylic acid in multiple animal models.

Science.gov (United States)

Bhandari, Raj K; Oda, Robert P; Petrikovics, Ilona; Thompson, David E; Brenner, Matthew; Mahon, Sari B; Bebarta, Vikhyat S; Rockwood, Gary A; Logue, Brian A

2014-05-01

Cyanide causes toxic effects by inhibiting cytochrome c oxidase, resulting in cellular hypoxia and cytotoxic anoxia, and can eventually lead to death. Cyanide exposure can be verified by direct analysis of cyanide concentrations or analyzing its metabolites, including thiocyanate (SCN(-)) and 2-amino-2-thiazoline-4-carboxylic acid (ATCA) in blood. To determine the behavior of these markers following cyanide exposure, a toxicokinetics study was performed in three animal models: (i) rats (250-300 g), (ii) rabbits (3.5-4.2 kg) and (iii) swine (47-54 kg). Cyanide reached a maximum in blood and declined rapidly in each animal model as it was absorbed, distributed, metabolized and eliminated. Thiocyanate concentrations rose more slowly as cyanide was enzymatically converted to SCN(-). Concentrations of ATCA did not rise significantly above the baseline in the rat model, but rose quickly in rabbits (up to a 40-fold increase) and swine (up to a 3-fold increase) and then fell rapidly, generally following the relative behavior of cyanide. Rats were administered cyanide subcutaneously and the apparent half-life (t1/2) was determined to be 1,510 min. Rabbits were administered cyanide intravenously and the t1/2 was determined to be 177 min. Swine were administered cyanide intravenously and the t1/2 was determined to be 26.9 min. The SCN(-) t1/2 in rats was 3,010 min, but was not calculated in rabbits and swine because SCN(-) concentrations did not reach a maximum. The t1/2 of ATCA was 40.7 and 13.9 min in rabbits and swine, respectively, while it could not be determined in rats with confidence. The current study suggests that cyanide exposure may be verified shortly after exposure by determining significantly elevated cyanide and SCN(-) in each animal model and ATCA may be used when the ATCA detoxification pathway is significant.

13 CFR 120.710 - What is the Loan Loss Reserve Fund?

Science.gov (United States)

2010-01-01

... in the MRF caused by delinquencies or losses on Microloans. An Intermediary must maintain the LLRF..., purchase rate and loss rate), loan volume to the extent that it impacts performance measures, and other...

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...

Development of sub-100 femtosecond timing and synchronization system.

Science.gov (United States)

Lin, Zhenyang; Du, Yingchao; Yang, Jin; Xu, Yilun; Yan, Lixin; Huang, Wenhui; Tang, Chuanxiang; Huang, Gang; Du, Qiang; Doolittle, Lawrence; Wilcox, Russell; Byrd, John

2018-01-01

The precise timing and synchronization system is an essential part for the ultra-fast electron and X-ray sources based on the photocathode injector where strict synchronization among RF, laser, and beams are required. In this paper, we present an integrated sub-100 femtosecond timing and synchronization system developed and demonstrated recently in Tsinghua University based on the collaboration with Lawrence Berkeley National Lab. The timing and synchronization system includes the fiber-based CW carrier phase reference distribution system for delivering stabilized RF phase reference to multiple receiver clients, the Low Level RF (LLRF) control system to monitor and generate the phase and amplitude controllable pulse RF signal, and the laser-RF synchronization system for high precision synchronization between optical and RF signals. Each subsystem is characterized by its blocking structure and is also expansible. A novel asymmetric calibration sideband signal method was proposed for eliminating the non-linear distortion in the optical synchronization process. According to offline and online tests, the system can deliver a stable signal to each client and suppress the drift and jitter of the RF signal for the accelerator and the laser oscillator to less than 100 fs RMS (∼0.1° in 2856 MHz frequency). Moreover, a demo system with a LLRF client and a laser-RF synchronization client is deployed and operated successfully at the Tsinghua Thomson scattering X-ray source. The beam-based jitter measurement experiments have been conducted to evaluate the overall performance of the system, and the jitter sources are discussed.

Modeling the interaction of a heavily beam loaded SRF cavity with its low-level RF feedback loops

Science.gov (United States)

Liu, Zong-Kai; Wang, Chaoen; Chang, Lung-Hai; Yeh, Meng-Shu; Chang, Fu-Yu; Chang, Mei-Hsia; Chang, Shian-Wen; Chen, Ling-Jhen; Chung, Fu-Tsai; Lin, Ming-Chyuan; Lo, Chih-Hung; Yu, Tsung-Chi

2018-06-01

A superconducting radio frequency (SRF) cavity provides superior stability to power high intensity light sources and can suppress coupled-bunch instabilities due to its smaller impedance for higher order modes. Because of these features, SRF cavities are commonly used for modern light sources, such as the TLS, CLS, DLS, SSRF, PLS-II, TPS, and NSLS-II, with an aggressive approach to operate the light sources at high beam currents. However, operating a SRF cavity at high beam currents may result with unacceptable stability problems of the low level RF (LLRF) system, due to drifts of the cavity resonant frequency caused by unexpected perturbations from the environment. As the feedback loop gets out of control, the cavity voltage may start to oscillate with a current-dependent characteristic frequency. Such situations can cause beam abort due to the activation of the interlock protection system, i.e. false alarm of quench detection. This malfunction of the light source reduces the reliability of SRF operation. Understanding this unstable mechanism to prevent its appearance becomes a primary task in the pursuit of highly reliable SRF operation. In this paper, a Pedersen model, including the response of the LLRF system, was used to simulate the beam-cavity interaction of a SRF cavity under heavy beam loading. Causes for the onset of instability at high beam current will be discussed as well as remedies to assure the design of a stable LLRF system.

FMC-based Neutron and Gamma Radiation Monitoring Module for xTCA Applications

CERN Document Server

Kozak, T; Napieralski, A

2012-01-01

The machines used in High Energy Physics (HEP) experiments, such as accelerators or tokamaks, are sources of gamma and neutron radiation fields. The radiation has a negative influence on electronics and can lead to the incorrect functioning of complex control and diagnostic system designed for HEP machines. Therefore, in most cases the electronic equipments is installed in radiation-safe areas, but in some cases this rule is omitted to decrease costs of the project. The European X-ray Free Electron Laser (E-XFEL), being under construction at DESY research center, is a good example. The E-XFEL uses single tunnel and part of the electronic system will be installed next to main beam pipe and exposed to radiation. The modern Advanced/Micro Telecommunications Computing Architecture (ATCA/μTCA) standards are foreseen as a base for control and diagnostic system for this new project. These flexible standards provide high reliability, availability and usability for the system which can be decreased by negative influe...

Rf system description for the ground test accelerator radio-frequency quadrupole

International Nuclear Information System (INIS)

Regan, A.H.; Brittain, D.; Rees, D.E.; Ziomek, D.

1992-01-01

This paper describes the RF system being used to provide RF power and to control the cavity field used for the ground test accelerator (GTA) radio-frequency quadrupole (RFQ). The RF system consists of a low-level RF (LLRF) control system that uses a tetrode as a high-power amplifier (HPA) as part of its plant to deliver up to 300 kW of peak power to the RFQ at a 2% duty factor. The LLRF control system implements in-phase and quadrature (I ampersand Q) control to maintain the cavity field within tolerances of 0.5% in amplitude and 0.5 degrees in phase in the presence of beam-induced instabilities. This paper describes the identified components and presents measured performance data. The user interface with the systems is described, and cavity field measurements are included

Modeling and Simulation of the Longitudinal Beam Dynamics - RF Station Interaction in the LHC Rings

International Nuclear Information System (INIS)

Mastorides, T

2008-01-01

A non-linear time-domain simulation has been developed to study the interaction between longitudinal beam dynamics and RF stations in the LHC rings. The motivation for this tool is to determine optimal LLRF configurations, to study system sensitivity on various parameters, and to define the operational and technology limits. It will be also used to study the effect of RF station noise, impedance, and perturbations on the beam life time and longitudinal emittance. It allows the study of alternative LLRF implementations and control algorithms. The insight and experience gained from our PEP-II simulation is important for this work. In this paper we discuss properties of the simulation tool that will be helpful in analyzing the LHC RF system and its initial results. Partial verification of the model with data taken during the LHC RF station commissioning is presented

A new high speed, Ultrascale+ based board for the ATLAS jet calorimeter trigger system

CERN Document Server

Rocco, Elena; The ATLAS collaboration

2018-01-01

A new high speed Ultrascale+ based board for the ATLAS jet calorimeter trigger system To cope with the enhanced luminosity at the Large Hadron Collider (LHC) in 2021, the ATLAS collaboration is planning a major detector upgrade. As a part of this, the Level 1 trigger based on calorimeter data will be upgraded to exploit the fine granularity readout using a new system of Feature EXtractors (FEX), which each reconstruct different physics objects for the trigger selection. The jet FEX (jFEX) system is conceived to provide jet identification (including large area jets) and measurements of global variables within a latency budget of less then 400ns. It consists of 6 modules. A single jFEX module is an ATCA board with 4 large FPGAs of the Xilinx Ultrascale+ family, that can digest a total input data rate of ~3.6 Tb/s using up to 120 Multi Gigabit Transceiver (MGT), 24 electrical optical devices, board control and power on the mezzanines to allow flexibility in upgrading controls functions and components without aff...

Novel automatic phase lock determination for superconducting cavity tests at vertical test stand at RRCAT

International Nuclear Information System (INIS)

Singh, Kunver Adarsh Pratap; Mohania, Praveen; Rajput, Vikas; Baxy, Deodatta; Shrivastava, Purushottam

2015-01-01

RRCAT has developed a Vertical Test Stand (VTS) which is used to test the Nb superconducting cavities under cryogenic conditions. In the VTS, RF cavity is characterized for its quality factor variation vs the accelerating gradient. The RF system is an essential part of the VTS which is required to provide stable RF power to the cavity in terms of amplitude, frequency and phase. RF system of VTS consists of several modules including the LLRF system. The LLRF system consists of the 'Frequency Control Module' which controls the input frequency to the SCRF cavity. Due to high quality factor, bandwidth of the cavity is less than 1 Hz. Even slight mechanical vibrations (microphonics) causes change in cavity resonance frequency resulting in total reflection of incident power. A PLL based frequency tracking module has been used to track the resonant frequency of RF cavity. This module changes RF source frequency according to change in Cavity resonance frequency. A novel method using a LabView based computer program has been developed which changes the phase of input RF signal using IQ modulator and monitors the transmitted power, incident and reflected power. The program plots the graph between phase and ratio of transmitted power to incident/reflected power and gives optimum locking phase for operation which has resulted in significant saving in the overall process time for the tests of the cavities in VTS. (author)

Adaptive feedforward of estimated ripple improves the closed loop system performance significantly

International Nuclear Information System (INIS)

Kwon, S.; Regan, A.; Wang, Y.M.; Rohlev, A.S.

1998-01-01

The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos National Laboratory will serve as the prototype for the low energy section of Acceleration Production of Tritium (APT) accelerator. This paper addresses the problem of LLRF control system for LEDA. The authors propose an estimator of the ripple and its time derivative and a control law which is based on PID control and adaptive feedforward of estimated ripple. The control law reduces the effect of the deterministic cathode ripple that is due to high voltage power supply and achieves tracking of desired set points

Online high voltage power supply ripple estimation and feedforward in LEDA

International Nuclear Information System (INIS)

Kwon, S.; Regan, A.; Wang, Y.M.; Rohlev, T.

1999-01-01

The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos National Laboratory will serve as the prototype for the low energy section of Acceleration Production of Tritium (APT) accelerator. This paper addresses the problem of LLRF control system for LEDA. They propose an estimator of the ripple and its time derivative and a control law which is based on PID control and adaptive feedforward of estimated ripple. The control law reduces the effect of the deterministic cathode ripple that is due to high voltage power supply and achieves tracking of desired set points

RF applications in digital signal processing

CERN Document Server

Schilcher, T

2008-01-01

Ever higher demands for stability, accuracy, reproducibility, and monitoring capability are being placed on Low-Level Radio Frequency (LLRF) systems of particle accelerators. Meanwhile, continuing rapid advances in digital signal processing technology are being exploited to meet these demands, thus leading to development of digital LLRF systems. The rst part of this course will begin by focusing on some of the important building-blocks of RF signal processing including mixer theory and down-conversion, I/Q (amplitude and phase) detection, digital down-conversion (DDC) and decimation, concluding with a survey of I/Q modulators. The second part of the course will introduce basic concepts of feedback systems, including examples of digital cavity eld and phase control, followed by radial loop architectures. Adaptive feed-forward systems used for the suppression of repetitive beam disturbances will be examined. Finally, applications and principles of system identi cation approaches will be summarized.

Modeling and simulation of Indus-2 RF feedback control system

International Nuclear Information System (INIS)

Sharma, D.; Bagduwal, P.S.; Tiwari, N.; Lad, M.; Hannurkar, P.R.

2012-01-01

Indus-2 synchrotron radiation source has four RF stations along with their feedback control systems. For higher beam energy and current operation amplitude and phase feedback control systems of Indus-2 are being upgraded. To understand the behaviour of amplitude and phase control loop under different operating conditions, modelling and simulation of RF feedback control system is done. RF cavity baseband I/Q model has been created due to its close correspondence with actual implementation and better computational efficiency which makes the simulation faster. Correspondence between cavity baseband and RF model is confirmed by comparing their simulation results. Low Level RF (LLRF) feedback control system simulation is done using the same cavity baseband I/Q model. Error signals are intentionally generated and response of the closed loop system is observed. Simulation will help us in optimizing parameters of upgraded LLRF system for higher beam energy and current operation. (author)

The Belle II PXD data acquisition and reduction system

Energy Technology Data Exchange (ETDEWEB)

Lange, Soeren; Gessler, Thomas; Kuehn, Wolfgang; Muenchow, David; Spruck, Bjoern [Giessen Univ. (Germany). 2. Physikalisches Inst.; Lin, Haichuan; Liu, Zhen-An; Xu, Hao; Zhao, Jingzhou [IHEP Beijing (China); Collaboration: Belle II Collaboration

2013-07-01

The Belle II DEPFET pixel detector (PXD) will deliver high data rates of up to 21.6 Gbytes/s for 3% detector occupancy. Data of this high rate must be buffered for 5 seconds, corresponding to the HLT (High Level Trigger) latency, and then a region-of-interest (ROI) filter is applied to reduce the data rate by a factor of ≥10 by charged track extrapolation from other detectors (SVD, CDC). The PXD readout system is based upon ATCA (Advanced Telecommunications Architecture). The 3rd PCB iteration uses a concept with a xTCA carrier board (with a Virtex-4 FX60 FPGA for ATCA backplane routing) and 4 AMC modules (each with a Xilinx Virtex-5 FX70T FPGA). The FPGA firmware implementation comprises a receiver core for the high speed optical links (≤6.25 Gbps), a buffer management with lookup of ≤270.000 pointers/s, DDR2 memory write (native port interface, ≥1.5 Gbytes/s), Gigabit ethernet (UDP stack in VHDL) and a parallelized ROI selection algorithm. Test results of all the components are presented.

Commercial FPGA based multipurpose controller: implementation perspective

International Nuclear Information System (INIS)

Arredondo, I.; Campo, M. del; Echevarria, P.; Belver, D.; Muguira, L.; Garmendia, N.; Hassanzadegan, H.; Eguiraun, M.; Jugo, J.; Etxebarria, V.

2012-01-01

This work presents a fast acquisition multipurpose controller, focussing on its EPICS integration and on its XML based configuration. This controller is based on a Lyrtech VHS-ADC board which encloses an FPGA, connected to a Host PC. This Host acts as local controller and implements an IOC integrating the device in an EPICS network. These tasks have been performed using Java as the main tool to program the PC to make the device fit the desired application. All the process includes the use of different technologies: JNA to handle C functions i.e. FPGA API, JavaIOC to integrate EPICS and XML w3c DOM classes to easily configure the particular application. In order to manage the functions, Java specific tools have been developed: Methods to manage the FPGA (read/write registers, acquire data,...), methods to create and use the EPICS server (put, get, monitor,...), mathematical methods to process the data (numeric format conversions,...) and methods to create/ initialize the application structure by means of an XML file (parse elements, build the DOM and the specific application structure). This XML file has some common nodes and tags for all the applications: FPGA registers specifications definition and EPICS variables. This means that the user only has to include a node for the specific application and use the mentioned tools. A main class is in charge of managing the FPGA and EPICS server according to this XML file. This multipurpose controller has been successfully used to implement a BPM and an LLRF application for the ESS-Bilbao (European Spallation Source) facility. (authors)

A leading-edge hardware family for diagnostics applications and low-level RF in CERN's ELENA ring

CERN Document Server

Angoletta, M E; Jaussi, M; Leiononen, P; Levens, T E; Molendijk, J C; Sanchez-Quesada, J; Simonin, J

2013-01-01

The CERN Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons transferred from the CERN’s Antiproton Decelerator (AD). The requirements for the acquisition and treatment of signals for longitudinal diagnostics are very demanding, owing to the revolution frequency swing as well as to the digital signal processing required. The requirements for the Low-Level Radio-Frequency (LLRF) system are very demanding as well, especially in terms of revolution frequency swing, dynamic range and low noise required by the cavity voltage control and digital signal processing to be performed. Both sets of requirements will be satisfied by using a leading-edge hardware family, developed to cover the LLRF needs of all synchrotrons in the Meyrin site; it will be first deployed in 2014 in the CERN’s PSB and in the medical machine MedAustron. This paper gives an overview of the main building blocks of the hardware family and of th...

SRF cavity testing using a FPGA Self Excited Loop

Energy Technology Data Exchange (ETDEWEB)

Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2017-08-30

Various authors have previously studied the theory and practice of cavity testing, notably an extensive treatment by Powers [1] and Padamsee [2]. The advent of the digital Low Level RF (LLRF) electronics based on Field Programmable Logic Arrays (FPGA) provides various improvements over the rather complex systems used in the past as well as enabling new measurement techniques.In this document we reintroduce a technique that seems to have fallen out of practice in recent times, that is obtaining the coupling constant β through measurements from just one port, the reflected power port, of the directional coupler placed in front of the cavity.

SRF cavity testing using a FPGA Self Excited Loop

CERN Document Server

Ben-Zvi, Ilan

2018-01-01

This document provides a detailed description of procedures for very-high precision calibration and testing of superconducting RF cavities using digital Low-Level RF (LLRF) electronics based on Field Programmable Gate Arrays (FPGA). The use of a Self-Excited Loop with an innovative procedure for fast turn-on allows the measurement of the forward, reflected and transmitted power from a single port of the directional coupler in front of the cavity, thus eliminating certain measurement errors. Various procedures for measuring the quality factor as a function of cavity fields are described, including a single RF pulse technique. Errors are estimated for the measurements.

ISTTOK real-time architecture

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Ivo S., E-mail: ivoc@ipfn.ist.utl.pt; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Hekkert, Tiago; Carvalho, Bernardo B.

2014-03-15

Highlights: • All real-time diagnostics and actuators were integrated in the same control platform. • A 100 μs control cycle was achieved under the MARTe framework. • Time-windows based control with several event-driven control strategies implemented. • AC discharges with exception handling on iron core flux saturation. • An HTML discharge configuration was developed for configuring the MARTe system. - Abstract: The ISTTOK tokamak was upgraded with a plasma control system based on the Advanced Telecommunications Computing Architecture (ATCA) standard. This control system was designed to improve the discharge stability and to extend the operational space to the alternate plasma current (AC) discharges as part of the ISTTOK scientific program. In order to accomplish these objectives all ISTTOK diagnostics and actuators relevant for real-time operation were integrated in the control system. The control system was programmed in C++ over the Multi-threaded Application Real-Time executor (MARTe) which provides, among other features, a real-time scheduler, an interrupt handler, an intercommunications interface between code blocks and a clearly bounded interface with the external devices. As a complement to the MARTe framework, the BaseLib2 library provides the foundations for the data, code introspection and also a Hypertext Transfer Protocol (HTTP) server service. Taking advantage of the modular nature of MARTe, the algorithms of each diagnostic data processing, discharge timing, context switch, control and actuators output reference generation, run on well-defined blocks of code named Generic Application Module (GAM). This approach allows reusability of the code, simplified simulation, replacement or editing without changing the remaining GAMs. The ISTTOK control system GAMs run sequentially each 100 μs cycle on an Intel{sup ®} Q8200 4-core processor running at 2.33 GHz located in the ATCA crate. Two boards (inside the ATCA crate) with 32 analog

ISTTOK real-time architecture

International Nuclear Information System (INIS)

Carvalho, Ivo S.; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Hekkert, Tiago; Carvalho, Bernardo B.

2014-01-01

Highlights: • All real-time diagnostics and actuators were integrated in the same control platform. • A 100 μs control cycle was achieved under the MARTe framework. • Time-windows based control with several event-driven control strategies implemented. • AC discharges with exception handling on iron core flux saturation. • An HTML discharge configuration was developed for configuring the MARTe system. - Abstract: The ISTTOK tokamak was upgraded with a plasma control system based on the Advanced Telecommunications Computing Architecture (ATCA) standard. This control system was designed to improve the discharge stability and to extend the operational space to the alternate plasma current (AC) discharges as part of the ISTTOK scientific program. In order to accomplish these objectives all ISTTOK diagnostics and actuators relevant for real-time operation were integrated in the control system. The control system was programmed in C++ over the Multi-threaded Application Real-Time executor (MARTe) which provides, among other features, a real-time scheduler, an interrupt handler, an intercommunications interface between code blocks and a clearly bounded interface with the external devices. As a complement to the MARTe framework, the BaseLib2 library provides the foundations for the data, code introspection and also a Hypertext Transfer Protocol (HTTP) server service. Taking advantage of the modular nature of MARTe, the algorithms of each diagnostic data processing, discharge timing, context switch, control and actuators output reference generation, run on well-defined blocks of code named Generic Application Module (GAM). This approach allows reusability of the code, simplified simulation, replacement or editing without changing the remaining GAMs. The ISTTOK control system GAMs run sequentially each 100 μs cycle on an Intel ® Q8200 4-core processor running at 2.33 GHz located in the ATCA crate. Two boards (inside the ATCA crate) with 32 analog

Control and management unit for a computation platform at the PANDA experiment

Energy Technology Data Exchange (ETDEWEB)

Galuska, Martin; Gessler, Thomas; Kuehn, Wolfgang; Lang, Johannes; Lange, Jens Soeren; Liang, Yutie; Liu, Ming; Spruck, Bjoern; Wang, Qiang [II. Physikalisches Institut, Justus-Liebig-Universitaet Giessen (Germany)

2010-07-01

The FAIR facility will provide high intensity antiproton and heavy ion beams for the PANDA and HADES experiments, leading to very high reaction rates. PANDA is expected to run at 10-20 MHz with a raw data output rate of up to 200 GB/s. A sophisticated data acquisition system is needed in order to select physically relevant events online. For this purpose a network of interconnected compute nodes can be used. Each compute node can be programmed to run various algorithms, such as online particle track recognition for high level triggering. An ATCA communication shelf provides power, cooling and high-speed interconnections to up to 14 nodes. A single shelf manager supervises and regulates the power distribution and temperature inside the shelf. The shelf manager relies on a local control chip on each node to relay sensor read-outs, provide hardware adresses and power requirements etc. An IPM controller based on an Atmel microcontroller was designed for this purpose, and a prototype was produced. The neccessary software is being developed to allow local communication with the components of the compute node and remote communication with the shelf manager conform to the ATCA specification.

A new high speed, Ultrascale+ based board for the ATLAS jet calorimeter trigger system

CERN Document Server

Rocco, Elena; The ATLAS collaboration

2018-01-01

To cope with the enhanced luminosity at the Large Hadron Collider (LHC) in 2021, the ATLAS collaboration is planning a major detector upgrade. As a part of this, the Level 1 trigger based on calorimeter data will be upgraded to exploit the fine granularity readout using a new system of Feature EXtractors (FEX), which each reconstruct different physics objects for the trigger selection. The jet FEX (jFEX) system is conceived to provide jet identification (including large area jets) and measurements of global variables within a latency budget of less then 400ns. It consists of 6 modules. A single jFEX module is an ATCA board with 4 large FPGAs of the Xilinx Ultrascale+ family, that can digest a total input data rate of ~3.6 Tb/s using up to 120 Multi Gigabit Transceiver (MGT), 24 electrical optical devices, board control and power on the mezzanines to allow flexibility in upgrading controls functions and components without affecting the main board. The 24-layers stack-up was carefully designed to preserve the s...

Accelerators 2010. Highlights and annual report

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-11-10

The following topics are dealt with: DESY II beam operation, DORIS III, PETRA III, FLASH, FLASH II, the European XFEL, a relativistic electron gun for atomic explorations, beam quality improvement, the international linear collider, new power supplies for DESY II, PETRA III power supplies, PETRA III beam position monitoring system, personnel safety, the FLASH refrigerator, the European XFEL-type RF waveguide distribution for FLASH, the FLASH injector low-level RF (LLRF) system upgrade, the precision RF field regulation at FLASH, ultrashort bunches at FLASH, the improved optical link design at FLASH, the accelerator module test facility, LLRF development for the European XFEL, the European XFEL cavities, niobium material for European-XFEL cavities, surface investigation on prototype cavities for the European XFEL, advances in large-grain resonators for superconducting RF technology, cavities for electron accelerator diagnostics in the European XFEL, temperature calculations for the European XFEL, electron interactions in free-electron lasers, achromatic and apochromatic beam transport, the DESY accelerator-idea market, new concepts for free-electron lasers. (HSI)

Accelerators 2010. Highlights and annual report

International Nuclear Information System (INIS)

2011-01-01

The following topics are dealt with: DESY II beam operation, DORIS III, PETRA III, FLASH, FLASH II, the European XFEL, a relativistic electron gun for atomic explorations, beam quality improvement, the international linear collider, new power supplies for DESY II, PETRA III power supplies, PETRA III beam position monitoring system, personnel safety, the FLASH refrigerator, the European XFEL-type RF waveguide distribution for FLASH, the FLASH injector low-level RF (LLRF) system upgrade, the precision RF field regulation at FLASH, ultrashort bunches at FLASH, the improved optical link design at FLASH, the accelerator module test facility, LLRF development for the European XFEL, the European XFEL cavities, niobium material for European-XFEL cavities, surface investigation on prototype cavities for the European XFEL, advances in large-grain resonators for superconducting RF technology, cavities for electron accelerator diagnostics in the European XFEL, temperature calculations for the European XFEL, electron interactions in free-electron lasers, achromatic and apochromatic beam transport, the DESY accelerator-idea market, new concepts for free-electron lasers. (HSI)

A development and integration analysis of commercial and in-house control subsystems

International Nuclear Information System (INIS)

Moore, D.M.; Dalesio, L.R.

1998-01-01

The acquisition and integration of commercial automation and control subsystems in physics research is becoming more common. It is presumed these systems present lower risk and less cost. This paper studies four subsystems used in the Accelerator Production of Tritium (APT) Low Energy Demonstration Accelerator (LEDA) at the Los Alamos National Laboratory (LANL). The radio frequency quadrupole (RFQ) resonance-control cooling subsystem (RCCS), the high-power RF subsystem and the RFQ vacuum subsystem were outsourced; the low-level RF (LLRF) subsystem was developed in-house. Based on the authors experience a careful evaluation of the costs and risks in acquisition, implementation, integration, and maintenance associated with these approaches is given

Determination of the Cyanide Metabolite 2-Aminothiazoline-4-Carboxylic Acid in Urine and Plasma by Gas Chromatography-Mass Spectrometry

National Research Council Canada - National Science Library

Logue, Brian A; Kirschten, Nicholas P; Petrikovics, Ilona; Moser, Matthew A; Rockwood, Gary A; Baskin, Steven I

2005-01-01

The cyanide metabolite 2-aminothiazoline.4-carboxylic acid (ATCA) is a promising biomarker for cyanide exposure because of its stability and the limitations of direct determination of cyanide and more abundant cyanide metabolites...

Low latency control board for LLRF system: SIMCON 3.1

Science.gov (United States)

Giergusiewicz, Wojciech; Jalmuzna, Wojciech; Pozniak, Krzysztof; Ignashin, Nikolay; Grecki, Mariusz; Makowski, Dariusz; Jezynski, Tomasz; Perkuszewski, Karol; Czuba, Krzysztof; Simrock, Stefan; Romaniuk, Ryszard

2005-09-01

A new version of the SIMCON system is presented in this paper. The SIMCON stands for the microwave, resonant, superconductive accelerator cavity simulator and controller (embracing the hardware and software layers). The current version of the SIMCON is 3.1. which is a considerable step forward from the previous 8-channel version 3.0. which was released at the beginning of 2005 and was made operable in April. Many important upgrades were implemented in SIMCON 3.1. It is a stand-alone VME board (whereas SIMCON 3.0 was modular) based on the Virtex II Pro 30 chip with two embedded Power PCs and DSP blocks. It has Ethernet and multiple gigabit optical I/Os. The Simcon 3.1 board provides 10 ADC channels. The architecture idea and block diagrams of the PCB for SIMCON 3.1. are presented. Some of the applied novel technical solutions, Protel"R" views and schemes are shown. A number of initial conclusions were drawn from a few month experience with the development of this new board. The tables of predicted system parameters are quoted.

Optical Spectra of Radio Planetary Nebulae in the Small Magellanic Cloud

Directory of Open Access Journals (Sweden)

Payne, J. L.

2008-06-01

Full Text Available We present preliminary results from spectral observations of four (4 candidate radio sources co-identified with known planetary nebulae (PNe in the Small Magellanic Cloud (SMC. These were made using the Radcliffe 1.9-meter telescope in Sutherland, South Africa. These radio PNe were originally found in Australia Telescope Compact Array (ATCA surveys of the SMC at 1.42 and 2.37~GHz, and were further confirmed by new high resolution ATCA images at 6 and 3 cm (4arcsec/2arcsec. Optical PNe and radio candidates are within 2arcsec and may represent a sub-population of selected radio bright objects. Nebular ionized masses of these objects may be 2.6~$M_odot$ or greater, supporting the existence of PNe progenitor central stars with masses up to 8 $M_odot$.

Optical spectra of radio planetary nebulae in the small Magellanic cloud

Directory of Open Access Journals (Sweden)

Payne J.L.

2008-01-01

Full Text Available We present preliminary results from spectral observations of four (4 candidate radio sources co-identified with known planetary nebulae (PNe in the Small Magellanic Cloud (SMC. These were made using the Radcliffe 1.9-meter telescope in Sutherland, South Africa. These radio PNe were originally found in Australia Telescope Compact Array (ATCA surveys of the SMC at 1.42 and 2.37 GHz, and were further confirmed by new high resolution ATCA images at 6 and 3 cm (400 /200 . Optical PNe and radio candidates are within 200 and may represent a sub- population of selected radio bright objects. Nebular ionized masses of these objects may be 2.6 Mo or greater, supporting the existence of PNe progenitor central stars with masses up to 8 Mo.

Coordinated mm/sub-mm observations of Sagittarius A* in May 2007

Energy Technology Data Exchange (ETDEWEB)

Kunneriath, D; Eckart, A; Bertram, T; Konig, S [University of Cologne, Zuelpicher Str. 77, D-50937 Cologne (Germany); Vogel, S [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Sjouwerman, L [National Radio Astronomy Observatory, PO Box 0, Socorro, NM 87801 (United States); Wiesemeyer, H [IRAM, Avenida Divina Pastora, 7, Nuecleo Central, E-18012 Granada (Spain); Schoedel, R [Instituto de AstrofIsica de AndalucIa, Camino Bajo de Huetor 50, 18008 Granada (Spain); Baganoff, F K [Center for Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139-4307 (United States); Morris, M; Mauerhan, J; Meyer, L [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Dovciak, M; Karas, V [Astronomical Institute, Academy of Sciences, BocnI II, CZ-14131 Prague (Czech Republic); Dowries, D [Institut de Radio Astronomie Millimetrique, Domaine Universitaire, 38406 St. Martin d' Heres (France); Krichbaum, T; Lu, R-S [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Krips, M [Harvard-Smithsonian Center for Astrophysics, SMA project, 60 Garden Street, MS 78 Cambridge, MA 02138 (United States); Markoff, S [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Kruislaan 403, 1098SJ Amsterdam (Netherlands); Duschl, W J, E-mail: eckart@phl.uni-koeln.de (and others)

2008-10-15

At the center of the Milky Way, with a distance of {approx}8 kpc, the compact source Sagittarius A* (SgrA*) can be associated with a super massive black hole of {approx}4x 10{sup 6}M{sub o-dot}. SgrA* shows strong variability from the radio to the X-ray wavelength domains. Here we report on simultaneous NIR/sub-millimeter/X-ray observations from May 2007 that involved the NACO adaptive optics (AO) instrument at the European Southern Observatory's Very Large Telescope, the Australian Telescope Compact Array (ATCA), the US mm-array CARMA, the IRAM 30m mm-telescope, and other telescopes. We concentrate on the time series of mm/sub-mm data from CARMA, ATCA, and the MAMBO bolometer at the IRAM 30m telescope.

Comparison of cyanide exposure markers in the biofluids of smokers and non-smokers.

Science.gov (United States)

Vinnakota, Chakravarthy V; Peetha, Naga S; Perrizo, Mitch G; Ferris, David G; Oda, Robert P; Rockwood, Gary A; Logue, Brian A

2012-11-01

Cyanide is highly toxic and is present in many foods, combustion products (e.g. cigarette smoke), industrial processes, and has been used as a terrorist weapon. In this study, cyanide and its major metabolites, thiocyanate and 2-amino-2-thiazoline-4-carboxylic acid (ATCA), were analyzed from various human biofluids of smokers (low-level chronic cyanide exposure group) and non-smokers to gain insight into the relationship of these biomarkers to cyanide exposure. The concentrations of each biomarker tested were elevated for smokers in each biofluid. Significant differences (p cyanide exposure, and other statistical methods were performed to better understand the relationship between cyanide and its metabolites. Of the markers studied, the results indicate plasma ATCA, in particular, showed excellent promise as a biomarker for chronic low-level cyanide exposure.

Chandra Takes on Heavy Jets and Massive Winds in 4U 1630-47

Science.gov (United States)

Neilsen, Joey

2014-11-01

Recently, Díaz Trigo et al. reported the discovery of relativistic baryons in a jet in XMM/ATCA observations of the 2012 outburst of the black hole 4U 1630-47. We present a search for a similarly massive jet earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. Despite a detection of radio emission with ATCA, we find no evidence of a heavy jet in the X-ray spectrum, with tight upper limits on the relativistic emission lines seen by Díaz Trigo eight months later. Instead, we find deep absorption lines from a massive, highly ionized disk wind, whose properties can be probed with detailed photoionization models. We explore several scenarios to explain the two modes of massive outflow in this remarkable black hole system.

Study of the interstellar medium towards RCW 103

OpenAIRE

Paron, Sergio Ariel; Reynoso, Estela Marta; Dubner, Gloria Mabel; Castelletti, Gabriela Marta

2017-01-01

RCW 103 is a shell type supernova remnant (SNR) that, according to near infrared observations, is interacting with a molecular cloud, specially to the south. In this paper we report on the study of the interstellar medium in an extended region towards RCW 103 based on HI 21 cm data acquired with the ATCA radiotelescope. Also, we report on the detection of HCO+ and CO emission in the rotational transition J=1-0 associated with the remnant. These observations were carried out with the millimete...

78 FR 52123 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

Science.gov (United States)

2013-08-22

... Management Act (Magnuson-Stevens Act) and the Atlantic Tunas Convention Act (ATCA). Under the Magnuson... August 28, 2013, 6 San Antonio, TX.... Hilton Palacio Del Rio, 200 S. with the Gulf of Mexico Fishery p.m...

Inflow of atomic gas fuelling star formation

DEFF Research Database (Denmark)

Michałowski, M. J.; Gentile, G.; Hjorth, Jeppe

2016-01-01

Gamma-ray burst host galaxies are deficient in molecular gas, and show anomalous metal-poor regions close to GRB positions. Using recent Australia Telescope Compact Array (ATCA) Hi observations we show that they have substantial atomic gas reservoirs. This suggests that star formation in these ga......Gamma-ray burst host galaxies are deficient in molecular gas, and show anomalous metal-poor regions close to GRB positions. Using recent Australia Telescope Compact Array (ATCA) Hi observations we show that they have substantial atomic gas reservoirs. This suggests that star formation...... in these galaxies may be fuelled by recent inflow of metal-poor atomic gas. While this process is debated, it can happen in low-metallicity gas near the onset of star formation because gas cooling (necessary for star formation) is faster than the Hi-to-H2 conversion....

Phase calibration strategies for synchrotron RF signals

Energy Technology Data Exchange (ETDEWEB)

Andreev, Aleksandr [TEMF, Technische Universitaet Darmstadt (Germany); Klingbeil, Harald [TEMF, Technische Universitaet Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Lens, Dieter [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

2016-07-01

For the FAIR facility that is currently under construction, the beam quality requirements impose several demands on the low-level RF (LLRF) systems. For example the phase error of the gap voltage of a specific RF cavity must be less than 1 . The RF reference signals for the FAIR synchrotron RF cavity systems are generated by direct digital synthesis modules (DDS) mounted in one crate called Group-DDS. In order to allow performing various multi-harmonic operations, each DDS unit operates at a certain mode defined by the harmonic number that can be changed during the operation. Since the DDS modules generate reference RF signals for different LLRF systems, the precise calibration of units to compensate the different phase response is of importance. The currently used calibration procedure is done with a fixed harmonic number for each module and uses the DDS module configured to the highest harmonic number as a reference. If the harmonic number of the DDS module is changed, one then has to repeat the calibration for the new values. Therefore, a new calibration method with respect to the absolute phases of DDS modules is under development and will be presented.

Developing Expert Tools for the LHC

CERN Document Server

AUTHOR|(CDS)2160780; Timkó, Helga

2017-10-12

This Thesis describes software tools developed for automated, precision setting-up of low-power level radio frequency (LLRF) loops, which will help expert users to have better control and faster setting-up of the radio-frequency (RF) system in the Large Hadron Collider (LHC) experiment. The aim was to completely redesign the software architecture, to add new features, to improve certain algorithms, and to increase the automation.

78 FR 57340 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

Science.gov (United States)

2013-09-18

... Tunas Convention Act (ATCA) and obligations pursuant to binding recommendations of the International...). You may submit attachments to electronic comments in Microsoft Word or Excel, WordPerfect, or Adobe... and appropriate to carry out recommendations of the International Commission for the Conservation of...

A Readout Driver for the ATLAS LAr Calorimeter at a High Luminosity LHC

CERN Document Server

Kielburg-Jeka, A; The ATLAS collaboration

2010-01-01

A new readout driver (ROD) is being developed as a central part of the signal processing of the ATLAS liquid-argon calorimeters for operation at the sLHC. In the architecture of the upgraded readout system, the ROD modules will have several challenging tasks: receiving of up to 1.4 Tb/s of data per board from the detector front-end on multiple high-speed serial links, low-latency data processing, data buffering, and data transmission to the ATLAS trigger and DAQ systems. In order to evaluate the different components, prototype boards in ATCA format equipped with modern Xilinx and Altera FPGAs have been built. We will report on the measured performance of the SERDES devices, the parallel signal processing using DSP slices, the implementation of trigger interfaces, using e.g. multi-Gb Ethernet, as well as the development of the ATCA infrastructure on the ROD prototype modules.

A Readout Driver for the ATLAS LAr Calorimeter at a High Luminosity LHC

CERN Document Server

Kielburg-Jeka, A

2011-01-01

A new readout driver (ROD) is being developed as a central part of the signal processing of the ATLAS liquid-argon calorimeters for operation at the High Luminosity LHC (HL-LHC). In the architecture of the upgraded readout system, the ROD modules will have several challenging tasks: receiving of up to 1.4 Tb/s of data per board from the detector front-end on multiple high-speed serial links, low-latency data processing, data buffering, and data transmission to the ATLAS trigger and DAQ systems. In order to evaluate the different components, prototype boards in ATCA format equipped with modern Xilinx and Altera FPGAs have been built. We will report on the measured performance of the SERDES devices, the parallel signal processing using DSP slices, the implementation of trigger interfaces, using e.g. multi-Gb Ethernet, as well as the development of the ATCA infrastructure on the ROD prototype modules.

DISCOVERY OF NUCLEAR WATER MASER EMISSION IN CENTAURUS A

Energy Technology Data Exchange (ETDEWEB)

Ott, Juergen; Meier, David S.; Walter, Fabian; Mao, Minnie Y., E-mail: jott@nrao.edu, E-mail: dmeier@nmt.edu, E-mail: walter@mpia.de, E-mail: mmao@nrao.edu [National Radio Astronomy Observatory, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801 (United States); and others

2013-07-10

We report the detection of a 22 GHz water maser line in the nearest (D {approx} 3.8 Mpc) radio galaxy Centaurus A (Cen A) using the Australia Telescope Compact Array (ATCA). The line is centered at a velocity of {approx}960 km s{sup -1}, which is redshifted by about 415 km s{sup -1} from the systemic velocity. Such an offset, as well as the width of {approx}120 km s{sup -1}, could be consistent with either a nuclear maser arising from an accretion disk of the central supermassive black hole (SMBH), or with a jet maser that is emitted from the material that is shocked near the base of the jet in Cen A. The best spatial resolution of our ATCA data constrains the origin of the maser feature within <3 pc of the SMBH. The maser exhibits an isotropic luminosity of {approx}1 L{sub Sun }, which classifies it as a kilomaser, and appears to be variable on timescales of months. A kilomaser can also be emitted by shocked gas in star-forming regions. Given the small projected distance from the core, the large offset from systemic velocity, and the smoothness of the line feature, we conclude that a jet maser line emitted by shocked gas around the base of the active galactic nucleus is the most likely explanation. For this scenario we can infer a minimum density of the radio jet of {approx}> 10 cm{sup -3}, which indicates substantial mass entrainment of surrounding gas into the propagating jet material.

77 FR 19175 - Atlantic Highly Migratory Species; 2012 Atlantic Bluefin Tuna Quota Specifications

Science.gov (United States)

2012-03-30

...). Attachments to electronic comments will be accepted in Microsoft Word or Excel, WordPerfect, or Adobe PDF file... active member of the International Commission for the Conservation of Atlantic Tunas (ICCAT), the United States implements binding ICCAT recommendations to comply with this international treaty. ATCA authorizes...

Optical spectra of radio planetary nebulae in the large Magellanic Cloud

Directory of Open Access Journals (Sweden)

Payne J.L.

2008-01-01

Full Text Available We present 11 spectra from 12 candidate radio sources co-identified with known planetary nebulae (PNe in the Large Magellanic Cloud (LMC. Originally found in Australia Telescope Compact Array (ATCA LMC surveys at 1.4, 4.8 and 8.64 GHz and confirmed by new high resolution ATCA images at 6 and 3 cm (4' /2' , these complement data recently presented for candidate radio PNe in the Small Magellanic Cloud (SMC. Their spectra were obtained using the Radcliff 1.9-meter telescope in Sutherland (South Africa. All of the optical PNe and radio candidates are within 2' and may represent a population of selected radio bright sample only. Nebular ionized masses of these objects are estimated to be as high as 1.8 Mfi, supporting the idea that massive PNe progenitor central stars lose much of their mass in the asymptotic giant branch (AGB phase or prior. We also identify a sub-population (33% of radio PNe candidates with prominent ionized iron emission lines.

The development of Global Feature eXtractor (gFEX) - the ATLAS calorimeter Level 1 trigger for ATLAS at High Luminosity LHC

CERN Document Server

AUTHOR|(SzGeCERN)759889; The ATLAS collaboration; Begel, Michael; Chen, Hucheng; Chen, Kai; Lanni, Francesco; Takai, Helio; Wu, Weihao

2017-01-01

As part of the ATLAS Phase-I Upgrade, the gFEX is designed to help maintain the ATLAS Level-1 trigger acceptance rate with the increasing LHC luminosity. The gFEX identifies patterns of energy associated with the hadronic decays of high momentum Higgs, W, & Z bosons, top quarks, and exotic particles in real time at the 40MHz LHC bunch crossing rate. The prototype v1 and v2 were designed and fully tested in 2015 and 2016 respectively. A pre-production gFEX board has been manufactured, which is an ATCA module consisting of three UltraScale+ FPGAs and one ZYNQ UltraScale+, and 35 MiniPODs are implemented in an ATCA module. This board receives coarse-granularity (0.2x0.2) information from the entire ATLAS calorimeters on up to 300 optical fibers and 96 links to the L1Topo at the speed up to 12.8 Gb/s.

HIGH-RESOLUTION RADIO OBSERVATIONS OF THE REMNANT OF SN 1987A AT HIGH FREQUENCIES

International Nuclear Information System (INIS)

Zanardo, Giovanna; Staveley-Smith, L.; Potter, T. M.; Ng, C.-Y.; Gaensler, B. M.; Manchester, R. N.; Tzioumis, A. K.

2013-01-01

We present new imaging observations of the remnant of Supernova (SN) 1987A at 44 GHz, performed in 2011 with the Australia Telescope Compact Array (ATCA). The 0.''35 × 0.''23 resolution of the diffraction-limited image is the highest achieved to date in high-dynamic range. We also present a new ATCA image at 18 GHz derived from 2011 observations, which is super-resolved to 0.''25. The flux density is 40 ± 2 mJy at 44 GHz and 81 ± 6 mJy at 18 GHz. At both frequencies, the remnant exhibits a ring-like emission with two prominent lobes, and an east-west brightness asymmetry that peaks on the eastern lobe. A central feature of fainter emission appears at 44 GHz. A comparison with previous ATCA observations at 18 and 36 GHz highlights higher expansion velocities of the remnant's eastern side. The 18-44 GHz spectral index is α = –0.80 (S ν ∝ν α ). The spectral index map suggests slightly steeper values at the brightest sites on the eastern lobe, whereas flatter values are associated with the inner regions. The remnant morphology at 44 GHz generally matches the structure seen with contemporaneous X-ray and Hα observations. Unlike the Hα emission, both the radio and X-ray emission peaks on the eastern lobe. The regions of flatter spectral index align and partially overlap with the optically visible ejecta. Simple free-free absorption models suggest that emission from a pulsar wind nebula or a compact source inside the remnant may now be detectable at high frequencies or at low frequencies if there are holes in the ionized component of the ejecta.

Interaction of the WAT Source in A3395 with the Intracluster Medium

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Using X-ray observations from Chandra and XMM-Newton and radio observations from the Australia Telescope Compact Array (ATCA), we have examined the merging environment of the bimodal cluster Abell 3395. From X-ray data we have produced thermodynamic maps of the cluster. The Wide Angle ...

Rapid interstellar scintillation of quasar PKS 1257-326

NARCIS (Netherlands)

Bignall, Hayley E.; Jauncey, David L.; Lovell, James E. J.; Tzioumis, Anastasios K.; Macquart, Jean-Pierre; Kedziora-Chudczer, Lucyna; Engvold, O

2005-01-01

PKS 1257-326 is one of three quasars known to show unusually large and rapid, intra-hour intensity variations, as a result of scintillation in the turbulent Galactic interstellar medium. We have measured time delays in the variability pattern arrival times at the VLA and the ATCA, as well as an

Environmental justice and the rights of indigenous peoples: international and domestic legal perspectives

National Research Council Canada - National Science Library

Westra, Laura

2008-01-01

... Peoples: Some Recent ATCA Jurisprudence First Nations of Canada and the Legal and Illegal Attacks on their Existence 71 103 125 PART III - JUSTIFYING GENOCIDE: PRINCIPLES AND REALITY 7 8 Genocide and Eco-crime: The Interface Aboriginal Rights in Domestic and International Law, and the Special Case of Arctic Peoples 163 187 PART...

Control system modelling for superconducting accelerator

International Nuclear Information System (INIS)

Czarski, T.; Pozniak, K.; Romaniuk, R.

2006-01-01

A digital control of superconducting cavities for a linear accelerator is presented. The LLRF - Low Level Radio Frequency system for FLASH project in DESY is introduced. FPGA based controller supported by MATLAB system was developed to investigate the novel firmware implementation. Algebraic model in complex domain is proposed for the system analyzing. Calibration procedure of a signal path is considered for a multi-channel control. Identification of the system parameters is carried out by the least squares method application. Control tables: Feed-Forward and Set- Point are determined for the required cavity performance, according to the recognized process. Feedback loop is tuned by fitting a complex gain of a corrector unit. Adaptive control algorithm is applied for feed-forward and feedback modes. Experimental results are presented for a cavity representative operation. (orig.)

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... ... present 18 GHz observations of the Bullet cluster using the Austalia Telescope Compact Array (ATCA), which show structure in the Sunyaev–Zeldovich effect; ... The SZE distribution in the western parts of the cluster are co-spatial with the radio halo indicative of a common origin for the hot and relativistic ...

Optical Spectra of Radio Planetary Nebulae in the Large Magellanic Cloud

Directory of Open Access Journals (Sweden)

Payne, J. L.

2008-12-01

Full Text Available We present 11 spectra from 12 candidate radio sources co-identified with known planetary nebulae (PNe in the Large Magellanic Cloud (LMC. Originally found in Australia Telescope Compact Array (ATCA LMC surveys at 1.4, 4.8 and 8.64~GHz and confirmed by new high resolution ATCA images at 6 and 3~cm (4arcsec/2arcsec, these complement data recently presented for candidate radio PNe in the Small Magellanic Cloud (SMC. Their spectra were obtained using the Radcliffe 1.9-meter telescope in Sutherland (South Africa. All of the optical PNe and radio candidates are within 2arcsec and may represent a population of selected radio bright sample only. Nebular ionized masses of these objects are estimated to be as high as 1.8~$M_odot$, supporting the idea that massive PNe progenitor central stars lose much of their mass in the asymptotic giant branch (AGB phase or prior. We also identify a sub-population (33\\% of radio PNe candidates with prominent ionized iron emission lines.

The FTK to Level-2 Interface Card (FLIC)

CERN Document Server

Wang, R.; The ATLAS collaboration; Auerbach, Benjamin; Blair, Robert; Drake, Gary; Love, Jeremy; Proudfoot, James; Anderson, J.; Zhang, Jinlong

2016-01-01

The FTK to Level-2 Interface Card (FLIC) of the ATLAS Fast TracKer (FTK) trigger upgrade is the final component in the FTK chain of custom electronics. The FTK performs full event tracking using the ATLAS Silicon detectors for every Level-1(L1) accepted event at 100 kHz. The FLIC is a custom Advanced Telecommunications Architecture (ATCA) card that interfaces the upstream FTK system with the ATLAS trigger and data acquisition (TDAQ) system, and allows for event processing on commercial PC blades making use of the 10 GB Ethernet full mesh ATCA back-plane. The FLIC receives data on 8 optical links at a bandwidth of about 1 Gbps per channel, reformats the data to the ATLAS standard record format, and performs the conversion from local to global module identifier using look up tables in SRAM. After processing, the event records are sent out to the TDAQ system using the S-LINK protocol at 2 Gbps, with a latency of O(10 microseconds). The data processing is handled in two Xilinx Virtex-6 FPGAs, with two additional ...

The FTK to Level-2 Interface Card (FLIC)

CERN Document Server

Anderson, John Thomas; The ATLAS collaboration; Drake, Gary; Love, Jeremy; Proudfoot, James; Wang, Rui; Zhang, Jinlong; Auerbach, Benjamin

2015-01-01

The FTK to Level-2 Interface Card (FLIC) of the ATLAS Fast TracKer (FTK) trigger upgrade is the final component in the FTK chain of custom electronics. The FTK performs full event tracking using the ATLAS Silicon detectors for every Level-1 accepted event at 100 kHz. The FLIC is a custom Advanced Telecommunications Architecture (ATCA) card that interfaces the upstream FTK system with the ATLAS trigger and data acquisition (TDAQ) system, and allows for event processing on commercial PC blades making use of the 10 GB Ethernet full mesh ATCA back-plane. The FLIC receives data on 8 optical links at a bandwidth of ~1 Gbps per channel, reformats the data to the ATLAS standard record format, and performs the conversion from local to global module identifier using look up tables in SRAM. After processing, the event records are sent out to the TDAQ system using the S-LINK protocol at 2 Gbps, with a latency of O(10 microseconds). The data processing is handled in two Xilinx Virtex-6 FPGAs, with two additional Virtex-6 ...

The Southern HII Region Discovery Survey

Science.gov (United States)

Wenger, Trey; Miller Dickey, John; Jordan, Christopher; Bania, Thomas M.; Balser, Dana S.; Dawson, Joanne; Anderson, Loren D.; Armentrout, William P.; McClure-Griffiths, Naomi

2016-01-01

HII regions are zones of ionized gas surrounding recently formed high-mass (OB-type) stars. They are among the brightest objects in the sky at radio wavelengths. HII regions provide a useful tool in constraining the Galactic morphological structure, chemical structure, and star formation rate. We describe the Southern HII Region Discovery Survey (SHRDS), an Australia Telescope Compact Array (ATCA) survey that discovered ~80 new HII regions (so far) in the Galactic longitude range 230 degrees to 360 degrees. This project is an extension of the Green Bank Telescope HII Region Discovery Survey (GBT HRDS), Arecibo HRDS, and GBT Widefield Infrared Survey Explorer (WISE) HRDS, which together discovered ~800 new HII regions in the Galactic longitude range -20 degrees to 270 degrees. Similar to those surveys, candidate HII regions were chosen from 20 micron emission (from WISE) coincident with 10 micron (WISE) and 20 cm (SGPS) emission. By using the ATCA to detect radio continuum and radio recombination line emission from a subset of these candidates, we have added to the population of known Galactic HII regions.

The peculiar cluster MACS J0417.5-1154 in the C and X-bands

Science.gov (United States)

Sandhu, Pritpal; Malu, Siddharth; Raja, Ramij; Datta, Abhirup

2018-06-01

We present 5.5 and 9.0 GHz Australia Telescope Compact Array (ATCA) observations of the cluster MACSJ0417.5-1154, one of the most massive galaxy clusters and one of the brightest in X-ray in the Massive Cluster Survey (MACS). We estimate diffuse emission at 5.5 and 9.0 GHz from our ATCA observations, and compare the results with the 235 MHz and 610 MHz GMRT observations and 1575 MHz VLA observations. We also estimate the diffuse emission at low frequencies from existing GLEAM survey data (using the MWA telescope (http://www.mwatelescope.org)), and find that the steepening reported in earlier studies may have been an artefact of underestimates of diffuse emission at low frequencies. High-frequency radio observations of galaxy cluster mergers therefore provide an important complement to low-frequency observations, not only for a probing the `on' and `off' state of radio halos in these mergers, but also to constrain energetics of cluster mergers. We comment on the future directions that further studies of this cluster can take.

Design and implementation of universal mathematical library supporting algorithm development for FPGA based systems in high energy physics experiments

International Nuclear Information System (INIS)

Jalmuzna, W.

2006-02-01

The X-ray free-electron laser XFEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short Xray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new perspectives for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated for LLRF system in VUV FEL experiment based on modern FPGA chips It is being developed by ELHEP group in Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller for stabilizing the vector sum of fields in cavities of one cryomodule in the experiment. The device can be also used as the simulator of the cavity and testbench for other devices. Flexibility and computation power of this device allow implementation of fast mathematical algorithms. This paper describes the concept, implementation and tests of universal mathematical library for FPGA algorithm implementation. It consists of many useful components such as IQ demodulator, division block, library for complex and floating point operations, etc. It is able to speed up implementation time of many complicated algorithms. Library have already been tested using real accelerator signals and the performance achieved is satisfactory. (Orig.)

Design and implementation of universal mathematical library supporting algorithm development for FPGA based systems in high energy physics experiments

Energy Technology Data Exchange (ETDEWEB)

Jalmuzna, W.

2006-02-15

The X-ray free-electron laser XFEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short Xray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new perspectives for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated for LLRF system in VUV FEL experiment based on modern FPGA chips It is being developed by ELHEP group in Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller for stabilizing the vector sum of fields in cavities of one cryomodule in the experiment. The device can be also used as the simulator of the cavity and testbench for other devices. Flexibility and computation power of this device allow implementation of fast mathematical algorithms. This paper describes the concept, implementation and tests of universal mathematical library for FPGA algorithm implementation. It consists of many useful components such as IQ demodulator, division block, library for complex and floating point operations, etc. It is able to speed up implementation time of many complicated algorithms. Library have already been tested using real accelerator signals and the performance achieved is satisfactory. (Orig.)

ISTTOK control system upgrade

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Ivo S., E-mail: ivoc@ipfn.ist.utl.pt; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Carvalho, Bernardo B.

2013-10-15

Highlights: •ISTTOK fast controller. •All real-time diagnostic and actuators were integrated in the control platform. •100 μs control cycle under the MARTe framework. •The ISTTOK control system upgrade provides reliable operation with an improved operational space. -- Abstract: The ISTTOK tokamak (Ip = 4 kA, BT = 0.5 T, R = 0.46 m, a = 0.085 m) is one of the few tokamaks with regular alternate plasma current (AC) discharges scientific programme. In order to improve the discharge stability and to increase the number of AC discharge cycles a novel control system was developed. The controller acquires data from 50 analog-to-digital converter (ADC) channels of real-time diagnostics and measurements: tomography, Mirnov coils, interferometer, electric probes, sine and cosine probes, bolometer, current delivered by the power supplies, loop voltage and plasma current. The system has a control cycle of 100 μs during which it reads all the diagnostics connected to the advanced telecommunications computing architecture (ATCA) digitizers and sends the control reference to ISTTOK actuators. The controller algorithms are executed on an Intel{sup ®} Q8200 chip with 4 cores running at 2.33 GHz and connected to the I/O interfaces through an ATCA based environment. The real-time control system was programmed in C++ on top of the Multi-threaded Application Real-Time executor (MARTe). To extend the duration of the AC discharges and the plasma stability a new magnetising field power supply was commissioned and the horizontal and vertical field power supplies were also upgraded. The new system also features a user-friendly interface based on HyperText Markup Language (HTML) and Javascript to configure the controller parameters. This paper presents the ISTTOK control system and the consequent update of real-time diagnostics and actuators.

ISTTOK control system upgrade

International Nuclear Information System (INIS)

Carvalho, Ivo S.; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Carvalho, Bernardo B.

2013-01-01

Highlights: •ISTTOK fast controller. •All real-time diagnostic and actuators were integrated in the control platform. •100 μs control cycle under the MARTe framework. •The ISTTOK control system upgrade provides reliable operation with an improved operational space. -- Abstract: The ISTTOK tokamak (Ip = 4 kA, BT = 0.5 T, R = 0.46 m, a = 0.085 m) is one of the few tokamaks with regular alternate plasma current (AC) discharges scientific programme. In order to improve the discharge stability and to increase the number of AC discharge cycles a novel control system was developed. The controller acquires data from 50 analog-to-digital converter (ADC) channels of real-time diagnostics and measurements: tomography, Mirnov coils, interferometer, electric probes, sine and cosine probes, bolometer, current delivered by the power supplies, loop voltage and plasma current. The system has a control cycle of 100 μs during which it reads all the diagnostics connected to the advanced telecommunications computing architecture (ATCA) digitizers and sends the control reference to ISTTOK actuators. The controller algorithms are executed on an Intel ® Q8200 chip with 4 cores running at 2.33 GHz and connected to the I/O interfaces through an ATCA based environment. The real-time control system was programmed in C++ on top of the Multi-threaded Application Real-Time executor (MARTe). To extend the duration of the AC discharges and the plasma stability a new magnetising field power supply was commissioned and the horizontal and vertical field power supplies were also upgraded. The new system also features a user-friendly interface based on HyperText Markup Language (HTML) and Javascript to configure the controller parameters. This paper presents the ISTTOK control system and the consequent update of real-time diagnostics and actuators

The data acquisition system of the Belle II Pixel Detector

Science.gov (United States)

Münchow, D.; Dingfelder, J.; Geßler, T.; Konorov, I.; Kühn, W.; Lange, S.; Lautenbach, K.; Levit, D.; Liu, Z.; Marinas, C.; Schnell, M.; Spruck, B.; Zhao, J.

2014-08-01

At the future Belle II experiment the DEPFET (DEPleted Field Effect Transistor) pixel detector will consist of about 8 million channels and is placed as the innermost detector. Because of its small distance to the interaction region and the high luminosity in Belle II, for a trigger rate of about 30 kHz with an estimated occupancy of about 3 % a data rate of about 22 GB/s is expected. Due to the high data rate, a data reduction factor higher than 30 is needed in order to stay inside the specifications of the event builder. The main hardware to reduce the data rate is a xTCA based Compute Node (CN) developed in cooperation between IHEP Beijing and University Giessen. Each node has as main component a Xilinx Virtex-5 FX70T FPGA and is equipped with 2 × 2 GB RAM , GBit Ethernet and 4 × 6.25 Gb/s optical links. An ATCA carrier board is able to hold up to four CN and supplies high bandwidth connections between the four CNs and to the ATCA backplane. To achieve the required data reduction on the CNs, regions of interest (ROI) are used. These regions are calculated in two independent systems by projecting tracks back to the pixel detector. One is the High Level Trigger (HLT) which uses data from the Silicon Vertex Detector (SVD), a silicon strip detector, and outer detectors. The other is the Data Concentrator (DATCON) which calculates ROIs based on SVD data only, in order to get low momentum tracks. With this information, only PXD data inside these ROIs will be forwarded to the event builder, while data outside of these regions will be discarded. First results of the test beam time in January 2014 at DESY with a Belle II vertex detector prototype and full DAQ chain will be presented.

Digital Low Level RF Systems for Fermilab Main Ring and Tevatron

Science.gov (United States)

Chase, B.; Barnes, B.; Meisner, K.

1997-05-01

At Fermilab, a new Low Level RF system is successfully installed and operating in the Main Ring. Installation is proceeding for a Tevatron system. This upgrade replaces aging CAMAC/NIM components for an increase in accuracy, reliability, and flexibility. These VXI systems are based on a custom three channel direct digital synthesizer(DDS) module. Each synthesizer channel is capable of independent or ganged operation for both frequency and phase modulation. New frequency and phase values are computed at a 100kHz rate on the module's Analog Devices ADSP21062 (SHARC) digital signal processor. The DSP concurrently handles feedforward, feedback, and beam manipulations. Higher level state machines and the control system interface are handled at the crate level using the VxWorks operating system. This paper discusses the hardware, software and operational aspects of these LLRF systems.

40-Gbps optical backbone network deep packet inspection based on FPGA

Science.gov (United States)

Zuo, Yuan; Huang, Zhiping; Su, Shaojing

2014-11-01

In the era of information, the big data, which contains huge information, brings about some problems, such as high speed transmission, storage and real-time analysis and process. As the important media for data transmission, the Internet is the significant part for big data processing research. With the large-scale usage of the Internet, the data streaming of network is increasing rapidly. The speed level in the main fiber optic communication of the present has reached 40Gbps, even 100Gbps, therefore data on the optical backbone network shows some features of massive data. Generally, data services are provided via IP packets on the optical backbone network, which is constituted with SDH (Synchronous Digital Hierarchy). Hence this method that IP packets are directly mapped into SDH payload is named POS (Packet over SDH) technology. Aiming at the problems of real time process of high speed massive data, this paper designs a process system platform based on ATCA for 40Gbps POS signal data stream recognition and packet content capture, which employs the FPGA as the CPU. This platform offers pre-processing of clustering algorithms, service traffic identification and data mining for the following big data storage and analysis with high efficiency. Also, the operational procedure is proposed in this paper. Four channels of 10Gbps POS signal decomposed by the analysis module, which chooses FPGA as the kernel, are inputted to the flow classification module and the pattern matching component based on TCAM. Based on the properties of the length of payload and net flows, buffer management is added to the platform to keep the key flow information. According to data stream analysis, DPI (deep packet inspection) and flow balance distribute, the signal is transmitted to the backend machine through the giga Ethernet ports on back board. Practice shows that the proposed platform is superior to the traditional applications based on ASIC and NP.

CI, [CII] and CO observations towards TNJ 1338–1942: Probing the ISM in a massive proto-cluster galaxy at z = 4.11

DEFF Research Database (Denmark)

König, S; Greve, T R; Seymour, N

2012-01-01

density, temperature, ambient UV-field) prevailing in the interstellar medium (ISM) of these objects. Here we report on ongoing CI, [CII] and CO observations of TNJ 1338–1942 at z = 4.11 with the IRAM 30m telescope, the JCMT and ATCA. With these observations we will make a first attempt at constraining...... the average ISM conditions in TNJ 1338–1942....

Cost model relationships between textile manufacturing processes and design details for transport fuselage elements

Science.gov (United States)

Metschan, Stephen L.; Wilden, Kurtis S.; Sharpless, Garrett C.; Andelman, Rich M.

1993-01-01

Textile manufacturing processes offer potential cost and weight advantages over traditional composite materials and processes for transport fuselage elements. In the current study, design cost modeling relationships between textile processes and element design details were developed. Such relationships are expected to help future aircraft designers to make timely decisions on the effect of design details and overall configurations on textile fabrication costs. The fundamental advantage of a design cost model is to insure that the element design is cost effective for the intended process. Trade studies on the effects of processing parameters also help to optimize the manufacturing steps for a particular structural element. Two methods of analyzing design detail/process cost relationships developed for the design cost model were pursued in the current study. The first makes use of existing databases and alternative cost modeling methods (e.g. detailed estimating). The second compares design cost model predictions with data collected during the fabrication of seven foot circumferential frames for ATCAS crown test panels. The process used in this case involves 2D dry braiding and resin transfer molding of curved 'J' cross section frame members having design details characteristic of the baseline ATCAS crown design.

16 kanałowy układ sterownika silników krokowych przesuwników fazy RF 1,3 GHz zasilających nadprzewodzące wnęki rezonansowe lasera na swobodnych elektronach FLASH

CERN Document Server

Kielar, E; Wierba, W

2011-01-01

The LLRF (Low Level Radio Frequency) System has to control also the RF coupling with the FLASH accelerator cavities. It is done remotely by controlling RF Phase Shifters driven by step motors. It was necessary to design the multichannel stepper motors driver controlled via Ethernet. The driver is built on the basis of low-power CMOS 8-bit AVR RISC microcontroller and the MODBUS protocol. The 16 drivers integrated on a single PCB allow for controlling 16 RF (Radio Frequency) Phase Shifters for the proper adjustment of the waveguides to cavities coupling.

The AD and ELENA orbit, trajectory and intensity measurement systems

Science.gov (United States)

Marco-Hernández, R.; Alves, D.; Angoletta, M. E.; Marqversen, O.; Molendijk, J.; Oponowicz, E.; Ruffieux, R.; Sánchez-Quesada, J.; SØby, L.

2017-07-01

This paper describes the new Antiproton Decelerator (AD) orbit measurement system and the Extra Low ENergy Antiproton ring (ELENA) orbit, trajectory and intensity measurement system. The AD machine at European Organization for Nuclear Research (CERN) is presently being used to decelerate antiprotons from 3.57 GeV/c to 100 MeV/c for matter vs anti-matter comparative studies. The ELENA machine, presently under commissioning, has been designed to provide an extra deceleration stage down to 13.7 MeV/c. The AD orbit system is based on 32 horizontal and 27 vertical electrostatic Beam Position Monitor (BPM) fitted with existing low noise front-end amplifiers while the ELENA system consists of 24 \\gls{BPM}s equipped with new low-noise head amplifiers. In both systems the front-end amplifiers generate a difference (delta) and a sum (sigma) signal which are sent to the digital acquisition system, placed tens of meters away from the AD or ELENA rings, where they are digitized and further processed. The beam position is calculated by dividing the difference signal by the sum signal either using directly the raw digitized data for measuring the turn-by-turn trajectory in the ELENA system or after down-mixing the signals to baseband for the orbit measurement in both machines. The digitized sigma signal will be used in the ELENA system to calculate the bunched beam intensity and the Schottky parameters with coasting beam after passing through different signal processing chain. The digital acquisition arrangement for both systems is based on the same hardware, also used in the ELENA Low Level Radio Frequency (LLRF) system, which follows the VME Switched Serial (VXS) enhancement of the Versa Module Eurocard 64x extension (VME64x) standard and includes VITA 57 standard Field Programmable Gate Array Mezzanine Card (FMC). The digital acquisition Field Programmable Gate Array (FPGA) and Digital Signal Processor (DSP) firmware shares many common functionalities with the LLRF system but

Fast track segment finding in the Monitored Drift Tubes of the ATLAS Muon Spectrometer using a Legendre transform algorithm

CERN Document Server

Ntekas, Konstantinos; The ATLAS collaboration

2018-01-01

The upgrade of the ATLAS first-level muon trigger for High- Luminosity LHC foresees incorporating the precise tracking of the Monitored Drift Tubes in the current system based on Resistive Plate Chambers and Thin Gap Chambers to improve the accuracy in the transverse momentum measurement and control the single muon trigger rate by suppressing low quality fake triggers. The core of the MDT trigger algorithm is the segment identification and reconstruction which is performed per MDT chamber. The reconstructed segment positions and directions are then combined to extract the muon candidate’s transverse momentum. A fast pattern recognition segment finding algorithm, called the Legendre transform, is proposed to be used for the MDT trigger, implemented in a FPGA housed on a ATCA blade.

Overview of the Pelletron Linac facility, Mumbai

International Nuclear Information System (INIS)

Pillay, R.G.

2011-01-01

The Pelletron LINAC Facility at TIFR, Mumbai, comprising the 14 MV Pelletron and the superconducting LINAC booster caters to a variety of experiments in basic and applied Sciences. The Liquid Helium Refrigeration plant for the LINAC has been upgraded to enhance the refrigeration capacity. New instrumentation and interface for control and monitor of the cryogenic parameters, beam diagnostics and beam transport devices have been developed and installed. Digital implementation of the LLRF control has been demonstrated. All seven beam lines in new user halls have been commissioned and several new experimental setups have been added. (author)

M10.6.9: Design and fabrication of AMC modules for controlling step motors, piezo and waveguide tuners

CERN Document Server

Przygoda, K; Kielar, E

2011-01-01

FLASH accelerator is using superconducting RF cavities to accelerate electron beam. These cavities must be precisely tuned to RF frequency due to very high Q factor (~109 unloaded Q and ~106 loaded Q). They are tuned by slight dimension change (particularly length) induced by tuners driven by step motors. For high gradients (~20MV/m and more) the cavities are dynamically detuned during RF pulse due to Lorentz Force Detuning (LFD). To keep them in resonance the fast tuners with piezos are used. Both slow and fast tuners need the control integrated with the LLRF system.

MULTIFREQUENCY RADIO MEASUREMENTS OF SUPERNOVA 1987A OVER 22 YEARS

International Nuclear Information System (INIS)

Zanardo, G.; Staveley-Smith, L.; Potter, T. M.; Ball, Lewis; Kesteven, M. J.; Manchester, R. N.; Tzioumis, A. K.; Gaensler, B. M.; Ng, C.-Y.

2010-01-01

We present extensive observations of the radio emission from the remnant of supernova (SN) 1987A made with the Australia Telescope Compact Array (ATCA), since the first detection of the remnant in 1990. The radio emission has evolved in time providing unique information on the interaction of the SN shock with the circumstellar medium. We particularly focus on the monitoring observations at 1.4, 2.4, 4.8, and 8.6 GHz, which have been made at intervals of 4-6 weeks. The flux density data show that the remnant brightness is now increasing exponentially, while the radio spectrum is flattening. The current spectral index value of -0.68 represents an 18 ± 3% increase over the last eight years. The exponential trend in the flux is also found in the ATCA imaging observations at 9 GHz, which have been made since 1992, approximately twice a year, as well as in the 843 MHz data set from the Molonglo Observatory Synthesis Telescope from 1987 to 2007 March. Comparisons with data at different wavelengths (X-ray, Hα) are made. The rich data set that has been assembled in the last 22 years forms a basis for a better understanding of the evolution of the supernova remnant.

Complex envelope control of pulsed accelerating fields in superconducting cavities

CERN Document Server

Czarski, T

2010-01-01

A digital control system for superconducting cavities of a linear accelerator is presented in this work. FPGA (Field Programmable Gate Arrays) based controller, managed by MATLAB, was developed to investigate a novel firmware implementation. The LLRF - Low Level Radio Frequency system for FLASH project in DESY is introduced. Essential modeling of a cavity resonator with signal and power analysis is considered as a key approach to the control methods. An electrical model is represented by the non-stationary state space equation for the complex envelope of the cavity voltage driven by the current generator and the beam loading. The electromechanical model of the superconducting cavity resonator including the Lorentz force detuning has been developed for a simulation purpose. The digital signal processing is proposed for the field vector detection. The field vector sum control is considered for multiple cavities driven by one klystron. An algebraic, complex domain model is proposed for the system analysis. The c...

Radio-continuum study of the supernova remnants in the large Magellanic Cloud: An SNR with a highly polarized breakout region: SNR J0455-6838

Directory of Open Access Journals (Sweden)

Crawford E.J.

2008-01-01

Full Text Available We present the results of new moderate resolution ATCA observations of SNR J0455-6838. We found that this SNR exhibits a mostly typical appearance with rather steep and curved α=-0.81±0.18 and D=43×31±1 pc. Regions of high polarization were detected, including unusually strong (~70% region corresponding to the northern breakout. Such a strong polarization in breakout regions has not been observed in any other SNR.

Radio-continuum jets around the peculiar galaxy pair ESO 295-IG022

Directory of Open Access Journals (Sweden)

Filipović M.D.

2010-01-01

Full Text Available We report new radio-continuum observations with the Australia Telescope Compact Array (ATCA of the region surrounding the peculiar galaxy pair ESO 295-IG022 at the centre of the poor cluster Abell S0102. We observed this cluster at wavelengths of λ=20/13 and 6/3 cm with the ATCA 6 km array. With these configurations, we achieved a resolution of ~2'' at 3 cm which is sufficient to resolve the jet-like structure of ~3' length detected at 20 cm. From our new high resolution images at 6 and 3 cm we confirm the presence of a double jet structure, most likely originating from the northern galaxy (ESO 295-IG022-N, bent and twisted towards the south. We found the spectral index of the jet to be very steep (α=-1.32. No point source was detected that could be associated with the core of ESO 295-IG022-N. On the other hand, ESO 295-IG022-S does not show any jet structure, but does show a point radio source. This source has variable flux and spectral index, and appears to be superposed on the line-of-sight of the jets (seen at 20-cm originating from the northern galaxy ESO 295-IG022-N. Finally, regions of very high and somewhat well ordered polarization were detected at the level of 70%.

ACCURATE OH MASER POSITIONS FROM THE SPLASH PILOT REGION

Energy Technology Data Exchange (ETDEWEB)

Qiao, Hai-Hua; Shen, Zhi-Qiang [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai, 200030 (China); Walsh, Andrew J.; Jordan, Christopher H. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth WA 6845 (Australia); Green, James A. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, PO Box 76, Epping, NSW 2121 (Australia); Breen, Shari L. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Dawson, J. R. [Department of Physics and Astronomy and MQ Research Centre in Astronomy, Astrophysics and Astrophotonics, Macquarie University, NSW 2109 (Australia); Ellingsen, Simon P. [School of Physical Sciences, Private Bag 37,University of Tasmania, Hobart 7001, TAS (Australia); Gómez, José F. [Instituto de Astrofísica de Andalucía, CSIC, Glorieta de la Astronomía s/n, E-18008, Granada (Spain); Lowe, Vicki; Jones, Paul A., E-mail: qiaohh@shao.ac.cn [Department of Astrophysics and Optic, School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia)

2016-12-01

We report on high spatial resolution observations, using the Australia Telescope Compact Array (ATCA), of ground-state OH masers. These observations were carried out toward 196 pointing centers previously identified in the Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) pilot region, between Galactic longitudes of 334° and 344° and Galactic latitudes of −2° and +2°. Supplementing our data with data from the MAGMO (Mapping the Galactic Magnetic field through OH masers) survey, we find maser emission toward 175 of the 196 target fields. We conclude that about half of the 21 nondetections were due to intrinsic variability. Due to the superior sensitivity of the followup ATCA observations, and the ability to resolve nearby sources into separate sites, we have identified 215 OH maser sites toward the 175 fields with detections. Among these 215 OH maser sites, 111 are new detections. After comparing the positions of these 215 maser sites to the literature, we identify 122 (57%) sites associated with evolved stars (one of which is a planetary nebula), 64 (30%) with star formation, two sites with supernova remnants, and 27 (13%) of unknown origin. The infrared colors of evolved star sites with symmetric maser profiles tend to be redder than those of evolved star sites with asymmetric maser profiles, which may indicate that symmetric sources are generally at an earlier evolutionary stage.

The COMPASS Tokamak Plasma Control Software Performance

Czech Academy of Sciences Publication Activity Database

Valcárcel, D.F.; Neto, A.; Carvalho, I.S.; Carvalho, B.B.; Fernandes, H.; Sousa, J.; Janky, F.; Havlíček, Josef; Beňo, R.; Horáček, Jan; Hron, Martin; Pánek, Radomír

2011-01-01

Roč. 58, č. 4 (2011), s. 1490-1496 ISSN 0018-9499. [Real Time Conference, RT10/17th./. Lisboa, 24.05.2010-28.05.2010] R&D Projects: GA MŠk 7G09042; GA ČR GD202/08/H057 Institutional research plan: CEZ:AV0Z20430508 Keywords : Real-Time * ATCA * Data Acquisition * Plasma Control Software Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.447, year: 2011 http://dx.doi.org/10.1109/TNS.2011.2143726

Development of a finite state machine for the automates operation of the LLRF control at FLASH

Energy Technology Data Exchange (ETDEWEB)

Brandt, A.

2007-07-15

The entry of digital signal processors in modern control systems not only allows for extended diagnostics compared to analog systems but also for sophisticated and tricky extensions of the control algorithms. With modern DSP- and FPGA-technology, the processing speed of digital systems is no longer inferior to analog systems in many applications. A higher degree of digitalization leads to an increased complexity of the systems and hence to higher requirements on their operators. The focus of research and development in the field of high frequency control has changed in the last few years and moved towards the direction of software development and complexity management. In the presented thesis, a frame for an automation concept of modern high frequency control systems is developed. The developed automation is based on the concept of finite state machines (FSM), which is established in industry for years. A flexible framework was developed, in which procedures communicate using standardized interfaces and can be exchanged easily. With that, the developer of high frequency control components as well as the operator on shift shall be empowered to improve and adapt the automation to changed conditions without special programming skills required. Along the automation concept a number of algorithms addressing various problems were developed which satisfy the needs of modern high frequency control systems. Among the developed and successfully tested algorithms are the calibration of incident and reflected wave of resonators without antennas, the fast adaptive compensation of repetitive errors, the robust estimation of the phase advance in the control loop and the latency adjustment for the rejection of instabilities caused by passband modes. During the development of the resonator theory, high value was set on the usability of the equation in algorithms for high frequency control. The usage of the common nomenclature of control theory emphasizes the underlying mathematical

Development of a finite state machine for the automated operation of the LLRF control at FLASH

International Nuclear Information System (INIS)

Brandt, A.

2007-07-01

The entry of digital signal processors in modern control systems not only allows for extended diagnostics compared to analog systems but also for sophisticated and tricky extensions of the control algorithms. With modern DSP- and FPGA-technology, the processing speed of digital systems is no longer inferior to analog systems in many applications. A higher degree of digitalization leads to an increased complexity of the systems and hence to higher requirements on their operators. The focus of research and development in the field of high frequency control has changed in the last few years and moved towards the direction of software development and complexity management. In the presented thesis, a frame for an automation concept of modern high frequency control systems is developed. The developed automation is based on the concept of finite state machines (FSM), which is established in industry for years. A flexible framework was developed, in which procedures communicate using standardized interfaces and can be exchanged easily. With that, the developer of high frequency control components as well as the operator on shift shall be empowered to improve and adapt the automation to changed conditions without special programming skills required. Along the automation concept a number of algorithms addressing various problems were developed which satisfy the needs of modern high frequency control systems. Among the developed and successfully tested algorithms are the calibration of incident and reflected wave of resonators without antennas, the fast adaptive compensation of repetitive errors, the robust estimation of the phase advance in the control loop and the latency adjustment for the rejection of instabilities caused by passband modes. During the development of the resonator theory, high value was set on the usability of the equation in algorithms for high frequency control. The usage of the common nomenclature of control theory emphasizes the underlying mathematical

Development of the Medium Energy Linac Systems

International Nuclear Information System (INIS)

Jang, Ji Ho; Kwon, Hyeok Jung; Kim, Dae Il; Kim, Han Sung; Park, Bum Sik; Seol, Kyung Tae; Song, Young Gi; Yun, Sang Pil; Cho, Yong Sub; Hong, In Seok

2008-05-01

The main purpose of this project is developing 100-MeV proton linear accelerator (linac) for proton engineering frontier project (PEFP). In the first phase of the PEFP, the development of the 20-MeV linac has successfully finished. Hence the work scope of this project is designing the linac to accelerate proton beams from 20-MeV up to 100-MeV, fabricating the linac up to 45 MeV, fabricating one set of the medium energy beam transport (MEBT) tank, and developing the low level radio frequency (LLRF) system and the control system. The basic role of the new proton accelerator is accelerating 20-mA proton beams from 20 MeV up to 100 MeV. The first step of the design procedure is optimizing and determining the accelerator parameters. The beam loss is also main concern in the design stage. The drift tube (DT) and the quadrupole magnets are designed to be optimized to the new linac design. The other purpose is confirming the new design by fabricating and tuning the drift tube linac (DTL). The 20MeV proton beam divided into two directions. One is supplying the beams to user group by turning on the 45-degree bending magnet. The other is guided into the 100-MeV DTL by tuning off the dipole magnet. That is why the PEFP MEBT located after 20-MeV DTL. The MEBT is realized as two small DTL tanks with three cells and a 45-degree bending magnet. The fabrication of one MEBT tank is another purpose of this project. The other purposes of this project is developing the LLRF system to control the RF signal and control system to monitor and control the vacuum system, magnet power supply, etc

Low-level feedback control for the phase regulation of CLIC Drive Beam Klystrons

CERN Document Server

AUTHOR|(SzGeCERN)752526

2015-01-01

The requirement of luminosity loss below 1% raises tight tolerances for the phase and power stability of the CLIC drive beam (DB) klystrons and consequently for the high voltage pulse ripple of the modulators. A low-level RF (LLRF) feedback system needs to be developed and combined with the modulator in order to guarantee the phase and amplitude tolerances. To this aim, three feedback control strategies were investigated, i) Proportional Integral (PI) controller, ii) Linear Quadratic Integral Regulator (LQI) and iii) Model Predictive Controller (MPC). The klystron, as well as the incident phase noise were modelled and used for the design and evaluation of the controllers. First simulation results are presented along with future steps and directions.

An IPMI-compliant control system for the ATLAS TileCal Phase-II Upgrade PreProcessor module

CERN Document Server

Zuccarello, Pedro Diego; The ATLAS collaboration

2016-01-01

Abstract–The electronics of the hadronic calorimeter of the ATLAS detector (TileCal) is being redesigned as part of the works that will lead to the High Luminosity Large Hadron Collider (HL-LHC). TileCal electronics is divided in front and back-end subsystems. While the front-end is inside the detector, the back-end is located off-detector inserted in an ATCA shelf. The main objective of this paper is to describe the work being carried out in the hardware management aspects of the back-end electronics of TileCal.

SIMCON 3.1. LLRF system control board measurements (for TESLA Test Facility)

Energy Technology Data Exchange (ETDEWEB)

Pietrasik, R.

2006-07-15

The SIMCON control systems for superconducting cavity resonators are described. These systems consist of analog and digital I/O systems, a clock system, an Ethernet link, optical input systems, a RS232 interface, a VME section with booting FPGA devices, and a Virtex2Pro section. The measurements of different parameters by this system are described. (HSI)

SIMCON 3.1. LLRF system control board measurements (for TESLA Test Facility)

International Nuclear Information System (INIS)

Pietrasik, R.

2006-03-01

The SIMCON control systems for superconducting cavity resonators are described. These systems consist of analog and digital I/O systems, a clock system, an Ethernet link, optical input systems, a RS232 interface, a VME section with booting FPGA devices, and a Virtex2Pro section. The measurements of different parameters by this system are described. (HSI)

RFTech report on cavity design, LLRF & HPRF systems and design integration, & costing

CERN Document Server

De Conto, J M; Zimmermann, F

2013-01-01

This report highlights results from the EuCARD WP4.3 RFTech network, which was active from April 2009 to July 2013. The objective of RFTech was bringing together RF experts from different laboratories and communities, e.g. proton & electron accelerators, or storage rings & linacs, to exchange ideas and to promote innovation on all aspects of RF technology. RFTech organized 4 primary annual workshops and the organized or co-organized several topical workshops or dedicated sessions in larger conferences, like MIXDES, ICAP 12 etc. The present document highlights the main topics covered during this networking activity. The RFTech activities related to superconducting RF infrastructures are described in the EuCARD report “European Infrastructures for R&D and Test of Superconducting Radio-Frequency Cavities and Cryo-modules” (Wolfgang Weingarten, ISBN 978-83-7207-952-7).

LLRF and timing system for the SCSS test accelerator at SPring-8

Energy Technology Data Exchange (ETDEWEB)

Otake, Yuji, E-mail: otake@spring8.or.jp [RIKEN, SPring-8 Center, XFEL Research and Development Division, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); JASRI, XFEL Division, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Ohshima, Takashi [RIKEN, SPring-8 Center, XFEL Research and Development Division, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); JASRI, XFEL Division, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hosoda, Naoyasu [JASRI, XFEL Division, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Maesaka, Hirokazu; Fukui, Toru [RIKEN, SPring-8 Center, XFEL Research and Development Division, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); JASRI, XFEL Division, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Kitamura, Masanobu [Hitachi Zosen Corporation, 7-89, Nanko-kita 1-chome, Suminoe-ku, Osaka 559-8559 (Japan); Shintake, Tsumoru [The Okinawa Institute of Science and Technology Graduate University, Tancha, Onna-Son, Kunigami, Okinawa 904-0495 (Japan)

2012-12-22

The 250 MeV SCSS test accelerator as an extreme-ultra violet (EUV) laser source has been built at SPring-8. The accelerator comprises a 500 kV thermionic gun, a velocity bunching system using multi-sub-harmonic bunchers (SHB) in an injector and a magnetic bunch compressor using a chicane of 4 bending magnets, a 5712 MHz main accelerator to accelerate an electron beam up to 250 MeV, and undulators to radiate the EUV laser. These bunch compression processes make short bunched electrons with a 300 A peak current and a 300 fs pulse width. The pulse width and peak current of an electron beam, which strongly affect the pulse width and intensity of the laser light, are mainly decided by the pulse compression ratio of the velocity bunching and the magnetic bunch compressing processes. The compression ratio is also determined due to an energy chirp along the beam bunch generated by an off-crest rf field at the SHB and cavities before the chicane. To constantly keep the beam pulse-width conducted by rf and timing signals, which are temporally controlled within subpicoseconds of the designed value, the low-level rf and timing system of the test accelerator has been developed. The system comprises a very low-noise and temporally stable reference signal source, in-phase and quadrature (IQ) modulators and demodulators, as well as VME type 12 bits analog-to-digital and digital-to-analog converter modules to manipulate an rf phase and amplitude by IQ functions for the cavity. We achieved that the SSB noise of the 5712 MHz reference signal source was less than -120 dBc/Hz at 1 kHz offset from the reference frequency; the phase setting and detecting resolution of the IQ-modulators and demodulators were within +/-0.5 Degree-Sign at 5712 MHz. A master trigger VME module and a trigger delay VME module were also developed to activate the components of the test accelerator. The time jitter of the delay module was less than 0.7 ps, sufficient for our present requirement. As a result, a beam energy variation of 0.06% was achieved and a time jitter of 46 fs between the acceleration rf signal and the beam was realized.

Longitudinal Bunch Position Control for the Super-B Accelerator

International Nuclear Information System (INIS)

Bertsche, Kirk; Rivetta, Claudio; Sullivam, Michael K.; SLAC; Drago, Alessandro; Frascati

2009-01-01

The use of normal conducting cavities and an ion-clearing gap will cause a significant RF accelerating voltage gap transient and longitudinal phase shift of the individual bunches along the bunch train in both rings of the SuperB accelerator. Small relative centroid position shifts between bunches of the colliding beams will have a large adverse impact on the luminosity due to the small β* y at the interaction point (IP). We investigate the possibility of minimizing the relative longitudinal position shift between bunches by reducing the gap transient in each ring and matching the longitudinal bunch positions of the two rings at the IP using feedback/feedforward techniques in the LLRF. The analysis is conducted assuming maximum use of the klystron power installed in the system

Cavity Voltage Phase Modulation MD blocks 3 and 4

CERN Document Server

Mastoridis, T; Butterworth, A; Molendijk, J; Tuckmantel, J

2013-01-01

The LHC RF/LLRF system is currently setup for extremely stable RF voltage to minimize transient beam loading effects. The present scheme cannot be extended beyond nominal beam current since the demanded power would push the klystrons to saturation. For beam currents above nominal (and possibly earlier), the cavity phase modulation by the beam (transient beam loading) will not be corrected, but the strong RF feedback and One-Turn Delay feedback will still be active for RF loop and beam stability in physics. To achieve this, the voltage set point should be adapted for each bunch. The goal of these MDs was to test thefirmware version of an iterative algorithm that adjusts the voltage set point to achieve the optimal phase modulation for klystron forward power considerations.

gFEX, the ATLAS Calorimeter Level-1 Real Time Processor

CERN Document Server

AUTHOR|(SzGeCERN)759889; The ATLAS collaboration; Begel, Michael; Chen, Hucheng; Lanni, Francesco; Takai, Helio; Wu, Weihao

2016-01-01

The global feature extractor (gFEX) is a component of the Level-1 Calorimeter trigger Phase-I upgrade for the ATLAS experiment. It is intended to identify patterns of energy associated with the hadronic decays of high momentum Higgs, W, & Z bosons, top quarks, and exotic particles in real time at the LHC crossing rate. The single processor board will be packaged in an Advanced Telecommunications Computing Architecture (ATCA) module and implemented as a fast reconfigurable processor based on three Xilinx Vertex Ultra-scale FPGAs. The board will receive coarse-granularity information from all the ATLAS calorimeters on 276 optical fibers with the data transferred at the 40 MHz Large Hadron Collider (LHC) clock frequency. The gFEX will be controlled by a single system-on-chip processor, ZYNQ, that will be used to configure all the processor Field-Programmable Gate Array (FPGAs), monitor board health, and interface to external signals. Now, the pre-prototype board which includes one ZYNQ and one Vertex-7 FPGA ...

gFEX, the ATLAS Calorimeter Level 1 Real Time Processor

CERN Document Server

Tang, Shaochun; The ATLAS collaboration

2015-01-01

The global feature extractor (gFEX) is a component of the Level-1Calorimeter trigger Phase-I upgrade for the ATLAS experiment. It is intended to identify patterns of energy associated with the hadronic decays of high momentum Higgs, W, & Z bosons, top quarks, and exotic particles in real time at the LHC crossing rate. The single processor board will be packaged in an Advanced Telecommunications Computing Architecture (ATCA) module and implemented as a fast reconfigurable processor based on three Xilinx Ultra-scale FPGAs. The board will receive coarse-granularity information from all the ATLAS calorimeters on 264 optical fibers with the data transferred at the 40 MHz LHC clock frequency. The gFEX will be controlled by a single system-on-chip processor, ZYNQ, that will be used to configure all the processor FPGAs, monitor board health, and interface to external signals. Now, the pre-prototype board which includes one ZYNQ and one Vertex-7 FPGA has been designed for testing and verification. The performance ...

Run Control Communication for the Upgrade of the ATLAS Muon-to-Central-Trigger-Processor Interface (MUCTPI)

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00223859; The ATLAS collaboration; Armbruster, Aaron James; Carrillo-Montoya, German D.; Chelstowska, Magda Anna; Czodrowski, Patrick; Deviveiros, Pier-Olivier; Eifert, Till; Ellis, Nicolas; Galster, Gorm Aske Gram Krohn; Haas, Stefan; Helary, Louis; Lagkas Nikolos, Orestis; Marzin, Antoine; Pauly, Thilo; Ryjov, Vladimir; Schmieden, Kristof; Silva Oliveira, Marcos Vinicius; Stelzer, Harald Joerg; Vichoudis, Paschalis; Wengler, Thorsten; Farthouat, Philippe

2018-01-01

The Muon-to-Central Trigger Processor Interface (MUCTPI) of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN will be upgraded to an ATCA blade system for Run 3. The new design requires development of new communication models for control, configuration and monitoring. A System-on-Chip (SoC) with a programmable logic part and a processor part will be used for communication to the run control system and to the MUCTPI processing FPGAs. Different approaches have been compared. First, we tried an available UDP-based implementation in firmware for the programmable logic. Although this approach works as expected, it does not provide any flexibility to extend the functionality to more complex operations, e.g. for serial protocols. Second, we used the SoC processor with an embedded Linux operating system and an application-specific software written in C++ using a TCP remote-procedure-call approach. The software is built and maintained using the Yocto/OpenEmbedded framework. This approach was successfully...

Run control communication for the upgrade of the ATLAS Muon-to-Central Trigger Processor Interface (MUCTPI)

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00223859; The ATLAS collaboration; Armbruster, Aaron James; Carrillo-Montoya, German D.; Chelstowska, Magda Anna; Czodrowski, Patrick; Deviveiros, Pier-Olivier; Eifert, Till; Ellis, Nicolas; Farthouat, Philippe; Galster, Gorm Aske Gram Krohn; Haas, Stefan; Helary, Louis; Lagkas Nikolos, Orestis; Marzin, Antoine; Pauly, Thilo; Ryjov, Vladimir; Schmieden, Kristof; Silva Oliveira, Marcos Vinicius; Stelzer, Harald Joerg; Vichoudis, Paschalis; Wengler, Thorsten

The Muon-to-Central-Trigger-Processor Interface (MUCTPI) of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN will be upgraded to an ATCA blade system for Run 3, starting in 2021. The new design requires development of new communication models for control, configuration and monitoring. A System-on-Chip (SoC) with a programmable logic part and a processor part will be used for communication to the run control system and to the MUCTPI processing FPGAs. Different approaches have been compared. First, we tried an available UDP-based implementation in firmware for the programmable logic. Although this approach works as expected, it does not provide any flexibility to extend the functionality to more complex operations, e.g. for serial protocols. Second, we used a SoC processor with an embedded Linux operating system and an application-specific software written in C++ using a TCP remote-procedure-call approach. The software is built and maintained using the framework of the Yocto Project. This approa...

Upgrade of the ATLAS Tile Calorimeter for the High Luminosity LHC

CERN Document Server

Tang, Fukun; The ATLAS collaboration

2017-01-01

The Tile Calorimeter (TileCal) is the hadronic calorimeter of ATLAS covering the central region of the ATLAS experiment. TileCal will undergo a major replacement of its on- and off-detector electronics in 2024 for the high luminosity program of the LHC. The calorimeter signals will be digitized and sent directly to the off-detector electronics, where the signals are reconstructed and transmitted to the first level of trigger at a rate of 40 MHz. This will provide a better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Three different options are presently being investigated for the front-end electronic upgrade. Extensive test beam studies are being employed to determine which option will be selected. The off-detector electronics are based on the Advanced Telecommunications Computing Architecture (ATCA) standard and are equipped with high performance optical connectors. The system is designed to operate in a high radiation envi...

Upgrade of the ATLAS Tile Calorimeter for the High Luminosity LHC

CERN Document Server

Tang, Fukun; The ATLAS collaboration

2017-01-01

The Tile Calorimeter (TileCal) is the hadronic calorimeter of ATLAS cover-ing the central region of the ATLAS experiment. TileCal will undergo a major replacement of its on- and off-detector electronics in 2024 for the high luminosity program of the LHC. The calorimeter signals will be digitized and sent directly to the off-detector electronics, where the signals are reconstructed and shipped to the first level of trigger at a rate of 40 MHz. This will provide a better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Three different options are presently being investigated for the front-end electronic upgrade. Extensive test beam studies are being employed to determine which option will be selected. The off-detector electronic is based on the Advanced Telecommunications Computing Architecture (ATCA) standard and is equipped with high performance optical connectors. The system is designed to operate in a high radiation environmen...

Characterization and manufacture of braided composites for large commercial aircraft structures

Science.gov (United States)

Fedro, Mark J.; Willden, Kurtis

1992-01-01

Braided composite materials, one of the advanced material forms which is under investigation in Boeing's ATCAS program, have been recognized as a potential cost-effective material form for fuselage structural elements. Consequently, there is a strong need for more knowledge in the design, manufacture, test, and analysis of textile structural composites. The overall objective of this work is to advance braided composite technology towards applications to a large commercial transport fuselage. This paper summarizes the mechanics of materials and manufacturing demonstration results which have been obtained in order to acquire an understanding of how braided composites can be applied to a commercial fuselage. Textile composites consisting of 1D, 2D triaxial, and 3D braid patterns with thermoplastic and two RTM resin systems were investigated. The structural performance of braided composites was evaluated through an extensive mechanical test program. Analytical methods were also developed and applied to predict the following: internal fiber architectures, stiffnesses, fiber stresses, failure mechanisms, notch effects, and the entire history of failure of the braided composites specimens. The applicability of braided composites to a commercial transport fuselage was further assessed through a manufacturing demonstration. Three foot fuselage circumferential hoop frames were manufactured to demonstrate the feasibility of consistently producing high quality braided/RTM composite primary structures. The manufacturing issues (tooling requirements, processing requirements, and process/quality control) addressed during the demonstration are summarized. The manufacturing demonstration in conjunction with the mechanical test results and developed analytical methods increased the confidence in the ATCAS approach to the design, manufacture, test, and analysis of braided composites.

SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Spilker, J. S.; Marrone, D. P. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Aravena, M. [Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago (Chile); Béthermin, M.; Breuck, C. de [European Southern Observatory, Karl Schwarzschild Straße 2, D-85748 Garching (Germany); Bothwell, M. S. [Cavendish Laboratory, University of Cambridge, JJ Thompson Ave, Cambridge CB3 0HA (United Kingdom); Carlstrom, J. E. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Chapman, S. C.; Rotermund, K. M. [Dalhousie University, Halifax, Nova Scotia (Canada); Collier, J. D.; Galvin, T.; Grieve, K.; O’Brien, A. [University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751 (Australia); Fassnacht, C. D. [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Gonzalez, A. H.; Ma, J. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); González-López, J. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago (Chile); Hezaveh, Y. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Malkan, M., E-mail: jspilker@as.arizona.edu [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); and others

2015-10-01

We present spatially resolved imaging obtained with the Australia Telescope Compact Array (ATCA) of three CO lines in two high-redshift gravitationally lensed dusty star-forming galaxies, discovered by the South Pole Telescope. Strong lensing allows us to probe the structure and dynamics of the molecular gas in these two objects, at z = 2.78 and z = 5.66, with effective source-plane resolution of less than 1 kpc. We model the lensed emission from multiple CO transitions and the dust continuum in a consistent manner, finding that the cold molecular gas as traced by low-J CO always has a larger half-light radius than the 870 μm dust continuum emission. This size difference leads to up to 50% differences in the magnification factor for the cold gas compared to dust. In the z = 2.78 galaxy, these CO observations confirm that the background source is undergoing a major merger, while the velocity field of the other source is more complex. We use the ATCA CO observations and comparable resolution Atacama Large Millimeter/submillimeter Array dust continuum imaging of the same objects to constrain the CO–H{sub 2} conversion factor with three different procedures, finding good agreement between the methods and values consistent with those found for rapidly star-forming systems. We discuss these galaxies in the context of the star formation—gas mass surface density relation, noting that the change in emitting area with observed CO transition must be accounted for when comparing high-redshift galaxies to their lower redshift counterparts.

International Linear Collider Accelerator Physics R and D

International Nuclear Information System (INIS)

Gollin, George D.; Davidsaver, Michael; Haney, Michael J.; Kasten, Michael; Chang, Jason; Chodash, Perry; Dluger, Will; Lang, Alex; Liu, Yehan

2008-01-01

to an event at the beginning of the run. We determined that the device installed in our beam, which was instrumented with an 8-bit 500 MHz ADC, could measure the beam timing to an accuracy of 0.4 picoseconds. Simulations of the device showed that an increase in ADC clock rate to 2 GHz would improve measurement precision by the required factor of four. As a result, we felt that a device of this sort, assuming matters concerning dynamic range and long-term stability can be addressed successfully, would work at the ILC. Cost effective operation of the ILC will demand highly reliable, fault tolerant and adaptive solutions for both hardware and software. The large numbers of subsystems and large multipliers associated with the modules in those subsystems will cause even a strong level of unit reliability to become an unacceptable level of system availability. An evaluation effort is underway to evaluate standards associated with high availability, and to guide ILC development with standard practices and well-supported commercial solutions. One area of evaluation involves the Advanced Telecom Computing Architecture (ATCA) hardware and software. We worked with an ATCA crate, processor monitors, and a small amount of ATCA circuit boards in order to develop a backplane 'spy' board that would let us watch the ATCA backplane communications and pursue development of an inexpensive processor monitor that could be used as a physics-driven component of the crate-level controls system. We made good progress, and felt that we had determined a productive direction to extend this work. We felt that we had learned enough to begin designing a workable processor monitor chip if there were to be sufficient interest in ATCA shown by the ILC community. Fault recognition is a challenging issue in the crafting a high reliability controls system. With tens of thousands of independent processors running hundreds of thousands of critical processes, how can the system identify that a problem has

VizieR Online Data Catalog: Fermi unassociated sources ATCA observations (Petrov+, 2013)

Science.gov (United States)

Petrov, L.; Mahony, E. K.; Edwards, P. G.; Sadler, E. M.; Schinzel, F. K.; McConnell, D.

2014-07-01

Table S1: catalogue of 146 objects detected at both 5 and 9GHz sub-bands of 2FGL sources marked as unassociated within the ellipse of 99% probability of their localization Table S2: catalogue of 229 objects detected only at 5GHz sub-band within the ellipses of 99% probability of localisation of Fermi sources marked as unassociated in 2FGL catalogue. Table S3: catalogue of 49 objects detected at sidelobes of either 5 or 9GHz beam within the ellipses of 99% probability of localisation of Fermi sources marked as unassociated in 2FGL catalogue. (3 data files).

Design and development of low level S-Band RF control system for IRFEL injector LINAC

International Nuclear Information System (INIS)

Mohania, Praveen; Mahawar, Ashish; Singh, Adarsh Pratap; Namdeo, Rajkumar; Baxy, Deodatta; Shrivastava, Purushottam

2015-01-01

A low level RF system has been designed and developed for phase and amplitude stabilization of S- Band microwave power being fed to fundamental buncher cavity and the injector LINAC structure of the Infra Red Free Electron Laser being developed at RRCAT Indore. The system uses analog phase shifters and voltage variable attenuators to control the phase and amplitude respectively, the control voltages for phase shifters and attenuators are generated using a 12 Bit ADC and is software controlled. The system has a slow feedback to correct phase and amplitude drifts occurring due to thermal variations and a fast feed forward mechanism to vary amplitude and phase of the output pulse to compensate beam loading and to shape the klystron output power. The present paper describes the design aspects of the LLRF system. (author)

Control and performance improvements of a pulse compressor in use for testing accelerating structures at high power

Directory of Open Access Journals (Sweden)

Benjamin Woolley

2017-10-01

Full Text Available New developments relating to compact X-band, SLED-I type pulse compressors being developed at CERN for testing high gradient structures are described. Pulse compressors of interest take rf pulses from one or more high power klystrons with duration typically >1.5  μs and deliver up to 5 times the input power for a shorter duration <250  ns. Time domain models for pulse compressor operation with low level rf (LLRF control have been developed. Input drive amplitude and phase for each pulse is evolved with a control algorithm from the pulse compressor output for previous pulses. The goal is to deliver precise amplitude for pulses to test stands and precise amplitude and phase for pulses to accelerator systems. Control algorithms have been developed and validated experimentally.

SPT0346-52: NEGLIGIBLE AGN ACTIVITY IN A COMPACT, HYPER-STARBURST GALAXY AT z = 5.7

Energy Technology Data Exchange (ETDEWEB)

Ma, Jingzhe; Gonzalez, Anthony H. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Vieira, J. D.; Sreevani, J. [Department of Astronomy and Department of Physics, University of Illinois, 1002 West Green St., Urbana, IL 61801 (United States); Aravena, M. [Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago (Chile); Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Béthermin, M.; Breuck, C. de; Gullberg, B. [European Southern Observatory, Karl Schwarzschild Straße 2, D-85748 Garching (Germany); Bothwell, M. S. [Cavendish Laboratory, University of Cambridge, JJ Thompson Ave, Cambridge CB3 0HA (United Kingdom); Brandt, W. N. [Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States); Carlstrom, J. E. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Chapman, S. C. [Dalhousie University, Halifax, Nova Scotia (Canada); Hezaveh, Y. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Litke, K.; Marrone, D. P.; Spilker, J. S. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Malkan, M. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); McDonald, M. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 37-582C, Cambridge, MA 02139 (United States); Murphy, E. J., E-mail: jingzhema@ufl.edu [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); and others

2016-12-01

We present Chandra ACIS-S and Australia Telescope Compact Array (ATCA) radio continuum observations of the strongly lensed dusty, star-forming galaxy SPT-S J034640-5204.9 (hereafter SPT0346-52) at z = 5.656. This galaxy has also been observed with ALMA, HST , Spitzer , Herschel , Atacama Pathfinder EXperiment, and the Very Large Telescope. Previous observations indicate that if the infrared (IR) emission is driven by star formation, then the inferred lensing-corrected star formation rate (SFR) (∼4500 M {sub ☉} yr{sup −1}) and SFR surface density Σ{sub SFR} (∼2000 M {sub ☉} yr{sup −1} kpc{sup −2}) are both exceptionally high. It remained unclear from the previous data, however, whether a central active galactic nucleus (AGN) contributes appreciably to the IR luminosity. The Chandra upper limit shows that SPT0346-52 is consistent with being star formation dominated in the X-ray, and any AGN contribution to the IR emission is negligible. The ATCA radio continuum upper limits are also consistent with the FIR-to-radio correlation for star-forming galaxies with no indication of an additional AGN contribution. The observed prodigious intrinsic IR luminosity of (3.6 ± 0.3) × 10{sup 13} L {sub ☉} originates almost solely from vigorous star formation activity. With an intrinsic source size of 0.61 ± 0.03 kpc, SPT0346-52 is confirmed to have one of the highest Σ{sub SFR} of any known galaxy. This high Σ{sub SFR}, which approaches the Eddington limit for a radiation pressure supported starburst, may be explained by a combination of very high star formation efficiency and gas fraction.

SPT0346-52: NEGLIGIBLE AGN ACTIVITY IN A COMPACT, HYPER-STARBURST GALAXY AT z = 5.7

International Nuclear Information System (INIS)

Ma, Jingzhe; Gonzalez, Anthony H.; Vieira, J. D.; Sreevani, J.; Aravena, M.; Ashby, M. L. N.; Béthermin, M.; Breuck, C. de; Gullberg, B.; Bothwell, M. S.; Brandt, W. N.; Carlstrom, J. E.; Chapman, S. C.; Hezaveh, Y.; Litke, K.; Marrone, D. P.; Spilker, J. S.; Malkan, M.; McDonald, M.; Murphy, E. J.

2016-01-01

We present Chandra ACIS-S and Australia Telescope Compact Array (ATCA) radio continuum observations of the strongly lensed dusty, star-forming galaxy SPT-S J034640-5204.9 (hereafter SPT0346-52) at z = 5.656. This galaxy has also been observed with ALMA, HST , Spitzer , Herschel , Atacama Pathfinder EXperiment, and the Very Large Telescope. Previous observations indicate that if the infrared (IR) emission is driven by star formation, then the inferred lensing-corrected star formation rate (SFR) (∼4500 M ☉ yr −1 ) and SFR surface density Σ SFR (∼2000 M ☉ yr −1 kpc −2 ) are both exceptionally high. It remained unclear from the previous data, however, whether a central active galactic nucleus (AGN) contributes appreciably to the IR luminosity. The Chandra upper limit shows that SPT0346-52 is consistent with being star formation dominated in the X-ray, and any AGN contribution to the IR emission is negligible. The ATCA radio continuum upper limits are also consistent with the FIR-to-radio correlation for star-forming galaxies with no indication of an additional AGN contribution. The observed prodigious intrinsic IR luminosity of (3.6 ± 0.3) × 10 13 L ☉ originates almost solely from vigorous star formation activity. With an intrinsic source size of 0.61 ± 0.03 kpc, SPT0346-52 is confirmed to have one of the highest Σ SFR of any known galaxy. This high Σ SFR , which approaches the Eddington limit for a radiation pressure supported starburst, may be explained by a combination of very high star formation efficiency and gas fraction.

Synergy of multi-frequency studies from observations of NGC 6334I

International Nuclear Information System (INIS)

Seifahrt, Andreas; Thorwirth, Sven; Menten, Karl M; Beuther, Henrik; Brogan, Crystal L; Hunter, Todd R; Stecklum, Bringfried; Leurini, Silvia

2008-01-01

We combine multi-frequency observations from the millimeter to near infrared wavelengths that demonstrate the spatial distributions of H 2 , CO, and NH 3 emission, which are all manifestations of various shocks driven by outflows of deeply embedded source(s) in NGC 6334I. In addition to the well-known northeast-southwest outflow we detect at least one more outflow in the region by combining observations from APEX, ATCA, SMA, Spitzer and VLT/ISAAC. Potential driving sources will be discussed. NGC 6334I exhibits several signs of active star formation and will be a major target for future observatories such as Herschel and ALMA.

Testing of super conducting low-beta 704 Mhz cavities at 50 Hz pulse repetition rate in view of SPL- first results

CERN Document Server

Höfle, W; Lollierou, J; Valuch, D; Chel, S; Devanz, G; Desmons, M; Piquet, O; Paparella, R; Pierini, P

2010-01-01

In the framework of the preparatory phase for the luminosity upgrade of the LHC (SLHC-PP ) it is foreseen to characterize two superconducting RF cavities and demonstrate compliance of the required SPL field stability in amplitude and phase using a prototype LLRF system. We report on the preparation for testing of two superconducting low-beta cavities at 50 Hz pulse repetition rate including the setting-up of the low level RF control system to evaluate the performance of the piezo-tuning system and cavity field stability in amplitude and phase. Results from tests with 50 Hz pulse repetition rate are presented. Simulations of the RF system will be used to predict the necessary specifications for power and bandwidth to control the cavity field and derive specifications for the RF system and its control. Exemplary results of the simulation are presented.

Cavity Voltage Phase Modulation MD

CERN Document Server

Mastoridis, Themistoklis; Molendijk, John; Timko, Helga; CERN. Geneva. ATS Department

2016-01-01

The LHC RF/LLRF system is currently configured for extremely stable RF voltage to minimize transient beam loading effects. The present scheme cannot be extended beyond nominal beam current since the demanded power would exceed the peak klystron power and lead to saturation. A new scheme has therefore been proposed: for beam currents above nominal (and possibly earlier), the cavity phase modulation by the beam will not be corrected (transient beam loading), but the strong RF feedback and One-Turn Delay feedback will still be active for loop and beam stability in physics. To achieve this, the voltage set point will be adapted for each bunch. The goal of this MD was to test a new algorithm that would adjust the voltage set point to achieve the cavity phase modulation that would minimize klystron forward power.

The Phase-I Trigger Readout Electronics Upgrade of the ATLAS Liquid Argon Calorimeters

CERN Document Server

Yang, Yi-lin; The ATLAS collaboration

2018-01-01

The Super Cell has been proposed in the Phase-I LAr upgrade to replace the existing trigger system "Trigger Tower" due to higher luminosity environments in Run 3 at LHC. The higher granularity of the Super Cell trigger systems requires higher data transmission and processing rate. The new system is also needed to be compatible with the existing trigger system. To fulfill these requirements, the new electronics including frond end and back end are developed. In the front-end part, the new LSB sums the LAr cell signals into Super Cell signals. The new baseplane distributes analog signals among FEBs, LTDB and TBB. The LTDB sums Super Cell signals to Trigger Tower signals and redirected the signals to TBB. The Analog signals are also digitized in LTDB and then sent to back end electronics. In the back-end part, the architecture is based on ATCA. The LAr carrier is used for monitoring and controlling. The LATOMEs inserted into the LAr carrier provide energy calculation from the digitized signals. So far, the demon...

Development and test of the DAQ system for a Micromegas prototype installed into the ATLAS experiment

CERN Document Server

Zibell, Andre; The ATLAS collaboration; Bianco, Michele; Martoiu, Victor Sorin

2015-01-01

A Micromegas (MM) quadruplet prototype with an active area of 0.5 m$^2$ that adopts the general design foreseen for the upgrade of the innermost forward muon tracking systems (Small Wheels) of the ATLAS detector in 2018-2019, has been built at CERN and is going to be tested in the ATLAS cavern environment during the LHC RUN-II period 2015-2017. The integration of this prototype detector into the ATLAS data acquisition system using custom ATCA equipment is presented. An ATLAS compatible ReadOutDriver (ROD) based on the Scalable Readout System (SRS), the Scalable Readout Unit (SRU), will be used in order to transmit the data after generating valid event fragments to the high-level Read Out System (ROS). The SRU will be synchronized with the LHC bunch crossing clock (40.08 MHz) and will receive the Level-1 trigger signals from the Central Trigger Processor (CTP) through the TTCrx receiver ASIC. The configuration of the system will be driven directly from the ATLAS Run Control System. By using the ATLAS TDAQ Soft...

Development and test of the DAQ system for a Micromegas prototype to be installed in the ATLAS experiment

CERN Document Server

Zibell, Andre; The ATLAS collaboration; Bianco, Michele; Martoiu, Victor Sorin

2015-01-01

A Micromegas (MM) quadruplet prototype with an active area of 0.5 m 2 that adopts the general design foreseen for the upgrade of the innermost forward muon tracking systems (Small Wheels) of the ATLAS detector in 2018-2019, has been built at CERN and is going to be tested in the ATLAS cavern environment during the LHC RUN-II period 2015-2017. The integration of this prototype detector into the ATLAS data acquisition system using custom ATCA equipment is presented. An ATLAS compatible Read Out Driver (ROD) based on the Scalable Readout System (SRS), the Scalable Readout Unit (SRU), will be used in order to transmit the data after generating valid event fragments to the high-level Read Out System (ROS). The SRU will be synchronized with the LHC bunch crossing clock (40.08 MHz) and will receive the Level-1 trigger signals from the Central Trigger Processor (CTP) through the TTCrx receiver ASIC. The configuration of the system will be driven directly from the ATLAS Run Control System. By using the ATLAS TDAQ Soft...

Real-time control of fusion reactors

International Nuclear Information System (INIS)

Goncalves, B.; Sousa, J.; Varandas, C.A.F.

2010-01-01

The next generation fusion experiments, e.g. ITER, will be highly complex and raise new challenges in the field of control and data acquisition systems. The more advanced operation scenarios have to be capable of sustaining long pulse steady-state plasma and to suppress plasma instabilities almost completely. Such scenarios will heavily rely on Multiple-Input-Multiple-Output (MIMO) fast control systems. To ensure safety for the operation these systems have to be robust and resilient to faults while ensuring high availability. Mindful of the importance of such features for future fusion experiments ATCA based systems have been successfully used in fusion experiment as MIMO fast controller. This is the most promising architecture to substantially enhance the performance and capability of existing standard systems delivering well high throughput as well as high availability. The real-time control needs of a fusion experiment, the rational for the presently pursued solutions, the existing problems and the broad scientific and technical questions that need to be addressed on the path to a fusion power plant will be discussed.

The Trigger Processor and Trigger Processor Algorithms for the ATLAS New Small Wheel Upgrade

CERN Document Server

Lazovich, Tomo; The ATLAS collaboration

2015-01-01

The ATLAS New Small Wheel (NSW) is an upgrade to the ATLAS muon endcap detectors that will be installed during the next long shutdown of the LHC. Comprising both MicroMegas (MMs) and small-strip Thin Gap Chambers (sTGCs), this system will drastically improve the performance of the muon system in a high cavern background environment. The NSW trigger, in particular, will significantly reduce the rate of fake triggers coming from track segments in the endcap not originating from the interaction point. We will present an overview of the trigger, the proposed sTGC and MM trigger algorithms, and the hardware implementation of the trigger. In particular, we will discuss both the heart of the trigger, an ATCA system with FPGA-based trigger processors (using the same hardware platform for both MM and sTGC triggers), as well as the full trigger electronics chain, including dedicated cards for transmission of data via GBT optical links. Finally, we will detail the challenges of ensuring that the trigger electronics can ...

AMMONIA AS A TEMPERATURE TRACER IN THE ULTRALUMINOUS GALAXY MERGER Arp 220

International Nuclear Information System (INIS)

Ott, Jürgen; Henkel, Christian; Weiß, Axel; Braatz, James A.

2011-01-01

We present Australia Telescope Compact Array (ATCA) and Robert C. Byrd Green Bank Telescope (GBT) observations of ammonia (NH 3 ) and the 1.2 cm radio continuum toward the ultraluminous infrared galaxy merger Arp 220. We detect the NH 3 (1,1), (2,2), (3,3), (4,4), (5,5), and (6,6) inversion lines in absorption against the unresolved, (62 ± 9) mJy continuum source at 1.2 cm. The peak apparent optical depths of the ammonia lines range from ∼0.05 to 0.18. The absorption lines are well described by single-component Gaussians with central velocities in between the velocities of the eastern and western cores of Arp 220. Therefore, the ammonia likely traces gas that encompasses both cores. The absorption depth of the NH 3 (1,1) line is significantly shallower than expected based on the depths of the other transitions. The shallow (1,1) profile may be caused by contamination from emission by a hypothetical, cold (∼ 14 cm –2 . This layer would have to be located behind or away from the radio continuum sources to produce the contaminating emission. The widths of the ammonia absorption lines are ∼120-430 km s –1 , in agreement with those of other molecular tracers. We cannot confirm the extremely large line widths of up to ∼1800 km s –1 previously reported for this galaxy. Using all of the ATCA detections except for the shallow (1,1) line, we determine a rotational temperature of (124 ± 19) K, corresponding to a kinetic temperature of T kin = (186 ± 55) K. Ammonia column densities depend on the excitation temperature. For excitation temperatures of 10 K and 50 K, we estimate N(NH 3 ) = (1.7 ± 0.1) × 10 16 cm –2 and (8.4 ± 0.5) × 10 16 cm –2 , respectively. The relation scales linearly for possible higher excitation temperatures. Our observations are consistent with an ortho-to-para-ammonia ratio of unity, implying that the ammonia formation temperature exceeds ∼30 K. In the context of a model with a molecular ring that connects the two nuclei in Arp

Local Group dSph radio survey with ATCA - II. Non-thermal diffuse emission

Science.gov (United States)

Regis, Marco; Richter, Laura; Colafrancesco, Sergio; Profumo, Stefano; de Blok, W. J. G.; Massardi, Marcella

2015-04-01

Our closest neighbours, the Local Group dwarf spheroidal (dSph) galaxies, are extremely quiescent and dim objects, where thermal and non-thermal diffuse emissions lack, so far, of detection. In order to possibly study the dSph interstellar medium, deep observations are required. They could reveal non-thermal emissions associated with the very low level of star formation, or to particle dark matter annihilating or decaying in the dSph halo. In this work, we employ radio observations of six dSphs, conducted with the Australia Telescope Compact Array in the frequency band 1.1-3.1 GHz, to test the presence of a diffuse component over typical scales of few arcmin and at an rms sensitivity below 0.05 mJy beam-1. We observed the dSph fields with both a compact array and long baselines. Short spacings led to a synthesized beam of about 1 arcmin and were used for the extended emission search. The high-resolution data mapped background sources, which in turn were subtracted in the short-baseline maps, to reduce their confusion limit. We found no significant detection of a diffuse radio continuum component. After a detailed discussion on the modelling of the cosmic ray (CR) electron distribution and on the dSph magnetic properties, we present bounds on several physical quantities related to the dSphs, such that the total radio flux, the angular shape of the radio emissivity, the equipartition magnetic field, and the injection and equilibrium distributions of CR electrons. Finally, we discuss the connection to far-infrared and X-ray observations.

Anterior Trans Cervicothoracic Approach for Complete Resection of Cervicothoracic Mediastinal Neurogenic Tumors

Directory of Open Access Journals (Sweden)

Reza Bagheri

2013-10-01

Full Text Available Introduction:Neurogenic mediastinal tumors comprise a wide range of benign and malignant diseases. A group of these tumors, located at thoracic apex, sometimes spread to cervical spaces causing numerous surgical difficulties. In thoracotomy approaches, due to proximity of the tumors to major blood vessels, complete removal of these tumors from cervical spaces is impossible or may cause intraoperative severe bleeding or other dangerous incidents Because of the adjacent major vessels  that are not visible.The aim of this study is to report cases of surgical treatment of such tumors using Anterior Trans Cervicothoracic Approach (ATCA. Materials and Methods:All patients with neurogenic tumors and cervicomediastinal (CM spread who underwent surgey with ATCA technique during 2005-2011 were included in our study. Then they were evaluated in terms of age, sex, clinical symptoms, radiological and pathological findings, technical success rate of the surgery, surgical complications and first-year relapse rate after the surgery. Results:Our study included 10 patients from whom 9 were female and 1 was male (M/F= 1/9 and the mean age was 27 years. The most common symptoms were pain and feeling of a lump. All patients were operated by this technique successfully. The most common pathological finding was neurofibroma (in 5 patients and surgical complications occurred in 2 patients (20% (Wound infection in 1 patient and brachial plexus injury in another patient. There was no mortality. Disease relapse was reported in 1 patient  ganglioneuroblastoma who underwent surgical resection for the second time. Conclusion: Considering the successful removal of the tumors and favorable exposure of major vessels in cervicomediastinal spaces, this technique is recommended to resect mediastinal tumors with spread to cervical spaces. However, a more definite conclusion requires further studies.

The Vela Cloud: A Giant H I Anomaly in the NGC 3256 GROUP

Science.gov (United States)

English, Jayanne; Koribalski, B.; Bland-Hawthorn, J.; Freeman, K. C.; McCain, Claudia F.

2010-01-01

We present Australia Telescope Compact Array (ATCA) observations of a galaxy-sized intergalactic H I cloud ("the Vela Cloud") in the NGC 3256 galaxy group. The group contains the prominent merging galaxy NGC 3256, which is surrounded by a number of H I fragments, the tidally disturbed galaxy NGC 3263, and several other peculiar galaxies. The Vela Cloud, with an H I mass of 3-5 × 10^9 M_{⊙}, resides southeast of NGC 3256 and west of NGC 3263, within an area of 9' × 16' (100 kpc × 175 kpc for an adopted distance of 38 Mpc). In our ATCA data the Vela Cloud appears as three diffuse components and contains four density enhancements. The Vela Cloud's properties, together with its group environment, suggest that it has a tidal origin. Each density enhancement contains ˜ 10^{8} M_{⊙} of H I gas, which is sufficient material for the formation of globular cluster progenitors. However, if we represent the enhancements as Bonnor-Ebert spheres, then the pressure of the surrounding H I would need to increase by at least a factor of 9 in order to cause the collapse of an enhancement. Thus we do not expect them to form massive bound stellar systems like super star clusters or tidal dwarf galaxies. Since the H I density enhancements have some properties in common with high-velocity clouds, we explore whether they may evolve to be identified with these starless clouds instead. Original plate material is copyright © the Royal Observatory Edinburgh and the Anglo-Australian Observatory. The plates were processed into the present compressed digital form with their permission. The Digitized Sky Survey was produced at the Space Telescope Science Institute under US Government grant NAG W-2166.

Multifrequency radio observations of a SNR in the LMC: The case of SNR J0527-6549 (DEM l204

Directory of Open Access Journals (Sweden)

Bozzetto L.M.

2010-01-01

Full Text Available We present a detailed study and results of new Australia Telescope Compact Array (ATCA observations of supernova remnant SNR J0527-6549. This Large Magellanic Cloud (LMC object follows a typical supernova remnant (SNR horseshoe morphology with a diameter of D=(66×58±1 pc which is among the largest SNRs in the LMC. Its relatively large size indicates older age while a steeper than expected radio spectral index of α=-0.92±0.11 is more typical of younger and energetic SNRs. Also, we report detections of regions with a high order of polarization at a peak value of ~54%±17% at 6 cm.

Measuring Dark Molecular Gas

Science.gov (United States)

Li, Di; Heiles, Carl E.

2017-01-01

It is now well known that a substantial fraction of Galactic molecular gas cannot be traced by CO emission. The thus dubbed CO dark molecular gas (DMG) occupy a large volume of ISM with intermediate extinction, where CO is either not self-shielded and/or subthermally excited. We explore the utilities of simple hydrides, such OH, CH, etc., in tracing DMG. We mapped and modeled the transition zone cross a cloud boundary and derived emperical OH abundance and DMG distribution formulae. We also obtained absorption measurements of various species using Arecibo, VLA, ATCA, and ALMA. The absorption technique has the potential to provide systematic quantification of DMG in the next few years.

Data transmission optical link for LLRF TESLA project part II: application for BER measurements

Science.gov (United States)

Pozniak, Krzysztof T.; Romaniuk, Ryszard S.; Jalmuzna, Wojciech; Olowski, Krzysztof; Perkuszewski, Karol; Zielinski, Jerzy; Kierzkowski, Krzysztof

2006-02-01

It may be predicted now, even assuming a very conservative approach, that the next generation of the Low Level RF control systems for future accelerators will use extensively such technologies like: very fast programmable circuits equipped with DSP, embedded PC and optical communication I/O functionalities, as well as multi-gigabit optical transmission of measurement data and control signals.

PSB beam longitudinal blow-up by phase modulation with the digital LLRF prototype system

CERN Document Server

Angoletta, M E; Butterworth, A; Findlay, A; Jaussi, M; Leinonen, P; Molendijk, J; Sanchez-Quesada, J

2014-01-01

The PSB will be upgraded to a new, Digital Low-Level RF (DLLRF) system in 2014 at the injectors’ restart after LS1. This DLLRF is an evolution of that successfully deployed in LEIR and comprises new hardware, software and implementation strategies. Machine development studies have been carried out in the PSB over recent years with the existing LEIR-style hardware installed in PSB ring four. These studies have allowed testing approaches and validating implementation strategies. This note focuses on a series of MDs carried out during the 2011 run where a new implementation of the longitudinal beam blow-up obtained by phase modulation was tested. Test results and effects on the beam are show for a CNGS-type beam. Finally, an overview is given of the final longitudinal blow-up implementation planned with the new hardware, which will be operationally deployed in 2014.

Validation of the superconducting 3.9 GHz cavity package for the European X-ray Free Electron Laser

Science.gov (United States)

Maiano, C. G.; Branlard, J.; Hüning, M.; Jensch, K.; Kostin, D.; Matheisen, A.; Möller, W.-D.; Sulimov, A.; Vogel, E.; Bosotti, A.; Chen, J. F.; Moretti, M.; Paparella, R.; Pierini, P.; Sertore, D.

2017-04-01

A full test of the cavity package concept under realistic operating condition was a necessary step before the assembly of the European XFEL (EXFEL) 3.9 GHz superconducting system and its installation in the accelerator. One cavity, equipped with magnetic shielding, power coupler and frequency tuner has been tested in a specially designed single cavity cryostat in one of the test benches of the DESY Accelerator Module Test Facility (AMTF). The cavity was operated at high pulsed power up to an accelerating field of 24 MV /m , above the quench accelerating field of 21 MV /m achieved during the continuous wave (CW) vertical qualification test and with a large margin with respect to the EXFEL maximum operating specification of 15 MV /m for the 3.9 GHz system. All subsystems under test—coupler, tuner, waveguide tuners, low level radio-frequency (LLRF) system—were qualified to their design performances.

A Novel Approach for Automatic Control of Piezoelectric Elements Used for Lorentz Force Detuning Compensation

CERN Document Server

Przygoda, K; Napieralski, A; Grecki, M

2010-01-01

Abstract: Linear accelerators such as Free Electron Lasers (FELs) use superconducting (SC) resonant cavities to accelerate electron beam to high energies. TESLA type resonators are extremely sensitive to detuning induced by mechanical deformations – Lorentz force detuning (LFD), mainly due to the extremely high quality factor (Q) of the 1.3 GHz resonance mode, in the range of 1e6. The resulting modulation of a resonance frequency of the cavity makes power consumption and stability performances of the Low-Latency Radio Frequency (LLRF) control more critical. In order to minimize the RF control efforts and desired stabilities, the fast piezoelectric actuators with digital control systems are commonly used. The paper presents a novel approach for automatic control of piezoelectric actuators used for compensation of Lorentz force detuning, the practical application and carried out tests in accelerating module ACC6 in Free-Electron Laser in Hamburg (FLASH).

Radio-continuum observations of small, radially polarised Supernova Remnant J0519-6902 in the large Magellanic cloud

Directory of Open Access Journals (Sweden)

Bozzetto L.M.

2012-01-01

Full Text Available We report on new Australian Telescope Compact Array (ATCA observations of SNR J0519-6902. The Supernova Remnant (SNR is small in size (~8 pc and exhibits a typical SNR spectrum with α = -0.53±0.07, with steeper spectral indices towards the northern limb of the remnant. SNR J0519-6902 contains a low level of radially orientated polarisation at wavelengths of 3 and 6 cm, which is typical of younger SNRs. A fairly strong magnetic field was estimated to ~171µG. The remnant appears to be the result of a typical Type Ia supernova, sharing many properties with another small and young Type Ia LMC SNR, J0509-6731. [Projekat Ministarstva nauke Republike Srbije, br. 176005

The disc-jet coupling in the neutron star X-ray binary 4U 1728-34

Science.gov (United States)

Tudose, Valeriu; Tzioumis, Anastasios; Belloni, Tomaso; Altamirano, Diego; Linares, Manuel; Mendez, Mariano; Hiemstra, Beike

2010-10-01

The present radio proposal is part of a multi-wavelength campaign focused on the study of the accretion/ejection process in the neutron star X-ray binary system 4U 1728-34. Our intention is to study the behaviour of the inner part of the accretion disc as inferred from the X-ray observations of the Fe emission line and the kHz quasi-periodic oscillations, and to link it to the properties of the radio jet. To achieve this goal we request 5 × 11h of observing time with ATCA, scheduled at regular intervals in the period 2010 August 27- October 13, the visibility window of the granted X-ray observations with RXTE (PI: Mendez) and Suzaku (PI: Linares).

Digital Low-Level RF Controls for Future Superconducting Linear Colliders

CERN Document Server

Simrock, Stefan

2005-01-01

The requirements for RF Control Systems of Superconducting Linear Colliders are not only defined in terms of the quality of field control but also with respect to operability, availability, and maintainability of the RF System, and the interfaces to other subsystems. The field control of the vector-sum of many cavities driven by one klystron in pulsed mode at high gradients is a challenging task since severe Lorentz force detuning, microphonics and beam induced field errors must be suppressed by several orders of magnitude. This is accomplished by a combination of local and global feedback and feedforward control. Sensors monitor individual cavity probe signals, and forward and reflected wave as well as the beam properties including beam energy and phase while actuators control the incident wave of the klystron and individual cavity resonance frequencies. The operability of a large llrf system requires a high degree of automation while the high availability requires robust algorithms, redundancy, and extremel...

RF upgrade program in LHC injectors and LHC machine

International Nuclear Information System (INIS)

Jensen, E.

2012-01-01

The main themes of the RF upgrade program are: the Linac4 project, the LLRF-upgrade and the study of a tuning-free wide-band system for PSB, the upgrade of the SPS 800 MHz amplifiers and beam controls and the upgrade of the transverse dampers of the LHC. Whilst LHC Splice Consolidation is certainly the top priority for LS1, some necessary RF consolidation and upgrade is necessary to assure the LHC performance for the next 3- year run period. This includes: 1) necessary maintenance and consolidation work that could not fit the shorter technical stops during the last years, 2) the upgrade of the SPS 200 MHz system from presently 4 to 6 cavities and possibly 3) the replacement of one LHC cavity module. On the longer term, the LHC luminosity upgrade requires crab cavities, for which some preparatory work in SPS Coldex must be scheduled during LS1. (author)

Validation of the superconducting 3.9 GHz cavity package for the European X-ray Free Electron Laser

Directory of Open Access Journals (Sweden)

C. G. Maiano

2017-04-01

Full Text Available A full test of the cavity package concept under realistic operating condition was a necessary step before the assembly of the European XFEL (EXFEL 3.9 GHz superconducting system and its installation in the accelerator. One cavity, equipped with magnetic shielding, power coupler and frequency tuner has been tested in a specially designed single cavity cryostat in one of the test benches of the DESY Accelerator Module Test Facility (AMTF. The cavity was operated at high pulsed power up to an accelerating field of 24  MV/m, above the quench accelerating field of 21  MV/m achieved during the continuous wave (CW vertical qualification test and with a large margin with respect to the EXFEL maximum operating specification of 15  MV/m for the 3.9 GHz system. All subsystems under test—coupler, tuner, waveguide tuners, low level radio-frequency (LLRF system—were qualified to their design performances.

Development of a multichannel RF field detector for the low-level RF control of the free-electron laser at Hamburg

International Nuclear Information System (INIS)

Hoffmann, Matthias

2008-10-01

Modern free electron lasers produce synchrotron radiation with constantly shortening wavelengths of up to 6 nm and pulse widths of up to 100 fs. That requires a constantly increasing stability of the beam energy and arrival time of the electron beam at the undulator entrance which is situated at the end of the accelerator. At the same time, the increasing speed of digital signal processing and data acquisition facilitates new possibilities for the digital radio frequency control and field detection. In this thesis the development of a multichannel radio frequency field detector for the low level radio frequency (LLRF) control of the superconducting cavities of the Free-Electron Laser at Hamburg (FLASH) is described. The applied method of IF sampling is state of the technology and is utilized in many areas of digital communication. It is evaluated concerning its applicability for the LLRF control. Analytical and numerical investigations of the noise behavior and transport in the control loop have been accomplished to define the requirements for the measurement accuracy of the field detector that was to be developed. Therefore, simplified models of the noise behavior of each system component of the control loop, e.g. amplifier, radio frequency mixer and analog-to-digital converter, were established and subsequently assorted to a the model of the control loop. Due to the application of the vector-sum control, where several separately measured field vectors are added to a vector-sum, requirements concerning the allowable compression error of the detector nonlinearity were defined. These were investigated by analytical and numerical methods, as well. Requirements for the hardware that was to be developed were compiled from the simulation results. For the development of the field detector, a modular and EMC-compatible concept with a high-level passive front-end for an improvement of the signal-to-noise ratio was chosen. The following tests in the lab delivered the

Development of a multichannel RF field detector for the low-level RF control of the free-electron laser at Hamburg

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, Matthias

2008-10-15

Modern free electron lasers produce synchrotron radiation with constantly shortening wavelengths of up to 6 nm and pulse widths of up to 100 fs. That requires a constantly increasing stability of the beam energy and arrival time of the electron beam at the undulator entrance which is situated at the end of the accelerator. At the same time, the increasing speed of digital signal processing and data acquisition facilitates new possibilities for the digital radio frequency control and field detection. In this thesis the development of a multichannel radio frequency field detector for the low level radio frequency (LLRF) control of the superconducting cavities of the Free-Electron Laser at Hamburg (FLASH) is described. The applied method of IF sampling is state of the technology and is utilized in many areas of digital communication. It is evaluated concerning its applicability for the LLRF control. Analytical and numerical investigations of the noise behavior and transport in the control loop have been accomplished to define the requirements for the measurement accuracy of the field detector that was to be developed. Therefore, simplified models of the noise behavior of each system component of the control loop, e.g. amplifier, radio frequency mixer and analog-to-digital converter, were established and subsequently assorted to a the model of the control loop. Due to the application of the vector-sum control, where several separately measured field vectors are added to a vector-sum, requirements concerning the allowable compression error of the detector nonlinearity were defined. These were investigated by analytical and numerical methods, as well. Requirements for the hardware that was to be developed were compiled from the simulation results. For the development of the field detector, a modular and EMC-compatible concept with a high-level passive front-end for an improvement of the signal-to-noise ratio was chosen. The following tests in the lab delivered the

Challenges for emerging new electronics standards for physics

International Nuclear Information System (INIS)

Larsen, R.S.

2012-01-01

A unique effort is underway between industry and the international physics community to extend the Telecom industry's Advanced Telecommunications Computing Architecture (ATCA and MicroTCA) to meet future needs of the physics machine controls, instrumentation and detector communities. New standard extensions for physics are described which have been designed to deliver unprecedented performance and high subsystem availability for accelerator controls, instrumentation and data acquisition. Key technical features include an out-of-band imbedded standard Intelligent Platform Management Interface (IPMI) system to manage hot-swap module replacement and hardware-software fail-over. New software standards or guidelines are in development which will extend the reach of platform independent software standards to simplify design of low level drivers. Efforts to make the new standards broadly available in the marketplace through lab-industry collaboration are discussed. (author)

VizieR Online Data Catalog: Local Group dSph radio survey with ATCA (Regis+, 2015)

Science.gov (United States)

Regis, M.; Richter, L.; Colafrancesco, S.; Massardi, M.; De Blok, W. J. G.; Profumo, S.; Orford, N.

2015-09-01

We present a catalogue of radio sources detected in the fields of six dwarf spheroidal galaxies of the Local Group, which are Carina, Fornax, Sculptor, BootesII, Segue2, and Hercules. Observations were performed during July/August 2011 with the six 22-m diameter Australia Telescope Compact Array antennae operating at 16cm wavelength. We mosaicked a region of radius of about one degree around the first three dwarfs, and of about half of degree around the last three dwarfs. The rms noise level is below 0.05mJy. The restoring beams FWHM ranged from 4.2x2.5-arcseconds to 30.0x2.1-arcseconds in the most elongated case. The catalogue includes different parameters describing 1835 entries which, in our classification, correspond to 1392 sources. See the publication for more details. (1 data file).

Measurements of SIMCON 3.1 LLRF control signal processing quality for VUV free-electron laser FLASH

Science.gov (United States)

Pietrasik, Rafal; Giergusiewicz, Wojciech; Jalmuzna, Wojciech; Pozniak, Krzysztof T.; Romaniuk, Ryszard S.; Simrock, Stefan

2006-10-01

The paper describes development of a new version of photonic and electronic control and measurement system for FLASH Laser under development in DESY Hamburg accelerator laboratory. The system is called SIMCON 3.1. and is a developmental continuation of previous systems SIMCON 1.0, SIMCON 2.1 and SIMCON 3.0. It differs from the previous systems by considerably bigger resources: 10 fast analog input channels, bigger FPGA chip with two power PC - CPU units, two multi-gigabit optical links, GbE interface, booting possibility from flash memory card. The PCB is done in VME mechanical and electrical standard. It is designed for usage in tests for FLASH Laser development.

Real-time software for the COMPASS tokamak plasma control

Czech Academy of Sciences Publication Activity Database

Valcárcel, D.F.; Duarte, A.S.; Neto, A.; Carvalho, I.S.; Carvalho, B.B.; Fernandes, H.; Sousa, J.; Sartori, F.; Janky, Filip; Cahyna, Pavel; Hron, Martin; Pánek, Radomír

2010-01-01

Roč. 85, 3-4 (2010), s. 470-473 ISSN 0920-3796. [IAEA Technical Meeting on Control, Data Acquisition and Remote Participation for Fusion Research/7th./. Aix – en – Provence, 15.06.2009-19.06.2009] Institutional research plan: CEZ:AV0Z20430508 Keywords : Real-time * ATCA * Data acquisition * Plasma control software Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.143, year: 2010 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V3C-4YXMP1Y-3&_user=6542793&_coverDate=07%2F31%2F2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000070123&_version=1&_urlVersion=0&_userid=6542793&md5=9005df0735c0dbb3a93a9c154b0d09c1&searchtype=a

CHANDRA OBSERVATIONS OF THE HIGH-MAGNETIC-FIELD RADIO PULSAR J1718-3718

International Nuclear Information System (INIS)

Zhu, W. W.; Kaspi, V. M.; Ng, C.-Y.; McLaughlin, M. A.; Pavlov, G. G.; Manchester, R. N.; Gaensler, B. M.; Woods, P. M.

2011-01-01

High-magnetic-field pulsars represent an important class of objects for studying the relationship between magnetars and radio pulsars. Here we report on four Chandra observations of the high-magnetic-field pulsar J1718-3718 (B = 7.4 x 10 13 G) taken in 2009 as well as a reanalysis of 2002 Chandra observations of the region. We also report an improved radio position for this pulsar based on ATCA observations. We detect X-ray pulsations at the pulsar's period in the 2009 data, with a pulsed fraction of 52% ± 13% in the 0.8-2.0 keV band. We find that the X-ray pulse is aligned with the radio pulse. The data from 2002 and 2009 show consistent spectra and fluxes: a merged overall spectrum is well fit by a blackbody of temperature 186 +19 -18 eV, slightly higher than predicted by standard cooling models; however, the best-fit neutron star atmosphere model is consistent with standard cooling. We find the bolometric luminosity L ∞ bb = 4 +5 -2 x 10 32 erg s -1 ∼0.3 E-dot for a distance of 4.5 kpc. We compile measurements of the temperatures of all X-ray-detected high-B pulsars as well as those of low-B radio pulsars and find evidence for the former being hotter on average than the latter.

RF Phase Scan for Beam Energy Measurement of KOMAC DTL

Energy Technology Data Exchange (ETDEWEB)

Kim, Hansung; Kwon, Hyeokjung; Kim, Seonggu; Lee, Seokgeun; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The energy gain through the drift tube linac is a function of the synchronous phase, therefore, the output beam energy from DTL can be affected by the RF phase setting in low-level RF (LLRF) system. The DTL at Korea Multi-purpose Accelerator Complex (KOMAC) consists of 11 tanks and the RF phase setting in each tank should be matched for synchronous acceleration in successive tanks. That means a proper setting of RF phase in each DTL tank is critical for efficient and loss-free operation. The matching RF phase can be determined based on the output energy measurement from the DTL tank. The beam energy can be measured by several methods. For example, we can use a bending magnet to determine the beam energy because the higher momentum of beam means the less deflection angle in the fixed magnetic field. By measuring the range of proton beam through a material with known stopping power also can be utilized to determine the beam energy. We used a well-known time-of-flight method to determine the output beam energy from the DTL tank by measuring beam phase with a beam position monitor (BPM). Based on the energy measurement results, proper RF operating point could be obtained. We performed a RF phase scan to determine the output beam energy from KOMAC DTL by using a time-of-flight method and to set RF operating point precisely. The measured beam energy was compared with a beam dynamics simulation and showed a good agreement. RF phase setting is critical issue for the efficient operation of the proton accelerator, we have a plan to implement and integrate the RF phase measurement system into an accelerator control system for future need.

Main injector synchronous timing system

International Nuclear Information System (INIS)

Blokland, W.; Steimel, J.

1998-01-01

The Synchronous Timing System is designed to provide sub-nanosecond timing to instrumentation during the acceleration of particles in the Main Injector. Increased energy of the beam particles leads to a small but significant increase in speed, reducing the time it takes to complete a full turn of the ring by 61 nanoseconds (or more than 3 rf buckets). In contrast, the reference signal, used to trigger instrumentation and transmitted over a cable, has a constant group delay. This difference leads to a phase slip during the ramp and prevents instrumentation such as dampers from properly operating without additional measures. The Synchronous Timing System corrects for this phase slip as well as signal propagation time changes due to temperature variations. A module at the LLRF system uses a 1.2 Gbit/s G-Link chip to transmit the rf clock and digital data (e.g. the current frequency) over a single mode fiber around the ring. Fiber optic couplers at service buildings split off part of this signal for a local module which reconstructs a synchronous beam reference signal. This paper describes the background, design and expected performance of the Synchronous Timing System. copyright 1998 American Institute of Physics

Main injector synchronous timing system

International Nuclear Information System (INIS)

Blokland, Willem; Steimel, James

1998-01-01

The Synchronous Timing System is designed to provide sub-nanosecond timing to instrumentation during the acceleration of particles in the Main Injector. Increased energy of the beam particles leads to a small but significant increase in speed, reducing the time it takes to complete a full turn of the ring by 61 nanoseconds (or more than 3 rf buckets). In contrast, the reference signal, used to trigger instrumentation and transmitted over a cable, has a constant group delay. This difference leads to a phase slip during the ramp and prevents instrumentation such as dampers from properly operating without additional measures. The Synchronous Timing System corrects for this phase slip as well as signal propagation time changes due to temperature variations. A module at the LLRF system uses a 1.2 Gbit/s G-Link chip to transmit the rf clock and digital data (e.g. the current frequency) over a single mode fiber around the ring. Fiber optic couplers at service buildings split off part of this signal for a local module which reconstructs a synchronous beam reference signal. This paper describes the background, design and expected performance of the Synchronous Timing System

Design of RF system for CYCIAE-230 superconducting cyclotron

Energy Technology Data Exchange (ETDEWEB)

Yin, Zhiguo, E-mail: bitbearAT@hotmail.com; Ji, Bin; Fu, Xiaoliang; Cao, Xuelong; Zhao, Zhenlu; Zhang, Tinajue

2017-05-11

The CYCIAE230 is a low-current, compact superconducting cyclotron designed for proton therapy. The Radio Frequency system consists of four RF cavities and applies second harmonic to accelerate beams. The driving power for the cavity system is estimated to be approximately 150 kW. The LLRF controller is a self-made device developed and tested at low power using a small-scale cavity model. In this paper, the resonator systems of an S.C. cyclotron in history are reviewed. Contrary to those RF systems, the cavities of the CYCIAE230 cyclotron connect two opposite dees. Two high-power RF windows are included in the system. Each window carries approximately 75 kW RF power from the driver to the cavities. Thus, the RF system for the CY-CIAE230 cyclotron is operated in driven push–pull mode. The two-way amplifier-coupler-cavity systems are operated with approximately the same amount of RF power but 180° out of phase compared with each other. The design, as well as the technical advantage and limitations of this operating mode, of the CYCIAE230 cyclotron RF system is analyzed.

Design of RF system for CYCIAE-230 superconducting cyclotron

Science.gov (United States)

Yin, Zhiguo; Ji, Bin; Fu, Xiaoliang; Cao, Xuelong; Zhao, Zhenlu; Zhang, Tinajue

2017-05-01

The CYCIAE230 is a low-current, compact superconducting cyclotron designed for proton therapy. The Radio Frequency system consists of four RF cavities and applies second harmonic to accelerate beams. The driving power for the cavity system is estimated to be approximately 150 kW. The LLRF controller is a self-made device developed and tested at low power using a small-scale cavity model. In this paper, the resonator systems of an S.C. cyclotron in history are reviewed. Contrary to those RF systems, the cavities of the CYCIAE230 cyclotron connect two opposite dees. Two high-power RF windows are included in the system. Each window carries approximately 75 kW RF power from the driver to the cavities. Thus, the RF system for the CY-CIAE230 cyclotron is operated in driven push-pull mode. The two-way amplifier-coupler-cavity systems are operated with approximately the same amount of RF power but 180° out of phase compared with each other. The design, as well as the technical advantage and limitations of this operating mode, of the CYCIAE230 cyclotron RF system is analyzed.

Study on transient beam loading compensation for China ADS proton linac injector II

Science.gov (United States)

Gao, Zheng; He, Yuan; Wang, Xian-Wu; Chang, Wei; Zhang, Rui-Feng; Zhu, Zheng-Long; Zhang, Sheng-Hu; Chen, Qi; Powers, Tom

2016-05-01

Significant transient beam loading effects were observed during beam commissioning tests of prototype II of the injector for the accelerator driven sub-critical (ADS) system, which took place at the Institute of Modern Physics, Chinese Academy of Sciences, between October and December 2014. During these tests experiments were performed with continuous wave (CW) operation of the cavities with pulsed beam current, and the system was configured to make use of a prototype digital low level radio frequency (LLRF) controller. The system was originally operated in pulsed mode with a simple proportional plus integral and deviation (PID) feedback control algorithm, which was not able to maintain the desired gradient regulation during pulsed 10 mA beam operations. A unique simple transient beam loading compensation method which made use of a combination of proportional and integral (PI) feedback and feedforward control algorithm was implemented in order to significantly reduce the beam induced transient effect in the cavity gradients. The superconducting cavity field variation was reduced to less than 1.7% after turning on this control algorithm. The design and experimental results of this system are presented in this paper. Supported by National Natural Science Foundation of China (91426303, 11525523)

Design and development of RF system for vertical test stand for characterization of superconducting RF cavities

International Nuclear Information System (INIS)

Mohania, Praveen; Rajput, Vikas; Baxy, Deodatta; Agrawal, Ankur; Mahawar, Ashish; Adarsh, Kunver; Singh, Pratap; Shrivastava, Purushottam

2011-01-01

RRCAT is developing a Vertical Test Stand (VTS) to test and qualify 1.3 GHz/650 MHz, SCRF Cavities in collaboration with Fermi National Accelerator Laboratory (FNAL) under Indian Institutions' Fermilab Collaboration. The technical details for VTS is being provided by FNAL, USA. The RF System of VTS needs to provide stable RF power to SCRF cavity with control of amplitude, relative phase and frequency. The incident, reflected, transmitted power and field decay time constant of the cavity are measured to evaluate cavity performance parameters (E, Qo). RF Power is supplied via 500 W Solid State amplifier, 1270-1310 MHz being developed by PHPMS, RRCAT. VTS system is controlled by PXI Platform and National Instruments LabVIEW software. Low Level RF (LLRF) system is used to track the cavity frequency using Phase Locked Loop (PLL). The system is comprised of several integrated functional modules which would be assembled, optimized, and tested separately. Required components and instruments have been identified and procurement for the same is underway. Inhouse development for the Solid State RF amplifier and instrument interfacing is in progress. This paper describes the progress on the development of the RF system for VTS. (author)

Modeling event building architecture for the triggerless data acquisition system for PANDA experiment at the HESR facility at FAIR/GSI

CERN Multimedia

CERN. Geneva

2012-01-01

A novel architecture is being proposed for the data acquisition and trigger system for PANDA experiment at the HESR facility at FAIR/GSI. The experiment will run without the hardware trigger signal and use timestamps to correlate detector data from a given time window. The broad physics program in combination with high rate of 2 10^7 interactions require very selective filtering algorithms which access information from almost all detectors. Therefore the effective filtering will happen later than it used to in today's systems ie after the event building. To assess that, the complete architecture will be built of two stages: the data concentrator stage providing event building and the rate reduction stage. For the former stage, which allows to switch 100 GB/s of event fragments to perform event building, we propose two layers of ATCA crates filled with compute nodes - modules designed at University of Giessen for trigger and data acquisition systems. Each board is equipped with 5 Virtex4 FX60 FPG...

The 100 strongest radio point sources in the field of the Large Magellanic Cloud at 1.4 GHz

Directory of Open Access Journals (Sweden)

Payne J.L.

2009-01-01

Full Text Available We present the 100 strongest 1.4 GHz point sources from a new mosaic image in the direction of the Large Magellanic Cloud (LMC. The observations making up the mosaic were made using Australia Telescope Compact Array (ATCA over a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 1000 at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact H ii regions, young SNRs and radio planetary nebulae. For the 1988 point sources we find a preliminary average spectral index (α of -0.53 and present a 1.4 GHz image showing source location in the direction of the LMC.

The ILC control system

International Nuclear Information System (INIS)

Carwardine, J.; Saunders, C.; Arnold, N.; Lenkszus, F.; Rehlich, K.; Simrock, S.; Banerjee, b.; Chase, B.; Gottschalk, E.; Joireman, P.; Kasley, P.; Lackey, S.; McBride, P.; Pavlicek, V.; Patrick, J.; Votava, M.; Wolbers, S.; Furukawa, K.; Michizono, S.; Larson, R.S.; Downing, R.

2007-01-01

Since the last ICALEPCS, a small multi-region team has developed a reference design model for a control system for the International Linear Collider as part of the ILC Global Design Effort. The scale and performance parameters of the ILC accelerator require new thinking in regards to control system design. Technical challenges include the large number of accelerator systems to be controlled, the large scale of the accelerator facility, the high degree of automation needed during accelerator operations, and control system equipment requiring 'Five Nines' availability. The R and D path for high availability touches the control system hardware, software, and overall architecture, and extends beyond traditional interfaces into the technical systems. Software considerations for HA include fault detection through exhaustive out-of-band monitoring and automatic state migration to redundant systems, while the telecom industry's emerging ATCA standard - conceived, specified, and designed for High Availability - is being evaluated for suitability for ILC front-end electronics.

The Development of the Global Feature eXtractor (gFEX) for ATLAS Level 1 Calorimeter Trigger at the LHC

CERN Document Server

Tang, Shaochun; The ATLAS collaboration; Chen, Hucheng

2018-01-01

During the ATLAS Phase-I upgrade, the gFEX will be designed to maintain the trigger acceptance against the increasing luminosity for the ATLAS Level-1 calorimeter trigger system. The gFEX is designed to identify patterns of energy associated with the hadronic decays of high momentum Higgs, W, & Z bosons, top quarks, and exotic particles in real time at the LHC crossing rate. The prototype v1 and v2 have been designed and fully tested in 2015 and 2016 respectively. With the lessons learned, a pre-production board with three UltraScale+ FPGAs and one ZYNQ UltraScale+, and 35 MiniPODs are implemented in an ATCA module. This board will receive coarse-granularity (0.2x0.2) information from the entire ATLAS calorimeters on up to 300 optical fibers and each FPGA has 24 links to the L1Topo at the speed up to 12.8 Gb/s.

Parallel processing method for high-speed real time digital pulse processing for gamma-ray spectroscopy

International Nuclear Information System (INIS)

Fernandes, A.M.; Pereira, R.C.; Sousa, J.; Neto, A.; Carvalho, P.; Batista, A.J.N.; Carvalho, B.B.; Varandas, C.A.F.; Tardocchi, M.; Gorini, G.

2010-01-01

A new data acquisition (DAQ) system was developed to fulfil the requirements of the gamma-ray spectrometer (GRS) JET-EP2 (joint European Torus enhancement project 2), providing high-resolution spectroscopy at very high-count rate (up to few MHz). The system is based on the Advanced Telecommunications Computing Architecture TM (ATCA TM ) and includes a transient record (TR) module with 8 channels of 14 bits resolution at 400 MSamples/s (MSPS) sampling rate, 4 GB of local memory, and 2 field programmable gate array (FPGA) able to perform real time algorithms for data reduction and digital pulse processing. Although at 400 MSPS only fast programmable devices such as FPGAs can be used either for data processing and data transfer, FPGA resources also present speed limitation at some specific tasks, leading to an unavoidable data lost when demanding algorithms are applied. To overcome this problem and foreseeing an increase of the algorithm complexity, a new digital parallel filter was developed, aiming to perform real time pulse processing in the FPGAs of the TR module at the presented sampling rate. The filter is based on the conventional digital time-invariant trapezoidal shaper operating with parallelized data while performing pulse height analysis (PHA) and pile up rejection (PUR). The incoming sampled data is successively parallelized and fed into the processing algorithm block at one fourth of the sampling rate. The following data processing and data transfer is also performed at one fourth of the sampling rate. The algorithm based on data parallelization technique was implemented and tested at JET facilities, where a spectrum was obtained. Attending to the observed results, the PHA algorithm will be improved by implementing the pulse pile up discrimination.

Advanced real-time control systems for magnetically confined fusion plasmas

International Nuclear Information System (INIS)

Goncalves, B.; Sousa, J.; Fernandes, H.; Rodrigues, A.P.; Carvalho, B.B.; Neto, A.; Varandas, C.A.F.

2008-01-01

Real-time control of magnetically confined plasmas is a critical issue for the safety, operation and high performance scientific exploitation of the experimental devices on regimes beyond the current operation frontiers. The number of parameters and the data volumes used for the plasma properties identification scale normally not only with the machine size but also with the technology improvements, leading to a great complexity of the plant system. A strong computational power and fast communication infrastructure are needed to handle in real-time this information, allowing just-in-time decisions to achieve the fusion critical plasma conditions. These advanced control systems require a tiered infrastructure including the hardware layer, the signal-processing middleware, real-time timing and data transport, the real-time operating system tools and drivers, the framework for code development, simulation, deployment and experiment parameterization and the human real-time plasma condition monitoring and management. This approach is being implemented at CFN by offering a vertical solution for the forthcoming challenges, including ITER, the first experimental fusion reactor. A given set of tools and systems are described on this paper, namely: (i) an ATCA based hardware multiple-input-multiple-output (MIMO) platform, PCI and PCIe acquisition and control modules; (ii) FPGA and DSP parallelized signal processing algorithms; (iii) a signal data and event distribution system over a 2.5/10Gb optical network with sub-microsecond latencies; (iv) RTAI and Linux drivers; and (v) the FireSignal, FusionTalk, SDAS FireCalc application tools. (author)

Automated detection of extended sources in radio maps: progress from the SCORPIO survey

Science.gov (United States)

Riggi, S.; Ingallinera, A.; Leto, P.; Cavallaro, F.; Bufano, F.; Schillirò, F.; Trigilio, C.; Umana, G.; Buemi, C. S.; Norris, R. P.

2016-08-01

Automated source extraction and parametrization represents a crucial challenge for the next-generation radio interferometer surveys, such as those performed with the Square Kilometre Array (SKA) and its precursors. In this paper, we present a new algorithm, called CAESAR (Compact And Extended Source Automated Recognition), to detect and parametrize extended sources in radio interferometric maps. It is based on a pre-filtering stage, allowing image denoising, compact source suppression and enhancement of diffuse emission, followed by an adaptive superpixel clustering stage for final source segmentation. A parametrization stage provides source flux information and a wide range of morphology estimators for post-processing analysis. We developed CAESAR in a modular software library, also including different methods for local background estimation and image filtering, along with alternative algorithms for both compact and diffuse source extraction. The method was applied to real radio continuum data collected at the Australian Telescope Compact Array (ATCA) within the SCORPIO project, a pathfinder of the Evolutionary Map of the Universe (EMU) survey at the Australian Square Kilometre Array Pathfinder (ASKAP). The source reconstruction capabilities were studied over different test fields in the presence of compact sources, imaging artefacts and diffuse emission from the Galactic plane and compared with existing algorithms. When compared to a human-driven analysis, the designed algorithm was found capable of detecting known target sources and regions of diffuse emission, outperforming alternative approaches over the considered fields.

Real-time control for long ohmic alternate current discharges

International Nuclear Information System (INIS)

Carvalho, Ivo S.; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Hekkert, Tiago; Carvalho, Bernardo B.; Gomes, Rui B.

2014-01-01

Highlights: • 40 Alternate plasma current (AC) semi-cycles without loss of ionization, more than 1 s of operation. • AC discharges automatic control: feedback loops, time-windows control strategy, goal oriented time-windows and exception handling. • Energy deposition and Carbon radiation evolution during the AC discharges. - Abstract: The ISTTOK tokamak has a long tradition on alternate plasma current (AC) discharges, but the old control system was limiting and lacked full system integration. In order to improve the AC discharges performance the ISTTOK fast control system was updated. This control system developed on site based on the Advanced Telecommunications Computing Architecture (ATCA) standard now integrates the information gathered by all the tokamak real-time diagnostics to produce an accurate observation of the plasma parameters. The real-time actuators were also integrated, allowing a Multiple Input Multiple Output (MIMO) control environment with several synchronization strategies available. The control system software was developed in C++ on top of a Linux system with the Multi-threaded Application Real-Time executor (MARTe) Framework to synchronize the real-time code execution under a 100μs control cycle. In addition, to simplify the discharge programming, a visual Human–Machine Interface (HMI) was also developed using the BaseLib2 libraries included in the MARTe Framework. This paper presents the ISTTOK control system and the optimizations that extended the AC current discharges duration to more than 1 s, corresponding to 40 semi-cycles without apparent degradation of the plasma parameters. This upgrade allows ISTTOK to be used as a low-cost material testing facility with long time exposures to nuclear fusion relevant plasmas, comparable (in duration) with medium size tokamaks

Real-time control for long ohmic alternate current discharges

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Ivo S., E-mail: ivoc@ipfn.ist.utl.pt; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Hekkert, Tiago; Carvalho, Bernardo B.; Gomes, Rui B.

2014-05-15

Highlights: • 40 Alternate plasma current (AC) semi-cycles without loss of ionization, more than 1 s of operation. • AC discharges automatic control: feedback loops, time-windows control strategy, goal oriented time-windows and exception handling. • Energy deposition and Carbon radiation evolution during the AC discharges. - Abstract: The ISTTOK tokamak has a long tradition on alternate plasma current (AC) discharges, but the old control system was limiting and lacked full system integration. In order to improve the AC discharges performance the ISTTOK fast control system was updated. This control system developed on site based on the Advanced Telecommunications Computing Architecture (ATCA) standard now integrates the information gathered by all the tokamak real-time diagnostics to produce an accurate observation of the plasma parameters. The real-time actuators were also integrated, allowing a Multiple Input Multiple Output (MIMO) control environment with several synchronization strategies available. The control system software was developed in C++ on top of a Linux system with the Multi-threaded Application Real-Time executor (MARTe) Framework to synchronize the real-time code execution under a 100μs control cycle. In addition, to simplify the discharge programming, a visual Human–Machine Interface (HMI) was also developed using the BaseLib2 libraries included in the MARTe Framework. This paper presents the ISTTOK control system and the optimizations that extended the AC current discharges duration to more than 1 s, corresponding to 40 semi-cycles without apparent degradation of the plasma parameters. This upgrade allows ISTTOK to be used as a low-cost material testing facility with long time exposures to nuclear fusion relevant plasmas, comparable (in duration) with medium size tokamaks.

The prototype design of gFEX — A component of the L1Calo Trigger for the ATLAS Phase-I upgrade

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00304146; The ATLAS collaboration; Chen, Kai; Lanni, Francesco; Takai, Helio; Tang, Shaochun; Wu, Weihao

2016-01-01

The ATLAS experiment will follow the upgrade steps of the Large Hadron Collider (LHC), which will undergo a series of upgrades to increase the luminosity in the next ten years. During the Phase-I upgrade, a new component will be designed for the ATLAS Level-1 calorimeter trigger system to maintain the trigger acceptance against the increasing luminosity - the global feature extractor (gFEX). The gFEX is intended to identify patterns of energy associated with the hadronic decays of high momentum Higgs, W & Z bosons, top quarks and exotic particles in real time at the LHC crossing rate. A prototype v1 with one System-on-Chip Xilinx ZYNQ FPGA, and one Vertex-7 FPGA for technology validation has been designed and tested in 2015. With the lessons learned from the prototype v1, a prototype v2 with three UltraScale FPGAs and one ZYNQ FPGA is implemented on an ATCA module. This board will receive coarse-granularity information from the entire ATLAS calorimeter on 276 optical fibers at the speed up to 12.8 Gb/s sy...

The development of the Global Feature Extractor for the LHC Run-3 upgrade of L1 Calorimeter trigger system

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00065614; The ATLAS collaboration; Chen, Hucheng; Chen, Kai; Lanni, Francesco; Takai, Helio; Tang, Shaochun; Wu, Weihao; ATLAS Collaboration

2016-01-01

The Global Feature Extractor (gFEX) is one of several modules in LHC Run-3 upgrade of Level 1 Calorimeter (L1Calo) trigger system in ATLAS experiment. It is a single Advanced Telecommunications Computing Architecture (ATCA) module for large-area jet identifying with three Xilinx Virtex UltraScale FPGAs for data processing and a system-on-chip (SoC) FPGA for control and monitoring. A pre-prototype board has been designed to verify all functionalities, which includes one Xilinx Virtex-7 FPGA, one Zynq FPGA, several MiniPODs, MicroPODs, DDR3 SDRAM and other components. The performance of pre-prototype has been tested and evaluated. As a major challenge, the high-speed links in FPGAs are stable at 12.8 Gb/s with Bit Error Ratio (BER) < 10-15 (no error detected). The low-latency parallel GPIO (General Purpose I/O) buses for communication between FPGAs are stable at 960 Mb/s. The peripheral components of Zynq FPGA like DDRs, UART, SPI flashes, Ethernet and so on, have also been verified. The test results of pre-...

La Freccia Rossa: An IR-dark cloud hosting the Milky Way intermediate-mass black hole candidate

Science.gov (United States)

Ravi, Vikram; Vedantham, Harish; Phinney, E. Sterl

2018-05-01

The dynamics of the high-velocity compact molecular cloud CO-0.40-0.22 have been interpreted as evidence for a ˜105M⊙ black hole within 60 pc of Sgr A*. Recently, Oka et al. have identified a compact millimetre-continuum source, CO-0.40-0.22*, with this candidate black hole. Here we present a collation of radio and infrared data at this location. ATCA constraints on the radio spectrum, and the detection of a mid-infrared counterpart, are in tension with an Sgr A*-like model for CO-0.40-0.22* despite the comparable bolometric to Eddington luminosity ratios under the IMBH interpretation. A protostellar-disk scenario is, however, tenable. CO-0.40-0.22(*) is positionally coincident with an arrowhead-shaped infrared-dark cloud (which we call the Freccia Rossa). If the VLSR ≈ 70 km s-1 systemic velocity of CO-0.40-0.22 is common to the entire Freccia Rossa system, we hypothesise that it is the remnant of a high-velocity cloud that has plunged into the Milky Way from the Galactic halo.

A search for AGN activity in Infrared-Faint Radio Sources (IFRS)

Science.gov (United States)

Lenc, Emil; Middelberg, Enno; Norris, Ray; Mao, Minnie

2010-04-01

We propose to observe a large sample of radio sources from the ATLAS (Australia Telescope Large Area Survey) source catalogue with the LBA, to determine their compactness. The sample consists of 36 sources with no counterpart in the co-located SWIRE survey (3.6 um to 160 um), carried out with the Spitzer Space Telescope. This rare class of sources, dubber Infrared-Faint Radio Sources (IFRS), is inconsistent with current galaxy evolution models. VLBI observations are an essential way to obtain further clues on what these objects are and why they are hidden from infrared observations. We will measure the flux densities on long baselines to determine their compactness. Only five IFRS have been previously targeted with VLBI observations (resulting in two detections). We propose using single baseline (Parkes-ATCA) eVLBI observations with the LBA at 1 Gbps to maximise sensitivity. With the observations proposed here we will increase the number of VLBI-observed IFRS from 5 to 36, allowing us to draw statistical conclusions about this intriguing new class of objects.

The development of the Global Feature Extractor for the LHC Run-3 upgrade of the ATLAS L1 Calorimeter trigger system

CERN Document Server

Wu, Weihao; The ATLAS collaboration; Chen, Hucheng; Lanni, Francesco; Takai, Helio; Tang, Shaochun; ATLAS TDAQ Collaboration

2016-01-01

The Global Feature Extractor (gFEX) is one of several modules in LHC Run-3 upgrade of Level 1 Calorimeter (L1Calo) trigger system in the ATLAS experiment. It is a single Advanced Telecommunications Computing Architecture (ATCA) module for large-area jet identification with three Xilinx UltraScale FPGAs for data processing and a system-on-chip (SoC) FPGA for control and monitoring. A pre-prototype board has been designed to verify all functionalities. The performance of this pre-prototype has been tested and evaluated. As a major achievement, the high-speed links in FPGAs are stable at 12.8 Gb/s with Bit Error Ratio (BER) < 10-15 (no error detected). The low-latency parallel GPIO (General Purpose I/O) buses for communication between FPGAs are stable at 960 Mb/s. Besides that, the peripheral components of Soc FPGA have also been verified. After laboratory tests, the link speed test with LAr (Liquid Argon Calorimeter) Digital Processing Blade (LDPB) AMC card has been carried out at CERN for determination of t...

The Topological Processor for the future ATLAS Level-1 Trigger: from design to commissioning

CERN Document Server

Simioni, E; The ATLAS collaboration

2014-01-01

The ATLAS detector at the Large Hadron Collider (LHC) is designed to measure decay properties of high energetic particles produced in the proton-proton collisions. During its first run, the LHC collided proton bunches at a frequency of 20 MHz, and therefore the detector required a Trigger system to efficiently select events down to a manageable event storage rate of about 400 Hz. By 2015 the LHC instantaneous luminosity will be increased up to 3$\\times$$10^{34}cm^{-2}s^{-1}$: this represent an unprecedented challenge faced by the ATLAS Trigger system. To cope with the higher event rate and efficiently select relevant events from physics point of view, a new element will be included in the Level-1 Trigger scheme after 2015: the Topological Processor (L1Topo).\\\\ The L1Topo system, currently developed at CERN, will consist initially of an ATCA crate and two L1Topo modules. A high density opto-electroconverter (AVAGO miniPOD) drives up to 1.6 Tb/s of data from the calorimeter and muon detectors into two high end ...

Magnetic fields in barred galaxies I. The atlas

CERN Document Server

Beck, R; Ehle, M; Harnett, J I; Haynes, R F; Shukurov, A M; Sokoloff, D D; Thierbach, M

2002-01-01

The total and polarized radio continuum emission of 20 barred galaxies was observed with the Very Large Array (VLA) at 3, 6, 18 and 22 cm and with the Australia Telescope Compact Array (ATCA) at 6 cm and 13 cm. Maps at 30 arcsec angular resolution are presented here. Polarized emission (and therefore a large-scale regular magnetic field) was detected in 17 galaxies. Most galaxies of our sample are similar to non-barred galaxies with respect to the radio/far-infrared flux correlation and equipartition strength of the total magnetic field. Galaxies with highly elongated bars are not always radio-bright. We discuss the correlation of radio properties with the aspect ratio of the bar and other measures of the bar strength. We introduce a new measure of the bar strength, \\Lambda, related to the quadrupole moment of the bar's gravitational potential. The radio surface brightness I of the barred galaxies in our sample is correlated with \\Lambda, I \\propto \\Lambda^0.4+/-0.1, and thus is highest in galaxies with a lon...

Multifrequency radio observations of SNR J0536-6735 (N 59B with associated pulsar

Directory of Open Access Journals (Sweden)

Bozzetto L.M.

2012-01-01

Full Text Available We present a study of new Australian Telescope Compact Array (ATCA observations of supernova remnant, SNR J0536-6735. This remnant appears to follow a shell morphology with a diameter of D=36x29 pc (with 1 pc uncertainty in each direction. There is an embedded HII region on the northern limb of the remnant which made various analysis and measurements (such as flux density, spectral index and polarisation difficult. The radio-continuum emission followed the same structure as the optical emission, allowing for extent and flux density estimates at 20 cm. We estimate the surface brightness at 1 GHz of 2.55x10−21 Wm−2 Hz−1 sr−1 for the SNR. Also, we detect a distinctive radio-continuum point source which confirms the previous suggestion of this remnant being associated with pulsar wind nebula (PWN. The tail of this remnant is not seen in the radio-continuum images and is only seen in the optical and X-ray images.

ATCA observations of the MACS-Planck Radio Halo Cluster Project. II. Radio observations of an intermediate redshift cluster sample

Science.gov (United States)

Martinez Aviles, G.; Johnston-Hollitt, M.; Ferrari, C.; Venturi, T.; Democles, J.; Dallacasa, D.; Cassano, R.; Brunetti, G.; Giacintucci, S.; Pratt, G. W.; Arnaud, M.; Aghanim, N.; Brown, S.; Douspis, M.; Hurier, J.; Intema, H. T.; Langer, M.; Macario, G.; Pointecouteau, E.

2018-04-01

Aim. A fraction of galaxy clusters host diffuse radio sources whose origins are investigated through multi-wavelength studies of cluster samples. We investigate the presence of diffuse radio emission in a sample of seven galaxy clusters in the largely unexplored intermediate redshift range (0.3 http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A94

The COMPASS Tokamak Plasma Control Software Performance

Science.gov (United States)

Valcarcel, Daniel F.; Neto, André; Carvalho, Ivo S.; Carvalho, Bernardo B.; Fernandes, Horácio; Sousa, Jorge; Janky, Filip; Havlicek, Josef; Beno, Radek; Horacek, Jan; Hron, Martin; Panek, Radomir

2011-08-01

The COMPASS tokamak has began operation at the IPP Prague in December 2008. A new control system has been built using an ATCA-based real-time system developed at IST Lisbon. The control software is implemented on top of the MARTe real-time framework attaining control cycles as short as 50 μs, with a jitter of less than 1 μs. The controlled parameters, important for the plasma performance, are the plasma current, position of the plasma current center, boundary shape and horizontal and vertical velocities. These are divided in two control cycles: slow at 500 μs and fast at 50 μs. The project has two phases. First, the software implements a digital controller, similar to the analog one used during the COMPASS-D operation in Culham. In the slow cycle, the plasma current and position are measured and controlled with PID and feedforward controllers, respectively, the shaping magnetic field is preprogrammed. The vertical instability and horizontal equilibrium are controlled with the faster 50-μs cycle PID controllers. The second phase will implement a plasma-shape reconstruction algorithm and controller, aiming at optimized plasma performance. The system was designed to be as modular as possible by breaking the functional requirements of the control system into several independent and specialized modules. This splitting enabled tuning the execution of each system part and to use the modules in a variety of applications with different time constraints. This paper presents the design and overall performance of the COMPASS control software.

MODELING THE AFTERGLOW OF THE POSSIBLE FERMI -GBM EVENT ASSOCIATED WITH GW150914

International Nuclear Information System (INIS)

Morsony, Brian J.; Workman, Jared C.; Ryan, Dominic M.

2016-01-01

We model the possible afterglow of the Fermi Gamma-ray Burst Monitor (GBM) event associated with LIGO detection GW150914, under the assumption that the gamma-rays are produced by a short GRB-like relativistic outflow. We model GW150914-GBM as both a weak, on-axis short GRB and normal short GRB seen far off-axis. Given the large uncertainty in the position of GW150914, we determine that the best chance of finding the afterglow is with ASKAP or possibly the Murchinson Widefield Array (MWA), with the flux from an off-axis short GRB reaching 0.2–4 mJy (0.12–16 mJy) at 150 MHz (863.5 MHz) by 1–12 months after the initial event. At low frequencies, the source would evolve from a hard to soft spectrum over several months. The radio afterglow would be detectable for several months to years after it peaks, meaning the afterglow may still be detectable and increasing in brightness NOW (2016 mid-July). With a localization from the MWA or ASKAP, the afterglow would be detectable at higher radio frequencies with the ATCA and in X-rays with Chandra or XMM .

Direct Evidence for Maser Emission from the 36.2 GHz Class I Transition of Methanol in NGC253

Science.gov (United States)

Chen, Xi; Ellingsen, Simon P.; Shen, Zhi-Qiang; McCarthy, Tiege P.; Zhong, Wei-Ye; Deng, Hui

2018-04-01

Observations made with the Jansky Very large Array (JVLA) at an angular resolution of ∼0.″1 have detected class I methanol maser emission from the 36.2 GHz transition toward the starburst galaxy NGC 253. The methanol emission is detected toward four sites which lie within the regions of extended methanol emission detected in previous lower angular resolution (a few arcseconds) observations. The peak flux densities of the detected compact components are in the range 3–9 mJy beam‑1. Combining the JVLA data with single-dish observations from the Shanghai Tianma Radio Telescope (TMRT) and previous interferometric observations with the Australia Telescope Compact Array (ATCA), we show that the 36.2 GHz class I methanol emission consists of both extended and compact structures, with typical scales of ∼6″ (0.1 kpc) and ∼0.″05 (1 pc), respectively. The strongest components have a brightness temperature of >103 K, much higher than the maximum kinetic temperature (∼100 K) of the thermal methanol emission from NGC 253. Therefore, these observations conclusively demonstrate for the first time the presence of maser emission from a class I methanol transition in an external galaxy.

Radio Observations of Elongated Pulsar Wind Nebulae

Science.gov (United States)

Ng, Stephen C.-Y.

2015-08-01

The majority of pulsars' rotational energy is carried away by relativistic winds, which are energetic particles accelerated in the magnetosphere. The confinement of the winds by the ambient medium result in synchrotron bubbles with broad-band emission, which are commonly referred to as pulsar wind nebulae (PWNe). Due to long synchrotron cooling time, a radio PWN reflects the integrated history of the system, complementing information obtained from the X-ray and higher energy bands. In addition, radio polarization measurements can offer a powerful probe of the PWN magnetic field structure. Altogether these can reveal the physical conditions and evolutionary history of a system.I report on preliminary results from high-resolution radio observations of PWNe associated with G327.1-1.1, PSRs J1015-5719, B1509-58, and J1549-4848 taken with the Australia Telescope Compact Array (ATCA). Their magnetic field structure and multiwavelength comparison with other observations are discussed.This work is supported by a ECS grant of the Hong Kong Government under HKU 709713P. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.

TESTING THE MAGNETAR MODEL VIA LATE-TIME RADIO OBSERVATIONS OF TWO MACRONOVA CANDIDATES

Energy Technology Data Exchange (ETDEWEB)

Horesh, Assaf [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Hotokezaka, Kenta; Piran, Tsvi [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Nakar, Ehud [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Hancock, Paul [International Centre for Radio Astronomy Research (ICRAR), Curtin University, GPO Box U1987, Perth WA 6845 (Australia)

2016-03-10

Compact binary mergers may have already been observed as they are the leading model for short gamma-ray bursts (sGRBs). Radioactive decay within the ejecta from these mergers is expected to produce an infrared flare, dubbed macronova (or kilonova), on a timescale of a week. Recently, two such macronova candidates were identified in followup observations of sGRBs, strengthening the possibility that those indeed arise from mergers. The same ejecta will also produce long-term (months to years) radio emission due to its interaction with the surrounding interstellar medium. In the search for this emission, we observed the two macronova candidates, GRB 130603B and GRB 060614, with the Jansky Very Large Array (VLA) and the Australia Telescope Compact Array (ATCA). Our observations resulted in null-detections, putting strong upper limits on the kinetic energy and mass of the ejecta. A possible outcome of a merger is a highly magnetized neutron star (a magnetar), which has been suggested as the central engine for GRBs. Such a magnetar will deposit a significant fraction of its energy into the ejecta leading to a brighter radio flare. Our results, therefore, rule out magnetars in these two events.

MODELING THE AFTERGLOW OF THE POSSIBLE FERMI -GBM EVENT ASSOCIATED WITH GW150914

Energy Technology Data Exchange (ETDEWEB)

Morsony, Brian J. [Department of Astronomy, University of Maryland, 1113 Physical Sciences Complex, College Park, MD 20742-2421 (United States); Workman, Jared C. [Department of Physical and Environmental Sciences, Colorado Mesa University, Grand Junction, CO 81501 (United States); Ryan, Dominic M., E-mail: morsony@astro.umd.edu [Department of Astronomy, University of California, Berkeley, 501 Campbell Hall #3411, Berkeley, CA 94720-3411 (United States)

2016-07-10

We model the possible afterglow of the Fermi Gamma-ray Burst Monitor (GBM) event associated with LIGO detection GW150914, under the assumption that the gamma-rays are produced by a short GRB-like relativistic outflow. We model GW150914-GBM as both a weak, on-axis short GRB and normal short GRB seen far off-axis. Given the large uncertainty in the position of GW150914, we determine that the best chance of finding the afterglow is with ASKAP or possibly the Murchinson Widefield Array (MWA), with the flux from an off-axis short GRB reaching 0.2–4 mJy (0.12–16 mJy) at 150 MHz (863.5 MHz) by 1–12 months after the initial event. At low frequencies, the source would evolve from a hard to soft spectrum over several months. The radio afterglow would be detectable for several months to years after it peaks, meaning the afterglow may still be detectable and increasing in brightness NOW (2016 mid-July). With a localization from the MWA or ASKAP, the afterglow would be detectable at higher radio frequencies with the ATCA and in X-rays with Chandra or XMM .

The Topological Processor for the future ATLAS Level-1 Trigger: from design to commissioning

CERN Document Server

INSPIRE-00226165

2014-01-01

The ATLAS detector at LHC will require a Trigger system to efficiently select events down to a manageable event storage rate of about 400 Hz. By 2015 the LHC instantaneous luminosity will be increased up to 3 x 10^34 cm-2s-1, this represents an unprecedented challenge faced by the ATLAS Trigger system. To cope with the higher event rate and efficiently select relevant events from a physics point of view, a new element will be included in the Level-1 Trigger scheme after 2015: the Topological Processor (L1Topo). The L1Topo system, currently developed at CERN, will consist initially of an ATCA crate and two L1Topo modules. A high density opto-electroconverter (AVAGO miniPOD) drives up to 1.6 Tb/s of data from the calorimeter and muon detectors into two high-end FPGA (Virtex7-690), to be processed in about 200 ns. The design has been optimized to guarantee excellent signal in- tegrity of the high-speed links and low latency data transmission on the Real Time Data Path (RTDP). The L1Topo receives data in a standa...

VizieR Online Data Catalog: Galaxy clusters: radio halos, relics and parameters (Yuan+, 2015)

Science.gov (United States)

Yuan, Z. S.; Han, J. L.; Wen, Z. L.

2017-10-01

A large number of radio halos, relics, and mini-halos have been discovered and measured in recent decades through observations with VLA (e.g., Giovannini & Feretti 2000NewA....5..335G; van Weeren et al. 2011A&A...533A..35V), GMRT (e.g., Venturi et al. 2007A&A...463..937V; Kale et al. 2015A&A...579A..92K), WSRT (e.g., van Weeren et al. 2010Sci...330..347V; Trasatti et al. 2015A&A...575A..45T), and also ATCA (e.g., Shimwell et al. 2014MNRAS.440.2901S, 2015MNRAS.449.1486S). We have checked the radio images of radio halos, relics, and mini-halos in the literature and collected in Table 1 the radio flux Sν at frequencies within a few per cent around 1.4 GHz, 610 MHz, and 325 MHz; we have interpolated the flux at an intermediate frequency if measurements are available at higher and lower frequencies. To establish reliable scaling relations, we include only the very firm detection of diffuse radio emission in galaxy clusters, and omit questionable detections or flux estimates due to problematic point-source subtraction. (3 data files).

Real-time algorithms for JET hard X-ray and gamma-ray profile monitor

International Nuclear Information System (INIS)

Fernandes, A.; Pereira, R.C.; Valcárcel, D.F.; Alves, D.; Carvalho, B.B.; Sousa, J.; Kiptily, V.; Correia, C.M.B.A.; Gonçalves, B.

2014-01-01

Highlights: • Real-time tools and mechanisms are required for data handling and machine control. • A new DAQ system, ATCA based, with embedded FPGAs, was installed at JET. • Different real-time algorithms were developed for FPGAs and MARTe application. • MARTe provides the interface to CODAS and to the JET real-time network. • The new DAQ system is capable to process and deliver data in real-time. - Abstract: The steady state operation with high energy content foreseen for future generation of fusion devices will necessarily demand dedicated real-time tools and mechanisms for data handling and machine control. Consequently, the real-time systems for those devices should be carefully selected and their capabilities previously established. The Joint European Torus (JET) is undertaking an enhancement program, which includes tests of relevant real-time tools for the International Thermonuclear Experimental Reactor (ITER), a key experiment for future fusion devices. In these enhancements a new Data AcQuisition (DAQ) system is included, with real-time processing capabilities, for the JET hard X-ray and gamma-ray profile monitor. The DAQ system is composed of dedicated digitizer modules with embedded Field Programmable Gate Array (FPGA) devices. The interface between the DAQ system, the JET control and data acquisition system and the JET real-time data network is provided by the Multithreaded Application Real-Time executor (MARTe). This paper describes the real-time algorithms, developed for both digitizers’ FPGAs and MARTe application, capable of meeting the DAQ real-time requirements. The new DAQ system, including the embedded real-time features, was commissioned during the 2012 experiments. Results achieved with these real-time algorithms during experiments are presented

Real-time algorithms for JET hard X-ray and gamma-ray profile monitor

Energy Technology Data Exchange (ETDEWEB)

Fernandes, A., E-mail: anaf@ipfn.ist.utl.pt [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa (Portugal); Pereira, R.C.; Valcárcel, D.F.; Alves, D.; Carvalho, B.B.; Sousa, J. [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa (Portugal); Kiptily, V. [EURATOM/CCFE Fusion Association, Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Correia, C.M.B.A. [Centro de Instrumentação, Dept. de Física, Universidade de Coimbra, 3004-516 Coimbra (Portugal); Gonçalves, B. [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa (Portugal)

2014-03-15

Highlights: • Real-time tools and mechanisms are required for data handling and machine control. • A new DAQ system, ATCA based, with embedded FPGAs, was installed at JET. • Different real-time algorithms were developed for FPGAs and MARTe application. • MARTe provides the interface to CODAS and to the JET real-time network. • The new DAQ system is capable to process and deliver data in real-time. - Abstract: The steady state operation with high energy content foreseen for future generation of fusion devices will necessarily demand dedicated real-time tools and mechanisms for data handling and machine control. Consequently, the real-time systems for those devices should be carefully selected and their capabilities previously established. The Joint European Torus (JET) is undertaking an enhancement program, which includes tests of relevant real-time tools for the International Thermonuclear Experimental Reactor (ITER), a key experiment for future fusion devices. In these enhancements a new Data AcQuisition (DAQ) system is included, with real-time processing capabilities, for the JET hard X-ray and gamma-ray profile monitor. The DAQ system is composed of dedicated digitizer modules with embedded Field Programmable Gate Array (FPGA) devices. The interface between the DAQ system, the JET control and data acquisition system and the JET real-time data network is provided by the Multithreaded Application Real-Time executor (MARTe). This paper describes the real-time algorithms, developed for both digitizers’ FPGAs and MARTe application, capable of meeting the DAQ real-time requirements. The new DAQ system, including the embedded real-time features, was commissioned during the 2012 experiments. Results achieved with these real-time algorithms during experiments are presented.

The ATCA CABB Line Survey on Centaurus A: Properties of the Molecular Gas from the Dust Lanes to the Central Engine

Science.gov (United States)

Ott, Juergen; Koribalski, Baerbel; Henkel, Christian; Edwards, Philip; Norris, Ray; Meier, David; Feain, Ilana; Curran, Steve; Martin-Pintado, Jesus; Beelen, Alexandre; Aalto, Susanne; Combes, Francoise; Israel, Frank; Muller, Sebastien; Espada, Daniel; Guelin, Michel; Black, John Harry; V-Trung, Dinh; Impellizzeri, Caterina M. V.; Persson, Carina

2011-10-01

Centaurus A with its host NGC5128 is the most nearby radio galaxy. Its molecular spectrum exhibits three prominent features: a) gas that is located in the outer disk and dust lanes, b) absorption lines that are supposedly close to the central AGN, and c) gas in emission from the nucleus. We propose to perform an extensive line survey toward CenA using the exciting new capabilities of CABB. The broad basebands and narrow zoom bands of CABB are ideal to capture the full breath of the CenA spectral features. Our multi-band line observations will allow us to derive the exact physical conditions of each component as well as the chemistry involved. We will therefore obtain a comprehensive view of the physics imprinted on the molecular spectrum of a radio galaxy and its host, reaching from the central supermassive black hole, through the accretion region and the inner disk to the outer dust lanes.

[Phenotypic and molecular characterization of a Colombian family with phenylketonuria].

Science.gov (United States)

Gélvez, Nancy; Acosta, Johana; López, Greizy; Castro, Derly; Prieto, Juan Carlos; Bermúdez, Martha; Tamayo, Marta L

2016-09-01

Phenylketonuria is a metabolic disorder characterized by severe neurological involvement and behavioral disorder, whose early diagnosis enables an effective treatment to avoid disease sequelae, thus changing the prognosis. Objective: To characterize a family with phenylketonuria in Colombia at clinical, biochemical and molecular levels. Materials and methods: The population consisted of seven individuals of a consanguineous family with four children with suggestive symptoms of phenylketonuria. After signing an informed consent, blood and urine samples were taken for colorimetric tests and high performance liquid and thin layer chromatographies. DNA extraction and sequencing of the 13 exons of the PAH gene were performed in all subjects. We designed primers for each exon with the Primer 3 software using automatic sequencing equipment Abiprism 3100 Avant. Sequences were analyzed using the SeqScape, v2.0, software. Results: We described the clinical and molecular characteristics of a Colombian family with phenylketonuria and confirmed the presence of the mutation c.398_401delATCA. We established a genotype-phenotype correlation, highlighting the interesting clinical variability found among the affected patients despite having the same mutation in all of them. Conclusions: Early recognition of this disease is very important to prevent its neurological and psychological sequelae, given that patients reach old age without diagnosis or proper management.

Galactic Black Holes in the Hard State: A Multi-Wavelength View of Accretion and Ejection

Science.gov (United States)

Kalemci; Tomsick, John A.; Migliari; Corbel; Markoff

2010-01-01

The canonical hard state is associated with emission from all three fundamental accretion components: the accretion disk, the hot accretion disk corona and the jet. On top of these, the hard state also hosts very rich temporal variability properties (low frequency QPOs in the PDS, time lags, long time scale evolution). Our group has been working on the major questions of the hard state both observationally (with mult i-wavelength campaigns using RXTE, Swift, Suzaku, Spitzer, VLA, ATCA, SMARTS) and theoretically (through jet models that can fit entire SEDs). Through spectral and temporal analysis we seek to determine the geometry of accretion components, and relate the geometry to the formation and emission from a jet. In this presentation I will review the recent contributions of our group to the field, including the Swift results on the disk geometry at low accretion rates, the jet model fits to the hard state SEDs (including Spitzer data) of GRO J1655-40, and the final results on the evolution of spectral (including X-ray, radio and infrared) and temporal properties of elected black holes in the hard states. I will also talk about impact of ASTROSAT to the science objective of our group.

Advanced Technology Composite Fuselage - Materials and Processes

Science.gov (United States)

Scholz, D. B.; Dost, E. F.; Flynn, B. W.; Ilcewicz, L. B.; Nelson, K. M.; Sawicki, A. J.; Walker, T. H.; Lakes, R. S.

1997-01-01

The goal of Boeing's Advanced Technology Composite Aircraft Structures (ATCAS) program was to develop the technology required for cost and weight efficient use of composite materials in transport fuselage structure. This contractor report describes results of material and process selection, development, and characterization activities. Carbon fiber reinforced epoxy was chosen for fuselage skins and stiffening elements and for passenger and cargo floor structures. The automated fiber placement (AFP) process was selected for fabrication of monolithic and sandwich skin panels. Circumferential frames and window frames were braided and resin transfer molded (RTM'd). Pultrusion was selected for fabrication of floor beams and constant section stiffening elements. Drape forming was chosen for stringers and other stiffening elements. Significant development efforts were expended on the AFP, braiding, and RTM processes. Sandwich core materials and core edge close-out design concepts were evaluated. Autoclave cure processes were developed for stiffened skin and sandwich structures. The stiffness, strength, notch sensitivity, and bearing/bypass properties of fiber-placed skin materials and braided/RTM'd circumferential frame materials were characterized. The strength and durability of cocured and cobonded joints were evaluated. Impact damage resistance of stiffened skin and sandwich structures typical of fuselage panels was investigated. Fluid penetration and migration mechanisms for sandwich panels were studied.

A study of the cool gas in the Large Magellanic Cloud. I. Properties of the cool atomic phase - a third H i absorption survey

Science.gov (United States)

Marx-Zimmer, M.; Herbstmeier, U.; Dickey, J. M.; Zimmer, F.; Staveley-Smith, L.; Mebold, U.

2000-02-01

The cool atomic interstellar medium of the Large Magellanic Cloud (LMC) seems to be quite different from that in the Milky Way. In a series of three papers we study the properties of the cool atomic hydrogen in the LMC (Paper I), its relation to molecular clouds using SEST-CO-observations (Paper II) and the cooling mechanism of the atomic gas based on ISO-[\\CII]-investigations (Paper III). In this paper we present the results of a third 21 cm absorption line survey toward the LMC carried out with the Australia Telescope Compact Array (ATCA). 20 compact continuum sources, which are mainly in the direction of the supergiant shell LMC 4, toward the surroundings of 30 Doradus and toward the eastern steep \\HI\\ boundary, have been chosen from the 1.4 GHz snapshot continuum survey of Marx et al. We have identified 20 absorption features toward nine of the 20 sources. The properties of the cool \\HI\\ clouds are investigated and are compared for the different regions of the LMC taking the results of Dickey et al. (survey 2) into account. We find that the cool \\HI\\ gas in the LMC is either unusually abundant compared to the cool atomic phase of the Milky Way or the gas is clearly colder (\\Tc\\ ~ 30 K) than that in our Galaxy (\\Tc\\ ~ 60 K). The properties of atomic clouds toward 30 Doradus and LMC 4 suggest a higher cooling rate in these regions compared to other parts of the LMC, probably due to an enhanced pressure near the shock fronts of LMC 4 and 30 Doradus. The detected cool atomic gas toward the eastern steep \\HI\\ boundary might be the result of a high compression of gas at the leading edge. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.

The radio relics and halo of El Gordo, a massive z = 0.870 cluster merger

Energy Technology Data Exchange (ETDEWEB)

Lindner, Robert R.; Baker, Andrew J.; Hughes, John P. [Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States); Battaglia, Nick [McWilliams Center for Cosmology, Wean Hall, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213 (United States); Gupta, Neeraj [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo (Netherlands); Knowles, Kenda; Moodley, Kavilan [Astrophysics and Cosmology Research Unit, University of KwaZulu-Natal, Durban 4041 (South Africa); Marriage, Tobias A. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States); Menanteau, Felipe [National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, 1205 W. Clark St., Urbana, IL 61801 (United States); Reese, Erik D. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd St., Philadelphia, PA 19104 (United States); Srianand, Raghunathan, E-mail: rlindner@astro.wisc.edu [IUCAA, Ganeshkhind, Pune 411007 (India)

2014-05-01

We present 610 MHz and 2.1 GHz imaging of the massive Sunyaev-Zel'dovich Effect selected z = 0.870 cluster merger ACT-CL J0102–4915 ({sup E}l Gordo{sup )}, obtained with the Giant Metrewave Radio Telescope and the Australia Telescope Compact Array (ATCA), respectively. We detect two complexes of radio relics separated by 3.'4 (1.6 Mpc) along the system's northwest-to-southeast collision axis that have high integrated polarization fractions (33%) and steep spectral indices (α between 1 and 2; S {sub ν}∝ν{sup –α}), consistent with creation via Fermi acceleration by shocks in the intracluster medium triggered by the cluster collision. From the spectral index of the relics, we compute a Mach number M=2.5{sub −0.3}{sup +0.7} and shock speed of 2500{sub −300}{sup +400} km s{sup −1}. With our wide-bandwidth, full-polarization ATCA data, we compute the Faraday depth φ across the northwest relic and find a range of values spanning Δφ = 30 rad m{sup –2}, with a mean value of (φ) = 11 rad m{sup –2} and standard deviation σ{sub φ} = 6 rad m{sup –2}. With the integrated line-of-sight gas density derived from new Chandra X-ray observations, our Faraday depth measurement implies B {sub ∥} ∼ 0.01 μG in the cluster outskirts. The extremely narrow shock widths in the relics (d {sub shock} ≤ 23 kpc), caused by the short synchrotron cooling timescale of relativistic electrons at z = 0.870, prevent us from placing a meaningful constraint on the magnetic field strength B using cooling time arguments. In addition to the relics, we detect a large (r {sub H} ≅ 1.1 Mpc radius), powerful (log (L {sub 1.4}/W Hz{sup –1}) = 25.66 ± 0.12) radio halo with a shape similar to El Gordo's 'bullet'-like X-ray morphology. The spatially resolved spectral-index map of the halo shows the synchrotron spectrum is flattest near the relics, along the system's collision axis, and in regions of high T {sub gas}, all locations associated

Fast digital feedback control systems for accelerator RF system using FPGA

International Nuclear Information System (INIS)

Bagduwal, Pritam Singh; Sharma, Dheeraj; Tiwari, Nitesh; Lad, M.; Hannurkar, P.R.

2012-01-01

Feedback control system plays important role for proper injection and acceleration of beam in particle accelerators by providing the required amplitude and phase stability of RF fields in accelerating structures. Advancement in the field of digital technology enables us to develop fast digital feedback control system for RF applications. Digital Low Level RF (LLRF) system offers the inherent advantages of Digital System like flexibility, adaptability, good repeatability and reduced long time drift errors compared to analog system. To implement the feedback control algorithm, I/Q control scheme is used. By properly sampling the down converted IF signal using fast ADC we get accurate feedback signal and also eliminates the need of two separate detectors for amplitude and phase detection. Controller is implemented in Vertex-4 FPGA. Codes for control algorithms which controls the amplitude and phase in all four quadrants with good accuracy are written in the VHDL. I/Q modulator works as common actuator for both amplitude and phase correction. Synchronization between RF, LO and ADC clock is indispensable and has been achieved by deriving the clock and LO signal from RF signal itself. Control system has been successfully tested in lab with phase and amplitude stability better then ±1% and ±1° respectively. High frequency RF signal is down converted to IF using the super heterodyne technique. Super heterodyne principal not only brings the RF signal to the Low IF frequency at which it can be easily processed but also enables us to use the same hardware and software for other RF frequencies with some minor modification. (author)

Calibrating the HISA temperature: Measuring the temperature of the Riegel-Crutcher cloud

Science.gov (United States)

Dénes, H.; McClure-Griffiths, N. M.; Dickey, J. M.; Dawson, J. R.; Murray, C. E.

2018-06-01

H I self absorption (HISA) clouds are clumps of cold neutral hydrogen (H I) visible in front of warm background gas, which makes them ideal places to study the properties of the cold atomic component of the interstellar medium (ISM). The Riegel-Crutcher (R-C) cloud is the most striking HISA feature in the Galaxy. It is one of the closest HISA clouds to us and is located in the direction of the Galactic Centre, which provides a bright background. High-resolution interferometric measurements have revealed the filamentary structure of this cloud, however it is difficult to accurately determine the temperature and the density of the gas without optical depth measurements. In this paper we present new H I absorption observations with the Australia Telescope Compact Array (ATCA) against 46 continuum sources behind the Riegel-Crutcher cloud to directly measure the optical depth of the cloud. We decompose the complex H I absorption spectra into Gaussian components using an automated machine learning algorithm. We find 300 Gaussian components, from which 67 are associated with the R-C cloud (0 temperature and find it to be between 20 and 80 K. Our measurements uncover a temperature gradient across the cloud with spin temperatures decreasing towards positive Galactic latitudes. We also find three new OH absorption lines associated with the cloud, which support the presence of molecular gas.

VizieR Online Data Catalog: Chemical properties of red MSX sources (RMSs) (Yu+, 2016)

Science.gov (United States)

Yu, N.; Xu, J.

2017-05-01

Our molecular line data come from the Millimetre Astronomy Legacy Team Survey at 90GHz (MALT90) (e.g., Foster+ 2011, J/ApJS/197/25; Jackson+ 2013PASA...30...57J). This project is performed with Mopra, a 22m single-dish radio telescope located near Coonabarabran in New South Wales, Australia. The angular resolution of Mopra is 38", with a beam efficiency between 0.49 at 86GHz and 0.42 at 115GHz. The pointing accuracy of the main MALT90 maps is about 8", and the absolute flux uncertainty is in the range of 10%-17% depending on the transition in question. The target clumps of this survey are selected from the 870um Atacama Pathfinder Experiment (APEX) Telescope Large Area Survey of the Galaxy (ATLASGAL; Schuller+ 2009A&A...504..415S; Contreras+ 2013, J/A+A/549/A45; superseded by J/A+A/568/A41). Using Australia Telescope Compact Array (ATCA), Urquhart+ (2007, J/A+A/461/11) observed radio emissions of 826 Red Midcourse Space Experiment (MSX) Sources (RMSs) in the southern sky. We also have checked our sources with the data taken from the Sydney University Molonglo Sky Survey (SUMSS) carried out at 843MHz with the Molonglo Observatory Synthesis Telescope (MOST; Mauch+ 2003, VIII/81). See section 2 for further explanations. (5 data files).

SEU mitigation exploratory tests in a ITER related FPGA

International Nuclear Information System (INIS)

Batista, Antonio J.N.; Leong, Carlos; Santos, Bruno; Fernandes, Ana; Ramos, Ana Rita; Santos, Joana P.; Marques, José G.; Teixeira, Isabel C.; Teixeira, João P.; Sousa, Jorge; Gonçalves, Bruno

2017-01-01

Data acquisition hardware of ITER diagnostics if located in the port cells of the tokamak, as an example, will be irradiated with neutrons during the fusion reactor operation. Due to this reason the majority of the hardware containing Field Programmable Gate Arrays (FPGA) will be placed after the ITER bio-shield, such as the cubicles instrumentation room. Nevertheless, it is worth to explore real-time mitigation of soft-errors caused by neutrons radiation in ITER related FPGAs. A Virtex-6 FPGA from Xilinx (XC6VLX365T-1FFG1156C) is used on the ATCA-IO-PROCESSOR board, included in the ITER Catalog of Instrumentation & Control (I & C) products – Fast Controllers. The Virtex-6 is a re-programmable logic device where the configuration is stored in Static RAM (SRAM), the functional data is stored in dedicated Block RAM (BRAM) and the functional state logic in Flip-Flops. Single Event Upsets (SEU) due to the ionizing radiation of neutrons cause soft errors, unintended changes (bit-flips) of the logic values stored in the state elements of the FPGA. Real-time SEU monitoring and soft errors repairing, when possible, were explored in this work. An FPGA built-in Soft Error Mitigation (SEM) controller detects and corrects soft errors in the FPGA Configuration Memory (CM). BRAM based SEU sensors with Error Correction Code (ECC) detect and repair the respective BRAM contents. Real-time mitigation of SEU can increase reliability and availability of data acquisition hardware for nuclear applications. The results of the tests performed using the SEM controller and the SEU sensors are presented for a Virtex-6 FPGA (XC6VLX240T-1FFG1156C) when irradiated with neutrons from the Portuguese Research Reactor (RPI), a 1 MW nuclear fission reactor, operated by IST in the neighborhood of Lisbon. Results show that the proposed SEU mitigation technique is able to repair the majority of the detected SEU soft-errors in the FPGA memory.

SEU mitigation exploratory tests in a ITER related FPGA

Energy Technology Data Exchange (ETDEWEB)

Batista, Antonio J.N., E-mail: toquim@ipfn.tecnico.ulisboa.pt [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Leong, Carlos [Instituto de Engenharia de Sistemas e Computadores – Investigação e Desenvolvimento (INESC-ID), 1000-029 Lisboa (Portugal); Santos, Bruno; Fernandes, Ana [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Ramos, Ana Rita; Santos, Joana P.; Marques, José G. [Centro de Ciências e Tecnologias Nucleares (C2TN), Instituto Superior Técnico (IST), Universidade de Lisboa - UL, 2695-066 Bobadela (Portugal); Teixeira, Isabel C.; Teixeira, João P. [Instituto de Engenharia de Sistemas e Computadores – Investigação e Desenvolvimento (INESC-ID), 1000-029 Lisboa (Portugal); Sousa, Jorge; Gonçalves, Bruno [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal)

2017-05-15

Data acquisition hardware of ITER diagnostics if located in the port cells of the tokamak, as an example, will be irradiated with neutrons during the fusion reactor operation. Due to this reason the majority of the hardware containing Field Programmable Gate Arrays (FPGA) will be placed after the ITER bio-shield, such as the cubicles instrumentation room. Nevertheless, it is worth to explore real-time mitigation of soft-errors caused by neutrons radiation in ITER related FPGAs. A Virtex-6 FPGA from Xilinx (XC6VLX365T-1FFG1156C) is used on the ATCA-IO-PROCESSOR board, included in the ITER Catalog of Instrumentation & Control (I & C) products – Fast Controllers. The Virtex-6 is a re-programmable logic device where the configuration is stored in Static RAM (SRAM), the functional data is stored in dedicated Block RAM (BRAM) and the functional state logic in Flip-Flops. Single Event Upsets (SEU) due to the ionizing radiation of neutrons cause soft errors, unintended changes (bit-flips) of the logic values stored in the state elements of the FPGA. Real-time SEU monitoring and soft errors repairing, when possible, were explored in this work. An FPGA built-in Soft Error Mitigation (SEM) controller detects and corrects soft errors in the FPGA Configuration Memory (CM). BRAM based SEU sensors with Error Correction Code (ECC) detect and repair the respective BRAM contents. Real-time mitigation of SEU can increase reliability and availability of data acquisition hardware for nuclear applications. The results of the tests performed using the SEM controller and the SEU sensors are presented for a Virtex-6 FPGA (XC6VLX240T-1FFG1156C) when irradiated with neutrons from the Portuguese Research Reactor (RPI), a 1 MW nuclear fission reactor, operated by IST in the neighborhood of Lisbon. Results show that the proposed SEU mitigation technique is able to repair the majority of the detected SEU soft-errors in the FPGA memory.

The Infrared-Radio Correlation of Dusty Star Forming Galaxies at High Redshift

Science.gov (United States)

Lower, Sidney; Vieira, Joaquin Daniel; Jarugula, Sreevani

2018-01-01

Far-infrared (FIR) and radio continuum emission in galaxies are related by a common origin: massive stars and the processes triggered during their birth, lifetime, and death. FIR emission is produced by cool dust, heated by the absorption of UV emission from massive stars, which is then re-emitted in the FIR. Thermal free-free radiation emitted from HII regions dominates the spectral energy density (SED) of galaxies at roughly 30 GHz, while non-thermal synchrotron radiation dominates at lower frequencies. At low redshift, the infrared radio correlation (IRC, or qIR) holds as a tight empirical relation for many star forming galaxy types, but until recently, there has not been sensitive enough radio observations to extend this relation to higher redshifts. Many selection biases cloud the results of these analyses, leaving the evolution of the IRC with redshift ambiguous. In this poster, I present CIGALE fitted spectral energy distributions (SEDs) for 24 gravitationally-lensed sources selected in the mm-wave from the South Pole Telescope (SPT) survey. I fit the IRC from infrared and submillimeter fluxes obtained with Herschel, Atacama Pathfinder Experiment (APEX), and SPT and radio fluxes obtained with ATCA at 2.1, 5.5, 9, and 30 GHz. This sample of SPT sources has a spectroscopic redshift range of 2.1poster, I will present the results of this study and compare our results to various results in the literature.

Neck Circumference to Assess Obesity in Preschool Children.

Science.gov (United States)

Kondolot, Meda; Horoz, Duygu; Poyrazoğlu, Serpil; Borlu, Arda; Öztürk, Ahmet; Kurtoğlu, Selim; Mazıcıoğlu, Mümtaz M

2017-03-01

Limited information is available about the use of neck circumference (NC) to assess obesity in preschool children. This study aims to provide NC percentiles and determine the cut-off levels of NC as a measure to assess obesity in preschool children. The data were obtained from the Anthropometry of Turkish Children aged 0-6 years (ATCA-06) study database. A total of 21 family health centers were chosen and children aged 2-6 years old from all socioeconomic levels were randomly selected from the lists of district midwives; 1766 children (874 male and 892 female; 88.3% of sample size) were included in the study. The smoothed centile curves of NC were constructed by the LMS method. Receiver operating characteristic (ROC) analysis was performed to calculate cut-off points for NC using body mass index ≥95 th percentile. Mean NC was greater in males than females. Cut-off values for obesity were found to be statistically significant in both genders other than 3 years old boys. The NC percentiles of Turkish preschool children were slightly greater than those of other European preschool children in both genders. This difference disappeared around the adiposity rebound period. The 97th percentile values for Turkish preschool children continue to be greater in both genders. NC may be useful to define obesity in preschool children. Since ethnic and various other factors may have a role in incidence of obesity, local reference data are important in assessment of obesity.

The relationship between Class I and Class II methanol masers at high angular resolution

Science.gov (United States)

McCarthy, T. P.; Ellingsen, S. P.; Voronkov, M. A.; Cimò, G.

2018-06-01

We have used the Australia Telescope Compact Array (ATCA) to make the first high-resolution observations of a large sample of class I methanol masers in the 95-GHz (80-71A+) transition. The target sources consist of a statistically complete sample of 6.7-GHz class II methanol masers with an associated 95-GHz class I methanol maser, enabling a detailed study of the relationship between the two methanol maser classes at arcsecond angular resolution. These sources have been previously observed at high resolution in the 36- and 44-GHz transitions, allowing comparison between all three class I maser transitions. In total, 172 95-GHz maser components were detected across the 32 target sources. We find that at high resolution, when considering matched maser components, a 3:1 flux density ratio is observed between the 95- and 44-GHz components, consistent with a number of previous lower angular resolution studies. The 95-GHz maser components appear to be preferentially located closer to the driving sources and this may indicate that this transition is more strongly inverted nearby to background continuum sources. We do not observe an elevated association rate between 95-GHz maser emission and more evolved sources, as indicated by the presence of 12.2-GHz class II masers. We find that in the majority of cases where both class I and class II methanol emission is observed, some component of the class I emission is associated with a likely outflow candidate.

Modeling event building architecture for the triggerless data acquisition system for PANDA experiment at the HESR facility at FAIR/GSI

International Nuclear Information System (INIS)

Korcyl, K; Konorov, I; Kühn, W; Schmitt, L

2012-01-01

A novel architecture is being proposed for the data acquisition and trigger system of the PANDA experiment at the HESR facility at FAIR/GSI. The experiment will run without hardware trigger signal using timestamps to correlate detector data from a given time window. The broad physics program in combination with the high rate of 2 * 10 7 interactions per second requires very selective filtering algorithms accessing information from many detectors. Therefore the effective filtering will happen later than in today's systems ie. after the event building. To assess that, the complete architecture will be built of two stages: the data concentrator stage providing event building and the rate reduction stage. For the former stage, which requires a throughput of 100 GB/s to perform event building, we propose two layers of ATCA crates filled with Compute Nodes - modules designed at IHEP and University of Giessen for trigger and data acquisition systems. Currently each board is equipped with 5 Virtex4 FX60 FPGAs and high bandwidth connectivity is provided by 8 front panel RocketIO ports and 12 backplane ports for the inter-module communication. We designed simplified models of the components of the architecture and using the SystemC library as support for the discrete event simulations, demonstrate the expected throughput of the full-size system. We also show impact of some architectural choices and key parameters on the architecture's performance.

Development of the power system for accelerator

International Nuclear Information System (INIS)

Kwon, Hyeokjung; Kim, D. I.; Kim, H. S.; Park, B. S.; Seol, K. T.; Yun, S. P.; Song, Y. G.; Jang, J. H.; Cho, Y. S.

2013-02-01

The 100-MeV proton linac needs 4 modulators whose specification is as follows, -115kV, 55A, and 9%. The development of the modulators were successfully finished and installed at Gyeongju site of KAERI. One of them was used and successfully tested in the 20-MeV linac operation at Daejeon site. The klystron is used to supply the high power RF into the accelerating structure. There are 2 klystrons for 20-MeV part of the linac and 7 klystrons from 20-MeV to 100-MeV region. The maximum voltage is ?105kV, the peak power is 1.6 MW, and the duty is 9%. All of the 7 klystrons have been fabricated, tested and installed. The high power RF system includes circulators, dummy lodes, RF windows, and wave-guides. The development of the high power RF components was finished and they were installed at the Gyeongju site. The 11 sets of RCCS (resonant control cooling system) will be used to control the cooling water temperature inside the accelerating structure. The temperature range of the cooling water covers between 21 .deg. C and 33 .deg. C with the 0.1 .deg. C control. All RCCSs were installed in the klystron gallery. Purposes of the 20-MeV linac operation at Daejeon site of KAERI (2007∼2011) are to supply proton beams to user, to porve the accelerator performance, to test the developed components including LLRF, diagnostics, and control system, and to measure the proton beam properties. During the period, the total number of samples reaches to 1,603 and the average machine availability becomes 96.2%. The 20-MeV linac was disassembled, moved and installed at Gyeongju site after finishing the test operation

Laser-to-RF phase detection with femtosecond precision for remote reference phase stabilization in particle accelerators

Energy Technology Data Exchange (ETDEWEB)

Lamb, Thorsten

2017-05-15

The operation of modern free-electron lasers (FELs) requires the synchronization of different accelerator subsystems with femtosecond precision. A pulsed optical synchronization system is for this reason operated at the Free-Electron Laser in Hamburg (FLASH) and it is under construction for the upcoming European X-ray Free-Electron Laser (XFEL). Laser pulses from the optical master oscillator are transmitted by timing stabilized optical fiberlinks to dedicated end stations along the accelerator. Devices which cannot operate with optical synchronization signals are instead conventionally synchronized with radio frequency (RF) reference signals. These signals are distributed in the accelerator by coaxial cables. Especially the low -level radio frequency (LLRF) system requires RF reference signals with femtosecond stability in order to meet nowadays femtosecond demands. Due to cable drifts and the length of the accelerators, this level of stability cannot be provided by conventional RF transport. A laser-to-RF (L2RF) phase detector has been invented, which allows to measure with femtosecond precision the relative phase between a phase stable optical pulse train from an optical fiberlink and an RF signal. The L2RF phase detector is based on an integrated MACH-ZEHNDER modulator (MZM) in which the phase error between both signals is encoded in an amplitude modulation of the optical pulse train. Different configurations, based on single output and dual output MZMs have been evaluated for different operation scenarios. A full mathematical representation of the chosen configuration has been derived. The impact of multiple error sources has been investigated. It has been proven that most error sources have only second or higher order influence on the detection principle which is a significant advantage over existing schemes. The invented L2RF phase detector is for example balanced and in its working point insensitive to power variations of the optical reference pulse train

Laser-to-RF phase detection with femtosecond precision for remote reference phase stabilization in particle accelerators

International Nuclear Information System (INIS)

Lamb, Thorsten

2017-05-01

The operation of modern free-electron lasers (FELs) requires the synchronization of different accelerator subsystems with femtosecond precision. A pulsed optical synchronization system is for this reason operated at the Free-Electron Laser in Hamburg (FLASH) and it is under construction for the upcoming European X-ray Free-Electron Laser (XFEL). Laser pulses from the optical master oscillator are transmitted by timing stabilized optical fiberlinks to dedicated end stations along the accelerator. Devices which cannot operate with optical synchronization signals are instead conventionally synchronized with radio frequency (RF) reference signals. These signals are distributed in the accelerator by coaxial cables. Especially the low -level radio frequency (LLRF) system requires RF reference signals with femtosecond stability in order to meet nowadays femtosecond demands. Due to cable drifts and the length of the accelerators, this level of stability cannot be provided by conventional RF transport. A laser-to-RF (L2RF) phase detector has been invented, which allows to measure with femtosecond precision the relative phase between a phase stable optical pulse train from an optical fiberlink and an RF signal. The L2RF phase detector is based on an integrated MACH-ZEHNDER modulator (MZM) in which the phase error between both signals is encoded in an amplitude modulation of the optical pulse train. Different configurations, based on single output and dual output MZMs have been evaluated for different operation scenarios. A full mathematical representation of the chosen configuration has been derived. The impact of multiple error sources has been investigated. It has been proven that most error sources have only second or higher order influence on the detection principle which is a significant advantage over existing schemes. The invented L2RF phase detector is for example balanced and in its working point insensitive to power variations of the optical reference pulse train

A dearth of OH/IR stars in the Small Magellanic Cloud

Science.gov (United States)

Goldman, Steven R.; van Loon, Jacco Th.; Gómez, José F.; Green, James A.; Zijlstra, Albert A.; Nanni, Ambra; Imai, Hiroshi; Whitelock, Patricia A.; Groenewegen, Martin A. T.; Oliveira, Joana M.

2018-01-01

We present the results of targeted observations and a survey of 1612-, 1665- and 1667-MHz circumstellar OH maser emission from asymptotic giant branch (AGB) stars and red supergiants (RSGs) in the Small Magellanic Cloud (SMC), using the Parkes and Australia Telescope Compact Array (ATCA) radio telescopes. No clear OH maser emission has been detected in any of our observations targeting luminous, long-period, large-amplitude variable stars, which have been confirmed spectroscopically and photometrically to be mid- to late-M spectral type. These observations have probed 3-4 times deeper than any OH maser survey in the SMC. Using a bootstrapping method with Large Magellanic Cloud (LMC) and Galactic OH/IR star samples and our SMC observation upper limits, we have calculated the likelihood of not detecting maser emission in any of the two sources considered to be the top maser candidates to be less than 0.05 per cent, assuming a similar pumping mechanism as the LMC and Galactic OH/IR sources. We have performed a population comparison of the Magellanic Clouds and used Spitzer IRAC and MIPS photometry to confirm that we have observed all high luminosity SMC sources that are expected to exhibit maser emission. We suspect that, compared to the OH/IR stars in the Galaxy and LMC, the reduction in metallicity may curtail the dusty wind phase at the end of the evolution of the most massive cool stars. We also suspect that the conditions in the circumstellar envelope change beyond a simple scaling of abundances and wind speed with metallicity.

LMC X-1: A New Spectral Analysis of the O-star in the Binary and Surrounding Nebula

Science.gov (United States)

Hyde, E. A.; Russell, D. M.; Ritter, A.; Filipović, M. D.; Kaper, L.; Grieve, K.; O'Brien, A. N.

2017-09-01

We provide new observations of the LMC X-1 O star and its extended nebula structure using spectroscopic data from VLT/UVES as well as Hα imaging from the Wide Field Imager on the Max Planck Gesellschaft/European Southern Observatory 2.2 m telescope and ATCA imaging of the 2.1 GHz radio continuum. This nebula is one of the few known to be energized by an X-ray binary. We use a new spectrum extraction technique that is superior to other methods used to obtain both radial velocities and fluxes. This provides an updated spatial velocity of ≃ 21.0 +/- 4.8 km s-1 for the O star. The slit encompasses both the photo-ionized and shock-ionized regions of the nebula. The imaging shows a clear arc-like structure reminiscent of a wind bow shock in between the ionization cone and shock-ionized nebula. The observed structure can be fit well by the parabolic shape of a wind bow shock. If an interpretation of a wind bow shock system is valid, we investigate the N159-O1 star cluster as a potential parent of the system, suggesting a progenitor mass of ˜60 M ⊙ for the black hole. We further note that the radio emission could be non-thermal emission from the wind bow shock, or synchrotron emission associated with the jet-inflated nebula. For both wind- and jet-powered origins, this would represent one of the first radio detections of such a structure.

Test results of an ITER relevant FPGA when irradiated with neutrons

Energy Technology Data Exchange (ETDEWEB)

Batista, Antonio J. N.; Santos, Bruno; Fernandes, Ana; Goncalves, Bruno [Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, 1049-001 Lisboa, (Portugal); Leong, Carlos; Teixeira, Joao P. [Instituto de Engenharia de Sistemas e Computadores - Investigacao e Desenvolvimento, 1000-029 Lisboa, (Portugal); Ramos, Ana Rita; Santos, Joana P.; Marques, Jose G. [Centro de Ciencias e Tecnologias Nucleares, Instituto Superior Tecnico, Universidade de Lisboa, 2695-066 Bobadela, (Portugal)

2015-07-01

The data acquisition and control instrumentation cubicles room of the ITER tokamak will be irradiated with neutrons during the fusion reactor operation. A Virtex-6 FPGA from Xilinx (XC6VLX365T-1FFG1156C) is used on the ATCA-IO-PROCESSOR board, included in the ITER Catalog of I and C products - Fast Controllers. The Virtex-6 is a re-programmable logic device where the configuration is stored in Static RAM (SRAM), functional data stored in dedicated Block RAM (BRAM) and functional state logic in Flip-Flops. Single Event Upsets (SEU) due to the ionizing radiation of neutrons causes soft errors, unintended changes (bit-flips) to the values stored in state elements of the FPGA. The SEU monitoring and soft errors repairing, when possible, were explored in this work. An FPGA built-in Soft Error Mitigation (SEM) controller detects and corrects soft errors in the FPGA configuration memory. Novel SEU sensors with Error Correction Code (ECC) detect and repair the BRAM memories. Proper management of SEU can increase reliability and availability of control instrumentation hardware for nuclear applications. The results of the tests performed using the SEM controller and the BRAM SEU sensors are presented for a Virtex-6 FPGA (XC6VLX240T-1FFG1156C) when irradiated with neutrons from the Portuguese Research Reactor (RPI), a 1 MW nuclear fission reactor operated by IST in the neighborhood of Lisbon. Results show that the proposed SEU mitigation technique is able to repair the majority of the detected SEU errors in the configuration and BRAM memories. (authors)

Fuzzy knowledge bases integration based on ontology

OpenAIRE

Ternovoy, Maksym; Shtogrina, Olena

2012-01-01

the paper describes the approach for fuzzy knowledge bases integration with the usage of ontology. This approach is based on metadata-base usage for integration of different knowledge bases with common ontology. The design process of metadata-base is described.

Foundation: Transforming data bases into knowledge bases

Science.gov (United States)

Purves, R. B.; Carnes, James R.; Cutts, Dannie E.

1987-01-01

One approach to transforming information stored in relational data bases into knowledge based representations and back again is described. This system, called Foundation, allows knowledge bases to take advantage of vast amounts of pre-existing data. A benefit of this approach is inspection, and even population, of data bases through an intelligent knowledge-based front-end.

Case-based reasoning: The marriage of knowledge base and data base

Science.gov (United States)

Pulaski, Kirt; Casadaban, Cyprian

1988-01-01

The coupling of data and knowledge has a synergistic effect when building an intelligent data base. The goal is to integrate the data and knowledge almost to the point of indistinguishability, permitting them to be used interchangeably. Examples given in this paper suggest that Case-Based Reasoning is a more integrated way to link data and knowledge than pure rule-based reasoning.

From oil-based mud to water-based mud

International Nuclear Information System (INIS)

Christiansen, C.

1991-01-01

Maersk Olie og Gas AS has used low toxic oil-based muds extensively since 1982 for drilling development wells and later in the development of horizontal well drilling techniques. However, in view of the strong drive towards a reduction in the amount of oil discharged to the North Sea from the oil industry, Maersk Olie og Gas AS initiated trials with new or improved types of water-based mud, first in deviated wells (1989) and then in horizontal wells (1990). The paper reviews Maersk Olie og Gas As experience with oil-based mud since the drilling of the first horizontal well in 1987, specifically with respect to cuttings washing equipment, oil retention on cuttings, and the procedure for monitoring of this parameter. It describes the circumstances leading to the decision to revert to water-based mud systems. Finally, it reviews the experience gained so far with the new improved types of water-based mud systems, mainly glycol and KCl/polymer mud systems. Comparison of operational data, such as rate of penetration, torque and drag, etc., is made between wells drilled with oil-based mud and water-based mud. The trials with the new improved types of water-based mud systems have been positive, i.e. horizontal wells can be drilled successfully with water-based mud. As a result, Maersk Olie og and Gas AS has decided to discontinue the use of low toxic oil-based muds in the Danish sector of the North Sea

The carbon inventory in a quiescent, filamentary molecular cloud in G328

International Nuclear Information System (INIS)

Burton, Michael G.; Ashley, Michael C. B.; Braiding, Catherine; Storey, John W. V.; Kulesa, Craig; Hollenbach, David J.; Wolfire, Mark; Glück, Christian; Rowell, Gavin

2014-01-01

We present spectral line images of [C I] 809 GHz, CO J = 1-0 115 GHz and H I 1.4 GHz line emission, and calculate the corresponding C, CO and H column densities, for a sinuous, quiescent giant molecular cloud about 5 kpc distant along the l = 328° sightline (hereafter G328) in our Galaxy. The [C I] data comes from the High Elevation Antarctic Terahertz telescope, a new facility on the summit of the Antarctic plateau where the precipitable water vapor falls to the lowest values found on the surface of the Earth. The CO and H I data sets come from the Mopra and Parkes/ATCA telescopes, respectively. We identify a filamentary molecular cloud, ∼75 × 5 pc long with mass ∼4 × 10 4 M ☉ and a narrow velocity emission range of just 4 km s –1 . The morphology and kinematics of this filament are similar in CO, [C I], and H I, though in the latter appears as self-absorption. We calculate line fluxes and column densities for the three emitting species, which are broadly consistent with a photodissociation region model for a GMC exposed to the average interstellar radiation field. The [C/CO] abundance ratio averaged through the filament is found to be approximately unity. The G328 filament is constrained to be cold (T Dust < 20 K) by the lack of far-IR emission, to show no clear signs of star formation, and to only be mildly turbulent from the narrow line width. We suggest that it may represent a GMC shortly after formation, or perhaps still in the process of formation.

The carbon inventory in a quiescent, filamentary molecular cloud in G328

Energy Technology Data Exchange (ETDEWEB)

Burton, Michael G.; Ashley, Michael C. B.; Braiding, Catherine; Storey, John W. V. [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Kulesa, Craig [Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Hollenbach, David J. [Carl Sagan Center, SETI Institute, 189 Bernado Avenue, Mountain View, CA 94043-5203 (United States); Wolfire, Mark [Astronomy Department, University of Maryland, College Park, MD 20742 (United States); Glück, Christian [KOSMA, I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln (Germany); Rowell, Gavin, E-mail: m.burton@unsw.edu.au [School of Chemistry and Physics, University of Adelaide, Adelaide, SA 5005 (Australia)

2014-02-20

We present spectral line images of [C I] 809 GHz, CO J = 1-0 115 GHz and H I 1.4 GHz line emission, and calculate the corresponding C, CO and H column densities, for a sinuous, quiescent giant molecular cloud about 5 kpc distant along the l = 328° sightline (hereafter G328) in our Galaxy. The [C I] data comes from the High Elevation Antarctic Terahertz telescope, a new facility on the summit of the Antarctic plateau where the precipitable water vapor falls to the lowest values found on the surface of the Earth. The CO and H I data sets come from the Mopra and Parkes/ATCA telescopes, respectively. We identify a filamentary molecular cloud, ∼75 × 5 pc long with mass ∼4 × 10{sup 4} M {sub ☉} and a narrow velocity emission range of just 4 km s{sup –1}. The morphology and kinematics of this filament are similar in CO, [C I], and H I, though in the latter appears as self-absorption. We calculate line fluxes and column densities for the three emitting species, which are broadly consistent with a photodissociation region model for a GMC exposed to the average interstellar radiation field. The [C/CO] abundance ratio averaged through the filament is found to be approximately unity. The G328 filament is constrained to be cold (T {sub Dust} < 20 K) by the lack of far-IR emission, to show no clear signs of star formation, and to only be mildly turbulent from the narrow line width. We suggest that it may represent a GMC shortly after formation, or perhaps still in the process of formation.

THE RADIO/GAMMA-RAY CONNECTION IN ACTIVE GALACTIC NUCLEI IN THE ERA OF THE FERMI LARGE AREA TELESCOPE

International Nuclear Information System (INIS)

Ackermann, M.; Ajello, M.; Allafort, A.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Angelakis, E.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bonamente, E.; Bouvier, A.; Brigida, M.; Bruel, P.

2011-01-01

We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose. We use both archival interferometric 8.4 GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15 GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100 MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of -7 for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 x 10 -6 to 9.0 x 10 -8 . Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability -7 ) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.

Computer-based multi-channel analyzer based on internet

International Nuclear Information System (INIS)

Zhou Xinzhi; Ning Jiaoxian

2001-01-01

Combined the technology of Internet with computer-based multi-channel analyzer, a new kind of computer-based multi-channel analyzer system which is based on browser is presented. Its framework and principle as well as its implementation are discussed

Combining Host-based and network-based intrusion detection system

African Journals Online (AJOL)

These attacks were simulated using hping. The proposed system is implemented in Java. The results show that the proposed system is able to detect attacks both from within (host-based) and outside sources (network-based). Key Words: Intrusion Detection System (IDS), Host-based, Network-based, Signature, Security log.

NMR studies concerning base-base interactions in oligonucleotides

International Nuclear Information System (INIS)

Hoogen, Y.T. van den.

1988-01-01

Two main subjects are treated in the present thesis. The firsst part principally deals with the base-base interactions in single-stranded oligoribonucleotides. The second part presents NMR and model-building studies of DNA and RNA duplexes containing an unpaired base. (author). 242 refs.; 26 figs.; 24 tabs

XML-Based SHINE Knowledge Base Interchange Language

Science.gov (United States)

James, Mark; Mackey, Ryan; Tikidjian, Raffi

2008-01-01

The SHINE Knowledge Base Interchange Language software has been designed to more efficiently send new knowledge bases to spacecraft that have been embedded with the Spacecraft Health Inference Engine (SHINE) tool. The intention of the behavioral model is to capture most of the information generally associated with a spacecraft functional model, while specifically addressing the needs of execution within SHINE and Livingstone. As such, it has some constructs that are based on one or the other.

Communication Base Station Log Analysis Based on Hierarchical Clustering

Directory of Open Access Journals (Sweden)

Zhang Shao-Hua

2017-01-01

Full Text Available Communication base stations generate massive data every day, these base station logs play an important value in mining of the business circles. This paper use data mining technology and hierarchical clustering algorithm to group the scope of business circle for the base station by recording the data of these base stations.Through analyzing the data of different business circle based on feature extraction and comparing different business circle category characteristics, which can choose a suitable area for operators of commercial marketing.

Value-based metrics and Internet-based enterprises

Science.gov (United States)

Gupta, Krishan M.

2001-10-01

Within the last few years, a host of value-based metrics like EVA, MVA, TBR, CFORI, and TSR have evolved. This paper attempts to analyze the validity and applicability of EVA and Balanced Scorecard for Internet based organizations. Despite the collapse of the dot-com model, the firms engaged in e- commerce continue to struggle to find new ways to account for customer-base, technology, employees, knowledge, etc, as part of the value of the firm. While some metrics, like the Balance Scorecard are geared towards internal use, others like EVA are for external use. Value-based metrics are used for performing internal audits as well as comparing firms against one another; and can also be effectively utilized by individuals outside the firm looking to determine if the firm is creating value for its stakeholders.

Integrated Case Based and Rule Based Reasoning for Decision Support

OpenAIRE

Eshete, Azeb Bekele

2009-01-01

This project is a continuation of my specialization project which was focused on studying theoretical concepts related to case based reasoning method, rule based reasoning method and integration of them. The integration of rule-based and case-based reasoning methods has shown a substantial improvement with regards to performance over the individual methods. Verdande Technology As wants to try integrating the rule based reasoning method with an existing case based system. This project focu...

Knowledge base verification based on enhanced colored petri net

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1998-12-31

Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

Knowledge base verification based on enhanced colored petri net

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1997-12-31

Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

Computer-based and web-based radiation safety training

Energy Technology Data Exchange (ETDEWEB)

Owen, C., LLNL

1998-03-01

The traditional approach to delivering radiation safety training has been to provide a stand-up lecture of the topic, with the possible aid of video, and to repeat the same material periodically. New approaches to meeting training requirements are needed to address the advent of flexible work hours and telecommuting, and to better accommodate individuals learning at their own pace. Computer- based and web-based radiation safety training can provide this alternative. Computer-based and web- based training is an interactive form of learning that the student controls, resulting in enhanced and focused learning at a time most often chosen by the student.

Content-Based Image Retrial Based on Hadoop

Directory of Open Access Journals (Sweden)

DongSheng Yin

2013-01-01

Full Text Available Generally, time complexity of algorithms for content-based image retrial is extremely high. In order to retrieve images on large-scale databases efficiently, a new way for retrieving based on Hadoop distributed framework is proposed. Firstly, a database of images features is built by using Speeded Up Robust Features algorithm and Locality-Sensitive Hashing and then perform the search on Hadoop platform in a parallel way specially designed. Considerable experimental results show that it is able to retrieve images based on content on large-scale cluster and image sets effectively.

Home-based versus centre-based cardiac rehabilitation.

Science.gov (United States)

Taylor, Rod S; Dalal, Hayes; Jolly, Kate; Moxham, Tiffany; Zawada, Anna

2010-01-20

The burden of cardiovascular disease world-wide is one of great concern to patients and health care agencies alike. Traditionally centre-based cardiac rehabilitation (CR) programmes are offered to individuals after cardiac events to aid recovery and prevent further cardiac illness. Home-based cardiac rehabilitation programmes have been introduced in an attempt to widen access and participation. To determine the effectiveness of home-based cardiac rehabilitation programmes compared with supervised centre-based cardiac rehabilitation on mortality and morbidity, health-related quality of life and modifiable cardiac risk factors in patients with coronary heart disease. We updated the search of a previous review by searching the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2007, Issue 4), MEDLINE, EMBASE and CINAHL from 2001 to January 2008. We checked reference lists and sought advice from experts. No language restrictions were applied. Randomised controlled trials (RCTs) that compared centre-based cardiac rehabilitation (e.g. hospital, gymnasium, sports centre) with home-based programmes, in adults with myocardial infarction, angina, heart failure or who had undergone revascularisation. Studies were selected independently by two reviewers, and data extracted by a single reviewer and checked by a second one. Authors were contacted where possible to obtain missing information. Twelve studies (1,938 participants) met the inclusion criteria. The majority of studies recruited a lower risk patient following an acute myocardial infarction (MI) and revascularisation. There was no difference in outcomes of home- versus centre-based cardiac rehabilitation in mortality risk ratio (RR) was1.31 (95% confidence interval (C) 0.65 to 2.66), cardiac events, exercise capacity standardised mean difference (SMD) -0.11 (95% CI -0.35 to 0.13), as well as in modifiable risk factors (systolic blood pressure; diastolic blood pressure; total cholesterol

14 CFR 119.47 - Maintaining a principal base of operations, main operations base, and main maintenance base...

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Maintaining a principal base of operations, main operations base, and main maintenance base; change of address. 119.47 Section 119.47 Aeronautics... Under Part 121 or Part 135 of This Chapter § 119.47 Maintaining a principal base of operations, main...

Model-Based Requirements Management in Gear Systems Design Based On Graph-Based Design Languages

Directory of Open Access Journals (Sweden)

Kevin Holder

2017-10-01

Full Text Available For several decades, a wide-spread consensus concerning the enormous importance of an in-depth clarification of the specifications of a product has been observed. A weak clarification of specifications is repeatedly listed as a main cause for the failure of product development projects. Requirements, which can be defined as the purpose, goals, constraints, and criteria associated with a product development project, play a central role in the clarification of specifications. The collection of activities which ensure that requirements are identified, documented, maintained, communicated, and traced throughout the life cycle of a system, product, or service can be referred to as “requirements engineering”. These activities can be supported by a collection and combination of strategies, methods, and tools which are appropriate for the clarification of specifications. Numerous publications describe the strategy and the components of requirements management. Furthermore, recent research investigates its industrial application. Simultaneously, promising developments of graph-based design languages for a holistic digital representation of the product life cycle are presented. Current developments realize graph-based languages by the diagrams of the Unified Modelling Language (UML, and allow the automatic generation and evaluation of multiple product variants. The research presented in this paper seeks to present a method in order to combine the advantages of a conscious requirements management process and graph-based design languages. Consequently, the main objective of this paper is the investigation of a model-based integration of requirements in a product development process by means of graph-based design languages. The research method is based on an in-depth analysis of an exemplary industrial product development, a gear system for so-called “Electrical Multiple Units” (EMU. Important requirements were abstracted from a gear system

Solid Base Catalysis

CERN Document Server

Ono, Yoshio

2011-01-01

The importance of solid base catalysts has come to be recognized for their environmentally benign qualities, and much significant progress has been made over the past two decades in catalytic materials and solid base-catalyzed reactions. The book is focused on the solid base. Because of the advantages over liquid bases, the use of solid base catalysts in organic synthesis is expanding. Solid bases are easier to dispose than liquid bases, separation and recovery of products, catalysts and solvents are less difficult, and they are non-corrosive. Furthermore, base-catalyzed reactions can be performed without using solvents and even in the gas phase, opening up more possibilities for discovering novel reaction systems. Using numerous examples, the present volume describes the remarkable role solid base catalysis can play, given the ever increasing worldwide importance of "green" chemistry. The reader will obtain an overall view of solid base catalysis and gain insight into the versatility of the reactions to whic...

Evidence-based monitoring and evaluation of the faith-based ...

African Journals Online (AJOL)

Background: The Islamic Medical Association of Uganda, has been implementing the faith-based approach to HIV prevention without baseline data on expected positive outcomes. Objectives: To establish evidence-based baseline data on expected positive outcomes of the faith-based approach to HIV prevention. Methods: ...

Covariance-Based Measurement Selection Criterion for Gaussian-Based Algorithms

Directory of Open Access Journals (Sweden)

Fernando A. Auat Cheein

2013-01-01

Full Text Available Process modeling by means of Gaussian-based algorithms often suffers from redundant information which usually increases the estimation computational complexity without significantly improving the estimation performance. In this article, a non-arbitrary measurement selection criterion for Gaussian-based algorithms is proposed. The measurement selection criterion is based on the determination of the most significant measurement from both an estimation convergence perspective and the covariance matrix associated with the measurement. The selection criterion is independent from the nature of the measured variable. This criterion is used in conjunction with three Gaussian-based algorithms: the EIF (Extended Information Filter, the EKF (Extended Kalman Filter and the UKF (Unscented Kalman Filter. Nevertheless, the measurement selection criterion shown herein can also be applied to other Gaussian-based algorithms. Although this work is focused on environment modeling, the results shown herein can be applied to other Gaussian-based algorithm implementations. Mathematical descriptions and implementation results that validate the proposal are also included in this work.

Model-Based Learning Environment Based on The Concept IPS School-Based Management

Directory of Open Access Journals (Sweden)

Hamid Darmadi

2017-03-01

Full Text Available The results showed: (1 learning model IPS-oriented environment can grow and not you love the cultural values of the area as a basis for the development of national culture, (2 community participation, and the role of government in implementing learning model of IPS-based environment provides a positive impact for the improvement of management school resources, (3 learning model IPS-based environment effectively creating a way of life together peacefully, increase the intensity of togetherness and mutual respect (4 learning model IPS-based environment can improve student learning outcomes, (5 there are differences in the expression of attitudes and results learning among students who are located in the area of conflict with students who are outside the area of conflict (6 analysis of the scale of attitudes among school students da SMA result rewards high school students to the values of unity and nation, respect for diversity and peaceful coexistence, It is recommended that the Department of Education authority as an institution of Trustees and the development of social and cultural values in the province can apply IPS learning model based environments.

A Web-Based Learning Support System for Inquiry-Based Learning

Science.gov (United States)

Kim, Dong Won; Yao, Jingtao

The emergence of the Internet and Web technology makes it possible to implement the ideals of inquiry-based learning, in which students seek truth, information, or knowledge by questioning. Web-based learning support systems can provide a good framework for inquiry-based learning. This article presents a study on a Web-based learning support system called Online Treasure Hunt. The Web-based learning support system mainly consists of a teaching support subsystem, a learning support subsystem, and a treasure hunt game. The teaching support subsystem allows instructors to design their own inquiry-based learning environments. The learning support subsystem supports students' inquiry activities. The treasure hunt game enables students to investigate new knowledge, develop ideas, and review their findings. Online Treasure Hunt complies with a treasure hunt model. The treasure hunt model formalizes a general treasure hunt game to contain the learning strategies of inquiry-based learning. This Web-based learning support system empowered with the online-learning game and founded on the sound learning strategies furnishes students with the interactive and collaborative student-centered learning environment.

Design of Composite Structures Using Knowledge-Based and Case Based Reasoning

Science.gov (United States)

Lambright, Jonathan Paul

1996-01-01

A method of using knowledge based and case based reasoning to assist designers during conceptual design tasks of composite structures was proposed. The cooperative use of heuristics, procedural knowledge, and previous similar design cases suggests a potential reduction in design cycle time and ultimately product lead time. The hypothesis of this work is that the design process of composite structures can be improved by using Case-Based Reasoning (CBR) and Knowledge-Based (KB) reasoning in the early design stages. The technique of using knowledge-based and case-based reasoning facilitates the gathering of disparate information into one location that is easily and readily available. The method suggests that the inclusion of downstream life-cycle issues into the conceptual design phase reduces potential of defective, and sub-optimal composite structures. Three industry experts were interviewed extensively. The experts provided design rules, previous design cases, and test problems. A Knowledge Based Reasoning system was developed using the CLIPS (C Language Interpretive Procedural System) environment and a Case Based Reasoning System was developed using the Design Memory Utility For Sharing Experiences (MUSE) xviii environment. A Design Characteristic State (DCS) was used to document the design specifications, constraints, and problem areas using attribute-value pair relationships. The DCS provided consistent design information between the knowledge base and case base. Results indicated that the use of knowledge based and case based reasoning provided a robust design environment for composite structures. The knowledge base provided design guidance from well defined rules and procedural knowledge. The case base provided suggestions on design and manufacturing techniques based on previous similar designs and warnings of potential problems and pitfalls. The case base complemented the knowledge base and extended the problem solving capability beyond the existence of

Feature-Based versus Category-Based Induction with Uncertain Categories

Science.gov (United States)

Griffiths, Oren; Hayes, Brett K.; Newell, Ben R.

2012-01-01

Previous research has suggested that when feature inferences have to be made about an instance whose category membership is uncertain, feature-based inductive reasoning is used to the exclusion of category-based induction. These results contrast with the observation that people can and do use category-based induction when category membership is…

WPS criterion proposition based on experimental data base interpretation

International Nuclear Information System (INIS)

Chapuliot, S.; Izard, J.P.; Moinereau, D.; Marie, S.

2011-01-01

This article gives the background and the methodology developed to define a K J based criterion for brittle fracture of Reactor Pressure Vessel (RPV) submitted to Pressurized Thermal Shock (PTS), and taking into account Warm Pre Stressing effect (WPS). The first step of this methodology is the constitution of an experimental data base. This work was performed through bibliography and partnerships, and allows merging experimental results dealing with: -) Various ferritic steels; -) Various material states (as received, thermally aged, irradiated...); -) Various mode of fracture (cleavage, inter-granular, mixed mode); -) Various specimen geometry and size (CT, SENB, mock-ups); -) Various thermo-mechanical transients. Based on this experimental data base, a simple K J based limit is proposed and compared to experimental results. Parametric studies are performed in order to define the main parameters of the problem. Finally, a simple proposition based on a detailed analysis of tests results is performed. This proposition giving satisfactory results in every cases, it constitutes a good candidate for integration in French RSE-M code for in service assessment. (authors)

ALMA OBSERVATIONS OF THE COLDEST PLACE IN THE UNIVERSE: THE BOOMERANG NEBULA

Energy Technology Data Exchange (ETDEWEB)

Sahai, R. [Jet Propulsion Laboratory, MS 183-900, California Institute of Technology, Pasadena, CA 91109 (United States); Vlemmings, W. H. T. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala (Sweden); Huggins, P. J. [Physics Department, New York University, 4 Washington Place, New York, NY 10003 (United States); Nyman, L.-Å. [Joint ALMA Observatory (JAO), Alonso de Cordova 3107, Vitacura, Santiago de Chile (Chile); Gonidakis, I., E-mail: raghvendra.sahai@jpl.nasa.gov [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Marsfield NSW 2122 (Australia)

2013-11-10

The Boomerang Nebula is the coldest known object in the universe, and an extreme member of the class of pre-planetary nebulae, objects which represent a short-lived transitional phase between the asymptotic giant branch and planetary nebula evolutionary stages. Previous single-dish CO (J = 1-0) observations (with a 45'' beam) showed that the high-speed outflow in this object has cooled to a temperature significantly below the temperature of the cosmic background radiation. Here we report the first observations of the Boomerang Nebula with ALMA in the CO J = 2-1 and J = 1-0 lines to resolve the structure of this ultra-cold nebula. We find a central hourglass-shaped nebula surrounded by a patchy, but roughly round, cold high-velocity outflow. We compare the ALMA data with visible-light images obtained with the Hubble Space Telescope and confirm that the limb-brightened bipolar lobes seen in these data represent hollow cavities with dense walls of molecular gas and dust producing both the molecular-emission-line and scattered-light structures seen at millimeter and visible wavelengths. The large diffuse biconical shape of the nebula seen in the visible wavelength range is likely due to preferential illumination of the cold, high-velocity outflow. We find a compact source of millimeter-wave continuum in the nebular waist—these data, together with sensitive upper limits on the radio continuum using observations with ATCA, indicate the presence of a substantial mass of very large (millimeter-sized) grains in the waist of the nebula. Another unanticipated result is the detection of CO emission regions beyond the ultra-cold region which indicate the re-warming of the cold gas, most likely due to photoelectric grain heating.

ALMA OBSERVATIONS OF THE COLDEST PLACE IN THE UNIVERSE: THE BOOMERANG NEBULA

International Nuclear Information System (INIS)

Sahai, R.; Vlemmings, W. H. T.; Huggins, P. J.; Nyman, L.-Å.; Gonidakis, I.

2013-01-01

The Boomerang Nebula is the coldest known object in the universe, and an extreme member of the class of pre-planetary nebulae, objects which represent a short-lived transitional phase between the asymptotic giant branch and planetary nebula evolutionary stages. Previous single-dish CO (J = 1-0) observations (with a 45'' beam) showed that the high-speed outflow in this object has cooled to a temperature significantly below the temperature of the cosmic background radiation. Here we report the first observations of the Boomerang Nebula with ALMA in the CO J = 2-1 and J = 1-0 lines to resolve the structure of this ultra-cold nebula. We find a central hourglass-shaped nebula surrounded by a patchy, but roughly round, cold high-velocity outflow. We compare the ALMA data with visible-light images obtained with the Hubble Space Telescope and confirm that the limb-brightened bipolar lobes seen in these data represent hollow cavities with dense walls of molecular gas and dust producing both the molecular-emission-line and scattered-light structures seen at millimeter and visible wavelengths. The large diffuse biconical shape of the nebula seen in the visible wavelength range is likely due to preferential illumination of the cold, high-velocity outflow. We find a compact source of millimeter-wave continuum in the nebular waist—these data, together with sensitive upper limits on the radio continuum using observations with ATCA, indicate the presence of a substantial mass of very large (millimeter-sized) grains in the waist of the nebula. Another unanticipated result is the detection of CO emission regions beyond the ultra-cold region which indicate the re-warming of the cold gas, most likely due to photoelectric grain heating

ALMA Observations of the Coldest Place in the Universe: The Boomerang Nebula

Science.gov (United States)

Sahai, R.; Vlemmings, W. H. T.; Huggins, P. J.; Nyman, L.-Å.; Gonidakis, I.

2013-11-01

The Boomerang Nebula is the coldest known object in the universe, and an extreme member of the class of pre-planetary nebulae, objects which represent a short-lived transitional phase between the asymptotic giant branch and planetary nebula evolutionary stages. Previous single-dish CO (J = 1-0) observations (with a 45'' beam) showed that the high-speed outflow in this object has cooled to a temperature significantly below the temperature of the cosmic background radiation. Here we report the first observations of the Boomerang Nebula with ALMA in the CO J = 2-1 and J = 1-0 lines to resolve the structure of this ultra-cold nebula. We find a central hourglass-shaped nebula surrounded by a patchy, but roughly round, cold high-velocity outflow. We compare the ALMA data with visible-light images obtained with the Hubble Space Telescope and confirm that the limb-brightened bipolar lobes seen in these data represent hollow cavities with dense walls of molecular gas and dust producing both the molecular-emission-line and scattered-light structures seen at millimeter and visible wavelengths. The large diffuse biconical shape of the nebula seen in the visible wavelength range is likely due to preferential illumination of the cold, high-velocity outflow. We find a compact source of millimeter-wave continuum in the nebular waist—these data, together with sensitive upper limits on the radio continuum using observations with ATCA, indicate the presence of a substantial mass of very large (millimeter-sized) grains in the waist of the nebula. Another unanticipated result is the detection of CO emission regions beyond the ultra-cold region which indicate the re-warming of the cold gas, most likely due to photoelectric grain heating.

An Extreme Protocluster of Luminous Dusty Starbursts in the Early Universe

Science.gov (United States)

Oteo, I.; Ivison, R. J.; Dunne, L.; Manilla-Robles, A.; Maddox, S.; Lewis, A. J. R.; de Zotti, G.; Bremer, M.; Clements, D. L.; Cooray, A.; Dannerbauer, H.; Eales, S.; Greenslade, J.; Omont, A.; Perez–Fournón, I.; Riechers, D.; Scott, D.; van der Werf, P.; Weiss, A.; Zhang, Z.-Y.

2018-03-01

We report the identification of an extreme protocluster of galaxies in the early universe whose core (nicknamed Distant Red Core, DRC, because of its very red color in Herschel SPIRE bands) is formed by at least 10 dusty star-forming galaxies (DSFGs), spectroscopically confirmed to lie at {z}spec}=4.002 via detection of [C I](1–0), 12CO(6–5), 12CO(4–3), 12CO(2–1), and {{{H}}}2{{O}}({2}11{--}{2}02) emission lines with ALMA and ATCA. These DSFGs are distributed over a 260 {kpc}× 310 {kpc} region and have a collective obscured star formation rate (SFR) of ∼ 6500 {M}ȯ {yr}}-1, considerably higher than those seen before in any protocluster at z≳ 4. Most of the star formation is taking place in luminous DSFGs since no Lyα emitters are detected in the protocluster core, apart from a Lyα blob located next to one of the DRC components, extending over 60 {kpc}. The total obscured SFR of the protocluster could rise to {SFR}∼ {{14,400}} {M}ȯ {yr}}-1 if all the members of an overdensity of bright DSFGs discovered around DRC in a wide-field Large APEX BOlometer CAmera 870 μm image are part of the same structure. [C I](1–0) emission reveals that DRC has a total molecular gas mass of at least {M}{{{H}}2}∼ 6.6× {10}11 {M}ȯ , and its total halo mass could be as high as ∼ 4.4× {10}13 {M}ȯ , indicating that it is the likely progenitor of a cluster at least as massive as Coma at z = 0.

Photonics applications and web engineering: WILGA Winter 2016

Science.gov (United States)

Romaniuk, Ryszard S.

2016-09-01

Since twenty years, young researchers form the Institute of Electronic Systems, Warsaw University of Technology, organize two times a year, under only a marginal supervision of the senior faculty members, under the patronage of WEiTI PW, KEiT PAN, SPIE, IEEE, PKOpto SEP and PSF, the WILGA Symposium on advanced, integrated functional electronic, photonic and mechatronic systems [1-5]. All aspects are considered like: research and development, theory and design, technology - material and construction, software and hardware, commissioning and tests, as well as pilot and practical applications. The applications concern mostly, which turned after several years to be a proud specialization of the WILGA Symposium, Internet engineering, high energy physics experiments, new power industry including fusion, nuclear industry, space and satellite technologies, telecommunications, smart municipal environment, as well as biology and medicine [6-8]. XXXVIIth WILGA Symposium was held on 29-31 January 2016 and gathered a few tens of young researchers active in the mentioned research areas. There were presented a few tens of technical papers which will be published in Proc.SPIE together with the accepted articles from the Summer Edition of the WILGA Symposium scheduled for 29.05-06.06.2016. This article is a digest of chosen presentations from WILGA Symposium 2016 Winter Edition. The survey is narrowed to a few chosen and main topical tracks, like electronics and photonics design using industrial standards like ATCA/MTCA, also particular designs of functional systems using this series of industrial standards. The paper, summarizing traditionally since many years the accomplished WILGA Symposium organized by young researchers from Warsaw University of Technology, is also the following part of a cycle of papers concerning their participation in design of new generations of electronic systems used in discovery experiments in Poland and in leading research laboratories of the world.

Set-Based Discrete Particle Swarm Optimization Based on Decomposition for Permutation-Based Multiobjective Combinatorial Optimization Problems.

Science.gov (United States)

Yu, Xue; Chen, Wei-Neng; Gu, Tianlong; Zhang, Huaxiang; Yuan, Huaqiang; Kwong, Sam; Zhang, Jun

2017-08-07

This paper studies a specific class of multiobjective combinatorial optimization problems (MOCOPs), namely the permutation-based MOCOPs. Many commonly seen MOCOPs, e.g., multiobjective traveling salesman problem (MOTSP), multiobjective project scheduling problem (MOPSP), belong to this problem class and they can be very different. However, as the permutation-based MOCOPs share the inherent similarity that the structure of their search space is usually in the shape of a permutation tree, this paper proposes a generic multiobjective set-based particle swarm optimization methodology based on decomposition, termed MS-PSO/D. In order to coordinate with the property of permutation-based MOCOPs, MS-PSO/D utilizes an element-based representation and a constructive approach. Through this, feasible solutions under constraints can be generated step by step following the permutation-tree-shaped structure. And problem-related heuristic information is introduced in the constructive approach for efficiency. In order to address the multiobjective optimization issues, the decomposition strategy is employed, in which the problem is converted into multiple single-objective subproblems according to a set of weight vectors. Besides, a flexible mechanism for diversity control is provided in MS-PSO/D. Extensive experiments have been conducted to study MS-PSO/D on two permutation-based MOCOPs, namely the MOTSP and the MOPSP. Experimental results validate that the proposed methodology is promising.

Evidence-based guidelines, time-based health outcomes, and the Matthew effect

NARCIS (Netherlands)

M.L.E. Essink-Bot (Marie-Louise); M.E. Kruijshaar (Michelle); J.J.M. Barendregt (Jan); L.G.A. Bonneux (Luc)

2007-01-01

textabstractBackground: Cardiovascular risk management guidelines are 'risk based'; health economists' practice is 'time based'. The 'medical' risk-based allocation model maximises numbers of deaths prevented by targeting subjects at high risk, for example, elderly and smokers. The time-based model

Evidence-based guidelines, time-based health outcomes, and the Matthew effect

NARCIS (Netherlands)

Essink-Bot, Marie-Louise; Kruijshaar, Michelle E.; Barendregt, Jan J.; Bonneux, Luc G. A.

2007-01-01

BACKGROUND: Cardiovascular risk management guidelines are 'risk based'; health economists' practice is 'time based'. The 'medical' risk-based allocation model maximises numbers of deaths prevented by targeting subjects at high risk, for example, elderly and smokers. The time-based model maximises

0-6621 : developing a mixture-based specification for flexible base.

Science.gov (United States)

2012-08-01

The Texas Department of Transportation : (TxDOT) currently utilizes Item 247, Flexible : Base, to specify a foundation course of flexible : base utilized in a pavement. Base materials are : not allowed to be used by the contractors until : the ...

Acids and bases solvent effects on acid-base strenght

CERN Document Server

Cox, Brian G

2013-01-01

Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

Characteristic-Based, Task-Based, and Results-Based: Three Value Systems for Assessing Professionally Produced Technical Communication Products.

Science.gov (United States)

Carliner, Saul

2003-01-01

Notes that technical communicators have developed different methodologies for evaluating the effectiveness of their work, such as editing, usability testing, and determining the value added. Explains that at least three broad value systems underlie the assessment practices: characteristic-based, task-based, and results-based. Concludes that the…

Designing Android Based Augmented Reality Location-Based Service Application

Directory of Open Access Journals (Sweden)

Alim Hardiansyah

2018-01-01

Full Text Available Android is an operating system for Linux based smartphone. Android provides an open platform for the developers to create their own application. The most developed and used application now is location based application. This application gives personalization service for mobile device user and is customized to their location. Location based service also gives an opportunity for the developers to develop and increase the value of service. One of the technologies that could be combined with location based application is augmented reality. Augmented reality combines the virtual world with the real one. By the assistance of augmented reality, our surrounding environment could interact in digital form. Information of objects and environment surround us could be added to the augmented reality system and presented. Based on the background, the writers tried to implement those technologies on now rapidly developing android application as a final project to achieve bachelor degree in Department of Informatics Engineering, Faculty of Information Technology and Visual Communication, Al Kamal Science and Technology Institute. This application could be functioned to locate school by using location based service technology with the assistance of navigational applications such as waze and google maps, in form of live direction process through the smartphone

Selective Distance-Based K+ Quantification on Paper-Based Microfluidics.

Science.gov (United States)

Gerold, Chase T; Bakker, Eric; Henry, Charles S

2018-04-03

In this study, paper-based microfluidic devices (μPADs) capable of K + quantification in aqueous samples, as well as in human serum, using both colorimetric and distance-based methods are described. A lipophilic phase containing potassium ionophore I (valinomycin) was utilized to achieve highly selective quantification of K + in the presence of Na + , Li + , and Mg 2+ ions. Successful addition of a suspended lipophilic phase to a wax printed paper-based device is described and offers a solution to current approaches that rely on organic solvents, which damage wax barriers. The approach provides an avenue for future alkali/alkaline quantification utilizing μPADs. Colorimetric spot tests allowed for K + quantification from 0.1-5.0 mM using only 3.00 μL of sample solution. Selective distance-based quantification required small sample volumes (6.00 μL) and gave responses sensitive enough to distinguish between 1.0 and 2.5 mM of sample K + . μPADs using distance-based methods were also capable of differentiating between 4.3 and 6.9 mM K + in human serum samples. Distance-based methods required no digital analysis, electronic hardware, or pumps; any steps required for quantification could be carried out using the naked eye.

VectorBase

Data.gov (United States)

U.S. Department of Health & Human Services — VectorBase is a Bioinformatics Resource Center for invertebrate vectors. It is one of four Bioinformatics Resource Centers funded by NIAID to provide web-based...

Owner-Based Role-Based Access Control OB-RBAC

NARCIS (Netherlands)

Saffarian, M.; Sadighi, Babak

Administration of an access control model deals with the question of who is authorized to update policies defined on the basis of that model. One of the models whose administration has absorbed relatively large research is the Role-Based Access Control (RBAC) model. All the existing role-based

Characteristics Data Base: Programmer's guide to the LWR Quantities Data Base

International Nuclear Information System (INIS)

Jones, K.E.; Moore, R.S.

1990-08-01

The LWR Quantities Data Base is a menu-driven PC data base developed as part of OCRWM's waste, technical data base on the characteristics of potential repository wastes, which also includes non-LWR spent fuel, high-level and other materials. This programmer's guide completes the documentation for the LWR Quantities Data Base, the user's guide having been published previously. The PC data base itself may be requested from the Oak Ridge National Laboratory, using the order form provided in Volume 1 of publication DOE/RW-0184

Interaction between scene-based and array-based contextual cueing.

Science.gov (United States)

Rosenbaum, Gail M; Jiang, Yuhong V

2013-07-01

Contextual cueing refers to the cueing of spatial attention by repeated spatial context. Previous studies have demonstrated distinctive properties of contextual cueing by background scenes and by an array of search items. Whereas scene-based contextual cueing reflects explicit learning of the scene-target association, array-based contextual cueing is supported primarily by implicit learning. In this study, we investigated the interaction between scene-based and array-based contextual cueing. Participants searched for a target that was predicted by both the background scene and the locations of distractor items. We tested three possible patterns of interaction: (1) The scene and the array could be learned independently, in which case cueing should be expressed even when only one cue was preserved; (2) the scene and array could be learned jointly, in which case cueing should occur only when both cues were preserved; (3) overshadowing might occur, in which case learning of the stronger cue should preclude learning of the weaker cue. In several experiments, we manipulated the nature of the contextual cues present during training and testing. We also tested explicit awareness of scenes, scene-target associations, and arrays. The results supported the overshadowing account: Specifically, scene-based contextual cueing precluded array-based contextual cueing when both were predictive of the location of a search target. We suggest that explicit, endogenous cues dominate over implicit cues in guiding spatial attention.

Brain-Based Learning and Standards-Based Elementary Science.

Science.gov (United States)

Konecki, Loretta R.; Schiller, Ellen

This paper explains how brain-based learning has become an area of interest to elementary school science teachers, focusing on the possible relationships between, and implications of, research on brain-based learning to the teaching of science education standards. After describing research on the brain, the paper looks at three implications from…

BEAT: A Web-Based Boolean Expression Fault-Based Test Case Generation Tool

Science.gov (United States)

Chen, T. Y.; Grant, D. D.; Lau, M. F.; Ng, S. P.; Vasa, V. R.

2006-01-01

BEAT is a Web-based system that generates fault-based test cases from Boolean expressions. It is based on the integration of our several fault-based test case selection strategies. The generated test cases are considered to be fault-based, because they are aiming at the detection of particular faults. For example, when the Boolean expression is in…

Rule-Based and Case-Based Reasoning in Housing Prices

OpenAIRE

Gabrielle Gayer; Itzhak Gilboa; Offer Lieberman

2004-01-01

People reason about real-estate prices both in terms of general rules and in terms of analogies to similar cases. We propose to empirically test which mode of reasoning fits the data better. To this end, we develop the statistical techniques required for the estimation of the case-based model. It is hypothesized that case-based reasoning will have relatively more explanatory power in databases of rental apartments, whereas rule-based reasoning will have a relative advantage in sales data. We ...

Object-Based Benefits without Object-Based Representations

OpenAIRE

Alvarez, George Angelo; Fougnie, Daryl; Cormiea, Sarah M

2012-01-01

The organization of visual information into objects strongly influences visual memory: Displays with objects defined by two features (e.g. color, orientation) are easier to remember than displays with twice as many objects defined by one feature (Olson & Jiang, 2002). Existing theories suggest that this ‘object-benefit’ is based on object-based limitations in working memory: because a limited number of objects can be stored, packaging features together so that fewer objects have to be remembe...

An Ontology-Based Tourism Recommender System Based on Spreading Activation Model

Science.gov (United States)

Bahramian, Z.; Abbaspour, R. Ali

2015-12-01

A tourist has time and budget limitations; hence, he needs to select points of interest (POIs) optimally. Since the available information about POIs is overloading, it is difficult for a tourist to select the most appreciate ones considering preferences. In this paper, a new travel recommender system is proposed to overcome information overload problem. A recommender system (RS) evaluates the overwhelming number of POIs and provides personalized recommendations to users based on their preferences. A content-based recommendation system is proposed, which uses the information about the user's preferences and POIs and calculates a degree of similarity between them. It selects POIs, which have highest similarity with the user's preferences. The proposed content-based recommender system is enhanced using the ontological information about tourism domain to represent both the user profile and the recommendable POIs. The proposed ontology-based recommendation process is performed in three steps including: ontology-based content analyzer, ontology-based profile learner, and ontology-based filtering component. User's feedback adapts the user's preferences using Spreading Activation (SA) strategy. It shows the proposed recommender system is effective and improves the overall performance of the traditional content-based recommender systems.

AN ONTOLOGY-BASED TOURISM RECOMMENDER SYSTEM BASED ON SPREADING ACTIVATION MODEL

Directory of Open Access Journals (Sweden)

Z. Bahramian

2015-12-01

Full Text Available A tourist has time and budget limitations; hence, he needs to select points of interest (POIs optimally. Since the available information about POIs is overloading, it is difficult for a tourist to select the most appreciate ones considering preferences. In this paper, a new travel recommender system is proposed to overcome information overload problem. A recommender system (RS evaluates the overwhelming number of POIs and provides personalized recommendations to users based on their preferences. A content-based recommendation system is proposed, which uses the information about the user’s preferences and POIs and calculates a degree of similarity between them. It selects POIs, which have highest similarity with the user’s preferences. The proposed content-based recommender system is enhanced using the ontological information about tourism domain to represent both the user profile and the recommendable POIs. The proposed ontology-based recommendation process is performed in three steps including: ontology-based content analyzer, ontology-based profile learner, and ontology-based filtering component. User’s feedback adapts the user’s preferences using Spreading Activation (SA strategy. It shows the proposed recommender system is effective and improves the overall performance of the traditional content-based recommender systems.

Contests versus Norms: Implications of Contest-Based and Norm-Based Intervention Techniques.

Science.gov (United States)

Bergquist, Magnus; Nilsson, Andreas; Hansla, André

2017-01-01

Interventions using either contests or norms can promote environmental behavioral change. Yet research on the implications of contest-based and norm-based interventions is lacking. Based on Goal-framing theory, we suggest that a contest-based intervention frames a gain goal promoting intensive but instrumental behavioral engagement. In contrast, the norm-based intervention was expected to frame a normative goal activating normative obligations for targeted and non-targeted behavior and motivation to engage in pro-environmental behaviors in the future. In two studies participants ( n = 347) were randomly assigned to either a contest- or a norm-based intervention technique. Participants in the contest showed more intensive engagement in both studies. Participants in the norm-based intervention tended to report higher intentions for future energy conservation (Study 1) and higher personal norms for non-targeted pro-environmental behaviors (Study 2). These findings suggest that contest-based intervention technique frames a gain goal, while norm-based intervention frames a normative goal.

Contests versus Norms: Implications of Contest-Based and Norm-Based Intervention Techniques

Directory of Open Access Journals (Sweden)

Magnus Bergquist

2017-11-01

Full Text Available Interventions using either contests or norms can promote environmental behavioral change. Yet research on the implications of contest-based and norm-based interventions is lacking. Based on Goal-framing theory, we suggest that a contest-based intervention frames a gain goal promoting intensive but instrumental behavioral engagement. In contrast, the norm-based intervention was expected to frame a normative goal activating normative obligations for targeted and non-targeted behavior and motivation to engage in pro-environmental behaviors in the future. In two studies participants (n = 347 were randomly assigned to either a contest- or a norm-based intervention technique. Participants in the contest showed more intensive engagement in both studies. Participants in the norm-based intervention tended to report higher intentions for future energy conservation (Study 1 and higher personal norms for non-targeted pro-environmental behaviors (Study 2. These findings suggest that contest-based intervention technique frames a gain goal, while norm-based intervention frames a normative goal.

Embracing a competency-based specialty curriculum for community-based nursing roles.

Science.gov (United States)

Levin, Pamela F; Swider, Susan M; Breakwell, Susan; Cowell, Julia M; Reising, Virginia

2013-01-01

The Quad Council competencies for public health nursing (PHN) provide guidance in developing curricula at both the generalist and specialist level. However, these competencies are based on nursing roles in traditional public health agencies and community/public health is defined more broadly than official agency practice. The question arises as to whether community-based specialties require largely the same knowledge and skill set as PHN. The purpose of the competency cross-mapping project reported here was to (a) assess the intersection of the Quad Council competencies with four community-based specialties and (b) ensure the appropriateness of a Quad Council-based curriculum to prepare graduates across these four specialties (home health, occupational health, environmental health, and school nursing). This article details the multistep cross-mapping process, including validation with practice leaders. Results indicate strong alignment of community-based specialty competencies with Quad Council competencies. Community-based specialty-specific content that did not align well is identified, along with examples of didactic and clinical strategies to address gaps. This work indicates that a Quad Council-based curriculum is appropriate to prepare graduates in community-based specialties when attention to the specialty-specific competencies in the clinical setting is included. This work guides the development of a doctorate of nursing practice curriculum in PHN, encompassing the four additional community-based specialties. © 2013 Wiley Periodicals, Inc.

Foundry based approach for InP based PIC development

NARCIS (Netherlands)

Smit, M.K.

2014-01-01

Europe is making significant investments in development of generic photonic foundry platform infrastructures for InP-based and Silicon Photonic ICs. Here we present the present status for the InP-based JePPIX platform.

Managing the Gap between Curriculum Based and Problem Based Learning

DEFF Research Database (Denmark)

Bygholm, Ann; Buus, Lillian

2009-01-01

/or but rather both/and. In this paper we describe an approach to design and delivery of online courses in computer science which on the one hand is based on a specified curriculum and on the other hand gives room for different learning strategies, problem based learning being one of them. We discuss......Traditionally there has been a clear distinction between curriculum based and problem based approaches to accomplish learning. Preferred approaches depend of course on conviction, culture, traditions and also on the specific learning situation. We will argue that it is not a question of either...

Groebner Bases Based Verification Solution for SystemVerilog Concurrent Assertions

Directory of Open Access Journals (Sweden)

Ning Zhou

2014-01-01

of polynomial ring algebra to perform SystemVerilog assertion verification over digital circuit systems. This method is based on Groebner bases theory and sequential properties checking. We define a constrained subset of SVAs so that an efficient polynomial modeling mechanism for both circuit descriptions and assertions can be applied. We present an algorithm framework based on the algebraic representations using Groebner bases for concurrent SVAs checking. Case studies show that computer algebra can provide canonical symbolic representations for both assertions and circuit designs and can act as a novel solver engine from the viewpoint of symbolic computation.

A Computer-Based Simulation of an Acid-Base Titration

Science.gov (United States)

Boblick, John M.

1971-01-01

Reviews the advantages of computer simulated environments for experiments, referring in particular to acid-base titrations. Includes pre-lab instructions and a sample computer printout of a student's use of an acid-base simulation. Ten references. (PR)

Research on the comparison of performance-based concept and force-based concept

Science.gov (United States)

Wu, Zeyu; Wang, Dongwei

2011-03-01

There are two ideologies about structure design: force-based concept and performance-based concept. Generally, if the structure operates during elastic stage, the two philosophies usually attain the same results. But beyond that stage, the shortage of force-based method is exposed, and the merit of performance-based is displayed. Pros and cons of each strategy are listed herein, and then which structure is best suitable to each method analyzed. At last, a real structure is evaluated by adaptive pushover method to verify that performance-based method is better than force-based method.

Priority-Based Hierarchical Operational Management for Multiagent-Based Microgrids

Directory of Open Access Journals (Sweden)

Takumi Kato

2014-03-01

Full Text Available Electricity consumption in the world is constantly increasing, making our lives become more and more dependent on electricity. There are several new paradigms proposed in the field of power grids. In Japan, especially after the Great East Japan Earthquake in March 2011, the new power grid paradigms are expected to be more resilient to survive several difficulties during disasters. In this paper, we focus on microgrids and propose priority-based hierarchical operational management for multiagent-based microgrids. The proposed management is a new multiagent-based load shedding scheme and multiagent-based hierarchical architecture to realize such resilient microgrids. We developed a prototype system and performed an evaluation of the proposed management using the developed system. The result of the evaluation shows the effectiveness of our proposal in power shortage situations, such as disasters.

Feature-based attention is functionally distinct from relation-based attention: The double dissociation between color-based capture and color-relation-based capture of attention.

Science.gov (United States)

Du, Feng; Jiao, Jun

2016-04-01

The present study used a spatial blink task and a cuing task to examine the boundary between feature-based capture and relation-based capture. Feature-based capture occurs when distractors match the target feature such as target color. The occurrence of relation-based capture is contingent upon the feature relation between target and distractor (e.g., color relation). The results show that color distractors that match the target-nontarget color relation do not consistently capture attention when they appear outside of the attentional window, but distractors appearing outside the attentional window that match the target color consistently capture attention. In contrast, color distractors that best match the target-nontarget color relation but not the target color, are more likely to capture attention when they appear within the attentional window. Consistently, color cues that match the target-nontarget color relation produce a cuing effect when they appear within the attentional window, while target-color matched cues do not. Such a double dissociation between color-based capture and color-relation-based capture indicates functionally distinct mechanisms for these 2 types of attentional selection. This also indicates that the spatial blink task and the uninformative cuing task are measuring distinctive aspects of involuntary attention. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Skull base tumours

Energy Technology Data Exchange (ETDEWEB)

Borges, Alexandra [Instituto Portugues de Oncologia Francisco Gentil, Servico de Radiologia, Rua Professor Lima Basto, 1093 Lisboa Codex (Portugal)], E-mail: borgesalexandra@clix.pt

2008-06-15

With the advances of cross-sectional imaging radiologists gained an increasing responsibility in the management of patients with skull base pathology. As this anatomic area is hidden to clinical exam, surgeons and radiation oncologists have to rely on imaging studies to plan the most adequate treatment. To fulfil these endeavour radiologists need to be knowledgeable about skull base anatomy, about the main treatment options available, their indications and contra-indications and needs to be aware of the wide gamut of pathologies seen in this anatomic region. This article will provide a radiologists' friendly approach to the central skull base and will review the most common central skull base tumours and tumours intrinsic to the bony skull base.

Skull base tumours

International Nuclear Information System (INIS)

Borges, Alexandra

2008-01-01

With the advances of cross-sectional imaging radiologists gained an increasing responsibility in the management of patients with skull base pathology. As this anatomic area is hidden to clinical exam, surgeons and radiation oncologists have to rely on imaging studies to plan the most adequate treatment. To fulfil these endeavour radiologists need to be knowledgeable about skull base anatomy, about the main treatment options available, their indications and contra-indications and needs to be aware of the wide gamut of pathologies seen in this anatomic region. This article will provide a radiologists' friendly approach to the central skull base and will review the most common central skull base tumours and tumours intrinsic to the bony skull base

State-based versus reward-based motivation in younger and older adults.

Science.gov (United States)

Worthy, Darrell A; Cooper, Jessica A; Byrne, Kaileigh A; Gorlick, Marissa A; Maddox, W Todd

2014-12-01

Recent decision-making work has focused on a distinction between a habitual, model-free neural system that is motivated toward actions that lead directly to reward and a more computationally demanding goal-directed, model-based system that is motivated toward actions that improve one's future state. In this article, we examine how aging affects motivation toward reward-based versus state-based decision making. Participants performed tasks in which one type of option provided larger immediate rewards but the alternative type of option led to larger rewards on future trials, or improvements in state. We predicted that older adults would show a reduced preference for choices that led to improvements in state and a greater preference for choices that maximized immediate reward. We also predicted that fits from a hybrid reinforcement-learning model would indicate greater model-based strategy use in younger than in older adults. In line with these predictions, older adults selected the options that maximized reward more often than did younger adults in three of the four tasks, and modeling results suggested reduced model-based strategy use. In the task where older adults showed similar behavior to younger adults, our model-fitting results suggested that this was due to the utilization of a win-stay-lose-shift heuristic rather than a more complex model-based strategy. Additionally, within older adults, we found that model-based strategy use was positively correlated with memory measures from our neuropsychological test battery. We suggest that this shift from state-based to reward-based motivation may be due to age related declines in the neural structures needed for more computationally demanding model-based decision making.

Image based Monument Recognition using Graph based Visual Saliency

DEFF Research Database (Denmark)

Kalliatakis, Grigorios; Triantafyllidis, Georgios

2013-01-01

This article presents an image-based application aiming at simple image classification of well-known monuments in the area of Heraklion, Crete, Greece. This classification takes place by utilizing Graph Based Visual Saliency (GBVS) and employing Scale Invariant Feature Transform (SIFT) or Speeded......, the images have been previously processed according to the Graph Based Visual Saliency model in order to keep either SIFT or SURF features corresponding to the actual monuments while the background “noise” is minimized. The application is then able to classify these images, helping the user to better...

Convergent Filter Bases

Directory of Open Access Journals (Sweden)

Coghetto Roland

2015-09-01

Full Text Available We are inspired by the work of Henri Cartan [16], Bourbaki [10] (TG. I Filtres and Claude Wagschal [34]. We define the base of filter, image filter, convergent filter bases, limit filter and the filter base of tails (fr: filtre des sections.

QuickBase

CERN Document Server

Conner, Nancy

2007-01-01

Ready to put Intuit's QuickBase to work? Our new Missing Manual shows you how to capture, modify, share, and manage data and documents with this web-based data-sharing program quickly and easily. No longer do you have to coordinate your team through a blizzard of emails or play frustrating games of "guess which document is the right one."QuickBase saves your organization time and money, letting you manage and share the information that makes your business tick: sales figures, project timelines, drafts of documents, purchase or work requests--whatever information you need to keep business flowi

Merits of using andalusite-based refractories compared to bauxite-based refractories

OpenAIRE

Nyoka, M.; Brazier, D.; Courtney, T.; Parry, R.A.

2013-01-01

Historically bauxite-based refractories have been used in applications where andalusite-based refractories could work. Bauxite-based refractories were chosen over andalusite-based refractories mainly because of the availability of low-cost Chinese bauxite and also because many furnaces were designed by international companies that cannot easily access high-quality products. Currently, the availability of low-cost bauxite is under threat as a result of high export duties and tariffs as well as...

Swarm-based medicine.

Science.gov (United States)

Putora, Paul Martin; Oldenburg, Jan

2013-09-19

Occasionally, medical decisions have to be taken in the absence of evidence-based guidelines. Other sources can be drawn upon to fill in the gaps, including experience and intuition. Authorities or experts, with their knowledge and experience, may provide further input--known as "eminence-based medicine". Due to the Internet and digital media, interactions among physicians now take place at a higher rate than ever before. With the rising number of interconnected individuals and their communication capabilities, the medical community is obtaining the properties of a swarm. The way individual physicians act depends on other physicians; medical societies act based on their members. Swarm behavior might facilitate the generation and distribution of knowledge as an unconscious process. As such, "swarm-based medicine" may add a further source of information to the classical approaches of evidence- and eminence-based medicine. How to integrate swarm-based medicine into practice is left to the individual physician, but even this decision will be influenced by the swarm.

Touch BASE

CERN Multimedia

Antonella Del Rosso

2015-01-01

In a recent Nature article (see here), the BASE collaboration reported the most precise comparison of the charge-to-mass ratio of the proton to its antimatter equivalent, the antiproton. This result is just the beginning and many more challenges lie ahead.   CERN's AD Hall, where the BASE experiment is set-up. The Baryon Antibaryon Symmetry Experiment (BASE) was approved in June 2013 and was ready to take data in August 2014. During these 14 months, the BASE collaboration worked hard to set up its four cryogenic Penning traps, which are the heart of the whole experiment. As their name indicates, these magnetic devices are used to trap antiparticles – antiprotons coming from the Antiproton Decelerator – and particles of matter – negative hydrogen ions produced in the system by interaction with a degrader that slows the antiprotons down, allowing scientists to perform their measurements. “We had very little time to set up the wh...

Evaluation of radiosurgery techniques–Cone-based linac radiosurgery vs tomotherapy-based radiosurgery

International Nuclear Information System (INIS)

Yip, Ho Yin; Mui, Wing Lun A.; Lee, Joseph W.Y.; Fung, Winky Wing Ki; Chan, Jocelyn M.T.; Chiu, G.; Law, Maria Y.Y.

2013-01-01

Performances of radiosurgery of intracranial lesions between cone-based Linac system and Tomotherapy-based system were compared in terms of dosimetry and time. Twelve patients with single intracranial lesion treated with cone-based Linac radiosurgery system from 2005 to 2009 were replanned for Tomotherapy-based radiosurgery treatment. The conformity index, homogeneity index (HI), and gradient score index (GSI) of each case was calculated. The Wilcoxon matched-pair test was used to compare the 3 indices between both systems. The cases with regular target (n = 6) and those with irregular target (n = 6) were further analyzed separately. The estimated treatment time between both systems was also compared. Significant differences were found in HI (p = 0.05) and in GSI (p = 0.03) for the whole group. Cone-based radiosurgery was better in GSI whereas Tomotherapy-based radiosurgery was better in HI. Cone-based radiosurgery was better in conformity index (p = 0.03) and GSI (p = 0.03) for regular targets, whereas Tomotherapy-based radiosurgery system performed significantly better in HI (p = 0.03) for irregular targets. The estimated total treatment time for Tomotherapy-based radiosurgery ranged from 24 minutes to 35 minutes, including 15 minutes of pretreatment megavoltage computed tomography (MVCT) and image registration, whereas that for cone-based radiosurgery ranged from 15 minutes for 1 isocenter to 75 minutes for 5 isocenters. As a rule of thumb, Tomotherapy-based radiosurgery system should be the first-line treatment for irregular lesions because of better dose homogeneity and shorter treatment time. Cone-based Linac radiosurgery system should be the treatment of choice for regular targets because of the better dose conformity, rapid dose fall-off, and reasonable treatment time

Evaluation of radiosurgery techniques–Cone-based linac radiosurgery vs tomotherapy-based radiosurgery

Energy Technology Data Exchange (ETDEWEB)

Yip, Ho Yin, E-mail: hoyinyip@yahoo.com.hk [Department of Radiotherapy, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong (China); Mui, Wing Lun A.; Lee, Joseph W.Y.; Fung, Winky Wing Ki; Chan, Jocelyn M.T.; Chiu, G. [Department of Radiotherapy, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong (China); Law, Maria Y.Y. [Medical Physics and Research Department, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong (China)

2013-07-01

Performances of radiosurgery of intracranial lesions between cone-based Linac system and Tomotherapy-based system were compared in terms of dosimetry and time. Twelve patients with single intracranial lesion treated with cone-based Linac radiosurgery system from 2005 to 2009 were replanned for Tomotherapy-based radiosurgery treatment. The conformity index, homogeneity index (HI), and gradient score index (GSI) of each case was calculated. The Wilcoxon matched-pair test was used to compare the 3 indices between both systems. The cases with regular target (n = 6) and those with irregular target (n = 6) were further analyzed separately. The estimated treatment time between both systems was also compared. Significant differences were found in HI (p = 0.05) and in GSI (p = 0.03) for the whole group. Cone-based radiosurgery was better in GSI whereas Tomotherapy-based radiosurgery was better in HI. Cone-based radiosurgery was better in conformity index (p = 0.03) and GSI (p = 0.03) for regular targets, whereas Tomotherapy-based radiosurgery system performed significantly better in HI (p = 0.03) for irregular targets. The estimated total treatment time for Tomotherapy-based radiosurgery ranged from 24 minutes to 35 minutes, including 15 minutes of pretreatment megavoltage computed tomography (MVCT) and image registration, whereas that for cone-based radiosurgery ranged from 15 minutes for 1 isocenter to 75 minutes for 5 isocenters. As a rule of thumb, Tomotherapy-based radiosurgery system should be the first-line treatment for irregular lesions because of better dose homogeneity and shorter treatment time. Cone-based Linac radiosurgery system should be the treatment of choice for regular targets because of the better dose conformity, rapid dose fall-off, and reasonable treatment time.

Nasal base narrowing: the combined alar base excision technique.

Science.gov (United States)

Foda, Hossam M T

2007-01-01

To evaluate the role of the combined alar base excision technique in narrowing the nasal base and correcting excessive alar flare. The study included 60 cases presenting with a wide nasal base and excessive alar flaring. The surgical procedure combined an external alar wedge resection with an internal vestibular floor excision. All cases were followed up for a mean of 32 (range, 12-144) months. Nasal tip modification and correction of any preexisting caudal septal deformities were always completed before the nasal base narrowing. The mean width of the external alar wedge excised was 7.2 (range, 4-11) mm, whereas the mean width of the sill excision was 3.1 (range, 2-7) mm. Completing the internal excision first resulted in a more conservative external resection, thus avoiding any blunting of the alar-facial crease. No cases of postoperative bleeding, infection, or keloid formation were encountered, and the external alar wedge excision healed with an inconspicuous scar that was well hidden in the depth of the alar-facial crease. Finally, the risk of notching of the alar rim, which can occur at the junction of the external and internal excisions, was significantly reduced by adopting a 2-layered closure of the vestibular floor (P = .01). The combined alar base excision resulted in effective narrowing of the nasal base with elimination of excessive alar flare. Commonly feared complications, such as blunting of the alar-facial crease or notching of the alar rim, were avoided by using simple modifications in the technique of excision and closure.

Developing effective web-based regional anesthesia education: a randomized study evaluating case-based versus non-case-based module design.

Science.gov (United States)

Kopp, Sandra L; Smith, Hugh M

2011-01-01

Little is known about the use of Web-based education in regional anesthesia training. Benefits of Web-based education include the ability to standardize learning material quality and content, build appropriate learning progressions, use interactive multimedia technologies, and individualize delivery of course materials. The goals of this investigation were (1) to determine whether module design influences regional anesthesia knowledge acquisition, (2) to characterize learner preference patterns among anesthesia residents, and (3) to determine whether learner preferences play a role in knowledge acquisition. Direct comparison of knowledge assessments, learning styles, and learner preferences will be made between an interactive case-based and a traditional textbook-style module design. Forty-three Mayo Clinic anesthesiology residents completed 2 online modules, a knowledge pretest, posttest, an Index of Learning Styles assessment, and a participant satisfaction survey. Interscalene and lumbar plexus regional techniques were selected as the learning content for 4 Web modules constructed using the Blackboard Vista coursework application. One traditional textbook-style module and 1 interactive case-based module were designed for each of the interscalene and lumbar plexus techniques. Participants scored higher on the postmodule knowledge assessment for both of the interscalene and lumbar plexus modules. Postmodule knowledge performance scores were independent of both module design (interactive case-based versus traditional textbook style) and learning style preferences. However, nearly all participants reported a preference for Web-based learning and believe that it should be used in anesthesia resident education. Participants did not feel that Web-base learning should replace the current lecture-based curriculum. All residents scored higher on the postmodule knowledge assessment, but this improvement was independent of the module design and individual learning styles

Mindfulness-based and acceptance-based interventions in sport and performance contexts.

Science.gov (United States)

Gardner, Frank L; Moore, Zella E

2017-08-01

Since mindfulness-based and acceptance-based practice models were first conceptualized and applied in sport in an attempt to enhance performance and overall well-being of athletes and performers, these state-of-the-art theoretical and practice models have substantially broadened our knowledge base and have been successfully incorporated into sport and performance practice domains worldwide. Evolving from a sound empirical foundation, mindfulness-based and acceptance-based models in sport psychology have accumulated a strong basic and applied empirical foundation. In the nearly 20 years since their incorporation in the context of sport, empirical findings have demonstrated efficacious outcomes associated with performance and personal well-being, as well as supported their theorized mechanisms of change. Particularly as sport and performance environments increasingly call upon practitioners to provide more comprehensive care to clientele, including a range of care from performance enhancement and maintenance, to general personal well-being, to subclinical and clinical issues, mindfulness-based and acceptance-based practitioners have the tools to offer robust, empirically informed interventions that can enhance skills and quality of life, and/or ameliorate personal struggles. Copyright © 2017 Elsevier Ltd. All rights reserved.

VO2-based radiative thermal transistor with a semi-transparent base

Science.gov (United States)

Prod'homme, Hugo; Ordonez-Miranda, Jose; Ezzahri, Younès; Drévillon, Jérémie; Joulain, Karl

2018-05-01

We study a radiative thermal transistor analogous to an electronic one made of a VO2 base placed between two silica semi-infinite plates playing the roles of the transistor collector and emitter. The fact that VO2 exhibits an insulator to metal transition is exploited to modulate and/or amplify heat fluxes between the emitter and the collector, by applying a thermal current on the VO2 base. We extend the work of precedent studies considering the case where the base can be semi-transparent so that heat can be exchanged directly between the collector and the emitter. Both near and far field cases are considered leading to 4 typical regimes resulting from the fact that the emitter-base and base-collector separation distances can be larger or smaller than the thermal wavelength for a VO2 layer opaque or semi-transparent. Thermal currents variations with the base temperatures are calculated and analyzed. It is found that the transistor can operate in an amplification mode as already stated in [1] or in a switching mode as seen in [2]. An optimum configuration for the base thickness and separation distance maximizing the thermal transistor modulation factor is found.

Facilitators' perceptions of problem-based learning and community-based education

Directory of Open Access Journals (Sweden)

Annali E Fichardt

2000-10-01

Full Text Available In 1997 the School for Nursing, University of the Orange Free State, changed from the traditional lecture method of teaching to problem-based learning and from a curative to a community-based approach. Lecturers from a traditional environment became facilitators and new skills such as listening, dialogue, negotiation, counselling and problemsolving were expected from them. Besides the role change, the environment changed from a structural classroom to an unstructured community. The aim of this research was to determine the perceptions and experiences of facilitators in problem-based learning and community-base education. *Please note: This is a reduced version of the abstract. Please refer to PDF for full text.

Frame-based safety analysis approach for decision-based errors

International Nuclear Information System (INIS)

Fan, Chin-Feng; Yihb, Swu

1997-01-01

A frame-based approach is proposed to analyze decision-based errors made by automatic controllers or human operators due to erroneous reference frames. An integrated framework, Two Frame Model (TFM), is first proposed to model the dynamic interaction between the physical process and the decision-making process. Two important issues, consistency and competing processes, are raised. Consistency between the physical and logic frames makes a TFM-based system work properly. Loss of consistency refers to the failure mode that the logic frame does not accurately reflect the state of the controlled processes. Once such failure occurs, hazards may arise. Among potential hazards, the competing effect between the controller and the controlled process is the most severe one, which may jeopardize a defense-in-depth design. When the logic and physical frames are inconsistent, conventional safety analysis techniques are inadequate. We propose Frame-based Fault Tree; Analysis (FFTA) and Frame-based Event Tree Analysis (FETA) under TFM to deduce the context for decision errors and to separately generate the evolution of the logical frame as opposed to that of the physical frame. This multi-dimensional analysis approach, different from the conventional correctness-centred approach, provides a panoramic view in scenario generation. Case studies using the proposed techniques are also given to demonstrate their usage and feasibility

From conventional software based systems to knowledge based systems

International Nuclear Information System (INIS)

Bologna, S.

1995-01-01

Even if todays nuclear power plants have a very good safety record, there is a continuous search for still improving safety. One direction of this effort address operational safety, trying to improve the handling of disturbances and accidents partly by further automation, partly by creating a better control room environment, providing the operator with intelligent support systems to help in the decision making process. Introduction of intelligent computerised operator support systems has proved to be an efficient way of improving the operators performance. A number of systems have been developed worldwide, assisting in tasks like process fault detection and diagnosis, selection and implementation of proper remedial actions. Unfortunately, the use of Knowledge Based Systems (KBSs), introduces a new dimension to the problem of the licensing process. KBSs, despite the different technology employed, are still nothing more than a computer program. Unfortunately, quite a few people building knowledge based systems seem to ignore the many good programming practices that have evolved over the years for producing traditional computer programs. In this paper the author will try to point out similarities and differences between conventional software based systems, and knowledge based systems, introducing also the concept of model based reasoning. (orig.) (25 refs., 2 figs.)

Case-based reasoning

CERN Document Server

Kolodner, Janet

1993-01-01

Case-based reasoning is one of the fastest growing areas in the field of knowledge-based systems and this book, authored by a leader in the field, is the first comprehensive text on the subject. Case-based reasoning systems are systems that store information about situations in their memory. As new problems arise, similar situations are searched out to help solve these problems. Problems are understood and inferences are made by finding the closest cases in memory, comparing and contrasting the problem with those cases, making inferences based on those comparisons, and asking questions whe

Lotus Base

DEFF Research Database (Denmark)

Mun, Terry; Bachmann, Asger; Gupta, Vikas

2016-01-01

exploration of Lotus genomic and transcriptomic data. Equally important are user-friendly in-browser tools designed for data visualization and interpretation. Here, we present Lotus Base, which opens to the research community a large, established LORE1 insertion mutant population containing an excess of 120...... such data, allowing users to construct, visualize, and annotate co-expression gene networks. Lotus Base takes advantage of modern advances in browser technology to deliver powerful data interpretation for biologists. Its modular construction and publicly available application programming interface enable...... developers to tap into the wealth of integrated Lotus data. Lotus Base is freely accessible at: https://lotus.au.dk....

Three dimensional pattern recognition using feature-based indexing and rule-based search

Science.gov (United States)

Lee, Jae-Kyu

In flexible automated manufacturing, robots can perform routine operations as well as recover from atypical events, provided that process-relevant information is available to the robot controller. Real time vision is among the most versatile sensing tools, yet the reliability of machine-based scene interpretation can be questionable. The effort described here is focused on the development of machine-based vision methods to support autonomous nuclear fuel manufacturing operations in hot cells. This thesis presents a method to efficiently recognize 3D objects from 2D images based on feature-based indexing. Object recognition is the identification of correspondences between parts of a current scene and stored views of known objects, using chains of segments or indexing vectors. To create indexed object models, characteristic model image features are extracted during preprocessing. Feature vectors representing model object contours are acquired from several points of view around each object and stored. Recognition is the process of matching stored views with features or patterns detected in a test scene. Two sets of algorithms were developed, one for preprocessing and indexed database creation, and one for pattern searching and matching during recognition. At recognition time, those indexing vectors with the highest match probability are retrieved from the model image database, using a nearest neighbor search algorithm. The nearest neighbor search predicts the best possible match candidates. Extended searches are guided by a search strategy that employs knowledge-base (KB) selection criteria. The knowledge-based system simplifies the recognition process and minimizes the number of iterations and memory usage. Novel contributions include the use of a feature-based indexing data structure together with a knowledge base. Both components improve the efficiency of the recognition process by improved structuring of the database of object features and reducing data base size

NSCT BASED LOCAL ENHANCEMENT FOR ACTIVE CONTOUR BASED IMAGE SEGMENTATION APPLICATION

Directory of Open Access Journals (Sweden)

Hiren Mewada

2010-08-01

Full Text Available Because of cross-disciplinary nature, Active Contour modeling techniques have been utilized extensively for the image segmentation. In traditional active contour based segmentation techniques based on level set methods, the energy functions are defined based on the intensity gradient. This makes them highly sensitive to the situation where the underlying image content is characterized by image nonhomogeneities due to illumination and contrast condition. This is the most difficult problem to make them as fully automatic image segmentation techniques. This paper introduces one of the approaches based on image enhancement to this problem. The enhanced image is obtained using NonSubsampled Contourlet Transform, which improves the edges strengths in the direction where the illumination is not proper and then active contour model based on level set technique is utilized to segment the object. Experiment results demonstrate that proposed method can be utilized along with existing active contour model based segmentation method under situation characterized by intensity non-homogeneity to make them fully automatic.

Data base EQDB - data base of the qualified equipment's for NPP

International Nuclear Information System (INIS)

Rovny, K.

2009-01-01

In the contribution, there is presented the project of the data base for qualified equipment's for nuclear power plants. The data base is operated by the 'Certification body which certified the products - the chosen equipment's for nuclear power plants', reg. No. P-028, at VUJE, Inc. Trnava. Data base will serve to the designers, the operators of the nuclear power plants and the workers from Nuclear regulatory authority of the Slovak Republic as a source of information about the state of concrete type equipment's qualification. In the first part of the contribution, there is information about the legislation and technical requirements for equipment's qualification, the way of demonstration and importance of the qualification for the operator. In the next part, there is presented the own structure of data base and the works with own data base regarding the examples of concrete equipment's. The data base will be accessible after the free registration on address WWW.EQDB.sk from 1.5.2009

Evidence-based radiography

International Nuclear Information System (INIS)

Hafslund, Bjorg; Clare, Judith; Graverholt, Birgitte; Wammen Nortvedt, Monica

2008-01-01

Evidence-based practice (EBP) offers the integration of the best research evidence with clinical knowledge and expertise and patient values. EBP is a well known term in health care. This paper discusses the implementation of EBP into radiography and introduces the term evidence-based radiography. Evidence-based radiography is radiography informed and based on the combination of clinical expertise and the best available research-based evidence, patient preferences and resources available. In Norway, EBP in radiography is being debated and radiographers are discussing the challenges of implementing EBP in both academic and clinical practice. This discussion paper explains why EBP needs to be a basis for a radiography curriculum and a part of radiographers' practice. We argue that Norwegian radiographers must increase participation in research and developing practice within their specific radiographic domain

Competency-Based Teaching in Radiology - Implementation and Evaluation of Interactive Workstation-Based Learning to Apply NKLM-Based Content.

Science.gov (United States)

Koestner, Wolfgang; Otten, Wiebke; Kaireit, Till; Wacker, Frank K; Dettmer, Sabine

2017-11-01

Purpose  New teaching formats are required to implement competency-based teaching in radiology teaching. Therefore, we have established and evaluated two practical competency-based radiological courses. Materials and Methods  The courses were held in a multimedia room with 25 computers and a professional DICOM viewer. Students were taught basic image analysis and presented clinical cases with a DICOM viewer under supervision of an instructor using desktop monitoring software. Two courses (elective course and obligatory course) were evaluated by the students (n = 160 and n = 100) and instructors (n = 9) using an anonymized online survey. Results  Courses were evaluated positively by the students and instructors. From the perspective of the students, the courses increased understanding of cross-sectional anatomy (elective/obligatory course: 97 %/95 %) and radiologic findings (97 %/99 %). Furthermore, the course increased the students' interest in radiology (61 %/65 %). The students considered this way of teaching to be relevant to their future occupation (92 % of students in the obligatory course). The higher incidence of teacher-student interaction and the possibility of independent image analysis were rated positively. The majority of instructors did not observe increased distractibility due to the computers (67 %) or notice worse preparation for MC tests (56 %). However, 56 % of instructors reported greater preparation effort. Conclusion  Practical competency-based radiological teaching using a DICOM viewer is a feasible innovative approach with high acceptance among students and instructors. It fosters competency-based learning as proposed by the model curriculum of the German Radiological Society (DRG) and the National Competency-based Catalogue of Learning Objectives for Undergraduate Medical Education (NKLM). Key Points   · Practical competency-based radiological teaching is highly accepted by students and instructors

Cultural and Rhetorical Bases for communicating knowledge in web based communities

DEFF Research Database (Denmark)

Kampf, Constance; Kommers, Piet

2008-01-01

Cultural and Rhetorical Bases for communicating knowledge in web based communities How can we extend learner-centred theories for educational technology to include, for instance, the cultural and rhetorical backgrounds which influence participants in online communities as they engage in knowledge...... via web-based communities the intersection of culture and rhetoric in web-based communication rhetoric and discourse in the process of communicating knowledge via technology heuristics for knowledge communication from teaching in online forums connections between identity and knowledge communication...... This call for papers invites papers focused on theoretical frameworks or empirical research which highlights the cultural and/or rhetorical aspects of communicating knowledge in web based communities. We are looking for work that brings together methods and perspectives across disciplines...

Characteristics Data Base: Programmer's guide to the High-Level Waste Data Base

International Nuclear Information System (INIS)

Jones, K.E.; Salmon, R.

1990-08-01

The High-Level Waste Data Base is a menu-driven PC data base developed as part of OCRWM's technical data base on the characteristics of potential repository wastes, which also includes spent fuel and other materials. This programmer's guide completes the documentation for the High-Level Waste Data Base, the user's guide having been published previously. 3 figs

An Alternative Collaborative Supervision Practice between University-Based Teachers and School-Based Teachers

Science.gov (United States)

Steele, Annfrid R.

2017-01-01

There is an increased focus in teacher education on research-based teaching as a means to develop a more research-based professional knowledge. However, research from several Western countries shows that neither school-based nor university-based teachers are familiar with how to integrate research-based knowledge in professional teacher practice.…

Paper based electronics platform

KAUST Repository

Nassar, Joanna Mohammad; Sevilla, Galo Andres Torres; Hussain, Muhammad Mustafa

2017-01-01

A flexible and non-functionalized low cost paper-based electronic system platform fabricated from common paper, such as paper based sensors, and methods of producing paper based sensors, and methods of sensing using the paper based sensors

Cholinesterase-based biosensors.

Science.gov (United States)

Štěpánková, Šárka; Vorčáková, Katarína

2016-01-01

Recently, cholinesterase-based biosensors are widely used for assaying anticholinergic compounds. Primarily biosensors based on enzyme inhibition are useful analytical tools for fast screening of inhibitors, such as organophosphates and carbamates. The present review is aimed at compilation of the most important facts about cholinesterase based biosensors, types of physico-chemical transduction, immobilization strategies and practical applications.

Strengths-based Learning

DEFF Research Database (Denmark)

Ledertoug, Mette Marie

-being. The Ph.D.-project in Strength-based learning took place in a Danish school with 750 pupils age 6-16 and a similar school was functioning as a control group. The presentation will focus on both the aware-explore-apply processes and the practical implications for the schools involved, and on measurable......Strength-based learning - Children͛s Character Strengths as Means to their Learning Potential͛ is a Ph.D.-project aiming to create a strength-based mindset in school settings and at the same time introducing strength-based interventions as specific tools to improve both learning and well...

Using Web-Based Peer Benchmarking to Manage the Client-Based Project

Science.gov (United States)

Raska, David; Keller, Eileen Weisenbach; Shaw, Doris

2013-01-01

The complexities of integrating client-based projects into marketing courses provide challenges for the instructor but produce richness of context and active learning for the student. This paper explains the integration of Web-based peer benchmarking as a means of improving student performance on client-based projects within a single semester in…

Novel nonlinear knowledge-based mean force potentials based on machine learning.

Science.gov (United States)

Dong, Qiwen; Zhou, Shuigeng

2011-01-01

The prediction of 3D structures of proteins from amino acid sequences is one of the most challenging problems in molecular biology. An essential task for solving this problem with coarse-grained models is to deduce effective interaction potentials. The development and evaluation of new energy functions is critical to accurately modeling the properties of biological macromolecules. Knowledge-based mean force potentials are derived from statistical analysis of proteins of known structures. Current knowledge-based potentials are almost in the form of weighted linear sum of interaction pairs. In this study, a class of novel nonlinear knowledge-based mean force potentials is presented. The potential parameters are obtained by nonlinear classifiers, instead of relative frequencies of interaction pairs against a reference state or linear classifiers. The support vector machine is used to derive the potential parameters on data sets that contain both native structures and decoy structures. Five knowledge-based mean force Boltzmann-based or linear potentials are introduced and their corresponding nonlinear potentials are implemented. They are the DIH potential (single-body residue-level Boltzmann-based potential), the DFIRE-SCM potential (two-body residue-level Boltzmann-based potential), the FS potential (two-body atom-level Boltzmann-based potential), the HR potential (two-body residue-level linear potential), and the T32S3 potential (two-body atom-level linear potential). Experiments are performed on well-established decoy sets, including the LKF data set, the CASP7 data set, and the Decoys “R”Us data set. The evaluation metrics include the energy Z score and the ability of each potential to discriminate native structures from a set of decoy structures. Experimental results show that all nonlinear potentials significantly outperform the corresponding Boltzmann-based or linear potentials, and the proposed discriminative framework is effective in developing knowledge-based

Using bio-based polymers for curing cement-based materials

NARCIS (Netherlands)

Zlopasa, J.; Koenders, E.A.B.; Picken, S.J.

2014-01-01

Curing is the process of controlling the rate and extent of moisture loss from the surface of cement based materials. It is the final stage in the production of cement-based materials and it is the essential part for achieving continuous hydration of cement, while avoiding cracking due to drying

Carbon-based sputtered coatings for enhanced chitosan-based films properties

Science.gov (United States)

Fernandes, C.; Calderon V., S.; Ballesteros, Lina F.; Cerqueira, Miguel A.; Pastrana, L. M.; Teixeira, José A.; Ferreira, P. J.; Carvalho, S.

2018-03-01

In order to make bio-based packaging materials competitive in comparison to petroleum-based one, some of their properties need to be improved, among which gas permeability is of crucial importance. Thus, in this work, carbon-based coatings were applied on chitosan-based films by radiofrequency reactive magnetron sputtering aiming to improve their barrier properties. Chemical and morphological properties were evaluated in order to determine the effect of the coatings on the chemical structure, surface hydrophobicity and barrier properties of the system. Chemical analysis, performed by electron energy loss spectroscopy and Fourier transform infrared spectroscopy, suggests similar chemical characteristics among all coatings although higher incorporation of hydrogen as the acetylene flux increases was observed. On the other hand, scanning transmission electron microscopy revealed that the porosity of the carbon layer can be tailored by the acetylene flux. More importantly, the chitosan oxygen permeability showed a monotonic reduction as a function of the acetylene flux. This study opens up new opportunities to apply nanostructured coatings on bio-based polymer for enhanced oxygen barrier properties.

Computer-based teaching is as good as face to face lecture-based teaching of evidence based medicine: a randomised controlled trial

Science.gov (United States)

2007-01-01

Background At postgraduate level evidence based medicine (EBM) is currently taught through tutor based lectures. Computer based sessions fit around doctors' workloads, and standardise the quality of educational provision. There have been no randomized controlled trials comparing computer based sessions with traditional lectures at postgraduate level within medicine. Methods This was a randomised controlled trial involving six postgraduate education centres in the West Midlands, U.K. Fifty five newly qualified foundation year one doctors (U.S internship equivalent) were randomised to either computer based sessions or an equivalent lecture in EBM and systematic reviews. The change from pre to post-intervention score was measured using a validated questionnaire assessing knowledge (primary outcome) and attitudes (secondary outcome). Results Both groups were similar at baseline. Participants' improvement in knowledge in the computer based group was equivalent to the lecture based group (gain in score: 2.1 [S.D = 2.0] versus 1.9 [S.D = 2.4]; ANCOVA p = 0.078). Attitudinal gains were similar in both groups. Conclusion On the basis of our findings we feel computer based teaching and learning is as effective as typical lecture based teaching sessions for educating postgraduates in EBM and systematic reviews. PMID:17659076

A model-based framework for design of intensified enzyme-based processes

DEFF Research Database (Denmark)

Román-Martinez, Alicia

This thesis presents a generic and systematic model-based framework to design intensified enzyme-based processes. The development of the presented methodology was motivated by the needs of the bio-based industry for a more systematic approach to achieve intensification in its production plants...... in enzyme-based processes which have found significant application in the pharmaceutical, food, and renewable fuels sector. The framework uses model-based strategies for (bio)-chemical process design and optimization, including the use of a superstructure to generate all potential reaction......(s)-separation(s) options according to a desired performance criteria and a generic mathematical model represented by the superstructure to derive the specific models corresponding to a specific process option. In principle, three methods of intensification of bioprocess are considered in this thesis: 1. enzymatic one...

Stolen Base Physics

Science.gov (United States)

Kagan, David

2013-01-01

Few plays in baseball are as consistently close and exciting as the stolen base. While there are several studies of sprinting, the art of base stealing is much more nuanced. This article describes the motion of the base-stealing runner using a very basic kinematic model. The model will be compared to some data from a Major League game. The…

An Evidence-Based Assessment of Faith-Based Programs: Do Faith-Based Programs "Work" to Reduce Recidivism?

Science.gov (United States)

Dodson, Kimberly D.; Cabage, Leann N.; Klenowski, Paul M.

2011-01-01

Faith-based organizations administer many of the prison-based programs aimed at reducing recidivism. Many of these organizations also manage treatment programs for substance abusers, at-risk juveniles, and ex-offenders. Much of the research on religiosity and delinquency indicates that the two are inversely related. Therefore, it seems plausible…

Case-based reasoning diagnostic technique based on multi-attribute similarity

Energy Technology Data Exchange (ETDEWEB)

Makoto, Takahashi [Tohoku University, Miyagi (Japan); Akio, Gofuku [Okayama University, Okayamaa (Japan)

2014-08-15

Case-based diagnostic technique has been developed based on the multi-attribute similarity. Specific feature of the developed system is to use multiple attributes of process signals for similarity evaluation to retrieve a similar case stored in a case base. The present technique has been applied to the measurement data from Monju with some simulated anomalies. The results of numerical experiments showed that the present technique can be utilizes as one of the methods for a hybrid-type diagnosis system.

Risk-based safety indicators

International Nuclear Information System (INIS)

Szikszai, T.

1997-01-01

The presentation discusses the following issues: The objectives of the risk-based indicator programme. The characteristics of the risk-based indicators. The objectives of risk-based safety indicators - in monitoring safety; in PSA applications. What indicators? How to produce the risk based indicators? PSA requirements

Supporting Case-Based Learning in Information Security with Web-Based Technology

Science.gov (United States)

He, Wu; Yuan, Xiaohong; Yang, Li

2013-01-01

Case-based learning has been widely used in many disciplines. As an effective pedagogical method, case-based learning is also being used to support teaching and learning in the domain of information security. In this paper, we demonstrate case-based learning in information security by sharing our experiences in using a case study to teach security…

A web-based data-querying tool based on ontology-driven methodology and flowchart-based model.

Science.gov (United States)

Ping, Xiao-Ou; Chung, Yufang; Tseng, Yi-Ju; Liang, Ja-Der; Yang, Pei-Ming; Huang, Guan-Tarn; Lai, Feipei

2013-10-08

Because of the increased adoption rate of electronic medical record (EMR) systems, more health care records have been increasingly accumulating in clinical data repositories. Therefore, querying the data stored in these repositories is crucial for retrieving the knowledge from such large volumes of clinical data. The aim of this study is to develop a Web-based approach for enriching the capabilities of the data-querying system along the three following considerations: (1) the interface design used for query formulation, (2) the representation of query results, and (3) the models used for formulating query criteria. The Guideline Interchange Format version 3.5 (GLIF3.5), an ontology-driven clinical guideline representation language, was used for formulating the query tasks based on the GLIF3.5 flowchart in the Protégé environment. The flowchart-based data-querying model (FBDQM) query execution engine was developed and implemented for executing queries and presenting the results through a visual and graphical interface. To examine a broad variety of patient data, the clinical data generator was implemented to automatically generate the clinical data in the repository, and the generated data, thereby, were employed to evaluate the system. The accuracy and time performance of the system for three medical query tasks relevant to liver cancer were evaluated based on the clinical data generator in the experiments with varying numbers of patients. In this study, a prototype system was developed to test the feasibility of applying a methodology for building a query execution engine using FBDQMs by formulating query tasks using the existing GLIF. The FBDQM-based query execution engine was used to successfully retrieve the clinical data based on the query tasks formatted using the GLIF3.5 in the experiments with varying numbers of patients. The accuracy of the three queries (ie, "degree of liver damage," "degree of liver damage when applying a mutually exclusive setting

Feature-Based Analysis of Plasma-Based Particle Acceleration Data

Energy Technology Data Exchange (ETDEWEB)

Rubel, Oliver [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Geddes, Cameron G. R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chen, Min [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cormier-Michel, Estelle [Tech-X Corp., Boulder, CO (United States); Bethel, E. Wes [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2014-02-01

Plasma-based particle accelerators can produce and sustain thousands of times stronger acceleration fields than conventional particle accelerators, providing a potential solution to the problem of the growing size and cost of conventional particle accelerators. To facilitate scientific knowledge discovery from the ever growing collections of accelerator simulation data generated by accelerator physicists to investigate next-generation plasma-based particle accelerator designs, we describe a novel approach for automatic detection and classification of particle beams and beam substructures due to temporal differences in the acceleration process, here called acceleration features. The automatic feature detection in combination with a novel visualization tool for fast, intuitive, query-based exploration of acceleration features enables an effective top-down data exploration process, starting from a high-level, feature-based view down to the level of individual particles. We describe the application of our analysis in practice to analyze simulations of single pulse and dual and triple colliding pulse accelerator designs, and to study the formation and evolution of particle beams, to compare substructures of a beam and to investigate transverse particle loss.

Convex-based void filling method for CAD-based Monte Carlo geometry modeling

International Nuclear Information System (INIS)

Yu, Shengpeng; Cheng, Mengyun; Song, Jing; Long, Pengcheng; Hu, Liqin

2015-01-01

Highlights: • We present a new void filling method named CVF for CAD based MC geometry modeling. • We describe convex based void description based and quality-based space subdivision. • The results showed improvements provided by CVF for both modeling and MC calculation efficiency. - Abstract: CAD based automatic geometry modeling tools have been widely applied to generate Monte Carlo (MC) calculation geometry for complex systems according to CAD models. Automatic void filling is one of the main functions in the CAD based MC geometry modeling tools, because the void space between parts in CAD models is traditionally not modeled while MC codes such as MCNP need all the problem space to be described. A dedicated void filling method, named Convex-based Void Filling (CVF), is proposed in this study for efficient void filling and concise void descriptions. The method subdivides all the problem space into disjointed regions using Quality based Subdivision (QS) and describes the void space in each region with complementary descriptions of the convex volumes intersecting with that region. It has been implemented in SuperMC/MCAM, the Multiple-Physics Coupling Analysis Modeling Program, and tested on International Thermonuclear Experimental Reactor (ITER) Alite model. The results showed that the new method reduced both automatic modeling time and MC calculation time

Knowledge base mechanisms

Energy Technology Data Exchange (ETDEWEB)

Suwa, M; Furukawa, K; Makinouchi, A; Mizoguchi, T; Mizoguchi, F; Yamasaki, H

1982-01-01

One of the principal goals of the Fifth Generation Computer System Project for the coming decade is to develop a methodology for building knowledge information processing systems which will provide people with intelligent agents. The key notion of the fifth generation computer system is knowledge used for problem solving. In this paper the authors describe the plan of Randd on knowledge base mechanisms. A knowledge representation system is to be designed to support knowledge acquisition for the knowledge information processing systems. The system will include a knowledge representation language, a knowledge base editor and a debugger. It is also expected to perform as a kind of meta-inference system. In order to develop the large scale knowledge base systems, a knowledge base mechanism based on the relational model is to be studied in the earlier stage of the project. Distributed problem solving is also one of the main issues of the project. 19 references.

Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

Science.gov (United States)

Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

2016-05-03

A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

Comparing grapheme-based and phoneme-based speech recognition for Afrikaans

CSIR Research Space (South Africa)

Basson, WD

2012-11-01

Full Text Available This paper compares the recognition accuracy of a phoneme-based automatic speech recognition system with that of a grapheme-based system, using Afrikaans as case study. The first system is developed using a conventional pronunciation dictionary...

Culture and group-based emotions: could group-based emotions be dialectical?

Science.gov (United States)

Lu, Minjie; Hamamura, Takeshi; Doosje, Bertjan; Suzuki, Satoko; Takemura, Kosuke

2017-08-01

Group-based emotions are experienced when individuals are engaged in emotion-provoking events that implicate the in-group. This research examines the complexity of group-based emotions, specifically a concurrence of positive and negative emotions, focusing on the role of dialecticism, or a set of folk beliefs prevalent in Asian cultures that views nature and objects as constantly changing, inherently contradictory, and fundamentally interconnected. Study 1 found that dialecticism is positively associated with the complexity of Chinese participants' group-based emotions after reading a scenario depicting a positive intergroup experience. Study 2 found that Chinese participants experienced more complex group-based emotions compared with Dutch participants in an intergroup situation and that this cultural difference was mediated by dialecticism. Study 3 manipulated dialecticism and confirmed its causal effect on complex group-based emotions. These studies also suggested the role of a balanced appraisal of an intergroup situation as a mediating factor.

Interdisciplinarity in translation teaching: competence-based education, translation task-based approach, context-based text typology

Directory of Open Access Journals (Sweden)

Edelweiss Vitol Gysel

2017-05-01

Full Text Available In the context of competence-based teaching, this paper draws upon the model of Translation Competence (TC put forward by the PACTE group (2003 to establish a dialogue between cognitive-constructivist paradigms for translation teaching and the model of the Context-based Text Typology (MATTHIESSEN et al., 2007. In this theoretical environment, it proposes a model for the design of a Teaching Unit (TU for the development of the bilingual competence in would-be-translators.To this end, it explores translation as a cognitive, communicative and textual activity (HURTADO ALBIR, 2011 and considers its teaching from the translation task-based approach (HURTADO ALBIR, 1999. This approach is illustrated through the practical example of the design of a TU elaborated for the subject ‘Introduction to Specialized Translation’,part of the curricular grid of the program ‘Secretariado Executivo’ at Universidade Federal de Santa Catarina. Aspects such as the establishment of learning objectives and their alignment with the translation tasks composing the TU are addressed for this specific pedagogical situation. We argue for the development of textual competences by means of the acquisition of strategies derived from the Context-based Text Typology to solve problems arising from the translation of different text types and contextual configurations.

Evidence-Based Toxicology.

Science.gov (United States)

Hoffmann, Sebastian; Hartung, Thomas; Stephens, Martin

Evidence-based toxicology (EBT) was introduced independently by two groups in 2005, in the context of toxicological risk assessment and causation as well as based on parallels between the evaluation of test methods in toxicology and evidence-based assessment of diagnostics tests in medicine. The role model of evidence-based medicine (EBM) motivated both proposals and guided the evolution of EBT, whereas especially systematic reviews and evidence quality assessment attract considerable attention in toxicology.Regarding test assessment, in the search of solutions for various problems related to validation, such as the imperfectness of the reference standard or the challenge to comprehensively evaluate tests, the field of Diagnostic Test Assessment (DTA) was identified as a potential resource. DTA being an EBM discipline, test method assessment/validation therefore became one of the main drivers spurring the development of EBT.In the context of pathway-based toxicology, EBT approaches, given their objectivity, transparency and consistency, have been proposed to be used for carrying out a (retrospective) mechanistic validation.In summary, implementation of more evidence-based approaches may provide the tools necessary to adapt the assessment/validation of toxicological test methods and testing strategies to face the challenges of toxicology in the twenty first century.

Aperiodic-metamaterial-based absorber

Directory of Open Access Journals (Sweden)

Quanlong Yang

2017-09-01

Full Text Available The periodic-metamaterial-based perfect absorber has been studied broadly. Conversely, if the unit cell in the metamaterial-based absorber is arranged aperiodically (aperiodic-metamaterial-based absorber, how does it perform? Inspired by this, here we present a systematic study of the aperiodic-metamaterial-based absorber. By investigating the response of metamaterial absorbers based on periodic, Fibonacci, Thue-Morse, and quasicrystal lattices, we found that aperiodic-metamaterial-based absorbers could display similar absorption behaviors as the periodic one in one hand. However, their absorption behaviors show different tendency depending on the thicknesses of the spacer. Further studies on the angle and polarization dependence of the absorption behavior are also presented.

Concurrent array-based queue

Science.gov (United States)

Heidelberger, Philip; Steinmacher-Burow, Burkhard

2015-01-06

According to one embodiment, a method for implementing an array-based queue in memory of a memory system that includes a controller includes configuring, in the memory, metadata of the array-based queue. The configuring comprises defining, in metadata, an array start location in the memory for the array-based queue, defining, in the metadata, an array size for the array-based queue, defining, in the metadata, a queue top for the array-based queue and defining, in the metadata, a queue bottom for the array-based queue. The method also includes the controller serving a request for an operation on the queue, the request providing the location in the memory of the metadata of the queue.

Metal-mediated DNA base pairing: alternatives to hydrogen-bonded Watson-Crick base pairs.

Science.gov (United States)

Takezawa, Yusuke; Shionoya, Mitsuhiko

2012-12-18

With its capacity to store and transfer the genetic information within a sequence of monomers, DNA forms its central role in chemical evolution through replication and amplification. This elegant behavior is largely based on highly specific molecular recognition between nucleobases through the specific hydrogen bonds in the Watson-Crick base pairing system. While the native base pairs have been amazingly sophisticated through the long history of evolution, synthetic chemists have devoted considerable efforts to create alternative base pairing systems in recent decades. Most of these new systems were designed based on the shape complementarity of the pairs or the rearrangement of hydrogen-bonding patterns. We wondered whether metal coordination could serve as an alternative driving force for DNA base pairing and why hydrogen bonding was selected on Earth in the course of molecular evolution. Therefore, we envisioned an alternative design strategy: we replaced hydrogen bonding with another important scheme in biological systems, metal-coordination bonding. In this Account, we provide an overview of the chemistry of metal-mediated base pairing including basic concepts, molecular design, characteristic structures and properties, and possible applications of DNA-based molecular systems. We describe several examples of artificial metal-mediated base pairs, such as Cu(2+)-mediated hydroxypyridone base pair, H-Cu(2+)-H (where H denotes a hydroxypyridone-bearing nucleoside), developed by us and other researchers. To design the metallo-base pairs we carefully chose appropriate combinations of ligand-bearing nucleosides and metal ions. As expected from their stronger bonding through metal coordination, DNA duplexes possessing metallo-base pairs exhibited higher thermal stability than natural hydrogen-bonded DNAs. Furthermore, we could also use metal-mediated base pairs to construct or induce other high-order structures. These features could lead to metal-responsive functional

Selective Sequential Zero-Base Budgeting Procedures Based on Total Factor Productivity Indicators

OpenAIRE

A. Ishikawa; E. F. Sudit

1981-01-01

The authors' purpose in this paper is to develop productivity-based sequential budgeting procedures designed to expedite identification of major problem areas in bugetary performance, as well as to reduce the costs associated with comprehensive zero-base analyses. The concept of total factor productivity is reviewed and its relations to ordinary and zero-based budgeting are discussed in detail. An outline for a selective sequential analysis based on monitoring of three key indicators of (a) i...

Replacing fossil based plastic performance products by bio-based plastic products-Technical feasibility.

Science.gov (United States)

van den Oever, Martien; Molenveld, Karin

2017-07-25

Larger scale market introduction of new bio-based products requires a clear advantage regarding sustainability, as well as an adequate techno-economic positioning relative to fossil based products. In a previous paper [Broeren et al., 2016], LCA results per kg and per functionality equivalent of bio-based plastics were presented, together with economic considerations. The present paper discusses the mechanical and thermal properties of a range of commercially available bio-based plastics based on polylactic acid (PLA), cellulose esters, starch and polyamides, and the feasibility of replacing fossil-based counterparts based on performance. The evaluation is approached from an end user perspective. First, potentially suitable bio-based plastics are selected based on manufacturers' specifications in technical data sheets, then a first experimental evaluation is performed on injection moulded ISO specimens, and finally a further selection of plastics is tested on large 50×70cm panels. This technical feasibility study indicates that so far bio-based plastics do not completely match the properties of high performance materials like flame retardant V-0 PC/ABS blends used in electronic devices. The performance gap is being decreased by the development of stereocomplex PLA and hybrid PLA blends with polycarbonate, which offer clearly improved properties with respect to maximum usage temperature and toughness. In addition, several materials meet the V-0 flammability requirements needed in specific durable applications. On the other hand, improving these properties so far has negative consequences for the bio-based content. This study also shows that replacement of bulk polymers like PS is feasible using PLA compounds with a bio-based content as high as 85%. Copyright © 2016 Elsevier B.V. All rights reserved.

From scientifically based research to evidence based learning

Directory of Open Access Journals (Sweden)

Rosa Cera

2016-02-01

Full Text Available This essay is a reflection on the peculiarities of the scientifically based research and on the distinctive elements of the EBL (evidence based learning, methodology used in the study on the “Relationship between Metacognition, Self-efficacy and Self-regulation in Learning”. The EBL method, based on the standardization of data, explains how the students’ learning experience can be considered as a set of “data” and can be used to explain how and when the research results can be considered generalizable and transferable to other learning situations. The reflections present in this study have also allowed us to illustrate the impact that its results have had on the micro and macro level of reality. They helped to fill in the gaps concerning the learning/teaching processes, contributed to the enrichment of the scientific literature on this subject and allowed to establish standards through rigorous techniques such as systematic reviews and meta-analysis.

Space Launch System Base Heating Test: Environments and Base Flow Physics

Science.gov (United States)

Mehta, Manish; Knox, Kyle S.; Seaford, C. Mark; Dufrene, Aaron T.

2016-01-01

The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen- hydrogen rocket engines in the core-stage and two 5-segment solid rocket boosters and as a result six hot supersonic plumes interact within the aft section of the vehicle during ight. Due to the complex nature of rocket plume-induced ows within the launch vehicle base during ascent and a new vehicle con guration, sub-scale wind tunnel testing is required to reduce SLS base convective environment uncertainty and design risk levels. This hot- re test program was conducted at the CUBRC Large Energy National Shock (LENS) II short-duration test facility to simulate ight from altitudes of 50 kft to 210 kft. The test program is a challenging and innovative e ort that has not been attempted in 40+ years for a NASA vehicle. This presentation discusses the various trends of base convective heat ux and pressure as a function of altitude at various locations within the core-stage and booster base regions of the two-percent SLS wind tunnel model. In-depth understanding of the base ow physics is presented using the test data, infrared high-speed imaging and theory. The normalized test design environments are compared to various NASA semi- empirical numerical models to determine exceedance and conservatism of the ight scaled test-derived base design environments. Brief discussion of thermal impact to the launch vehicle base components is also presented.

The physics data base

International Nuclear Information System (INIS)

Gault, F.D.

1984-01-01

The physics data base is introduced along with its associated data base management system. The emphasis is on data and their use and a classification of data and of data bases is developed to distinguish compilation organizations. The characteristics of these organizations are examined briefly and the long term consequences of the physics data base discussed. (orig.)

Characteristic properties of Fibonacci-based mutually unbiased bases

Energy Technology Data Exchange (ETDEWEB)

Seyfarth, Ulrich; Alber, Gernot [Institut fuer Angewandte Physik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Ranade, Kedar [Institut fuer Quantenphysik, Universitaet Ulm, Albert-Einstein-Allee 11, 89069 Ulm (Germany)

2012-07-01

Complete sets of mutually unbiased bases (MUBs) offer interesting applications in quantum information processing ranging from quantum cryptography to quantum state tomography. Different construction schemes provide different perspectives on these bases which are typically also deeply connected to various mathematical research areas. In this talk we discuss characteristic properties resulting from a recently established connection between construction methods for cyclic MUBs and Fibonacci polynomials. As a remarkable fact this connection leads to construction methods which do not involve any relations to mathematical properties of finite fields.

Querying archetype-based EHRs by search ontology-based XPath engineering.

Science.gov (United States)

Kropf, Stefan; Uciteli, Alexandr; Schierle, Katrin; Krücken, Peter; Denecke, Kerstin; Herre, Heinrich

2018-05-11

Legacy data and new structured data can be stored in a standardized format as XML-based EHRs on XML databases. Querying documents on these databases is crucial for answering research questions. Instead of using free text searches, that lead to false positive results, the precision can be increased by constraining the search to certain parts of documents. A search ontology-based specification of queries on XML documents defines search concepts and relates them to parts in the XML document structure. Such query specification method is practically introduced and evaluated by applying concrete research questions formulated in natural language on a data collection for information retrieval purposes. The search is performed by search ontology-based XPath engineering that reuses ontologies and XML-related W3C standards. The key result is that the specification of research questions can be supported by the usage of search ontology-based XPath engineering. A deeper recognition of entities and a semantic understanding of the content is necessary for a further improvement of precision and recall. Key limitation is that the application of the introduced process requires skills in ontology and software development. In future, the time consuming ontology development could be overcome by implementing a new clinical role: the clinical ontologist. The introduced Search Ontology XML extension connects Search Terms to certain parts in XML documents and enables an ontology-based definition of queries. Search ontology-based XPath engineering can support research question answering by the specification of complex XPath expressions without deep syntax knowledge about XPaths.

Problem Based Learning

DEFF Research Database (Denmark)

de Graaff, Erik; Guerra, Aida

, the key principles remain the same everywhere. Graaff & Kolmos (2003) identify the main PBL principles as follows: 1. Problem orientation 2. Project organization through teams or group work 3. Participant-directed 4. Experiental learning 5. Activity-based learning 6. Interdisciplinary learning and 7...... model and in general problem based and project based learning. We apply the principle of teach as you preach. The poster aims to outline the visitors’ workshop programme showing the results of some recent evaluations.......Problem-Based Learning (PBL) is an innovative method to organize the learning process in such a way that the students actively engage in finding answers by themselves. During the past 40 years PBL has evolved and diversified resulting in a multitude in variations in models and practices. However...

High stability vector-based direct power control for DFIG-based wind turbine

DEFF Research Database (Denmark)

Zhu, Rongwu; Chen, Zhe; Wu, Xiaojie

2015-01-01

This paper proposes an improved vector-based direct power control (DPC) strategy for the doubly-fed induction generator (DFIG)-based wind energy conversion system. Based on the small signal model, the proposed DPC improves the stability of the DFIG, and avoids the DFIG operating in the marginal...

Research on Fault Diagnosis Method Based on Rule Base Neural Network

Directory of Open Access Journals (Sweden)

Zheng Ni

2017-01-01

Full Text Available The relationship between fault phenomenon and fault cause is always nonlinear, which influences the accuracy of fault location. And neural network is effective in dealing with nonlinear problem. In order to improve the efficiency of uncertain fault diagnosis based on neural network, a neural network fault diagnosis method based on rule base is put forward. At first, the structure of BP neural network is built and the learning rule is given. Then, the rule base is built by fuzzy theory. An improved fuzzy neural construction model is designed, in which the calculated methods of node function and membership function are also given. Simulation results confirm the effectiveness of this method.

A comparative review of petroleum-based and bio-based acrolein production.

Science.gov (United States)

Liu, Lu; Ye, X Philip; Bozell, Joseph J

2012-07-01

Acrolein is an important chemical intermediate for many common industrial chemicals, leading to an array of useful end products. This paper reviews all the synthetic methods, including the former (aldol condensation) and contemporary (partial oxidation of propylene) manufacturing methods, the partial oxidation of propane, and most importantly, the bio-based glycerol-dehydration route. Emphasis is placed on the petroleum-based route from propylene and the bio-based route from glycerol, an abundantly available and relatively inexpensive raw material available from biodiesel production. This review provides technical details and incentives for industrial proyduction that justify a transition toward bio-based acrolein production. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Value-based pricing

OpenAIRE

Netseva-Porcheva Tatyana

2010-01-01

The main aim of the paper is to present the value-based pricing. Therefore, the comparison between two approaches of pricing is made - cost-based pricing and value-based pricing. The 'Price sensitively meter' is presented. The other topic of the paper is the perceived value - meaning of the perceived value, the components of perceived value, the determination of perceived value and the increasing of perceived value. In addition, the best company strategies in matrix 'value-cost' are outlined. .

Research-based design & design-based research: Affordances, limitations and synergies

NARCIS (Netherlands)

McKenney, Susan

2015-01-01

Research-based design is an orientation to educational development that is explicitly informed by existing research as well as formative evaluation. Design-based research is a genre of inquiry in which the design of innovative solutions to problems in educational practice provides the context for

Autopsy practice in forensic pathology - Evidence-based or experience-based?

DEFF Research Database (Denmark)

Colville-Ebeling, Bonnie; Freeman, Michael; Banner, Jytte

2014-01-01

Current autopsy practice in forensic pathology is to a large extent based on experience and individual customary practices as opposed to evidence and consensus based practices. As a result there is the potential for substantial variation in how knowledge is applied in each case. In the present case......-gathering and the use of check lists specific to certain injury causes are likely to result in less deviation from evidence-based practices in forensic pathology. Pre-autopsy data-gathering and check lists will help ensure a higher degree of standardization in autopsy reports thus enhancing the quality and accuracy...

Value-based management: Theoretical base, shareholders' request and the concept

Directory of Open Access Journals (Sweden)

Kaličanin Đorđe M.

2005-01-01

Full Text Available The pressure of financial markets, which is a consequence of shareholder revolution, directly affects the solution to the following dilemma: is the mission of corporations to maximize shareholders' wealth or to satisfy interests of other stakeholders? The domination of shareholder theory has caused the appearance of the valuebased management concept. Value-based management is a relevant concept and a process of management in modern environment. The importance of shareholder value requires transformation of traditional enterprise into value driven enterprise. This paper addresses theoretical base, shareholder revolution and the main characteristics of value-based management.

Elucidating the hard/soft acid/base principle: A perspective based on half-reactions

International Nuclear Information System (INIS)

Ayers, Paul W.; Parr, Robert G.; Pearson, Ralph G.

2006-01-01

A comprehensive analysis is presented for the acid-base double-exchange reaction as well as the associated acid-displacement and base-displacement 'half-reactions' with the goal of elucidating the meaning of the hard/soft acid/base (HSAB) principle and the conditions for its validity. When electron-transfer effects are important and other effects are negligible, the HSAB principle is driven by the surpassing stability of the soft acid/soft base product. When electrostatic effects dominate the reactivity, the HSAB principle is driven by the surpassing stability of the hard acid/hard base product. Because electron-transfer effects favor soft/soft interactions, while electrostatic effects favor hard/hard interactions, acid-base exchange reactions may be used to determine whether a reagent's reactivity is dominated by electron-transfer or by electrostatic effects. Because electron-transfer and electrostatic considerations separately favor the HSAB principle whenever the electronic chemical potentials of the acids and bases involved in the reaction are similar, our analysis provides strong support for the HSAB principle. The electronic chemical potential measures the intrinsic strength of acids and bases

Base-By-Base: single nucleotide-level analysis of whole viral genome alignments.

Science.gov (United States)

Brodie, Ryan; Smith, Alex J; Roper, Rachel L; Tcherepanov, Vasily; Upton, Chris

2004-07-14

With ever increasing numbers of closely related virus genomes being sequenced, it has become desirable to be able to compare two genomes at a level more detailed than gene content because two strains of an organism may share the same set of predicted genes but still differ in their pathogenicity profiles. For example, detailed comparison of multiple isolates of the smallpox virus genome (each approximately 200 kb, with 200 genes) is not feasible without new bioinformatics tools. A software package, Base-By-Base, has been developed that provides visualization tools to enable researchers to 1) rapidly identify and correct alignment errors in large, multiple genome alignments; and 2) generate tabular and graphical output of differences between the genomes at the nucleotide level. Base-By-Base uses detailed annotation information about the aligned genomes and can list each predicted gene with nucleotide differences, display whether variations occur within promoter regions or coding regions and whether these changes result in amino acid substitutions. Base-By-Base can connect to our mySQL database (Virus Orthologous Clusters; VOCs) to retrieve detailed annotation information about the aligned genomes or use information from text files. Base-By-Base enables users to quickly and easily compare large viral genomes; it highlights small differences that may be responsible for important phenotypic differences such as virulence. It is available via the Internet using Java Web Start and runs on Macintosh, PC and Linux operating systems with the Java 1.4 virtual machine.

Value-based pricing

Directory of Open Access Journals (Sweden)

Netseva-Porcheva Tatyana

2010-01-01

Full Text Available The main aim of the paper is to present the value-based pricing. Therefore, the comparison between two approaches of pricing is made - cost-based pricing and value-based pricing. The 'Price sensitively meter' is presented. The other topic of the paper is the perceived value - meaning of the perceived value, the components of perceived value, the determination of perceived value and the increasing of perceived value. In addition, the best company strategies in matrix 'value-cost' are outlined. .

An Analysis of Delay-based and Integrator-based Sequence Detectors for Grid-Connected Converters

DEFF Research Database (Denmark)

Khazraj, Hesam; Silva, Filipe Miguel Faria da; Bak, Claus Leth

2017-01-01

-signal cancellation operators are the main members of the delay-based sequence detectors. The aim of this paper is to provide a theoretical and experimental comparative study between integrator and delay based sequence detectors. The theoretical analysis is conducted based on the small-signal modelling......Detecting and separating positive and negative sequence components of the grid voltage or current is of vital importance in the control of grid-connected power converters, HVDC systems, etc. To this end, several techniques have been proposed in recent years. These techniques can be broadly...... classified into two main classes: The integrator-based techniques and Delay-based techniques. The complex-coefficient filter-based technique, dual second-order generalized integrator-based method, multiple reference frame approach are the main members of the integrator-based sequence detector and the delay...

Gender-based violence and the need for evidence-based primary ...

African Journals Online (AJOL)

Gender-based violence is a significant problem globally and in South Africa. The public and political discourse has been dominated by calls for increased penalties and convictions for perpetrators of various types of gender-based violence. However, these responses are unlikely to prevent such violence from occurring in ...

Skull base tumours part I: Imaging technique, anatomy and anterior skull base tumours

Energy Technology Data Exchange (ETDEWEB)

Borges, Alexandra [Instituto Portugues de Oncologia Francisco Gentil, Centro de Lisboa, Servico de Radiologia, Rua Professor Lima Basto, 1093 Lisboa Codex (Portugal)], E-mail: borgesalexandra@clix.pt

2008-06-15

Advances in cross-sectional imaging, surgical technique and adjuvant treatment have largely contributed to ameliorate the prognosis, lessen the morbidity and mortality of patients with skull base tumours and to the growing medical investment in the management of these patients. Because clinical assessment of the skull base is limited, cross-sectional imaging became indispensable in the diagnosis, treatment planning and follow-up of patients with suspected skull base pathology and the radiologist is increasingly responsible for the fate of these patients. This review will focus on the advances in imaging technique; contribution to patient's management and on the imaging features of the most common tumours affecting the anterior skull base. Emphasis is given to a systematic approach to skull base pathology based upon an anatomic division taking into account the major tissue constituents in each skull base compartment. The most relevant information that should be conveyed to surgeons and radiation oncologists involved in patient's management will be discussed.

Applications of lipid based formulation technologies in the delivery of biotechnology-based therapeutics.

Science.gov (United States)

du Plessis, Lissinda H; Marais, Etienne B; Mohammed, Faruq; Kotzé, Awie F

2014-01-01

In the last decades several new biotechnologically-based therapeutics have been developed due to progress in genetic engineering. A growing challenge facing pharmaceutical scientists is formulating these compounds into oral dosage forms with adequate bioavailability. An increasingly popular approach to formulate biotechnology-based therapeutics is the use of lipid based formulation technologies. This review highlights the importance of lipid based drug delivery systems in the formulation of oral biotechnology based therapeutics including peptides, proteins, DNA, siRNA and vaccines. The different production procedures used to achieve high encapsulation efficiencies of the bioactives are discussed, as well as the factors influencing the choice of excipient. Lipid based colloidal drug delivery systems including liposomes and solid lipid nanoparticles are reviewed with a focus on recent advances and updates. We further describe microemulsions and self-emulsifying drug delivery systems and recent findings on bioactive delivery. We conclude the review with a few examples on novel lipid based formulation technologies.

Skull base tumours part I: Imaging technique, anatomy and anterior skull base tumours

International Nuclear Information System (INIS)

Borges, Alexandra

2008-01-01

Advances in cross-sectional imaging, surgical technique and adjuvant treatment have largely contributed to ameliorate the prognosis, lessen the morbidity and mortality of patients with skull base tumours and to the growing medical investment in the management of these patients. Because clinical assessment of the skull base is limited, cross-sectional imaging became indispensable in the diagnosis, treatment planning and follow-up of patients with suspected skull base pathology and the radiologist is increasingly responsible for the fate of these patients. This review will focus on the advances in imaging technique; contribution to patient's management and on the imaging features of the most common tumours affecting the anterior skull base. Emphasis is given to a systematic approach to skull base pathology based upon an anatomic division taking into account the major tissue constituents in each skull base compartment. The most relevant information that should be conveyed to surgeons and radiation oncologists involved in patient's management will be discussed

Comparison of MRI-based and CT/MRI fusion-based postimplant dosimetric analysis of prostate brachytherapy

International Nuclear Information System (INIS)

Tanaka, Osamu; Hayashi, Shinya; Matsuo, Masayuki; Sakurai, Kota; Nakano, Masahiro; Maeda, Sunaho; Kajita, Kimihiro R.T.; Deguchi, Takashi; Hoshi, Hiroaki

2006-01-01

Purpose: The aim of this study was to compare the outcomes between magnetic resonance imaging (MRI)-based and computed tomography (CT)/MRI fusion-based postimplant dosimetry methods in permanent prostate brachytherapy. Methods and Materials: Between October 2004 and March 2006, a total of 52 consecutive patients with prostate cancer were treated by brachytherapy, and postimplant dosimetry was performed using CT/MRI fusion. The accuracy and reproducibility were prospectively compared between MRI-based dosimetry and CT/MRI fusion-based dosimetry based on the dose-volume histogram (DVH) related parameters as recommended by the American Brachytherapy Society. Results: The prostate volume was 15.97 ± 6.17 cc (mean ± SD) in MRI-based dosimetry, and 15.97 ± 6.02 cc in CT/MRI fusion-based dosimetry without statistical difference. The prostate V100 was 94.5% and 93.0% in MRI-based and CT/MRI fusion-based dosimetry, respectively, and the difference was statistically significant (p = 0.002). The prostate D90 was 119.4% and 114.4% in MRI-based and CT/MRI fusion-based dosimetry, respectively, and the difference was statistically significant (p = 0.004). Conclusion: Our current results suggested that, as with fusion images, MR images allowed accurate contouring of the organs, but they tended to overestimate the analysis of postimplant dosimetry in comparison to CT/MRI fusion images. Although this MRI-based dosimetric discrepancy was negligible, MRI-based dosimetry was acceptable and reproducible in comparison to CT-based dosimetry, because the difference between MRI-based and CT/MRI fusion-based results was smaller than that between CT-based and CT/MRI fusion-based results as previously reported

Problem-Oriented Corporate Knowledge Base Models on the Case-Based Reasoning Approach Basis

Science.gov (United States)

Gluhih, I. N.; Akhmadulin, R. K.

2017-07-01

One of the urgent directions of efficiency enhancement of production processes and enterprises activities management is creation and use of corporate knowledge bases. The article suggests a concept of problem-oriented corporate knowledge bases (PO CKB), in which knowledge is arranged around possible problem situations and represents a tool for making and implementing decisions in such situations. For knowledge representation in PO CKB a case-based reasoning approach is encouraged to use. Under this approach, the content of a case as a knowledge base component has been defined; based on the situation tree a PO CKB knowledge model has been developed, in which the knowledge about typical situations as well as specific examples of situations and solutions have been represented. A generalized problem-oriented corporate knowledge base structural chart and possible modes of its operation have been suggested. The obtained models allow creating and using corporate knowledge bases for support of decision making and implementing, training, staff skill upgrading and analysis of the decisions taken. The universal interpretation of terms “situation” and “solution” adopted in the work allows using the suggested models to develop problem-oriented corporate knowledge bases in different subject domains. It has been suggested to use the developed models for making corporate knowledge bases of the enterprises that operate engineer systems and networks at large production facilities.

Web-Based Learning Environment Based on Students’ Needs

Science.gov (United States)

Hamzah, N.; Ariffin, A.; Hamid, H.

2017-08-01

Traditional learning needs to be improved since it does not involve active learning among students. Therefore, in the twenty-first century, the development of internet technology in the learning environment has become the main needs of each student. One of the learning environments to meet the needs of the teaching and learning process is a web-based learning environment. This study aims to identify the characteristics of a web-based learning environment that supports students’ learning needs. The study involved 542 students from fifteen faculties in a public higher education institution in Malaysia. A quantitative method was used to collect the data via a questionnaire survey by randomly. The findings indicate that the characteristics of a web-based learning environment that support students’ needs in the process of learning are online discussion forum, lecture notes, assignments, portfolio, and chat. In conclusion, the students overwhelmingly agreed that online discussion forum is the highest requirement because the tool can provide a space for students and teachers to share knowledge and experiences related to teaching and learning.

Home Based Training: Main Strategy in Community Based Rehabilitation in Iran

Directory of Open Access Journals (Sweden)

Peiman Salamati

2006-10-01

Full Text Available Objective: Study of effectiveness of “home based training” in community based rehabilitation program on disabled people, under supervised of 21 pilot cities health and medical networks, who were trained and evaluated at the end of the course. Materials & Methods: In a cross-sectional study, 614 disabled people who had participated in “home based training” were selected with stratified random sampling method. They were evaluated according to function progress level variables by community based rehabilitation programme experts. Age, sex, disability groups, employment state and teacher’s relation variables were studied from their files and recording datas. Statistical analysis was performed with Chi-square test. Results: There was a relationship between age group and disability group with functional progress level (P = 0.014 & P <0.001. Low age groups, visional disabled group, epileptic patients and individuals with learning problems had the best results. High age groups, mixed disability group and individuals with verbal and hearing problems had the least results. There was a relationship between teacher’s relation with progress or nonprogress state (P = 0.038. Individuals that they were own teachers had the best results and individuals with teachers other than first or second relation or health worker had the least results. Conclusion: Home based training in community based rehabilitation programme is an effective method for improving disabled people in some selected groups.

How evidence-based are the recommendations in evidence-based guidelines?

Directory of Open Access Journals (Sweden)

Finlay A McAlister

2007-08-01

Full Text Available BACKGROUND: Treatment recommendations for the same condition from different guideline bodies often disagree, even when the same randomized controlled trial (RCT evidence is cited. Guideline appraisal tools focus on methodology and quality of reporting, but not on the nature of the supporting evidence. This study was done to evaluate the quality of the evidence (based on consideration of its internal validity, clinical relevance, and applicability underlying therapy recommendations in evidence-based clinical practice guidelines. METHODS AND FINDINGS: A cross-sectional analysis of cardiovascular risk management recommendations was performed for three different conditions (diabetes mellitus, dyslipidemia, and hypertension from three pan-national guideline panels (from the United States, Canada, and Europe. Of the 338 treatment recommendations in these nine guidelines, 231 (68% cited RCT evidence but only 105 (45% of these RCT-based recommendations were based on high-quality evidence. RCT-based evidence was downgraded most often because of reservations about the applicability of the RCT to the populations specified in the guideline recommendation (64/126 cases, 51% or because the RCT reported surrogate outcomes (59/126 cases, 47%. CONCLUSIONS: The results of internally valid RCTs may not be applicable to the populations, interventions, or outcomes specified in a guideline recommendation and therefore should not always be assumed to provide high-quality evidence for therapy recommendations.

Microfluidic paper-based biomolecule preconcentrator based on ion concentration polarization.

Science.gov (United States)

Han, Sung Il; Hwang, Kyo Seon; Kwak, Rhokyun; Lee, Jeong Hoon

2016-06-21

Microfluidic paper-based analytical devices (μPADs) for molecular detection have great potential in the field of point-of-care diagnostics. Currently, a critical problem being faced by μPADs is improving their detection sensitivity. Various preconcentration processes have been developed, but they still have complicated structures and fabrication processes to integrate into μPADs. To address this issue, we have developed a novel paper-based preconcentrator utilizing ion concentration polarization (ICP) with minimal addition on lateral-flow paper. The cation selective membrane (i.e., Nafion) is patterned on adhesive tape, and this tape is then attached to paper-based channels. When an electric field is applied across the Nafion, ICP is initiated to preconcentrate the biomolecules in the paper channel. Departing from previous paper-based preconcentrators, we maintain steady lateral fluid flow with the separated Nafion layer; as a result, fluorescent dyes and proteins (FITC-albumin and bovine serum albumin) are continuously delivered to the preconcentration zone, achieving high preconcentration performance up to 1000-fold. In addition, we demonstrate that the Nafion-patterned tape can be integrated with various geometries (multiplexed preconcentrator) and platforms (string and polymer microfluidic channel). This work would facilitate integration of various ICP devices, including preconcentrators, pH/concentration modulators, and micro mixers, with steady lateral flows in paper-based platforms.

Jobs to Manufacturing Careers: Work-Based Courses. Work-Based Learning in Action

Science.gov (United States)

Kobes, Deborah

2016-01-01

This case study, one of a series of publications exploring effective and inclusive models of work-based learning, finds that work-based courses bring college to the production line by using the job as a learning lab. Work-based courses are an innovative way to give incumbent workers access to community college credits and degrees. They are…

Base-By-Base: Single nucleotide-level analysis of whole viral genome alignments

Directory of Open Access Journals (Sweden)

Tcherepanov Vasily

2004-07-01

Full Text Available Abstract Background With ever increasing numbers of closely related virus genomes being sequenced, it has become desirable to be able to compare two genomes at a level more detailed than gene content because two strains of an organism may share the same set of predicted genes but still differ in their pathogenicity profiles. For example, detailed comparison of multiple isolates of the smallpox virus genome (each approximately 200 kb, with 200 genes is not feasible without new bioinformatics tools. Results A software package, Base-By-Base, has been developed that provides visualization tools to enable researchers to 1 rapidly identify and correct alignment errors in large, multiple genome alignments; and 2 generate tabular and graphical output of differences between the genomes at the nucleotide level. Base-By-Base uses detailed annotation information about the aligned genomes and can list each predicted gene with nucleotide differences, display whether variations occur within promoter regions or coding regions and whether these changes result in amino acid substitutions. Base-By-Base can connect to our mySQL database (Virus Orthologous Clusters; VOCs to retrieve detailed annotation information about the aligned genomes or use information from text files. Conclusion Base-By-Base enables users to quickly and easily compare large viral genomes; it highlights small differences that may be responsible for important phenotypic differences such as virulence. It is available via the Internet using Java Web Start and runs on Macintosh, PC and Linux operating systems with the Java 1.4 virtual machine.

Demographic-Based Content Analysis of Web-Based Health-Related Social Media.

Science.gov (United States)

Sadah, Shouq A; Shahbazi, Moloud; Wiley, Matthew T; Hristidis, Vagelis

2016-06-13

An increasing number of patients from diverse demographic groups share and search for health-related information on Web-based social media. However, little is known about the content of the posted information with respect to the users' demographics. The aims of this study were to analyze the content of Web-based health-related social media based on users' demographics to identify which health topics are discussed in which social media by which demographic groups and to help guide educational and research activities. We analyze 3 different types of health-related social media: (1) general Web-based social networks Twitter and Google+; (2) drug review websites; and (3) health Web forums, with a total of about 6 million users and 20 million posts. We analyzed the content of these posts based on the demographic group of their authors, in terms of sentiment and emotion, top distinctive terms, and top medical concepts. The results of this study are: (1) Pregnancy is the dominant topic for female users in drug review websites and health Web forums, whereas for male users, it is cardiac problems, HIV, and back pain, but this is not the case for Twitter; (2) younger users (0-17 years) mainly talk about attention-deficit hyperactivity disorder (ADHD) and depression-related drugs, users aged 35-44 years discuss about multiple sclerosis (MS) drugs, and middle-aged users (45-64 years) talk about alcohol and smoking; (3) users from the Northeast United States talk about physical disorders, whereas users from the West United States talk about mental disorders and addictive behaviors; (4) Users with higher writing level express less anger in their posts. We studied the popular topics and the sentiment based on users' demographics in Web-based health-related social media. Our results provide valuable information, which can help create targeted and effective educational campaigns and guide experts to reach the right users on Web-based social chatter.

Enriched Title-Based Keyword Index Generation Using dBase II.

Science.gov (United States)

Rajendran, P. P.

1986-01-01

Describes the use of a database management system (DBMS)--dBaseII--to create an enriched title-based keyword index for a collection of news items at the Renewable Energy Resources Information Center of the Asian Institute of Technology. The use of DBMSs in libraries in developing countries is emphasized. (Author/LRW)

Workplace Based Assessment in Psychiatry

Directory of Open Access Journals (Sweden)

Ayse Devrim Basterzi

2009-11-01

Full Text Available Workplace based assessment refers to the assessment of working practices based on what doctors actually do in the workplace, and is predominantly carried out in the workplace itself. Assessment drives learning and it is therefore essential that workplace-based assessment focuses on important attributes rather than what is easiest to assess. Workplacebased assessment is usually competency based. Workplace based assesments may well facilitate and enhance various aspects of educational supervisions, including its structure, frequency and duration etc. The structure and content of workplace based assesments should be monitored to ensure that its benefits are maximised by remaining tailored to individual trainees' needs. Workplace based assesment should be used for formative and summative assessments. Several formative assessment methods have been developed for use in the workplace such as mini clinical evaluation exercise (mini-cex, evidence based journal club assesment and case based discussion, multi source feedback etc. This review discusses the need of workplace based assesments in psychiatry graduate education and introduces some of the work place based assesment methods.

Proximity-Based Asynchronous Messaging Platform for Location-Based Internet of Things Service

Directory of Open Access Journals (Sweden)

Hyeong gon Jo

2016-07-01

Full Text Available The Internet of Things (IoT opens up tremendous opportunities to provide location-based applications. However, despite the services around a user being physically adjacent, common IoT platforms use a centralized structure, like a cloud-computing architecture, which transfers large amounts of data to a central server. This raises problems, such as traffic concentration, long service latency, and high communication cost. In this paper, we propose a physical distance-based asynchronous messaging platform that specializes in processing personalized data and location-based messages. The proposed system disperses traffic using a location-based message-delivery protocol, and has high stability.

Design-Based Research

DEFF Research Database (Denmark)

Gynther, Karsten; Christensen, Ove; Petersen, Trine Brun

2012-01-01

I denne artikel introduceres Design Based Research for første gang på dansk i et videnskabeligt tidsskrift. Artiklen præsenterer de grundlæggende antagelser, som ligger til grund for Design Based Research-traditionen, og artiklen diskuterer de principper, som ligger til grund for gennemførelse af...... et DBR-forskningsprojekt. Med udgangspunkt i forsknings- og udviklingsprojektet ELYK: E-læring, Yderområder og Klyngedannelse, præsenteres den innovationsmodel, som projektet har udviklet med udgangspunkt i Design Based Research traditionen. ELYKs DBR innovationsmodel har vist sig effektiv i forhold...

Memory-Based Shallow Parsing

NARCIS (Netherlands)

Tjong Kim Sang, E.F.

2002-01-01

We present memory-based learning approaches to shallow parsing and apply these to five tasks: base noun phrase identification, arbitrary base phrase recognition, clause detection, noun phrase parsing and full parsing. We use feature selection techniques and system combination methods for improving

‘"Education-based Research"

DEFF Research Database (Denmark)

Degn Johansson, Troels

This paper lays out a concept of education-based research-the production of research knowledge within the framework of tertiary design education-as an integration of problem-based learning and research-based education. This leads to a critique of reflective practice as the primary way to facilitate...... learning at this level, a discussion of the nature of design problems in the instrumentalist tradition, and some suggestions as to how design studies curricula may facilitate education-based research....

Memory-Based Shallow Parsing

OpenAIRE

Sang, Erik F. Tjong Kim

2002-01-01

We present memory-based learning approaches to shallow parsing and apply these to five tasks: base noun phrase identification, arbitrary base phrase recognition, clause detection, noun phrase parsing and full parsing. We use feature selection techniques and system combination methods for improving the performance of the memory-based learner. Our approach is evaluated on standard data sets and the results are compared with that of other systems. This reveals that our approach works well for ba...

Changing from a Rules-based to a Principles-based Accounting Logic: A Review

Directory of Open Access Journals (Sweden)

Marta Silva Guerreiro

2014-06-01

Full Text Available We explore influences on unlisted companies when Portugal moved from a code law, rules-based accounting system, to a principles-based accounting system of adapted International Financial Reporting Standards (IFRS. Institutionalisation of the new principles-based system was generally facilitated by a socio-economic and political context that increasingly supported IFRS logic. This helped central actors gain political opportunity, mobilise important allies, and accommodate major protagonists. The preparedness of unlisted companies to adopt the new IFRS-based accounting system voluntarily was explained by their desire to maintain social legitimacy. However, it was affected negatively by the embeddedness of rule-based practices in the ‘old’ prevailing institutional logic.

Constructing regional advantage: platform policies based on related variety and differentiated knowledge bases.

NARCIS (Netherlands)

Asheim, B.T.; Boschma, R.A.; Cooke, P.

2011-01-01

Constructing regional advantage: platform policies based on related variety and differentiated knowledge bases, Regional Studies. This paper presents a regional innovation policy model based on the idea of constructing regional advantage. This policy model brings together concepts like related