The D0 Silicon Microstrip Tracker Ahmed, S.N.; Aoki, M.; Åsman, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2011, Letnik:
634, Številka:
1
Journal Article
Recenzirano
Odprti dostop
This paper describes the mechanical design, the readout chain, the production, testing and the installation of the Silicon Microstrip Tracker of the D0 experiment at the Fermilab Tevatron collider. ...In addition, we describe the performance and operational experience of the detector during the experiment data collection between 2001 and 2010.
High-level triggers in ATLAS Radu, A.; Baines, J.T.M.; Baratella, A. ...
IEEE transactions on nuclear science,
04/2002, Letnik:
49, Številka:
2
Journal Article
Recenzirano
The trigger and data-acquisition system of ATLAS, a general-purpose experiment at the Large Hadron Collider (LHC), will be based on three levels of online selection. Starting from the bunch-crossing ...rate of 40 MHz (an interaction rate of 1 GHz at design luminosity-/spl sim/ 10/sup 34/ cm/sup -2/s/sup -1/), the first level trigger (LVL1) will reduce the rate to about 75 kHz using purpose-built hardware. An additional factor of about 10/sup 3/ in rate reduction is to be provided by the high-level triggers (HLTs) system, with two main functional components: the second-level trigger (LVL2) and the event filter(EF). LVL2 has to provide a fast decision (guided by the information from LVL1), using only a fraction of the full event, however, already at full granularity and can combine all subdetectors. At the EF, a refined selection is made with the. capability of full event reconstruction and the use of detailed calibration and alignment parameters. The HLT software architecture will provide a common and rather "lightweight" framework, able to execute the various selection algorithms and to control the sequence of execution according to the event properties and configuration parameters. System flexibility is a strong requirement in order to adapt to changes, e.g., in luminosity and background conditions. This paper will present the approach chosen for the software design of the HLT selection framework and of the algorithm interface, giving examples for selection sequences and algorithms. Based on currently existing prototypes, results for both the expected physics (signal efficiency, background rejection) and system (execution time) performance will also be shown.
The transverse energy carried by charged hadrons and by \({\pi}^-\) mesons is studied in interactions of \({\pi}^+\) and K\(^+\) mesons with protons and nuclei at 250 GeV/c. The data obtained on ...transverse energy flow at mid-rapidity can be described by the FRITIOF7.0 model with tuned parameters.
Radiation-hard/high-speed data transmission using optical links Gan, K.K.; Abi, B.; Fernando, W. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2009, Letnik:
607, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The silicon trackers of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN (Geneva) use optical links for data transmission. An upgrade of the trackers is planned for the Super LHC ...(SLHC), an upgrade of LHC with ten times higher luminosity. We investigate the radiation-hardness and bandwidth of various components for possible application in the data transmission upgrade. For the electrical connection between the front-end electronics and the optical link, we study the possible use of a micro twisted-pair cable. The bandwidth is measured to be 640
Mb/s for transmission up to 1.4
m and 320
Mb/s for transmission up to 4
m if the signal is pre-emphasized. For the optical devices, we irradiated Vertical-Cavity Surface-Emitting Laser (VCSEL) and GaAs PIN arrays from three vendors and silicon PIN arrays from one vendor. All arrays can be operated up to the SLHC dosage except for the GaAs PIN arrays, which have very low responsivities after irradiation. We have also demonstrated the feasibility of fabricating a novel optical package for housing VCSEL and PIN arrays with BeO (beryllium oxide) as the substrate for efficient removal of heat.
Spike production is studied in pp and π
+p/K
+p collisions in the beam-momentum range of 205–360 GeV/c. The pseudorapidity distribution of spike centers exhibits two narrow peaks in pp interactions, ...while having one wide bump in πp and Kp interactions. The position of the peaks is consistent with the expectation from a model of coherent gluon radiation at finite length. The interference between the quark color amplitudes obtained within this model causes two off-center peaks in pp data, but only one central peak in πp and Kp data.
The invariant spectra of
π
− mesons produced in (
π
+/K
+)p interactions at 250 GeV/
c are analysed in the framework of the hydrodynamical model of three-dimensionally expanding cylindrically ...symmetric finite systems. A satisfactory description of experimental data is achieved. The data favour the pattern according to which the hadron matter undergoes predominantly longitudinal expansion and non-relativistic transverse expansion with mean transverse velocity 〈
u
t〉=0.20±0.07, and is characterized by a large temperature inhomogeneity in the transverse direction: the extracted freeze-out temperature at the center of the tube and at the transverse rms radius are 140±3 MeV and 82±7 MeV, respectively. The width of the (longitudinal) space-time rapidity distribution of the pion source is found to be
Δη=1.36±0.02. Combining this estimate with results of the Bose-Einstein correlation analysis in the same experiment, one extracts a mean freeze-out time of the source of 〈
τ
f〉=1.4±0.1 fm/
c and its transverse geometrical rms radius,
R
G(rms)=1.2±0.2 fm.
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