Common tools for large experiment controls: A common approach for deployment, maintenance, and support

The four major LHC experiments have agreed to a common supervisory controls approach under the auspices of the Joint Controls Project (JCOP). This approach is based on a commercial SCADA product called PVSS. Apart from that, several other sub-projects of JCOP address common aspects of the experiments' Detector Controls Systems (DCS). Within JCOP a number of packages are being developed for the experiments. One of these is the so-called JCOP Framework which is a package of tools and devices to facilitate the implementation of the various control systems for the sub-detectors and their electronics. This framework went through a redesign to take into account user feedback, and now effort is being put into deployment as well as the consultancy for the users-the experiments. This is important as the detectors are being prepared for testbeams and increasingly also for the final systems. All experiments have by now built prototype controls applications and tested them in beam tests as well as part of integration tests for larger detector parts. The current state of the development and deployment of this framework and selected other JCOP sub-projects as well as the plans for the nearer and farther future, together with experience gathered during deployment, consultancy, and training are presented

The CERN Detector Safety System for the LHC Experiments

The Detector Safety System (DSS), currently being developed at CERN under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the protection of equipment for the four LHC experiments. Thus, the DSS will require a high degree of both availability and reliability. After evaluation of various possible solutions, a prototype is being built based on a redundant Siemens PLC front-end, to which the safety-critical part of the DSS task is delegated. This is then supervised by a PVSS SCADA system via an OPC server. The PLC front-end is capable of running autonomously and of automatically taking predefined protective actions whenever required. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabilities. Configuration of the code running in the PLCs will be completely data driven via the contents of a "Configuration Database". Thus, the DSS can easily adapt to the different and constantly evolving requirements of the LHC experiments during their construction, commissioning and exploitation phases.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 5 pages, PDF. PSN THGT00

Steps toward accurate large-area analyses of Genesis solar wind samples: evaluation of surface cleaning methods using total reflection X-ray fluorescence spectrometry

Total reflection X-ray fluorescence spectrometry (TXRF) was used to analyze residual surface contamination on Genesis solar wind samples and to evaluate different cleaning methods. To gauge the suitability of a cleaning method, two samples were analyzed following cleaning by lab-based TXRF. The analysis comprised an overview and a crude manual mapping of the samples by orienting them with respect to the incident X-ray beam in such a way that different regions were covered. The results show that cleaning with concentrated hydrochloric acid and a combination of hydrochloric acid and hydrofluoric acid decreased persistent inorganic contaminants substantially on one sample. The application of CO2 snow for surface cleaning tested on the other sample appears to be effective in removing one persistent Genesis contaminant, namely germanium. Unfortunately, the TXRF analysis results of the second sample were impacted by relatively high background contamination. This was mostly due to the relatively small sample size and that the solar wind collector was already mounted with silver glue for resonance ion mass spectrometry (RIMS) on an aluminium stub. Further studies are planned to eliminate this problem. In an effort to identify the location of very persistent contaminants, selected samples were also subjected to environmental scanning electron microscopy. The results showed excellent agreement with TXRF analysis

Theoretical Consideration of the Influence of Reforming Processes on the Fracture Strength of Solids Technical Report No. 105

Reformation processes effect on stress time-to- fracture behavior of solid

Kinetic considerations of the strength of oriented solids

Kinetics of mechanical strength of oriented and stressed solids based on statistical absolute reaction rate theor

Controlling front-end electronics boards using commercial solutions

LHCb is a dedicated B-physics experiment under construction at CERN's large hadron collider (LHC) accelerator. This paper will describe the novel approach LHCb is taking toward controlling and monitoring of electronics boards. Instead of using the bus in a crate to exercise control over the boards, we use credit-card sized personal computers (CCPCs) connected via Ethernet to cheap control PCs. The CCPCs will provide a simple parallel, I2C, and JTAG buses toward the electronics board. Each board will be equipped with a CCPC and, hence, will be completely independently controlled. The advantages of this scheme versus the traditional bus-based scheme will be described. Also, the integration of the controls of the electronics boards into a commercial supervisory control and data acquisition (SCADA) system will be shown. (5 refs)

A SUMMARY OF THE IEEE REAL TIME 2005 CONFERENCE HELD AT STOCKHOLM

ABSTRACT Bi-annually, the Nuclear and Plasma Sciences Society of IEEE sponsors the Real Time conference. At this conference it is mostly physicists that present their developments around the online systems in these fields. These presentations are focused mainly on real-time applications but nevertheless the whole range of control systems for detectors is covered, which is similar to the ICALEPCS conference. Even though the topics covered are quite similar the participants tend to be different with only a few people attending both events. Therefore, this paper will summarize and highlight the key presentations of the Real Time conference where they are interesting for the ICALEPCS community. Such topics are "system architecture", "front-end signal processing", "trigger and data acquisition", "online databases", and "online processing farms"

Variables affecting the probability of complete fusion of the medial clavicular epiphysis

In this study, we have combined data on clavicle fusion from different studies and applied a binomial logistic regression analysis. As such, we aimed to assess whether or not variables such as sex, socioeconomic status, and ethnicity influence the probability of having mature, i.e., completely fused clavicles at a given age. We further explored whether the method of clavicle examination, i.e., diagnosis from either a dry bone specimen, an examination of X-rays, or an examination of computed tomography scans, affects the probability of being diagnosed with mature clavicles. It appeared that only ethnicity did not significantly affect this probability. Finally, we illustrated how the logit model may be used to predict the probability of being diagnosed with mature clavicles

Steps Toward Accurate Large Area Analyzes of Genesis Solar Wind Samples: Evaluation of Surface Cleaning Methods Using Total Reflection X-ray Fluorescence Spectrometry

Total reflection X-ray fluorescence spectrometry (TXRF) was used to analyze residual surface contamination on Genesis solar wind samples and to evaluate different cleaning methods. The Genesis mission collected solar wind during a period of 854 days by embedding the charged particles into collectors made of various ultra clean materials such as silicon, sapphire and silicon-on-sapphire. The sample return capsule unexpectedly crashed on return to Earth fracturing the collectors and exposing them to the desert soil of the landing side. The ubiquitous contaminants are separated from the atoms of solar wind by only 5-15 nm, presenting significant challenges for solar wind analysis as well as the development of cleaning techniques. Currently, an ultrapure water and ozone UV radiation treatment is routinely applied to the collectors by the curatorial team at NASA’s Johnson Space Center. Additional cleaning steps involving various forms of acid treatment and/or carbon dioxide snow treatment are being evaluated as well. To gauge the suitability of the cleaning method, two samples were analyzed following cleaning by lab-based TXRF. The analysis comprised of an overview and a crude manual mapping of the samples by orienting them with respect to the incident X-ray beam in such way that different regions were covered. The results showed that cleaning with concentrated hydrochloric acid and a combination of hydrochloric acid and hydrofluoric acid decreased persistent inorganic contaminants substantially on one sample. Application of carbon dioxide snow for surface cleaning tested on the other sample appears to be effective in removing one persistent Genesis contaminant, namely germanium. Unfortunately, the TXRF analysis results of the second sample were impacted by relatively high background contamination. This was mostly due to the relatively small sample size and that the solar wind collector was already mounted with silver glue for resonance ion mass spectrometry (RIMS) on an aluminum stub. Further studies are planned to eliminate this problem. In an effort to identify the location of very persistent contaminants, selected samples were also subjected to environmental scanning electron microscopy. The results showed excellent agreement with TXRF analysis

Recurrence in generic staircases

The straight-line flow on almost every staircase and on almost every square tiled staircase is recurrent. For almost every square tiled staircase the set of periodic orbits is dense in the phase space