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Geometrical aspects of the design of fault current limiters (FCL) have a great impact on their performances. Recently, the University of Geneva have made certain optimizations by splitting the FCL into many small dissipative lengths in order to achieve a distributed transition along the device. For this paper, we have performed new 3D finite element method (FEM) simulations for studying the behavior of strip lines of a YB CO/Au FCL in an AC nominal use (sinusoidal current at industrial frequency) up to 3 Ic. The very large aspect ratio of the device needs a particular attention to the modeling and meshing process. The numerical results show that presence of sharp corners can influence the performance of the device. Due to the high value of the electric field in these areas, the local losses are much higher than in the case of smooth corners, and this may lead to burning and cracking the wafer. Ic- reversible damage experiments have confirmed these locations. In this paper we proposed new geometries, taking into account the length of the connecting path and the corners optimization in order to decrease the risk of very high localized losses in the meander. [ABSTRACT FROM AUTHOR]

For the ALICE experiment at the Large Hadron Collider (LHC) at CERN/Geneva, a high level trigger system (HLT) for online event selection and data compression has been developed and a computing cluster of several hundred dual-processor nodes is being installed. A major system integration test was carried out during the commissioning of the time projection chamber (TPC), where the HLT also provides a monitoring system. All major parts like a small computing cluster, hardware input devices, the online data transportation framework, and the HLT analysis could be tested successfully. A common interface for HLT processing components has been designed to run the components from either the online or offline analysis framework without changes. The interface adapts the component to the needs of the online processing and allows the developer to use the offline framework for easy development, debugging, and benchmarking. Following this approach, results can be compared directly. For the upcoming commissioning of the whole detector, the HLT is currently prepared to run online data analysis for the main detectors, e.g., the inner tracking system (ITS), the TPC, and the transition radiation detector (TRD). The HLT processing capability is indispensable for the photon spectrometer (PHOS), where the online pulse shape analysis reduces the data volume by a factor 20. A common monitoring framework is in place and detector calibration algorithms have been ported to the HLT. The paper describes briefly the architecture of the HLT system. It focuses on typical applications and component development. [ABSTRACT FROM AUTHOR]

The LHC accelerator, at present under construction at CERN, Geneva, will make use of 1232 superconducting dipole magnets. The coils are wound with Rutherford type cable based on copper stabilized NbTi superconductors. The LHC machine will be operated at 1.9 K in superfluid helium. The unprecedented mass production of the superconducting dipole magnets, which involves three main contractors in Europe, is running steadily according to plan. This paper reports the outstanding technical issues encountered throughout the execution of the main manufacturing steps, which are the coil winding, curing and clamping in the collar structure, the 15-m long computer-controlled welding, the high-precision positioning operations for the cold mass finishing and the helium leak testing. The achieved production rates are discussed as well as the CERN plan for the completion of these important contracts. [ABSTRACT FROM AUTHOR]