Sascha Schmeling

The detector safety system for 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 Large Hadron Collider (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.

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.

Common tools for large experiment controls-a common approach for deployment, maintenance, and support

The four major LHC experiments have agreed to 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

Controlling front-end electronics boards using commercial solutions

LHCb is a dedicated B-physics experiment under construction at CERNs 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.

An Alternative Proposal for the Graphical Representation of Anticolor Charge

We have developed a learning unit based on the Standard Model of particle physics, featuring novel typographic illustrations of elementary particles and particle systems. Since the unit includes antiparticles and systems of antiparticles, a visualization of anticolor charge was required. We propose an alternative to the commonly used complementary-color method, whereby antiparticles and antiparticle systems are identified through the use of stripes instead of a change in color. We presented our proposal to high school students and physics teachers, who evaluated it to be a more helpful way of distinguishing between color charge and anticolor charge.

Development and Evaluation of a Construct Map for the Understanding of the Expansion of the Universe

The expansion of the universe is one of three pillars of the Big Bang theory and, therefore, an important aspect in cosmology. How the understanding hereof, including the complex concept of an expanding space, is developing, is not yet completely understood. On the basis of a hypothesis of a different study, which constructed a first structural setup of student understanding in this field, we developed it further to be able to reflect students’ processes of understanding the concept of an expanding universe. The assignment of open answers of N=126 German students from 11th- and 12th grade classes (16-20 years old) showed a good classification of these students into this construct with high interrater reliabilities.

Message From the Editor for Contributions to the 2009 Real Time Conference Issue of TNS

The 52 papers in this special issue were originally presented at the 16th IEEE-NPSS Real Time Conference (RT2009), held in Beijing, China, in May 2009.