2,262 research outputs found
Commissioning and Calibration of the ALICE TPC
ALICE (A Large Ion Collider Experiment) is the dedicated heavy ion experiment
at the Large Hadron Collider at CERN. The main tracking device of ALICE is a
large volume TPC.
The milestones of the TPC commissioning as well as the current status of the
detector calibration are presented. The obtained resolutions in transverse
momentum, position as well as in specific energy loss (dE/dx) are presented and
results from noise and electron drift velocity measurements are addressed.Comment: 4 pages, 4 figures- To appear in the conference proceedings for Quark
Matter 2009, March 30 - April 4, Knoxville, Tennesse
Measurement of spark probability of GEM detector for CBM muon chamber (MUCH)
The stability of triple GEM detector setups in an environment of high
energetic showers is studied. To this end the spark probability in a shower
environment is compared to the spark probability in a pion beam.Comment: 5 pages, 10 figure
Isotopic Dependence of the Nuclear Caloric Curve
The A/Z dependence of projectile fragmentation at relativistic energies has
been studied with the ALADIN forward spectrometer at SIS. A stable beam of
124Sn and radioactive beams of 124La and 107Sn at 600 MeV per nucleon have been
used in order to explore a wide range of isotopic compositions. Chemical
freeze-out temperatures are found to be nearly invariant with respect to the
A/Z of the produced spectator sources, consistent with predictions for expanded
systems. Small Coulomb effects (\Delta T \approx 0.6 MeV) appear for residue
production near the onset of multifragmentation.Comment: 11 pages, 3 figures, accepted for publ. in Phys. Rev. Let
Tracing a phase transition with fluctuations of the largest fragment size: Statistical multifragmentation models and the ALADIN S254 data
A phase transition signature associated with cumulants of the largest
fragment size distribution has been identified in statistical
multifragmentation models and examined in analysis of the ALADIN S254 data on
fragmentation of neutron-poor and neutron-rich projectiles. Characteristics of
the transition point indicated by this signature are weakly dependent on the
A/Z ratio of the fragmenting spectator source. In particular, chemical
freeze-out temperatures are estimated within the range 5.9 to 6.5 MeV. The
experimental results are well reproduced by the SMM model.Comment: 7 pages, 3 figures, Proceedings of the International Workshop on
Multifragmentation and Related Topics (IWM2009), Catania, Italy, November
2009
Gross Properties and Isotopic Phenomena in Spectator Fragmentation
A systematic study of isotopic effects in the break-up of projectile
spectators at relativistic energies has been performed with the ALADiN
spectrometer at the GSI laboratory. Searching for signals of criticality in the
fragment production we have applied the model independent universal
fluctuations theory already proposed to track criticality signals in
multifragmentation to our data. The fluctuation of the largest fragment charge
and of the asymmetry of the two and three largest fragments and their bimodal
distribution have also been analysed.Comment: 6 pages, 4 figures, IX International Conference on Nucleus-Nucleus
Collisions, Rio de Janeiro, Brazil, August 28 - September 1, 200
Neutron recognition in the LAND detector for large neutron multiplicity
The performance of the LAND neutron detector is studied. Using an
event-mixing technique based on one-neutron data obtained in the S107
experiment at the GSI laboratory, we test the efficiency of various analytic
tools used to determine the multiplicity and kinematic properties of detected
neutrons. A new algorithm developed recently for recognizing neutron showers
from spectator decays in the ALADIN experiment S254 is described in detail. Its
performance is assessed in comparison with other methods. The properties of the
observed neutron events are used to estimate the detection efficiency of LAND
in this experiment.Comment: 16 pages, 8 figure
FIRE (facilitating implementation of research evidence) : a study protocol
Research evidence underpins best practice, but is not always used in healthcare. The Promoting Action on Research Implementation in Health Services (PARIHS) framework suggests that the nature of evidence, the context in which it is used, and whether those trying to use evidence are helped (or facilitated) affect the use of evidence. Urinary incontinence has a major effect on quality of life of older people, has a high prevalence, and is a key priority within European health and social care policy. Improving continence care has the potential to improve the quality of life for older people and reduce the costs associated with providing incontinence aids
Discriminant Analysis and Secondary-Beam Charge Recognition
The discriminant-analysis method has been applied to optimize the exotic-beam
charge recognition in a projectile fragmentation experiment. The experiment was
carried out at the GSI using the fragment separator (FRS) to produce and select
the relativistic secondary beams, and the ALADIN setup to measure their
fragmentation products following collisions with Sn target nuclei. The beams of
neutron poor isotopes around 124La and 107Sn were selected to study the isospin
dependence of the limiting temperature of heavy nuclei by comparing with
results for stable 124Sn projectiles. A dedicated detector to measure the
projectile charge upstream of the reaction target was not used, and alternative
methods had to be developed. The presented method, based on the multivariate
discriminant analysis, allowed to increase the efficacy of charge recognition
up to about 90%, which was about 20% more than achieved with the simple scalar
methods.Comment: 6 pages, 7 eps figures, elsart, submitted to Nucl. Instr. and Meth.
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