382 research outputs found
Integration and Conventional Systems at STAR
At the beginning of the design and construction of the STAR Detector, the
collaboration assigned a team of physicists and engineers the responsibility of
coordinating the construction of the detector. This group managed the general
space assignments for each sub-system and coordinated the assembly and planning
for the detector. Furthermore, as this group was the only STAR group with the
responsibility of looking at the system as a whole, the collaboration assigned
it several tasks that spanned the different sub-detectors. These items included
grounding, rack layout, cable distribution, electrical, power and water, and
safety systems. This paper describes these systems and their performance.Comment: 17 pages, 6 figures, Contribution to a NIM Volume Dedicated to the
Detectors and the Accelerator at RHI
The BRAN luminosity detectors for the LHC
This paper describes the several phases which led, from the conceptual
design, prototyping, construction and tests with beam, to the installation and
operation of the BRAN (Beam RAte of Neutrals) relative luminosity monitors for
the LHC. The detectors have been operating since 2009 to contribute, optimize
and maintain the accelerator performance in the two high luminosity interaction
regions (IR), the IR1 (ATLAS) and the IR5 (CMS). The devices are gas ionization
chambers installed inside a neutral particle absorber 140 m away from the
Interaction Points in IR1 and IR5 and monitor the energy deposited by
electromagnetic showers produced by high-energy neutral particles from the
collisions. The detectors have the capability to resolve the bunch-by-bunch
luminosity at the 40 MHz bunch rate, as well as to survive the extreme level of
radiation during the nominal LHC operation. The devices have operated since the
early commissioning phase of the accelerator over a broad range of luminosities
reaching 1.4*10^34 cm-2 s-1 with a peak pileup of 45 events per bunch crossing.
Even though the nominal design luminosity of the LHC has been exceeded, the
BRAN is operating well. After describing the multiple applications that the
BRAN can be used to monitor the luminosity of the accelerator, we discuss the
technical choices that led to its construction and the different tests
performed prior to the installation in two IRs of the LHC. Performance
simulations are presented together with operational results obtained during p-p
operations, including runs at 40 MHz bunch rate, Pb-Pb operations and p-Pb
operations.Comment: 22 pages, 32 Figure
Dilepton Production at SPS-energy Heavy Ion Collisions
The production of dileptons is studied within a hadronic transport model. We
investigate the sensitivity of the dilepton spectra to the initial
configuration of the hadronic phase in a ultrarelativistic heavy ion collision.
Possible in medium correction due to the modifications of pions and the pion
form factor in a hadronic gas are discussed.Comment: Dedicated to Gerry Brown in honor of the 32nd celebration of his 39th
birthday. 31 pages Latex including 13 eps-figures, uses psfig.sty and
epsf.st
The STAR Time Projection Chamber: A Unique Tool for Studying High Multiplicity Events at RHIC
The STAR Time Projection Chamber (TPC) is used to record collisions at the
Relativistic Heavy Ion Collider (RHIC). The TPC is the central element in a
suite of detectors that surrounds the interaction vertex. The TPC provides
complete coverage around the beam-line, and provides complete tracking for
charged particles within +- 1.8 units of pseudo-rapidity of the center-of-mass
frame. Charged particles with momenta greater than 100 MeV/c are recorded.
Multiplicities in excess of 3,000 tracks per event are routinely reconstructed
in the software. The TPC measures 4 m in diameter by 4.2 m long, making it the
largest TPC in the world.Comment: 28 pages, 11 figure
Dilepton production from p-p to Ca-Ca at the Bevalac
The DLS collaboration has recently completed a high statistics study of dilepton production at the Bevalac. In particular, we have measured dielectrons (e+e-) from p-p and p-d collisions to understand the basic dilepton production mechanisms in the energy range from 1.05 - 4.9 GeV. These data can be used to determine the basic processes which contribute to nucleon-nucleon dilepton production such as hadronic bremsstrahlung, vector meson processes, and hadronic Dalitz decay. The data show that a simple elastic bremsstrahlung calculation is insufficient to explain the data. Theoretical models are compared with the data. A new high statistics study of Ca-Ca at 1.05 A GeV has been made to study the collectivity of A-A collisions
IceCube - the next generation neutrino telescope at the South Pole
IceCube is a large neutrino telescope of the next generation to be
constructed in the Antarctic Ice Sheet near the South Pole. We present the
conceptual design and the sensitivity of the IceCube detector to predicted
fluxes of neutrinos, both atmospheric and extra-terrestrial. A complete
simulation of the detector design has been used to study the detector's
capability to search for neutrinos from sources such as active galaxies, and
gamma-ray bursts.Comment: 8 pages, to be published with the proceedings of the XXth
International Conference on Neutrino Physics and Astrophysics, Munich 200
Muon Track Reconstruction and Data Selection Techniques in AMANDA
The Antarctic Muon And Neutrino Detector Array (AMANDA) is a high-energy
neutrino telescope operating at the geographic South Pole. It is a lattice of
photo-multiplier tubes buried deep in the polar ice between 1500m and 2000m.
The primary goal of this detector is to discover astrophysical sources of high
energy neutrinos. A high-energy muon neutrino coming through the earth from the
Northern Hemisphere can be identified by the secondary muon moving upward
through the detector. The muon tracks are reconstructed with a maximum
likelihood method. It models the arrival times and amplitudes of Cherenkov
photons registered by the photo-multipliers. This paper describes the different
methods of reconstruction, which have been successfully implemented within
AMANDA. Strategies for optimizing the reconstruction performance and rejecting
background are presented. For a typical analysis procedure the direction of
tracks are reconstructed with about 2 degree accuracy.Comment: 40 pages, 16 Postscript figures, uses elsart.st
Results from the Antarctic Muon and Neutrino Detector Array (AMANDA)
We show new results from both the older and newer incarnations of AMANDA
(AMANDA-B10 and AMANDA-II, respectively). These results demonstrate that AMANDA
is a functioning, multipurpose detector with significant physics and
astrophysics reach. They include a new higher-statistics measurement of the
atmospheric muon neutrino flux and preliminary results from searches for a
variety of sources of ultrahigh energy neutrinos: generic point sources,
gamma-ray bursters and diffuse sources producing muons in the detector, and
diffuse sources producing electromagnetic or hadronic showers in or near the
detector.Comment: Invited talk at the XXth International Conference on Neutrino Physics
and Astrophysics (Neutrino 2002), Munich, Germany, May 25-30, 200
Sensitivity of the IceCube Detector to Astrophysical Sources of High Energy Muon Neutrinos
We present the results of a Monte-Carlo study of the sensitivity of the
planned IceCube detector to predicted fluxes of muon neutrinos at TeV to PeV
energies. A complete simulation of the detector and data analysis is used to
study the detector's capability to search for muon neutrinos from sources such
as active galaxies and gamma-ray bursts. We study the effective area and the
angular resolution of the detector as a function of muon energy and angle of
incidence. We present detailed calculations of the sensitivity of the detector
to both diffuse and pointlike neutrino emissions, including an assessment of
the sensitivity to neutrinos detected in coincidence with gamma-ray burst
observations. After three years of datataking, IceCube will have been able to
detect a point source flux of E^2*dN/dE = 7*10^-9 cm^-2s^-1GeV at a 5-sigma
significance, or, in the absence of a signal, place a 90% c.l. limit at a level
E^2*dN/dE = 2*10^-9 cm^-2s^-1GeV. A diffuse E-2 flux would be detectable at a
minimum strength of E^2*dN/dE = 1*10^-8 cm^-2s^-1sr^-1GeV. A gamma-ray burst
model following the formulation of Waxman and Bahcall would result in a 5-sigma
effect after the observation of 200 bursts in coincidence with satellite
observations of the gamma-rays.Comment: 33 pages, 13 figures, 6 table
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