The ATLAS Cathode Strip Chamber system consists of two end-caps with 16 chambers each. The CSC Readout Drivers (RODs) are purpose-built boards encapsulating 13 DSPs and around 40 FPGAs. The principal ...responsibility of each ROD is for the extraction of data from two chambers at a maximum trigger rate of 75 KHz. In addition, each ROD is in charge of the setup, control and monitoring of the on-detector electronics. This paper introduces the design of the CSC ROD software. The main features of this design include an event flow schema that decentralizes the different dataflow streams, which can thus operate asynchronously at its own natural rate; an event building mechanism that associates data transferred by the asynchronous streams belonging to the same event; and a sparcification algorithm that discards uninteresting events and thus reduces the data occupancy volume. The time constraints imposed by the trigger rate have made paramount the use of optimization techniques such as the curiously recurrent template pattern and the programming of critical code in assembly language. The behaviour of the CSC RODs has been characterized in order to validate its performance.
Data acquisition (DAQ) electronics are described for a system of high-rate cathode strip chambers (CSC) in the forward region of A Toroidal LHC ApparatuS (ATLAS) muon spectrometer. The system ...provides serial streams of control signals for switched capacitor array analog memories on the chambers and accepts a total of nearly 294 Gbit/s in serial raw data streams from 64 chambers in the design configuration. Processing of the data is done in two stages, leading to an output bandwidth of 2.56 Gbit/s. The architecture of the system is described, as are some important signal processing algorithms and hardware implementation details. Although designed for a specific application, the architecture is sufficiently general to be used in other contexts.
The ATLAS Cathode Strip Chamber system consists of two end-caps with 16 chambers each. The CSC Readout Drivers (RODs) are purpose-built boards encapsulating 13 DSPs and around 40 FPGAs. The principal ...responsibility of each ROD is for the extraction of data from two chambers at a maximum trigger rate of 75 KHz. In addition, each ROD is in charge of the setup, control and monitoring of the on-detector electronics. This paper introduces the design of the CSC ROD software. The main features of this design include an event flow schema that decentralizes the different dataflow streams, which can thus operate asynchronously at its own natural rate; an event building mechanism that associates data transferred by the asynchronous streams belonging to the same event; and a sparcification algorithm that discards uninteresting events and thus reduces the data occupancy volume. The time constraints imposed by the trigger rate have made paramount the use of optimization techniques such as the curiously recurrent template pattern and the programming of critical code in assembly language. The behaviour of the CSC RODs has been characterized in order to validate its performance.
The Muon Spectrometer of the ATLAS detector at the LHC is designed to provide high quality stand-alone muon identification, momentum measurement and trigger capabilities with high pseudorapidity ...coverage. Precision tracking at the inner-most station in the high pseudorapidity regions, 2.3 < |eta| < 2.7, is performed by 16 four-layered Cathode Strip Chambers on each end-cap. These are multi-wire proportional chambers with segmented cathodes providing excellent spatial resolution and high counting rate capability. The second cathode of each layer is coarsely segmented, providing the transverse coordinate. The detector level performance of the system is presented. The installation and commissioning effort for the Cathode Strip Chambers is described. Finally, the in situ performance is briefly discussed.
The Muon Spectrometer of the ATLAS detector at the LHC is designed to provide high quality stand-alone muon identification, momentum measurement and trigger capabilities with high pseudorapidity ...coverage. Precision tracking at the inner-most station in the high pseudorapidity regions, 2.3 < |eta| < 2.7, is performed by 16 four-layered Cathode Strip Chambers on each end-cap. These are multi-wire proportional chambers with segmented cathodes providing excellent spatial resolution and high counting rate capability. The second cathode of each layer is coarsely segmented, providing the transverse coordinate. The detector level performance of the system is presented. The installation and commissioning effort for the Cathode Strip Chambers is described. Finally, the in situ performance is briefly discussed.
The New Small Wheel electronics Iakovidis, G; Levinson, L; Afik, Y ...
arXiv (Cornell University),
05/2023
Paper, Journal Article
Odprti dostop
The increase in luminosity, and consequent higher backgrounds, of the LHC upgrades require improved rejection of fake tracks in the forward region of the ATLAS Muon Spectrometer. The New Small Wheel ...upgrade of the Muon Spectrometer aims to reduce the large background of fake triggers from track segments that are not originated from the interaction point. The New Small Wheel employs two detector technologies, the resistive strip Micromegas detectors and the "small" Thin Gap Chambers, with a total of 2.45 Million electrodes to be sensed. The two technologies require the design of a complex electronics system given that it consists of two different detector technologies and is required to provide both precision readout and a fast trigger. It will operate in a high background radiation region up to about 20 kHz/cm\(^{2}\) at the expected HL-LHC luminosity of \(\mathcal{L}\)=7.5\(\times10^{34}\)cm\(^{-2}\)s\(^{-1}\). The architecture of the system is strongly defined by the GBTx data aggregation ASIC, the newly-introduced FELIX data router and the software based data handler of the ATLAS detector. The electronics complex of this new detector was designed and developed in the last ten years and consists of multiple radiation tolerant Application Specific Integrated Circuits, multiple front-end boards, dense boards with FPGA's and purpose-built Trigger Processor boards within the ATCA standard. The New Small Wheel has been installed in 2021 and is undergoing integration within ATLAS for LHC Run 3. It should operate through the end of Run 4 (December 2032). In this manuscript, the overall design of the New Small Wheel electronics is presented.
The Muon Spectrometer of the ATLAS detector at the LHC is designed to provide high quality stand-alone muon identification, momentum measurement and trigger capabilities with high pseudorapidity ...coverage. Precision tracking at the inner-most station in the high pseudorapidity regions, 2.0 ≪ |η| ≪ 2:7, is performed by 16 four-layered Cathode Strip Chambers on each end-cap. These are multi-wire proportional chambers with segmented cathodes providing excellent spatial resolution and high counting rate capability. The second cathode of each layer is coarsely segmented, providing the transverse coordinate. The detector level performance of the system is presented. The installation and commissioning effort for the Cathode Strip Chambers is described. Finally, the in situ performance is briefly discussed.
The first measurement of B(D{sup 0}{yields}{phi}X{sup 0}) and an upper limit for B(D{sup +}{yields}{phi}X{sup +}) are determined from 22.3 pb{sup -1} of e{sup +}e{sup -} annihilation data at a c.m. ...energy of 4.03 GeV. The data were recorded by the Beijing Spectrometer (BES) at BEPC. A recoil charge method is applied to charm threshold data to determine the charge of the D meson in the recoil from 9054{+-}309{+-}416 reconstructed D{sup 0}, D{sup +} mesons. The branching fractions B(D{sup 0}{yields}{phi}X{sup 0})=(1.71{sub -0.71}{sup +0.76}{+-}0.17)%, and B(D{sup +}{yields}{phi}X{sup +})<1.8% are determined from 10 events with a reconstructed D and a recoiling {phi}. In addition, a 90% C.L. upper limit of B(D{sup +}{yields}{phi}e{sup +}X{sup 0})<1.6% is determined from a search for semileptonic decays of the D{sup +}. (c) 2000 The American Physical Society.
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