Search results for "Particle detector"
showing 10 items of 200 documents
Coexisting structures in 115Sn and 116Sn
1998
Abstract Excited states up to I ≈ 20 in 115 Sn and 116 Sn, populated via the ( 18 O, αxn) reactions, have been studied using the DORIS Ge detector array in conjunction with charged particle detectors. In both nuclei, spherical as well as regular, deformed level structures were found. The spherical states are interpreted to arise from pure neutron configurations, while the deformed, intruder bands obviously involve proton 2p-2h excitations across the Z = 50 shell gap.
A comparison of the performance of irradiated p-in-n and n-in-n silicon microstrip detectors read out with fast binary electronics
2000
Abstract Both n-strip on n-bulk and p-strip on n-bulk silicon microstrip detectors have been irradiated at the CERN PS to a fluence of 3×10 14 p cm −2 and their post-irradiation performance compared using fast binary readout electronics. Results are presented for test beam measurements of the efficiency and resolution as a function of bias voltage made at the CERN SPS, and for noise measurements giving detector strip quality. The detectors come from four different manufacturers and were made as prototypes for the SemiConductor Tracker of the ATLAS experiment at the CERN LHC.
Silicon microstrip detectors for the ATLAS SCT
2002
Abstract The ATLAS Semiconductor Tracker at the Large Hadron Collider (LHC) will incorporate ∼20,000 individual silicon microstrip sensors representing ∼60 m 2 of silicon. Production and delivery of the sensors is already underway and scheduled for completion by late 2002. The sensors have been optimised for operation in the harsh radiation environment of the LHC, and subjected to an extensive qualification program in which their pre- and post-irradiation characteristics have been evaluated. The sensor design features are reviewed, together with their electrical characteristics and the Quality Control procedures adopted by ATLAS during production.
Alignment of the NOMAD-STAR detector
2000
Abstract This note describes the alignment of the NOMAD-STAR detector. This is the B 4 C-silicon target installed in the NOMAD spectrometer in 1997. NOMAD-STAR is composed of modules of 12 silicon detectors each giving a total length of 72 cm. Ten of these modules (called ladders) are assembled to form a layer. There are five layers interleaved with passive boron carbide plates. The total surface of silicon is 1.14 m 2 . Energetic muons from the flat-top of the CERN SPS cycle provide the necessary information to perform a very precise software alignment. This alignment is needed to ensure that the impact parameter measurement needed for the identification of taus in a detector like NOMAD-ST…
TRACKING WITH THE ALEPH TIME PROJECTION CHAMBER
1991
The tracking performance of the ALEPH time projection chamber (TPC) has been studied using the data taken during the LEP (Large Electron-Positron Collider) running periods in 1989 and 1990. After careful correction of residual distortions and optimization of coordinate reconstruction algorithms, a single coordinate resolution of 173 mu m in the azimuthal and 740 mu m in the longitudinal direction is achieved. This results in a momentum resolution for the TPC alone of Delta p/p/sup 2/=0.0012 (GeV/c)/sup -1/. In combination with the ALEPH inner tracking chamber (ITC), a total momentum resolution of Delta p/p/sup 2/=0.0008 (GeV/c)/sup -1/, close to the design specifications, is reached. >
EMMA – a new underground cosmic-ray experiment
2008
An experiment observing underground muons originating from cosmic-ray air showers is under preparation in the Pyhasalmi mine, Finland. The aim is to cover an area of about 200-300 m(2), and the detector setup is capable of measuring the muon multiplicity and their lateral distribution. The detector is placed at a depth of about 85 m (corresponding about 240 m w.e.), which gives a threshold energy of muons of about 45 GeV. The detection of the multimuon events is motivated by partly unknown composition of the primary cosmic rays in the energy region of 10(15)-10(16) eV, i.e., the knee region. In addition, by measuring only the higher energy muons of the air shower, the lowest energy muons be…
Measurement ofb-jet shapes in inclusive jet production inpp¯collisions ats=1.96 TeV
2008
We present a measurement of the shapes of b-jets using 300 pb(-1) of data obtained with the upgraded Collider Detector at Fermilab (CDF II) in p(p)overbar collisions at center-of-mass energy root s=1.96 TeV. This measurement covers a wide transverse momentum range, from 52 to 300 GeV/c. Samples of heavy-flavor enhanced jets together with inclusive jets are used to extract the average shapes of b-jets. The b-jets are expected to be broader than inclusive jets. Moreover, b-jets containing a single b-quark are expected to be narrower than those containing a b(b)overbar pair from gluon splitting. The measured b-jet shapes are found to be significantly broader than expected from the PYTHIA and H…
Use of an FPGA to identify electromagnetic clusters and isolated hadrons in the ATLAS level-1 calorimeter trigger
2003
Abstract At the full LHC design luminosity of 10 34 cm −2 s −1 , there will be approximately 109 proton–proton interactions per second. The ATLAS level-1 trigger is required to have an acceptance factor of ∼10−3. The calorimeter trigger covers the region |η|⩽5.0, and φ=0 to 2π. The distribution of transverse energy over the trigger phase space is analysed to identify candidates for electrons/photons, isolated hadrons, QCD jets and non-interacting particles. The Cluster Processor of the level-1 calorimeter trigger is designed to identify transverse energy clusters associated with the first two of these. The algorithms based on the trigger tower energies which have been designed to identify s…
The AMANDA neutrino detector - Status report
2000
Abstract The first stage of the AMANDA High Energy Neutrino Detector at the south Pole, the 302 PMT array AMANDA-B10, is taking data since 1997. We describe results on atmospheric neutrinos, limits on indirect WIMP detection, seasonal muon flux variation, relativistic monopole flux limits, a search for gravitational collapse neutrinos, and a depth scan of the optical ice properties. The next stage 19-string detector AMANDA-II with ∼650 PMTs will be completed in spring 2000.
Inclusive D∗-meson production in ep scattering at low Q2 in the GM-VFN scheme at NLO
2009
Abstract We have calculated the next-to-leading order cross sections for the inclusive production of D ∗ -mesons in ep collisions at HERA for finite, although very small Q 2 . In this Q 2 -range, the same approximations as for photoproduction can be used. Our calculation is performed in the general-mass variable-flavour-number scheme. In this approach, large logarithms of the charm transverse momentum are resummed and finite terms depending on m 2 / p T 2 are kept in the hard scattering cross sections. The theoretical results are compared with recent data from the ZEUS Collaboration at HERA. On average, we find good agreement.