92988840
Resolution and efficiency of the ATLAS muon drift-tube chambers at high background rates
Abstract The resolution and efficiency of a precision drift-tube chamber for the ATLAS muon spectrometer with final read-out electronics was tested at the Gamma Irradiation Facility at CERN in a 100 GeV muon beam at photon irradiation rates of up to 990 Hz / cm 2 , which corresponds to twice the highest background rate expected in ATLAS. A silicon strip detector telescope served as external reference in the beam. The pulse-height measurement of the read-out electronics was used to perform time-slewing corrections, which lead to an improvement of the average drift-tube resolution from 104 to 82 μ m without irradiation, and from 128 to 108 μ m at the maximum expected rate. The measured drift-tube efficiency agrees with the expectation from the dead time of the read-out electronics up to the maximum expected rate.
118899725
Test, Integration and Commissioning of Monitored Drift Tube Chambers for the ATLAS Barrel Muon Spectrometer
c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. The ATLAS experiment at the Large Hadron Collider (LHC) at CERN is currently being assembled and to be ready for data taking in 2007. In the barrel region of its muon spectrometer, a toroidal air-core magnet is instrumented with three layers of Monitored Drift Tube (MDT) chambers as precision tracking detectors; the middle and outer layers of drift chambers also carry Resistive Plate chambers (RPCs) of the trigger system. The barrel part of the spectrometer consists of a total of 682 muon stations, with sizes ranging from 1 m 2 to 11 m 2. The installation of the muon detectors has started in January 2005. At the of the second largest chamber type—each covering an area of up to 8 m 2 —are being built for the outermost barrel region. The MDT chambers have to pass a series of stringent tests before installation to ensure their proper operation in the experiment. At the production site in Munich, these tests include gas tightness, high voltage stability and measurements of the noise rate, and the response to cosmic muons. In addition, the individual wire positions and electronic time offsets of the drift tubes are determined from the cosmic ray data. After shipment to CERN, a subset of the tests is repeated and the MDT chambers are integrated on a common support frame with the trigger chambers. The completed muon station is is further checked with cosmic rays. All results are stored in the ATLAS commissioning database and constitute an important basis for LHC data taking. We present the test methods and results, an overview on the integration work of the muon detectors and report on the experience with the installation of the first stations in the ATLAS experiment.
108271361
Concepts for the readout of time projection chambers
While the use of CCD’s for the readout of TPC’s offers a reliable and ever more of the digitization concept. The problem of precision of currently available FADC’s is discussed together with two proposals for a solution.
126243744
Measurement of the reaction π−p→π+π−n on a transversely polarized target at 17.2 GeV
Preliminary results from a high statistics measurement (1 M events) of the reaction π−p→π+π−n on strong polarization effects which must be attributed to amplitudes corresponding to ’’A1’’ exchange.
122359864
Large-scale production of Monitored Drift Tube chambers for the ATLAS muon spectrometer
Abstract Precision drift tube chambers with a sense wire positioning accuracy of better than 20 μm are under construction for the ATLAS muon spectrometer. 70% of the 88 large chambers for the outermost layer of the central part of the spectrometer have been assembled. Measurements during chamber construction of the positions of the sense wires and of the sensors for the optical alignment monitoring system demonstrate that the requirements for the mechanical precision of the chambers are fulfilled.
120324718
Integration, commissioning and installation of monitored drift tube chambers for the ATLAS barrel muon spectrometer
The ATLAS experiment at the Large Hadron Collider (LHC) at CERN is currently being assembled to be ready to take data in 2007. Its muon spectrometer is designed to achieve a momentum resolution better than 10% at 1 TeV. In the barrel part, a toroidal air-core magnet is instrumented with three layers of Monitored Drift Tube (MDT) chambers for precision tracking. The Max-Planck-Institut fur Physik and the Ludwig-Maximilians-University in Munich have built 88 MDT chambers for the outermost barrel layer. We report on our experience with the tests of the MDT chambers, their integration with the Resistive Plate trigger chambers and the installation of the muon stations in the experiment. First results of their commissioning in the ATLAS detector will be presented.
110855495
Performance of novel silicon n-in-p planar pixel sensors
Abstract The performance of novel n-in-p planar pixel detectors designed for future upgrades of the ATLAS Pixel system is presented. The n-in-p silicon sensors technology is a promising candidate for the pixel upgrade thanks to its radiation hardness and cost effectiveness that allow for enlarging the area instrumented with pixel detectors. The n-in-p modules presented here are composed of pixel sensors produced by CiS connected by bump-bonding to the ATLAS read-out chip FE-I3. The characterization of these devices has been performed before and after irradiation up to a fluence of 5×10 15 1 MeV n eq cm −2 . Charge collection measurements carried out with radioactive sources have proven the functioning of this technology up to these particle fluences. First results from beam test data with a 120 GeV/ c pion beam at the CERN-SPS are also discussed, demonstrating a high tracking efficiency of (98.6±0.3)% and a high collected charge of about 10 ke for a device irradiated at the maximum fluence and biased at 1 kV.
110917125
Radiation hard strip detectors for large-scale silicon trackers
Abstract Major challenges in building silicon strip detectors for future high luminosity experiments are the high radiation level and the huge number of sensors required for the construction of the precision layers of the complete tracking system. Single-sided p + n strip detectors for ATLAS SCT designed and fabricated at the MPI Semiconductor Laboratory have been exposed to 3×10 14 /cm 2 24 GeV protons. The major features of the design, including the biasing technique using implanted resistors, are discussed and results are presented. The technology was transferred to CiS, Germany, a company capable of the desired large-scale production. Results of this industrially fabricated sensors look very promising and show the expected radiation hardness.
195859757
Radiation hard strip detectors on oxygenated silicon
Recent results of the RD48 (ROSE) collaboration suggest the usage of oxygen enriched silicon for sensors operated in the harsh radiation environment of future high luminosity experiments. To investigate if the anticipated beneficial properties are still present after full processing of the wafers, strip detectors for the innermost ring of the ATLAS forward region have been fabricated on oxygen enriched silicon by CiS, Germany. These sensors, together with sensors on standard and thin substrates, have been exposed to 3/spl middot/10/sup 14/ 24 GeV/c protons/cm/sup 2/ at the CERN PS. We are presenting here the comparison between the sensors based on the CV measurements and the investigation of the charge collection efficiency obtained with a /sup 90/Sr source and the analogue readout chip SCT128A.
109337702
A module concept for the upgrades of the ATLAS pixel system using the novel SLID-ICV vertical integration technology
The presented R&D activity is focused on the development of a new pixel module concept for the foreseen upgrades of the ATLAS detector towards the Super LHC employing thin n-in-p silicon sensors together with a novel vertical integration technology. A first set of pixel sensors with active thicknesses of 75??m and 150??m has been produced using a thinning technique developed at the Max-Planck-Institut f?r Physik (MPP) and the MPI Semiconductor Laboratory (HLL). Charge Collection Efficiency (CCE) measurements of these sensors irradiated with 26?MeV protons up to a particle fluence of 1016neqcm?2 have been performed, yielding higher values than expected from the present radiation damage models. The novel integration technology, developed by the Fraunhofer Institut EMFT, consists of the Solid-Liquid InterDiffusion (SLID) interconnection, being an alternative to the standard solder bump-bonding, and Inter-Chip Vias (ICVs) for routing signals vertically through electronics. This allows for extracting the digitized signals from the back side of the readout chips, avoiding wire-bonding cantilevers at the edge of the devices and thus increases the active area fraction. First interconnections have been performed with wafers containing daisy chains to investigate the efficiency of SLID at wafer-to-wafer and chip-to-wafer level. In a second interconnection process the present ATLAS FE-I3 readout chips were connected to dummy sensor wafers at chip-to-wafer level. Preparations of ICV within the ATLAS readout chips for back side contacting and the future steps towards a full demonstrator module will be presented.
55678390
TESTS AND DEVELOPMENT OF DUOPLASMATRON AND MULTI-APERTURE HEAVY ION SOURCES FOR AN RF LINAC
The goal of the program of ion source development for an rf linac has been to produce currents of up to 100 mA of the heavier gaseous ions such as argon and xenon, of good emittance (.02 ..pi.. cm mr, normalized) and charge state 1/sup +/. Existing facilities and hardware utilized included the 470 kV Bevatron injector, the 750 kV injector for the 50 MeV ESCAR linac, the 80 kV Bevatron test stand, a 20 kV LLL test stand and existing duoplasmatron and CTR sources. A summary of test results is shown.