141 research outputs found
Preliminary analysis of the drive system of the CTA LST Telescope and its integration in the whole PLC architecture
This work aims to present a preliminary analysis of the drive system configuration for the CTA telescopes array and more specifically a possible architecture for the sub-array of Large Size Telescopes - LSTs. The first part of this document is focused on the control command architecture of the drive system dedicated to the LST including a view on some mechanical aspects concerning the telescopes of this class. In particular the current investigation on the interfaces between the drive system and the automatic system in charge of the camera mast control system (e.g. the arch damping) is presented. In the second part of this work the issue of the integration of the telescope drive system within a global PLC (Programmable Logic Controller) architecture for the CTA array is addressed with the corresponding links to the control software layer
From Design to Production Control Through the Integration of Engineering Data Management and Workflow Management Systems
At a time when many companies are under pressure to reduce "times-to-market"
the management of product information from the early stages of design through
assembly to manufacture and production has become increasingly important.
Similarly in the construction of high energy physics devices the collection of
(often evolving) engineering data is central to the subsequent physics
analysis. Traditionally in industry design engineers have employed Engineering
Data Management Systems (also called Product Data Management Systems) to
coordinate and control access to documented versions of product designs.
However, these systems provide control only at the collaborative design level
and are seldom used beyond design. Workflow management systems, on the other
hand, are employed in industry to coordinate and support the more complex and
repeatable work processes of the production environment. Commercial workflow
products cannot support the highly dynamic activities found both in the design
stages of product development and in rapidly evolving workflow definitions. The
integration of Product Data Management with Workflow Management can provide
support for product development from initial CAD/CAM collaborative design
through to the support and optimisation of production workflow activities. This
paper investigates this integration and proposes a philosophy for the support
of product data throughout the full development and production lifecycle and
demonstrates its usefulness in the construction of CMS detectors.Comment: 18 pages, 13 figure
Detector Construction Management and Quality Control: Establishing and Using a CRISTAL System
The CRISTAL (Cooperating Repositories and an Information System for Tracking
Assembly Lifecycles) project is delivering a software system to facilitate the
management of the engineering data collected at each stage of production of
CMS. CRISTAL captures all the physical characteristics of CMS components as
each sub-detector is tested and assembled. These data are retained for later
use in areas such as detector slow control, calibration and maintenance.
CRISTAL must, therefore, support different views onto its data dependent on the
role of the user. These data viewpoints are investigated in this paper. In the
recent past two CMS Notes have been written about CRISTAL. The first note, CMS
1996/003, detailed the requirements for CRISTAL, its relationship to other CMS
software, its objectives and reviewed the technology on which it would be
based. CMS 1997/104 explained some important design concepts on which CRISTAL
is and showed how CRISTAL integrated the domains of product data man- agement
and workflow management. This note explains, through the use of diagrams, how
CRISTAL can be established for detector production and used as the information
source for analyses, such as calibration and slow controls, carried out by
physicists. The reader should consult the earlier CMS Notes and conference
papers for technical detail on CRISTAL - this note concentrates on issues
surrounding the practical use of the CRISTAL software.Comment: 16 pages, 14 figure
C.R.I.S.T.A.L. Concurrent Repository & Information System for Tracking Assembly and production Lifecycles: A data capture and production management tool for the assembly and construction of the CMS ECAL detector
The CMS experiment will comprise several very large high resolution detectors for physics. Each detector may be constructed of well over a million parts and will be produced and assembled during the next decade by specialised centres distributed world-wide. Each constituent part of each detector must be accurately measured and tested locally prior to its ultimate assembly and integration in the experimental area at CERN. The CRISTAL project (Concurrent Repository and Information System for Tracking Assembly and production Lifecycles) [1] aims to monitor and control the quality of the production and assembly process to aid in optimising the performance of the physics detectors and to reject unacceptable constituent parts as early as possible in the construction lifecycle. During assembly CRISTAL will capture all the information required for subsequent detector calibration. Distributed instances of Object databases linked via CORBA [2] and with WWW/Java-based query processing are the main technology aspects of CRISTAL.The CMS experiment will comprise several very large high resolution detectors for physics. Each detector may be constructed of well over a million parts and will be produced and assembled during the next decade by specialised centres distributed world-wide. Each constituent part of each detector must be accurately measured and tested locally prior to its ultimate assembly and integration in the experimental area at CERN. The CRISTAL project (Concurrent Repository and Information System for Tracking Assembly and production Lifecycles) [1] aims to monitor and control the quality of the production and assembly process to aid in optimising the performance of the physics detectors and to reject unacceptable constituent parts as early as possible in the construction lifecycle. During assembly CRISTAL will capture all the information required for subsequent detector calibration. Distributed instances of Object databases linked via CORBA [2] and with WWW/Java-based query processing are the main technology aspects of CRISTAL
Status and Plans for the Array Control and Data Acquisition System of the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) is the next-generation atmospheric
Cherenkov gamma-ray observatory. CTA will consist of two installations, one in
the northern, and the other in the southern hemisphere, containing tens of
telescopes of different sizes. The CTA performance requirements and the
inherent complexity associated with the operation, control and monitoring of
such a large distributed multi-telescope array leads to new challenges in the
field of the gamma-ray astronomy. The ACTL (array control and data acquisition)
system will consist of the hardware and software that is necessary to control
and monitor the CTA arrays, as well as to time-stamp, read-out, filter and
store -at aggregated rates of few GB/s- the scientific data. The ACTL system
must be flexible enough to permit the simultaneous automatic operation of
multiple sub-arrays of telescopes with a minimum personnel effort on site. One
of the challenges of the system is to provide a reliable integration of the
control of a large and heterogeneous set of devices. Moreover, the system is
required to be ready to adapt the observation schedule, on timescales of a few
tens of seconds, to account for changing environmental conditions or to
prioritize incoming scientific alerts from time-critical transient phenomena
such as gamma ray bursts. This contribution provides a summary of the main
design choices and plans for building the ACTL system.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
The camera of the fifth H.E.S.S. telescope. Part I: System description
In July 2012, as the four ground-based gamma-ray telescopes of the H.E.S.S.
(High Energy Stereoscopic System) array reached their tenth year of operation
in Khomas Highlands, Namibia, a fifth telescope took its first data as part of
the system. This new Cherenkov detector, comprising a 614.5 m^2 reflector with
a highly pixelized camera in its focal plane, improves the sensitivity of the
current array by a factor two and extends its energy domain down to a few tens
of GeV.
The present part I of the paper gives a detailed description of the fifth
H.E.S.S. telescope's camera, presenting the details of both the hardware and
the software, emphasizing the main improvements as compared to previous
H.E.S.S. camera technology.Comment: 16 pages, 13 figures, accepted for publication in NIM
The Cherenkov Telescope Array Large Size Telescope
The two arrays of the Very High Energy gamma-ray observatory Cherenkov
Telescope Array (CTA) will include four Large Size Telescopes (LSTs) each with
a 23 m diameter dish and 28 m focal distance. These telescopes will enable CTA
to achieve a low-energy threshold of 20 GeV, which is critical for important
studies in astrophysics, astroparticle physics and cosmology. This work
presents the key specifications and performance of the current LST design in
the light of the CTA scientific objectives.Comment: 4 pages, 5 figures, In Proceedings of the 33rd International Cosmic
Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at
arXiv:1307.223
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