A fast track reconstruction algorithm for the ATLAS second level trigger is presented. The timing performance (
3.5
ms
for a jet reconstruction at low luminosity) is satisfactory; the transverse ...impact parameter resolution (
75
μm
) is sufficient to perform an on-line b-tagging, and the full three-dimensional reconstruction produces good seeds for more sophisticated track searches.
Thin Gap Gas Chambers were proposed for a possible upgrade of the end-caps of the DELPHI detector at LEP. Two full prototypes were built and tested at the CERN 20GeV/c SPS pion beam. The main ...construction parameters of the detector and the on-board front-end electronics characteristics are reviewed. Test beam results from the full prototypes, showing the general feasibility of the detector, will be presented.
Thin Gap Gas Chambers have been proposed for an upgrade of the end-caps of the DELPHI detector at LEP due to their very limited longitudinal size combined with high efficiency and high granularity. ...Two full prototypes of the detector have been built and tested. We report on the on-board processor for coordinate computation and data transmission.
We measured the spatial resolution of a 300 μm thick 75 × 500
μm silicon pixel detector as a function of the track angle using a 120 GeV pion beam.
We observed that 13% of tracks perpendicular to the ...detector give a signal on two neighboring pixels; this fraction increases to 50% at an angle of 15° w.r.t. the normal incidence direction. The average spatial resolution is 28.2 μm at 0° and 14.6 μm at 15°. The detector efficiency is not affected by the charge sharing between pixels.
Our data agree with the predictions of a simple geometrical model describing the charge sharing in the region between pixels. This model can be the basis for a full simulation of the behaviour of a pixel detector.
The ATLAS IBL BOC prototype Schroer, N
Journal of instrumentation,
12/2011, Letnik:
6, Številka:
12
Journal Article
Recenzirano
Odprti dostop
The Pixel Detector of the ATLAS experiment at CERN will be upgraded with an Insertable B-Layer (IBL) in 2013. To handle the data readout the currently used VME card pairs consisting of a back of ...crate card (BOC) and a read out driver (ROD) are being redesigned. This paper presents details of the hardware design of the new BOC prototype, which takes advantage from modern FPGA technology and commercial optical modules and abandons the need for a variety of custom components used on the old card. Also the throughput is four times higher and additional features are implemented.
An Insertable B-Layer is planned for the upgrade of the ATLAS detector and will add a fourth and innermost pixel layer to the existing Pixel Detector. 12 million pixels attached to new FE-I4 readout ...ASICs will require new off-detector electronics which is currently realized with two VME-based boards: a Back Of Crate module implementing optical I/O functionality and a Readout Driver module for data processing. This paper illustrates the new readout chain, focusing on the design of the new Readout Driver Card, which, with a fourfold integration with respect to the previous design, builds up the detector data, controls the calibration procedures and interacts via Gigabit links with a novel calibration farm. Future prospects and back compatibility to the existing system are also addressed.
Thin Gap Gas Chambers have been proposed for an upgrade of the endcaps of the DELPHI detector at LEP. Two full size chambers have been built and a study of the optimal operating conditions has been ...carried out. In this paper the main construction parameters are discussed and test results are given. Tests of the electronic readout were performed and the general feasibility of the detector is demonstrated.
Study of aging effects in the HPC readout chambers Cattai, A.; De Min, A.; Feindt, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/1995, Letnik:
367, Številka:
1
Journal Article
Recenzirano
The readout chambers of the HPC calorimeter are affected by large aging. This stimulated intense experimental activity aimed at developing a reliable monitor of the evolution of the detector response ...and at understanding the origin of the aging. Both of these aspects are discussed. Particular attention is devoted to a series of tests performed with HPC units equipped with graphite inserts in the readout chambers.
The Insertable-B-Layer (IBL) is a new pixel detector layer to be installed at the ATLAS experiment at the LHC, CERN in 2013. It will be integrated into the general pixel readout and software ...framework, hence the off-detector readout electronics has to support the new front-end electronics whilst maintaining a high degree of interoperability to the components of the existing system. The off-detector readout is realised using a number of VME card pairs ROD and BOC plus a VME crate controller and a custom timing distribution system. The main elements of the new BOC design comprise optical interfaces towards the detector, signal conditioning and data recovery logic. We present the demonstrator used to verify the design approach. The demonstrator is based on a XILINX SP605 FPGA evaluation board and uses a Microblaze processor inside the FPGA to provide easy and flexible access to all essential BOC functions and the corresponding emulator modules, which enable full test of the entire BOC functionality even without any external components. However, optical interfaces may be connected via a mezzanine card. We present the details of the emulation circuitries together with measurement results showing the operation of the BOC logic.
Silicon pixel sensors developed by the ATLAS collaboration to meet LHC requirements and to withstand hadronic irradiation to fluences of up to
10
15
n
eq
/
cm
2
have been evaluated using a test beam ...facility at CERN providing a magnetic field. The Lorentz angle was measured and found to alter from 9.0° before irradiation, when the detectors operated at
150
V
bias at
B=1.48
T
, to 3.1° after irradiation and operating at
600
V
bias at
1.01
T
. In addition to the effect due to magnetic field variation, this change is explained by the variation of the electric field inside the detectors arising from the different bias conditions.
The depletion depths of irradiated sensors at various bias voltages were also measured. At
600
V
bias
280
μm
thick sensors depleted to
≈200
μm
after irradiation at the design fluence of
1×10
15
1
MeV
n
eq
/
cm
2
and were almost fully depleted at a fluence of
0.5×10
15
1
MeV
n
eq
/
cm
2
.
The spatial resolution was measured for angles of incidence between 0° and 30°. The optimal value was found to be better than
5.3
μm
before irradiation and
7.4
μm
after irradiation.
PDF
