1,835 research outputs found
Mapping the material distribution of a complex structure in an electron beam
No full textThe simulation and analysis of High Energy Physics experiments require a realisticsimulation of the detector material and its distribution. The challenge is to describe all activeand passive parts of large scale detectors like ATLAS in terms of their size, position and materialcomposition. The common method for estimating the radiation length by weighing individualcomponents, adding up their contributions and averaging the resulting material distribution overextended structures provides a good general estimate, but can deviate significantly from the materialactually present.A method has been developed to assess its material distribution with high spatial resolutionusing the reconstructed scattering angles and hit positions of high energy electron tracks traversingan object under investigation. The study presented here shows measurements for an extendedstructure with a highly inhomogeneous material distribution. The structure under investigation isan End-of-Substructure-card prototype designed for the ATLAS Inner Tracker strip tracker — aPCB populated with components of a large range of material budgets and sizes.The measurements presented here summarise requirements for data samples and reconstructedelectron tracks for reliable image reconstruction of large scale, inhomogeneous samples, choicesof pixel sizes compared to the size of features under investigation as well as a bremsstrahlungcorrection for high material densities and thicknesses
Advanced monolithic active pixel sensors for tracking, vertexing and calorimetry with full CMOS capability
No full textFirst design of a crystal-based extraction of 6 GeV electrons for the DESY II Booster Synchrotron
No full textA proof-of-principle experimental setup for the extraction of 6 GeV electrons from the DESY II Booster Synchrotron using the channeling effect in a bent crystal is elaborated. Various aspects of the experimental setup were investigated in detail, such as the particle beam dynamics during the extraction process, the manufacturing and characterization of bent crystals, and the detection of the extracted beam. In order to optimize the crystal geometry, the overall process of beam extraction was simulated, taking into account the influence of radiation energy losses. As result it is concluded that the multi-turn electron beam extraction efficiency can reach up to 16%. In principle this crystal-based beam extraction technique can be applied at any electron synchrotron in order to provide multi-GeV electron beams in a parasitic mode. This technique will allow to supply fixed-target experiments by intense high-quality monoenergetic electron beams. Furthermore, electron/positron crystal-based extraction from future lepton colliders may provide an access to unique experimental conditions for ultra-high energy fixed-target experiments including searches for new physics beyond the Standard Model
Searches for MSSM Higgs Bosons with the DELPHI detector up to =209 GeV
No full textSearches for hA pair production and hZ production have been performed. Special emphasis has been put on searches, in which the Higgs can decay invisibly into neutralinos. The data collected by the DELPHI experiment at centre-of-mass energies between 191.6 and 201.7 GeV for the year 1999 and between 201.7 and 209.0 GeV for the ongoing data taking in 2000 has been used. These analyses are used, in combination with our results at lower energies, to set 95% confidence levels on the existence of a light neutral Higgs Boson h and a neutral pseudoscalar Higgs Boson A in a mass range of 85-115 GeV/c /sup 2/. Combining the searches for visible and invisible Higgs decays allows to obtain 95% confidence levels on the existence of h independent of the branching ratio into invisible decays, if the visible decays are taken to be the SM ones. The MSSM parameter space excluded by these searches has been determined. (9 refs)
LYCORIS - A Large Area Strip Telescope
No full textThe LYCORIS Large Area Silicon Strip Telescope for the DESY II Test Beam Facility is presented. The DESY II Test Beam Facility provides elec- tron and positron beams for beam tests of up to 6 GeV. A new telescope with a large 10 × 20 cm2 coverage area based on a 25 μm pitch strip sensor is to be installed within the PCMAG 1 T solenoid. The current state of the system is presented
LYCORIS - A Large Area Strip Telescope
No full textThe LYCORIS Large Area Silicon Strip Telescope for the DESY II Test Beam Facility is presented. The DESY II Test Beam Facility provides elec- tron and positron beams for beam tests of up to 6 GeV. A new telescope with a large 10x20 cm2 coverage area based on a 25 {\mu}m pitch strip sensor is to be installed within the PCMAG 1 T solenoid. The current state of the system is presented
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