Control System for the LEDA 6.7-MeV Proton Beam Halo Experiment

Measurement of high-power proton beam-halo formation is the ongoing scientific experiment for the Low Energy Demonstration Accelerator (LEDA) facility. To attain this measurement goal, a 52-magnet beam line containing several types of beam diagnostic instrumentation is being installed. The Experimental Physics and Industrial Control System (EPICS) and commercial software applications are presently being integrated to provide a real-time, synchronous data acquisition and control system. This system is comprised of magnet control, vacuum control, motor control, data acquisition, and data analysis. Unique requirements led to the development and integration of customized software and hardware. EPICS real-time databases, Interactive Data Language (IDL) programs, LabVIEW Virtual Instruments (VI), and State Notation Language (SNL) sequences are hosted on VXI, PC, and UNIX-based platforms which interact using the EPICS Channel Access (CA) communication protocol. Acquisition and control hardware technology ranges from DSP-based diagnostic instrumentation to the PLC-controlled vacuum system. This paper describes the control system hardware and software design, and implementation.Comment: LINAC2000 Conference, 4 pg

Advancing the application of systems thinking in health:analysing the contextual and social network factors influencing the use of sustainability indicators in a health system - a comparative study in Nepal and Somaliland

BACKGROUND: Health systems strengthening is becoming a key component of development agendas for low-income countries worldwide. Systems thinking emphasizes the role of diverse stakeholders in designing solutions to system problems, including sustainability. The objective of this paper is to compare the definition and use of sustainability indicators developed through the Sustainability Analysis Process in two rehabilitation sectors, one in Nepal and one in Somaliland, and analyse the contextual factors (including the characteristics of system stakeholder networks) influencing the use of sustainability data. METHODS: Using the Sustainability Analysis Process, participants collectively clarified the boundaries of their respective systems, defined sustainability, and identified sustainability indicators. Baseline indicator data was gathered, where possible, and then researched again 2 years later. As part of the exercise, system stakeholder networks were mapped at baseline and at the 2-year follow-up. We compared stakeholder networks and interrelationships with baseline and 2-year progress toward self-defined sustainability goals. Using in-depth interviews and observations, additional contextual factors affecting the use of sustainability data were identified. RESULTS: Differences in the selection of sustainability indicators selected by local stakeholders from Nepal and Somaliland reflected differences in the governance and structure of the present rehabilitation system. At 2 years, differences in the structure of social networks were more marked. In Nepal, the system stakeholder network had become more dense and decentralized. Financial support by an international organization facilitated advancement toward self-identified sustainability goals. In Somaliland, the small, centralised stakeholder network suffered a critical rupture between the system's two main information brokers due to competing priorities and withdrawal of international support to one of these. Progress toward self-defined sustainability was nil. CONCLUSIONS: The structure of the rehabilitation system stakeholder network characteristics in Nepal and Somaliland evolved over time and helped understand the changing nature of relationships between actors and their capacity to work as a system rather than a sum of actors. Creating consensus on a common vision of sustainability requires additional system-level interventions such as identification of and support to stakeholders who promote systems thinking above individual interests

Integrating commercial and legacy systems with EPICS

The Experimental Physics and Industrial Control System (EPICS) is a software toolkit, developed by a worldwide collaboration, which significantly reduces the level of effort required to implement a new control system. Recent developments now also significantly reduce the level of effort required to integrate commercial, legacy and/or site-authored control systems with EPICS. This paper will illustrate with an example both the level and type of effort required to use EPICS with other control system components as well as the benefits that may arise

he mosses of the Wadden S ea islands Rottumeroog, Vuurtorenduin and Zuiderduin (part 2)

Abstract: The mosses of the Wadden Sea islands Rottumeroog, Vuurtorenduinand Zuiderduin (part 2) This is the second paper on the bryophyte flora of the West Frisian barrier islands Rottumerplaat, Rottumeroog, Vuurtorenduin and Zuiderduin. The first paper (Kruijeret al., 2000) gives an overview of the recent geologic history of the islands and presents the findings of the bryophyte inventories in 1999. Thisfollow up includes additional records of bryophytes from Rottumeroog collected in 1994, supplements the 1999 inventory of Rottumeroog and Zuiderduin, and presents the findings of the 2001 inventory of these islands and Vuurtorenduin; the bryoflora of Vuurtorenduin was previously unknown. The 2001 inventory results in a list of 36 bryophyte species on Rottumeroog, 6 species on Vuurtorenduin, and 5 species on Zuiderduin. We have found no significant changes in the total nu mber of bryophyte species on Rottumer-oog since 1973, despite the occurrence of dramatic events in this period. The bryologically most interesting site on Rottumeroog (‘tuin van Toxopeus’) has disappearedby floods in 1998-1999 together with, amongst others, the rare species Moerckia hibernica en Bryum calophyllum. Interesting ‘new’ species are, amongst others,Eurhynchium speciosum, Hylocomium splendens, Orthotrichum affine,O. diaphanum, Tortula truncata, Cephalozia bicuspidata, andCephaloziella divaricata. These species were only found in the proximityof the ‘tuin van Toxopeus’ and are under threat to be swallowed by the sea.Dicranum scoparium and Syntrichia ruralis var. ruralis are ‘new’ species for Rottumeroog which have not been found again in 2001: the growing site ofDicranum scoparium has been covered by sand, the growing site of S. ruralisvar. ruralis (roof of a building) has been destroyed