646 research outputs found
First flight data from the PAMELA spectrometer
Abstract PAMELA is a satellite-borne experiment designed to study charged particles in the cosmic radiation, optimized in particular for antimatter components search. The experiment is mounted on the Resurs DK1 satellite that was launched on June 15th 2006 from Baikonur cosmodrome and is now collecting data from a semi-polar elliptical orbit around the Earth. The core of the PAMELA apparatus is a magnetic spectrometer, designed to determine precisely the rigidity and the absolute charge of particles crossing the detector. The tracking system is composed of six planes of silicon microstrip detectors dipped in an almost uniform magnetic field generated by a permanent magnet made of an Nd–Fe–B alloy. Some preliminary analysis about the spectrometer's performances, made using data collected since July 2006 till June 2007, are here reviewed
Status of the PAMELA silicon tracker
PAMELA is a composite particle detector which will be launched during the first half of 2006 on board the Russian satellite Resurs DK-1 from Baikonur cosmodrome in Kazakhstan. This experiment is mainly conceived for the study of cosmic-ray antiparticles and for the search for light antinuclei, but other issues related to the cosmic-ray physics will be investigated. In this work the structure of the whole apparatus is shortly discussed with particular attention to the magnetic spectrometer, which has been designed and built in Firenze
CaloCube: a novel calorimeter for high-energy cosmic rays in space
In order to extend the direct observation of high-energy cosmic rays up to
the PeV region, highly performing calorimeters with large geometrical
acceptance and high energy resolution are required. Within the constraint of
the total mass of the apparatus, crucial for a space mission, the calorimeters
must be optimized with respect to their geometrical acceptance, granularity and
absorption depth. CaloCube is a homogeneous calorimeter with cubic geometry, to
maximise the acceptance being sensitive to particles from every direction in
space; granularity is obtained by relying on small cubic scintillating crystals
as active elements. Different scintillating materials have been studied. The
crystal sizes and spacing among them have been optimized with respect to the
energy resolution. A prototype, based on CsI(Tl) cubic crystals, has been
constructed and tested with particle beams. Some results of tests with
different beams at CERN are presented.Comment: Seven pages, seven pictures. Proceedings of INSTR17 Novosibirs
Measurement of forward photon production cross-section in proton-proton collisions at = 13 TeV with the LHCf detector
In this paper, we report the production cross-section of forward photons in
the pseudorapidity regions of and ,
measured by the LHCf experiment with proton--proton collisions at =
13 TeV. The results from the analysis of 0.191 of data
obtained in June 2015 are compared to the predictions of several hadronic
interaction models that are used in air-shower simulations for
ultra-high-energy cosmic rays. Although none of the models agree perfectly with
the data, EPOS-LHC shows the best agreement with the experimental data among
the models.Comment: 21 pages, 4 figure
Spatial Resolution of Double-Sided Silicon Microstrip Detectors for the PAMELA Apparatus
The PAMELA apparatus has been assembled and it is ready to be launched in a
satellite mission to study mainly the antiparticle component of cosmic rays. In
this paper the performances obtained for the silicon microstrip detectors used
in the magnetic spectrometer are presented. This subdetector reconstructs the
curvature of a charged particle in the magnetic field produced by a permanent
magnet and consequently determines momentum and charge sign, thanks to a very
good accuracy in the position measurements (better than 3 um in the bending
coordinate). A complete simulation of the silicon microstrip detectors has been
developed in order to investigate in great detail the sensor's characteristics.
Simulated events have been then compared with data gathered from minimum
ionizing particle (MIP) beams during the last years in order to tune free
parameters of the simulation. Finally some either widely used or original
position finding algorithms, designed for such kind of detectors, have been
applied to events with different incidence angles. As a result of the analysis,
a method of impact point reconstruction can be chosen, depending on both the
particle's incidence angle and the cluster multiplicity, so as to maximize the
capability of the spectrometer in antiparticle tagging.Comment: 28 pages, 18 figures, submitted to Nuclear Instruments and Methods in
Physics Research
Enhancement of hadron–electron discrimination in calorimeters by detection of the neutron component
In many physics experiments where calorimeters are employed, the requirement of an accurate energy measurement is accompanied by the requirement of very high hadronelectron discrimination power. Normally the latter requirement is achieved by designing a high-granularity detector with sufficient depth so that the showers can fully develop. This method has many drawbacks ranging from the high number of electronic channels to the high mass of the detector itself. Some of these drawbacks may in fact severely limit the deployment of such a detector in many experiments, most notably in space-based ones. Another method, proposed by our group and currently under investigation, relies on the use of scintillation detectors which are sensitive to the neutron component of the hadron showers. Here a review of the current status will be presented starting with the simulations performed both with GEANT4 and FLUKA. A small prototype detector has been built and has been tested in a high-energy pion/electron beam behind a "shallow" calorimeter. Results are encouraging and indicate that it is possible to enhance the discrimination power of an existing calorimeter by the addition of a small-mass neutron detector, thus paving the way for better performing astroparticle experiments. © 2010 Elsevier B.V. All rights reserved
The performance of the LHCf detector for hadronic showers
The Large Hadron Collider forward (LHCf) experiment has been designed to use
the LHC to benchmark the hadronic interaction models used in cosmic-ray
physics. The LHCf experiment measures neutral particles emitted in the very
forward region of LHC collisions. In this paper, the performances of the LHCf
detectors for hadronic showers was studied with MC simulations and beam tests.
The detection efficiency for neutrons is from 60% to 70% above 500 GeV. The
energy resolutions are about 40% and the position resolution is 0.1 to 1.3mm
depend on the incident energy for neutrons. The energy scale determined by the
MC simulations and the validity of the MC simulations were examined using 350
GeV proton beams at the CERN-SPS.Comment: 15pages, 19 figure
A powerful tracking detector for cosmic rays: the magnetic spectrometer of the PAMELA satellite experiment
Abstract The WiZaxd-PAMELA detector will be ready within some months to be installed on board of the Russian satellite Resurs-DK1. The satellite will follow, for at least 3 years, a quasi polar orbit with an inclination of 70.4° with respect to the equatorial plane. The experiment will allow the measurement of the antiproton and positron spectra within a wide momentum range and the search for light anti-nuclei in cosmic rays. The detector subsystems have been tested and the final assembly phase is in progress. In this paper we describe the structure of the PAMELA magnetic spectrometer, its current status and some precautions taken to satisfy the requirements of the mission
Pamela tracking system: status report
The Pamela apparatus will be launched at the end of 2002 on board of the Resurs DK Russian satellite. The tracking system, composed of six planes of silicon sensors inserted inside a permanent magnetic field was intensively tested during these last years. Results of tests have shown a good signal-to-noise ratio and an excellent spatial resolution, which should allow to measure the antiproton flux in an energy range from 80 MeV up to 190 GeV. The production of the final detector modules is about to start and mechanical and thermal tests on the tracking tower are being performed according to the specifications of the Russian launcher and satellite. r 2002 Elsevier Science B.V. All rights reserved
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