2,700 research outputs found
Feasibility study to characterize the production of antineutrons in high energy collisions through charge exchange interactions
Simulations to evaluate the feasibility of identification and
kinematic characterization via the hadronic charge exchange (CEX) interaction
are reported. The target neutrons are those
composing the silicon nuclei of which inner tracking devices present in LHC
experiments are made. Simulations of collisions in PYTHIA were carried out
at different energies to investigate production and the expected
energy spectra. Then, two types of GEANT4 simulations were performed,
placing an point source at the ALICE primary vertex as a working
example. In the first simulation, the was kept at an arbitrary (1 GeV)
fix value to develop an identification and kinematics reconstruction
protocol. The second GEANT4 simulation used the resulting PYTHIA at
TeV energy spectra. In both simulations, the
occurrence of CEX interactions was identified by the unique outgoing .
The simplified simulation allowed to estimate a 0.11% CEX-interaction
identification efficiency at GeV. The CEX-partner identification
is challenging because of the presence of silicon nucleus-fragmentation
protons. Momentum correlations between the and all possible
pairs showed that CEX-partner identification and
kinematics reconstruction corresponds to minimal momentum-loss events. The use
of ITS information is found to improve identification and
kinematic characterization in both simulations. The final protocol applied to
the realistic simulation resulted in a identification and kinematic
reconstruction efficiency of 0.006%, based solely on pair
observable. Thus, the expected rate of identified and kinematically
reconstructed should lie in the order of 100,000 per second,
illustrating the feasibility of the method.Comment: 6 pages, 11 figure
Origin of the high energy proton component below the geomagnetic cutoff in near earth orbit
The high flux proton component observed by AMS below the geomagnetic cutoff can be well accounted for by assuming these particles to be secondaries originating from the interaction of Cosmic Ray protons with the atmosphere. Simulation results are reporte
SISTEMA DE MONITOREO PARA EL ESTUDIO HIDRODINÁMICO DE LA LAGUNA DEL CARPINTERO
Una de las características más importantes de los estuarios o lagunas, es la interacción entre el agua dulce y la de mar. La dinámica de estos es afectada por las mareas, el oleaje, el viento, la precipitación pluvial, la evaporación, los flujos de agua dulce y el transporte de sedimentos. El estudio de la hidrodinámica en estos ecosistemas es uno de los aspectos más importantes que se necesitan para crear las bases necesarias para una correcta y debida planeación en diseño de obras de infraestructura turística y social. Por tal motivo en el presente trabajo se desarrollo un sistema de monitoreo con la finalidad de comenzar a generar una base de datos de gran importancia para poder realizar un estudio hidrodinámico de la Laguna del Carpintero, situada en el centro de la ciudad de Tampico. El sistema está compuesto por un mareógrafo ultrasónico que permite el monitoreo en tiempo real del nivel del agua con una exactitud de ±7mm y de su temperatura con una resolución de ±0.5ºC
The use of cosmic muons in detecting heterogeneities in large volumes
The muon intensity attenuation method to detect heterogeneities in large
matter volumes is analyzed. Approximate analytical expressions to estimate the
collection time and the signal to noise ratio, are proposed and validated by
Monte Carlo simulations. Important parameters, including point spread function
and coordinate reconstruction uncertainty are also estimated using Monte Carlo
simulations.Comment: 8 pages, 11 figures, submetted to NIM
Proton and Helium Spectra from the CREAM-III Flight
Primary cosmic-ray elemental spectra have been measured with the
balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment since 2004. The
third CREAM payload (CREAM-III) flew for 29 days during the 2007-2008 Antarctic
season. Energies of incident particles above 1 TeV are measured with a
calorimeter. Individual elements are clearly separated with a charge resolution
of ~0.12 e (in charge units) and ~0.14 e for protons and helium nuclei,
respectively, using two layers of silicon charge detectors. The measured proton
and helium energy spectra at the top of the atmosphere are harder than other
existing measurements at a few tens of GeV. The relative abundance of protons
to helium nuclei is 9.53+-0.03 for the range of 1 TeV/n to 63 TeV/n. The ratio
is considerably smaller than other measurements at a few tens of GeV/n. The
spectra become softer above ~20 TeV. However, our statistical uncertainties are
large at these energies and more data are needed
Design and construction of a Cherenkov imager for charge measurement of nuclear cosmic rays
A proximity focusing Cherenkov imager called CHERCAM, has been built for the
charge measurement of nuclear cosmic rays with the CREAM instrument. It
consists of a silica aerogel radiator plane across from a detector plane
equipped with 1,600 1" diameter photomultipliers. The two planes are separated
by a ring expansion gap. The Cherenkov light yield is proportional to the
charge squared of the incident particle. The expected relative light collection
accuracy is in the few percents range. It leads to an expected single element
separation over the range of nuclear charge Z of main interest 1 < Z < 26.
CHERCAM is designed to fly with the CREAM balloon experiment. The design of the
instrument and the implemented technical solutions allowing its safe operation
in high altitude conditions (radiations, low pressure, cold) are presented.Comment: 24 pages, 19 figure
The AMS-02 RICH Imager Prototype - In-Beam Tests with 20 GeV/c per Nucleon Ions -
A prototype of the AMS Cherenkov imager (RICH) has been tested at CERN by
means of a low intensity 20 GeV/c per nucleon ion beam obtained by
fragmentation of a primary beam of Pb ions. Data have been collected with a
single beam setting, over the range of nuclear charges 2<Z<~45 in various beam
conditions and using different radiators. The charge Z and velocity beta
resolutions have been measured.Comment: 4 pages, contribution to the ICRC 200
Towards the critical behavior for the light nuclei by NIMROD detector
The critical behavior for the light nuclei with A has been
investigated experimentally by the NIMROD multi-detectors. The wide variety of
observables indicate the critical point has been reached in the disassembly of
hot nuclei at an excitation energy of 5.60.5 MeV/u.Comment: 4 pages, 2 figures; Proceeding of 18th Nuclear Physics Division
Conference of the Euro. Phys. Society (NPDC18) "Phase transitions in strongly
interacting matter", Prague, 23.8.-29.8. 2004. To be published in Nuclear
Physics
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