Performance of the LHCb muon system Alves, AA Jr; Anderlini, L; Anelli, M ...
Journal of instrumentation,
02/2013, Letnik:
7, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The performance of the LHCb Muon system and its stability across the full 2010 data taking with LHC running at square root s = 7 TeV energy is studied. The optimization of the detector setting and ...the time calibration performed with the first collisions delivered by LHC is described. Particle rates, measured for the wide range of luminosities and beam operation conditions experienced during the run, are compared with the values expected from simulation. The space and time alignment of the detectors, chamber efficiency, time resolution and cluster size are evaluated. The detector performance is found to be as expected from specifications or better. Notably the overall efficiency is well above the design requirements.
The performance of the muon identification in LHCb is extracted from data using muons and hadrons produced in J/psi arrow right mu super(+) mu super(-) , Lambda super(0) arrow right ppi super(-) and ...D* super(+) arrow right pi super(+)D super(0)(K super(-)pi super(+)) decays. The muon identification procedure is based on the pattern of hits in the muon chambers. A momentum dependent binary requirement is used to reduce the probability of hadrons to be misidentified as muons to the level of 1%, keeping the muon efficiency in the range of 95-98%. As further refinement, a likelihood is built for the muon and non-muon hypotheses. Adding a requirement on this likelihood that provides a total muon efficiency at the level of 93%, the hadron misidentification probabilities are below 0.6%.
A new front-end board is under development for the CERN SPS Multi ORbit Position System (MOPOS). Based on logarithmic amplifiers, it measures the beam position over a large dynamic range of beam ...intensities and resolves the multi-batch structure of the SPS beams. Analogue data are digitized at 10 MS/s, packed in frames by an FPGA and on every turn sent to the readout board, via a 2.4 Gb/s optical transmission link. A first prototype has been successfully tested with several SPS beams. This paper presents an overall description of the system and its capabilities highlighted by the first beam measurements.
We present a custom integrated circuit, named DIALOG (DIagnostic, time Adjustment and LOGics), which is a fundamental building block in the front-end architecture of the LHCb Muon detector. DIALOG is ...realized in IBM 0.25 mum technology, using radiation-hardening layout techniques. DIALOG integrates important tools for detector time alignment procedures and time alignment monitoring on the front-end system. In particular, it integrates 16 programmable delays, which can be regulated in steps of 1 ns. Other features, necessary for the Muon trigger operation and for a safe front-end monitoring are integrated into DIALOG. It generates the information, that will be used by the trigger, as a combination of its 16 inputs from the Amplifier-Shaper-Discriminator (ASD) chips, it generates the thresholds of the ASD, it monitors the rate of all its input channels. We describe the circuit architecture, its internal blocks and its main modes of operation. Measurements performed on final prototypes are also reported
High-rate particle triggering with triple-GEM detector Alfonsi, M.; Bencivenni, G.; de Simone, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2004, Letnik:
518, Številka:
1
Journal Article
Recenzirano
We report the results of a systematic study of the time performance of triple-GEM detectors operated with Ar/CO
2/CF
4 and Ar/CF
4/iso-C
4H
10 gas mixtures.
This study and the detector development ...has been performed in the framework of an R&D activity on detectors for the innermost part (region R1) of the first muon station (M1) of the LHCb experiment.
The use of fast gas mixtures allows to achieve a time resolution better than
5
ns
(r.m.s.) and a single detector efficiency up to ∼ 99% in a
20
ns
time window. Discharge studies have been performed at the
πM1 hadron beam facility of the Paul Scherrer Institute. Local aging properties were investigated exposing the detector to a collimated
5.9
keV
X-rays beam.
The whole R&D activity with different gas mixtures has been performed with small
10×10
cm
2
triple-GEM detector prototypes.
A full size prototype (module-0) constituted by two
20×24
cm
2
triple-GEM detectors, equipped with front-end electronics based on ASDQ chip, has been built and successfully tested, with the chosen Ar/CO
2/CF
4=45/15/40 gas mixture, at the electron test beam facility at the Laboratori Nazionali di Frascati.
Pseudomonas aeruginosa and Burkholderia cenocepacia are opportunistic pathogens causing important chronic pulmonary infections in patients affected by cystic fibrosis (CF). The interplay of bacterial ...and host factors involved in the establishment and evolution of these infections needs further clarification. We investigated the susceptibility of P. aeruginosa and B. cenocepacia derived from CF patients or from the environment to hyperimmune sera obtained from the same CF patients and evaluated the amount of specific antibodies present in these sera. Our data indicate that the bactericidal activity of human serum against these two bacteria is mostly complement-mediated, and that the mucous layer probably confers serum-resistance to B. cenocepacia. The mean amount of antibodies against P. aeruginosa was higher than that against B. cenocepacia. The contribution of these data to the assessment of the importance of the humoral immune response in CF pulmonary infections by Pseudomonas and Burkholderia is briefly discussed.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The Muon detector of the Large Hadron Collider (LHCb) experiment at the Center for Nuclear Research plays a fundamental role in the first trigger level. It is mainly realized by means of a MWPC ...technology and consists of about 126,000 front-end channels. High efficiency is necessary both at detector and front-end level to satisfy the trigger requirement of five hits per five Muon stations with an overall efficiency of 95%. This corresponds to having a single front-end channel detection efficiency of 99% within a time window of 20 ns and also poses the problem of an accurate time alignment of the whole detector. The problem is addressed by designing two custom integrated circuits, named DIALOG and SYNC, realized in the IBM 0.25 /spl mu/m technology.
DIALOG: an ASIC for timing of the LHCb muon detector Cadeddu, S; De Leo, V; Deplano, C ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2004, Letnik:
518, Številka:
1
Journal Article
Recenzirano
The muon detector of the LHCb experiment at CERN plays a fundamental role in the first trigger level. It is mainly realized by means of a multi-wire proportional chambers technology and consists of ...about 126,000 front-end channels. High efficiency is necessary both at detector and front-end level to satisfy the trigger requirement of five hits per five muon stations with an overall efficiency of 95%. This corresponds to having a single front-end channel detection efficiency of 99% within a time window of 20
ns, and also poses the problem of an accurate time alignment of the whole detector. The problem is addressed by designing two custom integrated circuits, named DIagnostic, time Adjustment and LOGics (DIALOG) and SYNC. DIALOG integrates important tools for detector time alignment procedures and time alignment monitoring on the front-end system. Many other features, necessary for the muon trigger operation and for a safe front-end monitoring, are integrated on DIALOG.
We report the results of a systematic study of the performance of
10×10
cm
2
triple-GEM detectors operated with several gas mixtures.
In a previous paper, we pointed out that adding CF
4 to the ...standard Ar/CO
2 gas mixture allows to improve the time resolution of the detector from
∼10
ns
down to
∼6
ns
(r.m.s.). In this paper, we discuss the results obtained with CF
4 and iso-C
4H
10-based gas mixtures, during a beam test at the πM1 beam facility of the Paul Scherrer Institute (PSI).
Preliminary results concerning the discharge probability of triple-GEM detector, when exposed to both high intensity pion/proton beam and α-particles from a radioactive source are presented. Gain measurements and aging tests, using a high intensity
5.9
keV
X-ray tube, are eventually discussed.
We report the results of a systematic study of the time performance of triple-GEM detectors operated with several gas mixtures which are new for this kind of detectors. We show that a considerable ...improvement, with respect to the traditional gas mixture Ar/CO
2 (70/30), is obtained with the fast and high yield based CF
4 and iso-C
4H
10 gas mixtures; time resolutions better than 5
ns. Discharge studies have been performed with high intensity π/proton beams at the Paul Sherrer Institute (PSI). The results show that the operation of the detector is very stable, if a small fraction of iso-C
4H
10 or a large amount of CF
4, is use.
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