The European X-ray Free Electron Laser facility (XFEL) is currently under construction at DESY in the Hamburg area in Germany. A linear accelerator consisting of 102 accelerator modules is used to ...accelerate the electron beam. Each module contains eight superconducting RF cavities and one magnet package, all operating in a 2 K super-fluid helium bath. Each magnet package consists of three nested magnets. Two cos θ-type correction dipole magnets horizontal and vertical deflecting are glued onto the surface of the beam pipe being the inner wall of the cryostat vessel. They are inside of a superferric quadrupole magnet. Each magnet package together with a conduction cooled current lead assembly, based on a CERN design, will be tested at room temperature and at 2 K in a special cryostat XMTS at DESY. It allows access for the field measurement equipment into the magnet bore at room temperature by using an anti-cryostat. The cold magnet project is realized by three groups as in kind contributions to the XFEL project. CIEMAT designs and provides the magnets and DESY the current leads. Magnet testing at DESY is performed together with IFJ PAN. A description of the XMTS facility, the magnetic field measurement systems used (harmonic coils and stretched wire setups) are given. Finally a short discussion of the results obtained for the first third of the magnets is presented. All magnets tested so far perform very well up to the design current. The quality and strength of the magnetic field are as designed.
A new linear accelerator, i.e., the European X-ray Free-Electron Laser (XFEL), is under construction at DESY in Hamburg. The construction started in early 2009, and the commissioning is planned for ...2016. The design energy of the electron beam is 17.5 GeV (0.05-4.7 nm wavelength), and more than 27000 flashes/s are expected. The accelerator contains 102 cryomodules equipped with a string of eight superconducting RF cavities and one superconducting magnet package. Each magnet consists of two cos -θ-type correction dipoles, horizontal and vertical deflecting. They are glued onto the surface of the beam pipe and are surrounded by a superferric quadrupole magnet. The package is mounted inside of a compact stainless steel vessel with a length of 30 cm and a diameter of 20 cm. Each package and current lead assembly was tested separately at room temperature and together at 2 K in a dedicated superfluid helium cryostat at DESY. A summary of the results is reported here. During the cold test, special emphasis was given to hysteresis and persistent current effects, as the operating current varies from very low currents at the beginning of the accelerator to the full design current 50 A at the end.
Abstract
The radiation and magnetic field tolerant step-down DC/DC converter system is developed to supply low-voltage power for the ATLAS ITk Strip Detector. The system is modular and consists of ...custom designed crates with embedded cooling plates, backplane, and DC/DC converter modules. Each converter module comprises two or four power channels. Each channel comprises a 48-to-11 V DC/DC converter, hardware overcurrent and overvoltage protection circuits, correction circuitry to compensate for voltage drops along the cables, and control and monitoring functionality based on the AMACStar chip. We present the design and performance of such a DC/DC converter system, including evaluation of its radiation tolerance.
This paper describes the design and implementation of the grounding and shielding system for the ATLAS SemiConductor Tracker (SCT). The mitigation of electromagnetic interference and noise pickup ...through power lines is the critical design goal as they have the potential to jeopardize the electrical performance. We accomplish this by adhering to the ATLAS grounding rules, by avoiding ground loops and isolating the different subdetectors. Noise sources are identified and design rules to protect the SCT against them are described. A rigorous implementation of the design was crucial to achieve the required performance. This paper highlights the location connection and assembly of the different components that affect the grounding and shielding system: cables, filters, cooling pipes, shielding enclosure, power supplies and others. Special care is taken with the electrical properties of materials and joints. The monitoring of the grounding system during the installation period is also discussed. Finally, after connecting more than four thousand SCT modules to all of their services, electrical, mechanical and thermal within the wider ATLAS experimental environment, dedicated tests show that noise pickup is minimised.
The ATLAS SemiConductor Tracker (SCT) is one of the largest existing semiconductor detectors. It is situated between the Pixel detector and the Transition Radiation Tracker at one of the four ...interaction points of the Large Hadron Collider (LHC). During 2006-2007 the detector was lowered into the ATLAS cavern and installed in its final position. For the assembly, integration and commissioning phase, a complete Detector Control System (DCS) was developed to ensure the safe operation of the tracker. This included control of the individual powering of the silicon modules, a bi-phase cooling system and various types of sensors monitoring the SCT environment and the surrounding test enclosure. The DCS software architecture, performance and operational experience will be presented in the view of a validation of the DCS for the final SCT installation and operation phase.
The barrel modules of the ATLAS semiconductor tracker Alonso, J.; Anderson, B.; Andricek, L. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2006, Letnik:
568, Številka:
2
Journal Article
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This paper describes the silicon microstrip modules in the barrel section of the SemiConductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The module requirements, ...components and assembly techniques are given, as well as first results of the module performance on the fully assembled barrels that make up the detector being installed in the ATLAS experiment.
The influence of methods of parsley root pretreatment (different slices dimensions and blanching) before convection drying on the kinetics of dried product rehydration were examined. Kinetics of the ...process was tested within the range of 0-6 hours. Relative increase in mass of dried parsley root was determined. The approximation of experimental data with assumed kinetic equation gave good results. Analysis of the rehydration course showed that slices dimensions and blanching influence the kinetics of dried parsley root rehydration
Highly integrated readout electronics were developed and produced for the 182000 channels of the four TPCs of the NA49 heavy-ion fixed target experiment at the CERN SPS. The large number of channels, ...the high packing density and required cost minimization led to the choice of a custom electronics system. The requirements, the design and the performance of the electronics components are described.
The cell wall envelope of Gram-positive pathogens functions as a scaffold for the attachment of virulence factors and as a sieve that prevents diffusion of molecules. Here the isd genes ...(iron-regulated surface determinant) of Staphylococcus aureus were found to encode factors responsible for hemoglobin binding and passage of heme-iron to the cytoplasm, where it acts as an essential nutrient. Heme-iron passage required two sortases that tether Isd proteins to unique locations within the cell wall. Thus, Isd appears to act as an import apparatus that uses cell wall-anchored proteins to relay heme-iron across the bacterial envelope.
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