Commissioning and Performance of the ATLAS Liquid Argon Calorimeters

The ATLAS liquid argon (LAr) calorimeter system consists of an electromagnetic barrel calorimeter and two end-caps with electromagnetic, hadronic and forward calorimeters. The construction of the full calorimeter system is completed since mid-2004. The detector has been operated with LAr at nominal high voltage and fully equipped with readout electronics. Online software, monitoring tools and offline signal reconstruction have been developed for data collection and processing. Extensive tests with calibration pulses have been carried out, and the electronics calibration scheme for all 182468 channels has been exercised. Since Augst 2006, cosmic muon data have been collected together with the rest of the ATLAS detector system as part of the ATLAS commissioning program. The reconstructed LAr signals from energy deposited by cosmic rays are compared to the prediction derived from measured detector parameters and calibration pulses. The uniformity of the detector response within regions that have sufficient cosmic muons are examined. The expected performance of the LAr calorimeter for ATLAS physics, based on previous beam tests and Monte Carlo simulation, is also summarised.Comment: Parallel talk at ICHEP08, Philadelphia, USA, July 2008. 5 pages, LaTeX, 4 eps figures; v2: resubmitted article with updated style file provided by the ICHEP proceedings team. No other change

Vertex-Detector R&D for CLIC

A detector concept based on hybrid planar pixel-detector technology is under development for the CLIC vertex detector. It comprises fast, low-power and small-pitch readout ASICs implemented in 65 nm CMOS technology (CLICpix) coupled to ultra-thin sensors via low-mass interconnects. The power dissipation of the readout chips is reduced by means of power pulsing, allowing for a cooling system based on forced gas flow. In this paper the CLIC vertex-detector requirements are reviewed and the current status of R&D on sensors, readout and detector integration is presented.Comment: 12 pages, 7 figures. Talk presented at the 13th Topical Seminar on Innovative Particle and Radiation Detectors (IPRD13), 7 - 10 October 2013, Siena, Ital

Probing Extra Dimensions with ATLAS

In the late nineties several authors suggested that the extra dimensions predicted by string theory might lead to observable effects at high energy colliders. The ATLAS experiment which will start taking data at the LHC in 2007 will be an excellent place to search for such effects. The sensitivity of ATLAS to signatures of Extra Dimensions will be presented.Comment: 4 pages, 1 figure, to appear in Proceedings of SUSY06, the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine, California, 12-17 June 200

CLIC Background Studies and optimization of the innermost tracker elements

The harsh machine background at the Compact Linear Collider (CLIC) forms a strong constraint on the design of the innermost part of the tracker. For the CLIC Conceptual Design Report, the detector concepts developed for the International Linear Collider (ILC) were adapted to the CLIC environment. We present the new layout for the Vertex Detector and the Forward Tracking Disks of the CLIC detector concepts, as well as the background levels in these detectors. We also study the dependence of the background rates on technology parameters like thickness of the active layer and detection threshold.Comment: 7 pages, 5 figures, LCWS 201

CLIC e+e- Linear Collider Studies - Input to the Snowmass process 2013

This paper addresses the issues in question for Energy Frontier Lepton and Gamma Colliders by the Frontier Capabilities group of the Snowmass 2013 process and is structured accordingly. It will be accompanied by a paper describing the Detector and Physics studies for the CLIC project currently in preparation for submission to the Energy Frontier group.Comment: Submitted to the Snowmass process 2013. arXiv admin note: substantial text overlap with arXiv:1208.140

Giving the International Court of Justice the Cold Shoulder: The Impact of Sanchez-Llamas v. Oregon on the United States International Relations

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Air pollution and fog detection through vehicular sensors

We describe a method for the automatic recognition of air pollution and fog from a vehicle. Our system consists of sensors to acquire main data from cameras as well as from Light Detection and Recognition (LIDAR) instruments. We discuss how this data can be collected, analyzed and merged to determine the degree of air pollution or fog. Such data is essential for control systems of moving vehicles in making autonomous decisions for avoidance. Backend systems need such data for forecasting and strategic traffic planning and control. Laboratory based experimental results are presented for weather conditions like air pollution and fog, showing that the recognition scenario works with better than adequate results. This paper demonstrates that LIDAR technology, already onboard for the purpose of autonomous driving, can be used to improve weather condition recognition when compared with a camera only system. We conclude that the combination of a front camera and a LIDAR laser scanner is well suited as a sensor instrument set for air pollution and fog recognition that can contribute accurate data to driving assistance and weather alerting-systems

Quality assurance of sintered refractories through nondestructive testing with microwaves

For quality assurance of refractories for the glass industry an early nondestructive testing is required. Α possibility for nondestructive testing, especially in the green product, is given by the transidon of microwaves, as this requires no coupling medium like water. In this work, some basic physical characteristics were measured which determine microwave absorption through refractories and flaw detection. For different refractories the dielectric constant, specific attenuation coefficient as well as dependence of the attenuation on the frequency were determined. It is shown that a high dielectric constant improves the detection of flaws. In order to improve flaw detection and resolution, lenses and frequency modulation were used successfully. Best results for the refractories investigated were achieved with a lens with a focal length of 86 mm. Measurements were then extended to other types of refractories, i.e. chromalumina, zirconmuUite and zirconsilica, as well as to unfired bricks. Here, especially one isostatic-pressed zirconsilica brick has shown the lowest specific attenuation coefficient due to low porosity and high dielectric constant. Furthermore, a test device for complete C-scans of large refractory samples was developed and tested successfully. Α number of refractories without or with natural and artificial flaws, respectively, were checked. Nondestructive testing with microwaves has now been sufficiently developed to be transferred to industrial use