213,665 research outputs found
ATLAS IBL Pixel Upgrade
The upgrade for ATLAS detector will undergo different phase towards
super-LHC. The first upgrade for the Pixel detector will consist of the
construction of a new pixel layer which will be installed during the first
shutdown of the LHC machine (LHC phase-I upgrade). The new detector, called
Insertable B-Layer (IBL), will be inserted between the existing pixel detector
and a new (smaller radius) beam-pipe at a radius of 3.3 cm. The IBL will
require the development of several new technologies to cope with increase of
radiation or pixel occupancy and also to improve the physics performance which
will be achieved by reducing the pixel size and of the material budget. Three
different promising sensor technologies (planar-Si, 3D-Si and diamond) are
currently under investigation for the pixel detector. An overview of the
project with particular emphasis on pixel module is presented in this paper.Comment: 3 pages, 3 figures, presented at the 12th Topical Seminar on
Innovative Particle and Radiation Detectors (IPRD10) 7 - 10 June 2010, Siena
(IT). Accepted by Nuclear Physics B (Proceedings Supplements) (2011
Results from the Commissioning of the ATLAS Pixel Detector with Cosmic data
The ATLAS pixel detector is the innermost detector of the ATLAS experiment at
the Large Hadron Collider at CERN. With approximately 80 million readout
channels, the ATLAS silicon pixel detector is a high-acceptance,
high-resolution, low-noise tracking device. Providing the desired refinement in
charged track pattern recognition capability in order to meet the stringent
track reconstruction requirements, the pixel detector largely defines the
ability of ATLAS to effectively resolve primary and secondary vertices and
perform efficient flavor tagging essential for discovery of new physics.
Being the last sub-system installed in ATLAS by July 2007, the pixel detector
was successfully connected, commissioned, and tested in situ while meeting an
extremely tight schedule, and was ready to take data upon the projected turn-on
of the LHC. Since fall 2008, the pixel detector has been included in the
combined ATLAS detector operation, collecting cosmic muon data. Details from
the pixel detector installation and commissioning, as well as details on
calibration procedures and the results obtained with collected cosmic data, are
presented along with a summary of the detector status.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July
2009, eConf C090726. Contents: 9 pages, 13 figures, 9 reference
Measurement of the energy resolution and calibration of hybrid pixel detectors with GaAs:Cr sensor and Timepix readout chip
This paper describes an iterative method of per-pixel energy calibration of
hybrid pixel detectors with GaAs:Cr sensor and Timepix readout chip. A
convolution of precisely measured spectra of characteristic X-rays of different
metals with the resolution and the efficiency of the pixel detector is used for
the calibration. The energy resolution of the detector is also measured during
the calibration. The use of per-pixel calibration allows to achieve a good
energy resolution of the Timepix detector with GaAs:Cr sensor: 8% and 13% at 60
keV and 20 keV, respectively
Optical Readout in a Multi-Module System Test for the ATLAS Pixel Detector
The innermost part of the ATLAS experiment at the LHC, CERN, will be a pixel
detector. The command messages and the readout data of the detector are
transmitted over an optical data path. The readout chain consists of many
components which are produced at several locations around the world, and must
work together in the pixel detector. To verify that these parts are working
together as expected a system test has been built up. In this paper the system
test setup and the operation of the readout chain is described. Also, some
results of tests using the final pixel detector readout chain are given.Comment: 6 pages, 10 figures, Pixel 2005 proceedings preprin
The new radiation-hard optical links for the ATLAS pixel detector
The ATLAS detector is currently being upgraded with a new layer of pixel
based charged particle tracking and a new arrangement of the services for the
pixel detector. These upgrades require the replacement of the opto-boards
previously used by the pixel detector. In this report we give details on the
design and production of the new opto-boards.Comment: Presentation at the DPF 2013 Meeting of the American Physical Society
Division of Particles and Fields, Santa Cruz, California, August 13-17, 201
A low mass pixel detector upgrade for CMS
The CMS pixel detector has been designed for a peak luminosity of
10^34cm-2s-1 and a total dose corresponding to 2 years of LHC operation at a
radius of 4 cm from the interaction region. Parts of the pixel detector will
have to be replaced until 2015. The detector performance will be degraded for
two reasons: radiation damage of the innermost layers and the planned increase
of the LHC peak luminosity by a factor of 2-3. Based on the experience in
planning, constructing and commissioning of the present pixel detector, we
intend to upgrade the whole pixel detector in 2015. The main focus is on
lowering the material budget and adding more tracking points. We will present
the design of a new low mass pixel system consisting of 4 barrel layers and 3
end cap disks on each side. The design comprises of thin detector modules and a
lightweight mechanical support structure using CO2 cooling. In addition, large
efforts have been made to move material from the services out of the tracking
region.Comment: 10 pages, 10 figures, Proceeding of RD09 - 9th International
Conference on Large Scale Applications and Radiation Hardness of
Semiconductor Detectors 30 September - 2 October 2009, Florence, Ital
Status of the CMS Phase I Pixel Detector Upgrade
A new pixel detector for the CMS experiment is being built, owing to the
instantaneous luminosities anticipated for the Phase I Upgrade of the LHC. The
new CMS pixel detector provides four-hit tracking while featuring a
significantly reduced material budget as well as new cooling and powering
schemes. A new front-end readout chip mitigates buffering and bandwidth
limitations, and comprises a low-threshold comparator. These improvements allow
the new pixel detector to sustain and improve the efficiency of the current
pixel tracker at the increased requirements imposed by high luminosities and
pile-up. This contribution gives an overview of the design of the upgraded
pixel detector and the status of the upgrade project, and presents test beam
performance measurements of the production read-out chip.Comment: Presented at the 10th International "Hiroshima" Symposium on the
Development and Application of Semiconductor Tracking Detectors, Xi'an, Chin
Nano-optical observation of cascade switching in a parallel superconducting nanowire single photon detector
The device physics of parallel-wire superconducting nanowire single photon
detectors is based on a cascade process. Using nano-optical techniques and a
parallel wire device with spatially-separate pixels we explicitly demonstrate
the single- and multi-photon triggering regimes. We develop a model for
describing efficiency of a detector operating in the arm-trigger regime. We
investigate the timing response of the detector when illuminating a single
pixel and two pixels. We see a change in the active area of the detector
between the two regimes and find the two-pixel trigger regime to have a faster
timing response than the one-pixel regime.Comment: 11 pages, 2 figure
The ONSEN Data Reduction System for the Belle II Pixel Detector
We present an FPGA-based online data reduction system for the pixel detector
of the future Belle II experiment. The occupancy of the pixel detector is
estimated at 3 %. This corresponds to a data output rate of more than 20 GB/s
after zero suppression, dominated by background. The Online Selection Nodes
(ONSEN) system aims to reduce the background data by a factor of 30. It
consists of 33 MicroTCA cards, each equipped with a Xilinx Virtex-5 FPGA and 4
GiB DDR2 RAM. These cards are hosted by 9 AdvancedTCA carrier boards. The ONSEN
system buffers the entire output data from the pixel detector for up to 5
seconds. During this time, the Belle II high-level trigger PC farm performs an
online event reconstruction, using data from the other Belle II subdetectors.
It extrapolates reconstructed tracks to the layers of the pixel detector and
defines regions of interest around the intercepts. Based on this information,
the ONSEN system discards all pixels not inside a region of interest before
sending the remaining hits to the event builder system. During a beam test with
one layer of the pixel detector and four layers of the surrounding silicon
strip detector, including a scaled-down version of the high-level trigger and
data acquisition system, the pixel data reduction using regions of interest was
exercised. We investigated the data produced in more than 20 million events and
verified that the ONSEN system behaved correctly, forwarding all pixels inside
regions of interest and discarding the rest.Comment: 7 pages, 10 figure
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