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1.	Abdellaoui, G., et al. (författare) Meteor studies in the framework of the JEM-EUSO program 2017 Ingår i: Planetary and Space Science. - : Elsevier. - 0032-0633 .- 1873-5088. ; 143, s. 245-255 Tidskriftsartikel (refereegranskat)abstract We summarize the state of the art of a program of UV observations from space of meteor phenomena, a secondary objective of the JEM-EUSO international collaboration. Our preliminary analysis indicates that JEM-EUSO, taking advantage of its large FOV and good sensitivity, should be able to detect meteors down to absolute magnitude close to 7. This means that JEM-EUSO should be able to record a statistically significant flux of meteors, including both sporadic ones, and events produced by different meteor streams. Being unaffected by adverse weather conditions, JEM-EUSO can also be a very important facility for the detection of bright meteors and fireballs, as these events can be detected even in conditions of very high sky background. In the case of bright events, moreover, exhibiting some persistence of the meteor train, preliminary simulations show that it should be possible to exploit the motion of the ISS itself and derive at least a rough 3D reconstruction of the meteor trajectory. Moreover, the observing strategy developed to detect meteors may also be applied to the detection of nuclearites, exotic particles whose existence has been suggested by some theoretical investigations. Nuclearites are expected to move at higher velocities than meteoroids, and to exhibit a wider range of possible trajectories, including particles moving upward after crossing the Earth. Some pilot studies, including the approved Mini-EUSO mission, a precursor of JEM-EUSO, are currently operational or in preparation. We are doing simulations to assess the performance of Mini-EUSO for meteor studies, while a few meteor events have been already detected using the ground-based facility EUSO-TA.
2.	Aguilar, J. A., et al. (författare) First results of the instrumentation line for the deep-sea ANTARES neutrino telescope 2006 Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 26:4-5, s. 314-324 Tidskriftsartikel (refereegranskat)abstract In 2005, the ANTARES Collaboration deployed and operated at a depth of 2500 m a so-called Mini Instrumentation Line equipped with Optical Modules (MILOM) at the ANTARES site. The various data acquired during the continuous operation from April to December 2005 of the MILOM confirm the satisfactory performance of the Optical Modules, their front-end electronics and readout system. as well as the calibration devices of the detector. The in situ measurement of the Optical Module time response yields a resolution better than 0.5 ns. The performance of the acoustic positioning system, which enables the spatial reconstruction of the ANTARES detector with a precision of about 10 cm, is verified. These results demonstrate that with the full ANTARES neutrino telescope the design angular resolution of better than 0.3 degrees can be realistically achieved.
3.	Aguilar, J. A., et al. (författare) The data acquisition system for the ANTARES neutrino telescope 2007 Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 570:1, s. 107-116 Tidskriftsartikel (refereegranskat)abstract The ANTARES neutrino telescope is being constructed in the Mediterranean Sea. It consists of a large three-dimensional array of photo-multiplier tubes. The data acquisition system of the detector takes care of the digitisation of the photo-multiplier tube signals, data transport, data filtering, and data storage. The detector is operated using a control program interfaced with all elements. The design and the implementation of the data acquisition system are described. (c) 2006 Elsevier B.V. All rights reserved.
4.	Ambrosio, M, et al. (författare) The MACRO detector at Gran Sasso 2002 Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 486:3, s. 663-707 Tidskriftsartikel (refereegranskat)abstract MACRO was an experiment that ran in the Laboratori Nazionali del Gran Sasso from 1988 to 2000. Its principal goal was to observe magnetic monopoles or set significantly lower experimental flux limits than had been previously available in the velocity range from about beta = 10(-4) to unity. In addition it made a variety of other observations. Examples are: setting flux limits on other so far unobserved particles such as nuclearites and lightly ionizing particles, searching for WIMP annihilations in the Earth and the Sun and for neutrino bursts from stellar collapses in or near our Galaxy, and making measurements relevant to high energy muon and neutrino astronomy and of the flux of up-going muons as a function of nadir angle showing evidence for neutrino oscillations. The apparatus consisted of three principal types of detectors: liquid scintillator counters, limited streamer tubes, and nuclear track etch detectors. In addition, over part of its area it contained a transition radiation detector. The general design philosophy emphasized redundancy and complementarity. This paper describes the technical aspects of the complete MACRO detector, its operational performance, and the techniques used to calibrate it and verify its proper operation. It supplements a previously published paper which described the first portion of the detector that was built and operated. (C) 2002 Elsevier Science B.V. All rights reserved.
5.	Abdellaoui, G., et al. (författare) First observations of speed of light tracks by a fluorescence detector looking down on the atmosphere 2018 Ingår i: Journal of Instrumentation. - : IOP PUBLISHING LTD. - 1748-0221. ; 13 Tidskriftsartikel (refereegranskat)abstract EUSO-Balloon is a pathfinder mission for the Extreme Universe Space Observatory onboard the Japanese Experiment Module (JEM-EUSO). It was launched on the moonless night of the 25(th) of August 2014 from Timmins, Canada. The flight ended successfully after maintaining the target altitude of 38 km for five hours. One part of the mission was a 2.5 hour underflight using a helicopter equipped with three UV light sources (LED, xenon flasher and laser) to perform an inflight calibration and examine the detectors capability to measure tracks moving at the speed of light. We describe the helicopter laser system and details of the underflight as well as how the laser tracks were recorded and found in the data. These are the first recorded laser tracks measured from a fluorescence detector looking down on the atmosphere. Finally, we present a first reconstruction of the direction of the laser tracks relative to the detector.
6.	Aguilar, J A, et al. (författare) Study of large hemispherical photomultiplier tubes for the ANTARES neutrino telescope 2005 Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 555:1-2, s. 132-141 Tidskriftsartikel (refereegranskat)abstract The ANTARES neutrino telescope, to be immersed depth in the Mediterranean Sea, will consist of a three-dimensional matrix of 900 large area photomultiplier tubes housed in pressure-resistant glass spheres. The selection of the optimal photomultiplier was a critical step for the project and required an intensive phase of tests and developments carried out in close collaboration with the main manufacturers worldwide. This paper provides an overview of the tests performed by the collaboration and describes in detail the features of the photomultiplier tube chosen for ANTARES. (c) 2005 Elsevier B.V. All rights reserved.
7.	Aglietta, M, et al. (författare) The cosmic ray primary composition between 10(15) and 10(16) eV from Extensive Air Showers electromagnetic and TeV muon data 2004 Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 20:6, s. 641-652 Tidskriftsartikel (refereegranskat)abstract The cosmic ray primary composition in the energy range between 10(15) and 10(16) eV, i.e., around the "knee" of the primary spectrum, has been studied through the combined measurements of the EAS-TOP air shower array (2005 m a. s.l., 10(5) m(2) collecting area) and the MACRO underground detector (963 m.a.s.l., 3100 m w.e. of minimum rock overburden, 920 m(2) effective area) at the National Gran Sasso Laboratories. The used observables are the air shower size (N-c) measured by EAS-TOP and the muon number (N-mu) recorded by MACRO. The two detectors are separated on average by 1200 m of rock, and located at a respective zenith angle of about 30degrees. The energy threshold at the surface for muons reaching the MACRO depth is approximately 1.3 TeV. Such muons are produced in the early stages of the shower development and in a kinematic region quite different from the one relevant for the usual N-mu - N-e studies. The measurement leads to a primary composition becoming heavier at the knee of the primary spectrum, the knee itself resulting from the steepening of the spectrum of a primary light component (p, He) of Deltay = 0.7 +/- 0.4 at E-0 similar to 4 x 10(15) eV. The result confirms the ones reported from the observation of the low energy muons at the surface (typically in the GeV energy range), showing that the conclusions do not depend on the production region kinematics. Thus, the hadronic interaction model used (CORSIKA/QGSJET) provides consistent composition results from data related to secondaries produced in a rapidity region exceeding the central one. Such an evolution of the composition in the knee region supports the "standard" galactic acceleration/propagation models that imply rigidity dependent breaks of the different components.. and therefore breaks occurring at lower energies in the spectra of the light nuclei. (C) 2003 Elsevier B.V. All rights reserved.
8.	Aglietta, M, et al. (författare) The cosmic ray proton, helium and CNO fluxes in the 100 TeV energy region from TeV muons and EAS atmospheric Cherenkov light observations of MACRO and EAS-TOP 2004 Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 21:3, s. 223-240 Tidskriftsartikel (refereegranskat)abstract The primary cosmic ray (CR) proton, helium and CNO fluxes in the energy range 80-300 TeV are studied at the National Gran Sasso Laboratories by means of EAS-TOP (Campo Imperatore, 2005 m a.s.l.) and MACRO (deep underground, 3100 m w.e., the surface energy threshold for a muon reaching the detector being E-mu(th) approximate to 1.3 TeV). The measurement is based on: (a) the selection of primaries based on their energy/nucleon (i.e., with energy/nucleon sufficient to produce a muon with energy larger than 1.3 TeV) and the reconstruction of the shower geometry by means of the muons recorded by MACRO in the deep underground laboratories; (b) the detection of the associated atmospheric Cherenkov light (C.l.) signals by means of the C.l. detector of EAS-TOP. The C.l. density at core distance r > 100 m is directly related to the total primary energy E-0. Proton and helium ("p + He") and proton, helium and CNO ("p + He + CNO") primaries are thus selected at E-0 approximate to 80 TeV, and at E-0 similar or equal to 250 TeV, respectively. Their flux is measured: J(p+He)(80 TeV) = (1.8 +/- 0.4) x 10(-6) m(-1)-s(-1) sr(-1) TeV-1, and J(p+He+CNO)(250 TeV) = (1.1 +/- 0.3) x 10(-7) m(-2)-s(-1) sr(-1) TeV-1, their relative weights being J(p+He)(J(p+He+CNO)) over bar (250 TeV) = 0.78 +/- 0.17. By using the measurements of the proton spectrum obtained from the direct experiments and hadron flux data in the atmosphere, we obtain for the relative weights of the three components at 250 TeV: J(p) : J(He) : J(CNO) = (0.20 +/- 0.08) : (0.58 +/- 0.19) : (0.22 +/- 0.17). This corresponds to the dominance of helium over proton primaries at 100-1000 TeV, and a possible non-negligible contribution from CNO. The lateral distribution of Cherenkov light in Extensive Air Showers (EASs), which is related to the rate of energy deposit of the primary in the atmosphere, is measured for a selected proton and helium primary beam, and good agreement is found when compared with the one calculated with the CORSIKA/QGSJET simulation model. (C) 2004 Elsevier B.V. All rights reserved.
9.	Aguilar, J A, et al. (författare) Transmission of light in deep sea water at the site of the ANTARES neutrino telescope 2005 Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 23:1, s. 131-155 Tidskriftsartikel (refereegranskat)abstract The ANTARES neutrino telescope is a large photomultiplier array designed to detect neutrino-induced upward-going muons by their Cherenkov radiation. Understanding the absorption and scattering of light in the deep Mediterranean is fundamental to optimising the design and performance of the detector. This paper presents measurements of blue and UV light transmission at the ANTARES site taken between 1997 and 2000. The derived values for the scattering length and the angular distribution of particulate scattering were found to be highly correlated, and results are therefore presented in terms of an absorption length;,ab, and an effective scattering length lambda(sct)(eff). The values for blue (UV) light are found to be lambda(abs) similar or equal to 60(26) m, lambda(sct)(eff similar or equal to) 265(122) m, with significant (similar to15%) time variability. Finally, the results of ANTARES simulations showing the effect of these water properties on the anticipated performance of the detector are presented. (C) 2004 Elsevier B.V. All rights reserved.
10.	Ambrosio, M, et al. (författare) A combined analysis technique for the search for fast magnetic monopoles with the MACRO detector 2002 Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 18:1, s. 27-41 Tidskriftsartikel (refereegranskat)abstract We describe a search method for fast moving (beta = v/c > 5 x 10(-3)) magnetic monopoles using simultaneously the scintillator, streamer tube and track-etch subdetectors of the MACRO apparatus. The first two subdetectors are used primarily for the identification of candidates while the track-etch one is used as the final tool for their rejection or confirmation. Using this technique, a first sample of more than two-years of data has been analyzed without any evidence of a magnetic monopole. We set a 90% CL upper limit to the local monopole flux of 1.5 x 10(-15) cm(-2) s(-1) sr(-1) in the velocity range 5 x 10(-3) less than or equal to beta less than or equal to 0.99 and for nucleon decay catalysis cross-section smaller than similar to1 mb (C) 2002 Elsevier Science B.V. All rights reserved.
11.	Ambrosio, M, et al. (författare) Atmospheric neutrino oscillations from upward throughgoing muon multiple scattering in MACRO 2003 Ingår i: Physics Letters B. - 0370-2693 .- 1873-2445. ; 566:1-2, s. 35-44 Tidskriftsartikel (refereegranskat)abstract The energy of atmospheric neutrinos detected by MACRO was estimated using multiple Coulomb scattering of upward throughgoing muons. This analysis allows a test of atmospheric neutrino oscillations, relying on the distortion of the muon energy distribution. These results have been combined with those coming from the upward throughgoing muon angular distribution only. Both analyses are independent of the neutrino flux normalization and provide strong evidence, above the for level, in favour of neutrino oscillations. (C) 2003 Published by Elsevier B.V.
12.	Ambrosio, M, et al. (författare) Final results of magnetic monopole searches with the MACRO experiment 2002 Ingår i: European Physical Journal C. - : Springer. - 1434-6044 .- 1434-6052. ; 25:4, s. 511-522 Tidskriftsartikel (refereegranskat)abstract We present the final results obtained by the MACRO experiment in the search for GUT magnetic monopoles in the penetrating cosmic radiation, for the range 4 x 10(-5) < 3 < 1. Several searches with all the MACRO sub-detectors (i.e. scintillation counters, limited streamer tubes and nuclear track detectors) were performed, both in stand alone and combined ways. No candidates were detected and a 90% Confidence Level (C.L.) upper limit to the local magnetic monopole flux was set at the level of 1.4 x 10(-16) cm(-2) s(-1) sr(-1). This result is the first experimental limit obtained in direct searches which is well below the Parker bound in the whole 3 range in which GUT magnetic monopoles are,expected.
13.	Ambrosio, M, et al. (författare) Matter effects in upward-going muons and sterile neutrino oscillations 2001 Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 517:1-2, s. 59-66 Tidskriftsartikel (refereegranskat)abstract The angular distribution of upward-going muons produced by atmospheric neutrinos in the rock below the MACRO detector shows anomalies in good agreement with two flavor nu (mu) --> nu (tau) oscillations with maximum mixing and Deltam(2) around 0.0024 eV(2). Exploiting the dependence of magnitude of the matter effect on oscillation channel, and using a set of 809 upward-going muons observed in MACRO, we show that the two flavor nu (mu) --> nu (s) oscillation is disfavored with 99% C.L. with respect to nu (mu) --> nu (tau). (C) 2001 Elsevier Science B.V. All rights reserved.
14.	Ambrosio, M, et al. (författare) Measurement of the residual energy of muons in the Gran Sasso underground laboratories 2003 Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 19:3, s. 313-328 Tidskriftsartikel (refereegranskat)abstract The MACRO detector was located in the Hall B of the Gran Sasso underground laboratories under an average rock overburden of 3700 hg/cm(2). A transition radiation detector composed of three identical modules, covering a total horizontal area of 36 m(2), was installed inside the empty upper part of the detector in order to measure the residual energy of muons. This paper presents the measurement of the residual energy of single and double muons crossing the apparatus. Our data show that double muons are more energetic than single ones. This measurement is performed over a standard rock depth range from 3000 to 6500 hg/cm(2). (C) 2002 Elsevier Science B.V. All rights reserved.
15.	Ambrosio, M, et al. (författare) Moon and Sun shadowing effect in the MACRO detector 2003 Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 20:2, s. 145-156 Tidskriftsartikel (refereegranskat)abstract Using data collected by the MACRO experiment from 1989 to the end of its operations in 2000, we have studied in the underground muon flux the shadowing. effects due to both the Moon and the Sun. We have observed the shadow cast by the Moon at its apparent position with a significance of 6.5sigma. The Moon shadowing effect has been used to verify the pointing capability of the detector and to determine the instrument resolution for the search of muon excesses from any direction of the celestial sphere. The dependence of the effect on the geomagnetic field is clearly shown by splitting the data sample in day and night observations. The Sun shadow, observed with a significance of 4.6sigma is displaced by about 0.6degrees from its apparent position. In this case however the explanation resides in the configuration of the Solar and Interplanetary Magnetic Fields, which affect the propagation of cosmic ray particles between the Sun, and the Earth. The displacement of the Sun shadow with respect to the real Sun position has been used to establish an upper limit on the antimatter flux in cosmic rays of about 48% at 68% c.l. and primary energies of about 20 TeV. (C) 2003 Elsevier B.V. All rights reserved.
16.	Ambrosio, M, et al. (författare) Muon energy estimate through multiple scattering with the MACRO detector 2002 Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 492:3, s. 376-386 Tidskriftsartikel (refereegranskat)abstract Muon energy measurement represents an important issue for any experiment addressing neutrino-induced up-going muon studies. Since the neutrino oscillation probability depends on the neutrino energy, a measurement of the muon energy adds an important piece of information concerning the neutrino system. We show in this paper how the MACRO limited streamer tube system can be operated in drift mode by using the TDCs included in the QTPs, an electronics designed for magnetic monopole search. An improvement of the space resolution is obtained, through an analysis of the multiple scattering of muon tracks as they pass through our detector. This information can be used further to obtain an estimate of the energy of muons crossing the detector. Here we present the results of two dedicated tests, performed at CERN PS-T9 and SPS-X7 beam lines, to provide a full check of the electronics and to exploit the feasibility of such a multiple scattering analysis. We show that by using a neural network approach, we are able to reconstruct the muon energy for E-mu < 40 GeV. The test beam data provide an absolute energy calibration, which allows us to apply this method to MACRO data. (C) 2002 Elsevier Science B.V. All rights reserved.
17.	Ambrosio, M, et al. (författare) Search for cosmic ray sources using muons detected by the MACRO experiment 2003 Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 18:6, s. 615-627 Tidskriftsartikel (refereegranskat)abstract The MACRO underground detector at Gran Sasso Laboratory recorded 60 million secondary cosmic ray muons from February 1989 until December 2000. Different techniques were used to analyze this sample in search for density excesses from astrophysical point-like sources. No evidence for DC excesses for any source in an all-sky survey is reported. In addition, searches for muon excess correlated with the known binary periods of Cygnus X-3 and Hercules X-1, and searches for statistically significant bursting episodes from known gamma-ray sources are also proved negative. (C) 2002 Elsevier Science B.V. All rights reserved.
18.	Ambrosio, M, et al. (författare) Search for diffuse neutrino flux from astrophysical sources with MACRO 2003 Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 19:1, s. 1-13 Tidskriftsartikel (refereegranskat)abstract Many galactic and extragalactic astrophysical sources are currently considered promising candidates as high-energy neutrino emitters. Astrophysical neutrinos can be detected as upward-going muons produced in charged-current interactions with the medium surrounding the detector. The expected neutrino fluxes from various models start to dominate on the atmospheric neutrino background at neutrino energies above some tens of TeV. We present the results of a search for an excess of high-energy upward-going muons among the sample of data collected by MACRO during similar to5.8 years of effective running time. No significant evidence for this signal was found. As a consequence, an upper limit on the flux of upward-going muons from high-energy neutrinos was set at the level of 1.7 x 10(-14) cm(-2) s(-1) sr(-1). The corresponding upper limit for the diffuse neutrino flux was evaluated assuming a neutrino power law spectrum. Our result was compared with theoretical predictions and upper limits from other experiments. (C) 2002 Elsevier Science B.V. All rights reserved.
19.	Ambrosio, M, et al. (författare) Search for nucleon decays induced by GUT magnetic monopoles with the MACRO experiment 2002 Ingår i: European Physical Journal C. - : Springer. - 1434-6044 .- 1434-6052. ; 26:2, s. 163-172 Tidskriftsartikel (refereegranskat)abstract The interaction of a Grand Unification Magnetic Monopole with a nucleon can lead to a barion-number violating process in which the nucleon decays into a lepton and one or more mesons (catalysis of nucleon decay). In this paper we report an experimental study of the effects of a catalysis process in the MACRO detector. Using a dedicated analysis we obtain new magnetic monopole (MM) flux upper limits at the level of similar to 3 (.) 10(-16) cm(-2) s(-1) sr(-1) for 1.1(.) 10(-4) less than or equal to \beta\ less than or equal to 5 (.) 10(-3), based on the search for catalysis events in the MACRO data. We also analyze the dependence of the MM flux limit on the catalysis cross section.
20.	Ambrosio, M, et al. (författare) Search for the sidereal and solar diurnal modulations in the total MACRO muon data set 2003 Ingår i: Physical Review D. Particles and fields. - : American Physical Society. - 0556-2821 .- 1089-4918. ; 67:4 Tidskriftsartikel (refereegranskat)abstract We have analyzed 44.3M single muons collected by MACRO from 1991 through 2000 in 2145 live days of operation. We have searched for the solar diurnal, apparent sidereal, and pseudosidereal modulation of the underground muon rate by computing hourly deviations of the muon rate from 6 month averages. We find evidence for statistically significant modulations with the solar diurnal and the sidereal periods. The amplitudes of these modulations are <0.1%, and are at the limit of the detector statistics. The pseudosidereal modulation is not statistically significant. The solar diurnal modulation is due to the daily atmospheric temperature variations at 20 km, the altitude of primary cosmic ray interactions with the atmosphere; MACRO is the deepest experiment to report this result. The sidereal modulation is in addition to the expected Compton-Getting modulation due to solar system motion relative to the local standard of rest; it represents motion of the solar system with respect to the galactic cosmic rays toward the galactic plane.
21.	Togo, V, et al. (författare) Calibrations of CR39 and Makrofol nuclear track detectors and search for exotic particles 2003 Ingår i: Nuclear physics B, Proceedings supplements. - : Elsevier. - 0920-5632 .- 1873-3832. ; 125, s. 217-221 Tidskriftsartikel (refereegranskat)abstract We present the final results of the search for exotic massive particles in the cosmic radiation performed with the MACRO underground experiment. Magnetic monopoles and nuclearites flux upper limits obtained with the CR39 nuclear track subdetector, the scintillation and streamer tube subdetectors are given. Searches at high altitude with the SLIM experiment are in progress.
22.	Ambrosio, M, et al. (författare) Measurements of atmospheric muon neutrino oscillations, global analysis of the data collected with MACRO detector 2004 Ingår i: European Physical Journal C. - : Springer. - 1434-6044 .- 1434-6052. ; 36:3, s. 323-339 Tidskriftsartikel (refereegranskat)abstract The final analysis of atmospheric neutrino events collected with the MACRO detector is presented. Three different classes of events, generated by neutrinos in different energy ranges, are studied looking at rates, angular distributions and estimated energies. The results are consistent for all the subsamples and indicate a flux deficit that depends on energy and path - length of neutrinos. The no - oscillation hypothesis is excluded at similar to 5sigma, while the hypothesis of nu(mu) --> nu(tau) oscillation gives a satisfactory description of all data. The parameters with highest probability in a two flavor scenario are sin(2) 2theta(m) = 1 and Deltam(2) = 0.0023 eV(2). This result is independent of the absolute normalization of the atmospheric neutrino fluxes. The data can also be used to put experimental constrain on this normalization.
23.	Adriani, O., et al. (författare) Pamela's measurements of magnetospheric effects on high-energy solar particles 2015 Ingår i: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 801:1 Tidskriftsartikel (refereegranskat)abstract The nature of particle acceleration at the Sun, whether through flare reconnection processes or through shocks driven by coronal mass ejections, is still under scrutiny despite decades of research. The measured properties of solar energetic particles (SEPs) have long been modeled in different particle-acceleration scenarios. The challenge has been to disentangle the effects of transport from those of acceleration. The Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) instrument enables unique observations of SEPs including the composition and angular distribution of the particles about the magnetic field, i.e., pitch angle distribution, over a broad energy range (>80 MeV)-bridging a critical gap between space-based and ground-based measurements. We present high-energy SEP data from PAMELA acquired during the 2012 May 17 SEP event. These data exhibit differential anisotropies and thus transport features over the instrument rigidity range. SEP protons exhibit two distinct pitch angle distributions: a low-energy population that extends to 90 degrees and a population that is beamed at high energies (>1 GeV), consistent with neutron monitor measurements. To explain a low-energy SEP population that exhibits significant scattering or redistribution accompanied by a high-energy population that reaches the Earth relatively unaffected by dispersive transport effects, we postulate that the scattering or redistribution takes place locally. We believe that these are the first comprehensive measurements of the effects of solar energetic particle transport in the Earth's magnetosheath.
24.	Bongi, M, et al. (författare) PAMELA : A satellite experiment for antiparticles measurement in cosmic rays 2004 Ingår i: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 51:3, s. 854-859 Tidskriftsartikel (refereegranskat)abstract PAMELA is a satellite-borne experiment that will study the antiproton and positron fluxes in cosmic rays in a wide range of energy (from 80 MeV up to 190 GeV for antiprotons and from 50 MeV up to 270 GeV for positrons) and with high statistics, and that will measure the antihelium/helium ratio with a sensitivity of the order of 10(-8). The detector will fly on-board a polar orbiting Resurs DK1 satellite, which will be launched into space by a Soyuz rocket in 2004 from Baikonur cosmodrome in Kazakhstan, for a 3-year-long mission. Particle identification and energy measurements are performed in the PAMELA apparatus using the following subdetectors: a magnetic spectrometer made up of a permanent magnet equipped with double-sided microstrip silicon detectors, an electromagnetic imaging calorimeter composed of layers of tungsten absorber and silicon detectors planes, a transition radiation detector made of straw tubes interleaved with carbon fiber radiators, a plastic scintillator time-of-flight and trigger system, a set of anticounter plastic scintillator detectors, and a neutron detector. The features of the detectors and the main results obtained in beam test sessions are presented.
25.	Carbone, R., et al. (författare) Pamela observation of the 2012 may 17 gle event 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract The PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) satellite-borne experiment has been collecting data in orbit since July 2006, providing accurate measurements of the energy spectra and composition of the cosmic radiation from a few hundred MeV/n up to hundred GeV/n. This wide interval of measured energies makes PAMELA a unique instrument for Solar Energetic Particle (SEP) observations. Not only does it span the energy range between the ground-based neutron monitor data and the observations of SEPs from space, but also PAMELA carries out the first direct measurements of the composition for the highest energy SEP events, including those causing Ground Level Enhancements (GLEs). PAMELA has registered many SEP events in solar cycle 24 including the 2012 May 17 GLE event (GLE 71), offering unique opportunities to address the question of high-energy SEP origin. Experimental performances and preliminary results on the 2012 May 17 events will be presented. We will discuss the derived particle injection time and compare with other time scales at the Sun including the flare and CME onset times.
26.	Di Felice, V., et al. (författare) Solar modulation of galactic hydrogen and helium over the 23rd solar minimum with the PAMELA experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract PAMELA has been orbiting the Earth for more than six years, gathering data on solar, galactic and trapped cosmic rays during the time of the last solar minimum. The apparatus comprises a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail catcher scintillator and a neutron detector. The combination of these devices allows charged particle and antiparticle identification over a wide energy range and with an unprecedented precision. The quasi-polar orbit of the instrument, with an inclination of 70 degrees, makes it possible to measure low energy particles starting from about 100 MeV/n. In this work we present the time and rigidity dependence of the galactic proton and helium fluxes over the first 4 years of operation during the A < 0 solar minimum of solar cycle 23.
27.	Martucci, M., et al. (författare) Analysis on H spectral shape during the early 2012 SEPs with the PAMELA experiment 2014 Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 742, s. 158-161 Tidskriftsartikel (refereegranskat)abstract The satellite-borne PAMELA experiment has been continuously collecting data since 2006. This apparatus is designed to study charged particles in the cosmic radiation. The combination of a permanent magnet, a silicon strip tracker and a silicon-tungsten imaging calorimeter, and the redundancy of instrumentation allow very precise studies on the physics of cosmic rays in a wide energy range and with high statistics. This makes PAMELA a very suitable instrument for Solar Energetic Particle (SEP) observations. Not only does it span the energy range between the ground-based neutron monitor data and the observations of SEPs from space, but PAMELA also carries out the first direct measurements of the composition for the highest energy SEP events, including those causing Ground Level Enhancements (GLEs). In particular, PAMELA has registered many SEP events during solar cycle 24, offering unique opportunities to address the question of high-energy SEP origin. A preliminary analysis on proton spectra behaviour during this event is presented in this work.
28.	Munini, R., et al. (författare) Solar modulation of galactic cosmic rays electrons and positrons over the 23rd solar minimum with the pamela experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract The satellite-borne PAMELA experiment has been continuously collecting data since 15th June 2006, when it was launched from the Baikonur cosmodrome to detect the charged component of cosmic rays over a wide energy range and with an unprecedented statistics. The apparatus design is particularly suited for particle and antiparticle identification. The satellite quasi-polar orbit, with an inclination of 70 degrees, allows particles to be measure down to 100 MeV/n. This makes the instrument suited for the investigation of phenomena related to galactic cosmic ray solar modulation in the inner heliosphere. Data for oppositely charged particles were collected from 2006 to 2009, during the A< 0 solar minimum of solar cycle 23. The time and rigidity dependence of galactic cosmic ray electron and positron fluxes were measured. These fluxes provide important information for the study of charge dependent solar modulation effects.
29.	Ricci, M., et al. (författare) Study on 2012 march 7 solar particle event and forbush decrease with the PAMELA experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract The PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astro-physics) space-borne experiment was launched on 15 June 2006 and has been continuously collecting data since then. The apparatus measures electrons, positrons, protons, anti-protons and heavier nuclei from about 100 MeV to several hundreds of GeV. The on-board instrumentation is built around a permanent magnet with a silicon microstrip tracker, providing charge and track detection information. During solar maximum conditions of solar cycle 24, PAMELA has been providing key information about solar energetic particles (SEPs) and their influence at Earth. We discuss here the recent 2012 March 7 SEP event with a brief comment on the subsequent Forbush decrease, registered by PAMELA. This event was also observed by Fermi/LAT exhibiting unprecedented time-extended γ-ray emission (> 100 MeV) lasting nearly 20 hours. We compare the derived accelerated ion population at the Sun with the ion population measured in space by PAMELA and discuss the implications for particle acceleration.
30.	Adriani, O., et al. (författare) Antiprotons in primary cosmic radiation with PAMELA experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract The latest measurements of antiprotons spectrum and antiproton-to-proton ratio in primary cosmic rays with PAMELA experiment are presented. They are in good agreement with model of secondary production of antiprotons in Galaxy, but they do not completely rule other sources at the high-energies.
31.	Adriani, O., et al. (författare) Cosmic-Ray Positron Energy Spectrum Measured by PAMELA 2013 Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 111:8, s. 081102- Tidskriftsartikel (refereegranskat)abstract Precision measurements of the positron component in the cosmic radiation provide important information about the propagation of cosmic rays and the nature of particle sources in our Galaxy. The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy. The combined measurements of the cosmic-ray positron energy spectrum and fraction provide a unique tool to constrain interpretation models. During the recent solar minimum activity period from July 2006 to December 2009, approximately 24 500 positrons were observed. The results cannot be easily reconciled with purely secondary production, and additional sources of either astrophysical or exotic origin may be required.
32.	Adriani, O., et al. (författare) Measurement of Boron and Carbon Fluxes in Cosmic Rays with the Pamela Experiment 2014 Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 791:2, s. 93- Tidskriftsartikel (refereegranskat)abstract The propagation of cosmic rays inside our galaxy plays a fundamental role in shaping their injection spectra into those observed at Earth. One of the best tools to investigate this issue is the ratio of fluxes for secondary and primary species. The boron-to-carbon (B/C) ratio, in particular, is a sensitive probe to investigate propagation mechanisms. This paper presents new measurements of the absolute fluxes of boron and carbon nuclei as well as the B/C ratio from the PAMELA space experiment. The results span the range 0.44-129 GeV/n in kinetic energy for data taken in the period 2006 July to 2008 March.
33.	Boezio, M., et al. (författare) The PAMELA experiment and antimatter in the universe 2014 Ingår i: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 228:1-3, s. 101-109 Tidskriftsartikel (refereegranskat)abstract On the 15th of June 2006, the PAMELA satellite-borne experiment was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. The primary scientific goal is the measurement of the antiproton and positron energy spectra. Antiparticles are a natural component of the cosmic radiation being produced in the interaction between cosmic rays and the interstellar matter. They have been shown to be extremely interesting for understanding the propagation mechanisms of cosmic rays. Furthermore, novel sources of primary cosmic-ray antiparticles of either astrophysical or exotic origin (e.g. annihilation of dark matter particles) can also be probed. In this paper we review the PAMELA antiparticle results and their significance for the field of astroparticle physics.
34.	Bruno, A., et al. (författare) PAMELA's measurements of geomagnetic cutoff variations during solar energetic particle events 2015 Ingår i: Proceedings of Science. - : Proceedings of Science (PoS). Konferensbidrag (refereegranskat)abstract Data from the PAMELA satellite experiment were used to measure the geomagnetic cutoff for high-energy ( 80 MeV) protons during the solar particle events on 2006 December 13 and 14. The variations of the cutoff latitude as a function of rigidity were studied on relatively short timescales, corresponding to single spacecraft orbits (about 94 minutes). Estimated cutoff values were cross-checked with those obtained by means of a trajectory tracing approach based on dynamical empirical modeling of the Earth's magnetosphere. We find significant variations in the cutoff latitude, with a maximum suppression of about 6 deg for 80 MeV protons during the main phase of the storm. The observed reduction in the geomagnetic shielding and its temporal evolution were compared with the changes in the magnetosphere configuration, investigating the role of IMF, solar wind and geomagnetic (Kp, Dst and Sym-H indexes) variables and their correlation with PAMELA cutoff results.
35.	Bruno, A., et al. (författare) PAMELA's measurements of geomagnetically trapped and albedo protons 2015 Ingår i: Proceedings of Science. - : Proceedings of Science (PoS). Konferensbidrag (refereegranskat)abstract Data from the PAMELA satellite experiment were used to perform a detailed measurement of under-cutoff protons at low Earth orbits. On the basis of a trajectory tracing approach using a realistic description of the magnetosphere, protons were classified into geomagnetically trapped and re-entrant albedo. The former include stably-trapped protons in the South Atlantic Anomaly, which were analyzed in the framework of the adiabatic theory, investigating energy spectra, spatial and angular distributions; results were compared with the predictions of the AP8 and the PSB97 empirical trapped models. The albedo protons were classified into quasi-trapped, concentrating in the magnetic equatorial region, and un-trapped, spreading over all latitudes and including both short-lived (precipitating) and long-lived (pseudo-trapped) components. Features of the penumbra region around the geomagnetic cutoff were investigated as well. PAMELA observations significantly improve the characterization of the high energy proton populations in near Earth orbits. The.
36.	Bruno, A., et al. (författare) Solar energetic particle events : Trajectory analysis and flux reconstruction with PAMELA 2015 Ingår i: Proceedings of Science. - : Proceedings of science. Konferensbidrag (refereegranskat)abstract The PAMELA satellite experiment is providing first direct measurements of Solar Energetic Particles (SEPs) with energies from about 80 MeV to several GeV in near-Earth space, bridging the low energy data by other space-based instruments and the Ground Level Enhancement (GLE) data by the worldwide network of neutron monitors. Its unique observational capabilities include the possibility of measuring the flux angular distribution and thus investigating possible anisotropies. This work reports the analysis methods developed to estimate the SEP energy spectra as a function of the particle pitch-angle with respect to the Interplanetary Magnetic Field (IMF) direction. The crucial ingredient is provided by an accurate simulation of the asymptotic exposition of the PAMELA apparatus, based on a realistic reconstruction of particle trajectories in the Earth's magnetosphere. As case study, the results for the May 17, 2012 event are presented.
37.	Casolino, M., et al. (författare) New upper limit on strange quark matter flux with the PAMELA experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract In this work we present a new upper limit for anomalous charge / mass (Z/A) particles with PAMELA experiment. These particles would exhibit a low velocity in the Time-of-Flight system and an high rigidity in the tracker. The redundant nature of the PAMELA detectors make it particularly suited to search for these particles in a mass number (10 ≤ A ≤ 105), charge (1≤ Z ≤ 8) and rigidity (0.4 ≤ R ≤ 1200 GV) range complementary to those of ground-based experiments.
38.	Formato, V., et al. (författare) Galactic boron and carbon fluxes measured by the PAMELA experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract The PAMELA experiment is a satellite-borne apparatus that performs measurements of the cosmic radiation with a particular focus on antiparticles and light nuclei. The heart of experiment is a magnetic spectrometer to measure the particle rigidity and sign of charge. A Time-of-Flight system, a Silicon-Tungsten calorimeter, and a neutron detector allow particle identification and lepton/hadron discrimination. The apparatus is surrounded by a set of anticoincidence scintillation counters to reject multi-particle events. In this work we will present the Boron and Carbon fluxes measured by PAMELA from July 2006 to March 2008. Such data, and in particular the B/C flux ratio, can help the modelling of the galactic cosmic rays propagation. This can be a crucial point in predicting the astrophysical background of antimatter (positrons and antiprotons) in cosmic rays in the search for a dark matter signal.
39.	Formato, V., et al. (författare) Hydrogen and helium isotopes flux in cosmic rays with the PAMELA experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature, with particular focus on the antimatter component. The detector consists of a permanent magnet spectrometer core to provide rigidity and charge sign information, a Time-of-Flight system for velocity and charge information, a Silicon-Tungsten calorimeter and a Neutron detector for lepton/hadron identification. The beta and rigidity information allow to identify isotopes for Z = 1 and Z = 2 particles in the energy range 100 MeV/n to 1 GeV/n. In this work we will present the final PAMELA results on the H and He isotope fluxes measured during the 23rd solar minimum from 2006 to 2007. Such fluxes carry relevant information helpful in constraining parameters in galactic cosmic rays propagation models complementary to those obtained from other secondary to primary measurements such as the boron-to-carbon ratio.
40.	Formato, V., et al. (författare) Measurement of hydrogen and helium isotopes flux in galactic cosmic rays with the PAMELA experiment 2014 Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 742, s. 273-275 Tidskriftsartikel (refereegranskat)abstract PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature, with particular focus on the antimatter component. The detector consists of a permanent magnet spectrometer core to provide rigidity and charge sign information, a Time-of-Flight system for velocity and charge information, a Silicon-Tungsten calorimeter and a Neutron detector for lepton/hadron identification. The velocity and rigidity information allow the identification of different isotopes for Z = 1 and Z = 2 particles in the energy range 100 MeV/n to 1 GeV/n. In this work we will present the PAMELA results on the H and He isotope fluxes based on the data collected during the 23rd solar minimum from 2006 to 2007. Such fluxes carry relevant information helpful in constraining parameters in galactic cosmic rays propagation models complementary to those obtained from other secondary to primary measurements such as the boron-to-carbon ratio.
41.	Karelin, A. V., et al. (författare) Detection of a change in the North-South ratio of count rates of particles of high-energy cosmic rays during a change in the polarity of the magnetic field of the Sun 2015 Ingår i: JETP Letters. - 0021-3640 .- 1090-6487. ; 101:4, s. 228-231 Tidskriftsartikel (refereegranskat)abstract A change in the ratio of the intensities of particles of high-energy cosmic rays arriving from the North and South in the time interval of 2010-2014 has been detected with a calorimeter entering into the experimental complex of the PAMELA satellite experiment since June 2006. The polarity of the magnetic field of the Sun changed in a part of this time interval. Thus, the results indicate that the North-South asymmetry of cosmic ray fluxes is related to the magnetic field of the Sun.
42.	Karelin, A. V., et al. (författare) Measurement of electron-positron spectrum in high-energy cosmic rays in the PAMELA experiment 2015 Ingår i: 24TH EUROPEAN COSMIC RAY SYMPOSIUM (ECRS). - : IOP Publishing. Konferensbidrag (refereegranskat)abstract At present the existing data on the cosmic ray electron energy spectra in the high energy range are fragmented, and the situation is exacerbated by their small number. In the satellite PAMELA experiment measurements at high energies are carried out by the calorimeter. The experimental data accumulated for more than 8 years of measurements, with the information of the calorimeter, the neutron detector and the scintillation counters made it possible to obtain the total spectrum of high-energy electrons and positrons in energy range 0.3-3 TeV.
43.	Karelin, A. V., et al. (författare) Measurement of the large-scale anisotropy of cosmic rays in the PAMELA experiment 2015 Ingår i: JETP Letters. - 0021-3640 .- 1090-6487. ; 101:5, s. 295-298 Tidskriftsartikel (refereegranskat)abstract Large-scale anisotropy or so-called sidereal-diurnal wave has been detected in the PAMELA satellite experiment in the time interval of 2006–2014. The magnitude of anisotropy has been measured simultaneously for the Southern and Northern Hemispheres in the equatorial coordinate system. The results confirm the data of ground-based experiments.
44.	Koldobskiy, S. A., et al. (författare) Deuteron spectrum measurements under radiation belt with PAMELA instrument 2016 Ingår i: Nuclear and Particle Physics Proceedings. - : Elsevier. - 2405-6014. ; 273-275, s. 2345-2347 Tidskriftsartikel (refereegranskat)abstract In this work the results of data analysis of the deuteron albedo radiation obtained in the PAMELA experiment are presented. PAMELA is an international space experiment carried out on board of the satellite Resurs DK-1. The high precision detectors allow to register and identify cosmic ray particles in a wide energy range. The albedo deuteron spectrum in the energy range 70 - 600 MeV/nucleon has been measured.
45.	Koldobskiy, S., et al. (författare) Measuring the albedo deuteron flux in the PAMELA satellite experiment 2015 Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 79:3, s. 294-297 Tidskriftsartikel (refereegranskat)abstract The results of measuring albedo deuteron fluxes in the vicinity of the Earth are presented. The data were obtained in the PAMELA experiment conducted aboard the Resurs DK-1 artificial Earth satellite. High-precision detectors of the instrument setup allow us to identify albedo deuterons and measure their spectra in the energy interval from 70 to 600 MeV/nucleon at altitudes of 350–600 km for different geomagnetic latitudes.
46.	Martucci, M., et al. (författare) Magnetospheric effects on high-energy solar particles during the 2012 May 17th event measured with the PAMELA experiment 2015 Ingår i: Proceedings of Science. - : Proceedings of Science (PoS). Konferensbidrag (refereegranskat)abstract The great challenge in constraining scenarios for solar energetic particle (SEP) acceleration is due to the fact that the signatures of acceleration itself are heavily modified by transport within interplanetary space. During transport, SEPs are subject to pitch angle scattering by the turbulent magnetic field, adiabatic focusing, or reflecting magnetic structures. Ground Level Enhancements (GLEs) provide an ideal way to study acceleration with minimal transport. In this work, we present a unique high-energy SEP observation from PAMELA of the 2012 May 17 GLE and interpret the observed pitch angle distributions as a result of local scattering (1 AU) by the Earth's magnetosheath.
47.	Merge, M., et al. (författare) Multi-particle analysis of the december 13th 2006 forbush decrease with PAMELA experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract In this paper we present PAMELA multi-particle observation of the Forbush decrease (FD) following the December 13th 2006 solar particle event. The FD is the sudden decrease of the galactic cosmic ray flux due to the transit of a Coronal Mass Ejection (CME). The satellite-borne experiment PAMELA on-board Resurs-DK1 satellite and consist of a magnetic spectrometer with time-of-flight and calorimeter detectors. PAMELA can study in real time with high precision the temporal and energetic evolution of several particle fluence during and after crossing of the magnetic cloud generated by the CME. The effect is stronger than what detected on ground with neutron monitor. With flux reduction can be as high as 30% decreasing at 1.5GV. No difference of the FD has been found for different particles proving that there is no charge sign dependence of FD for this event.
48.	Mikhailov, V. V., et al. (författare) Anisotropy analysis of positron data with the PAMELA experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract The PAMELA experiment is carried out on board of satellite the Resurs DK1 since 2006 for precision study of cosmic ray antiparticles. The instrument is equipped with magnetic spectrometer, silicon-tungsten imaging electromagnetic calorimeter, neutron detector which give possibility to separate electron and positron over wide energy range up to hundreds GeVs and to measure their incoming direction with accuracy about 2 degree. For each detected particle a space arriving direction was reconstructed using trajectory inside the instrument and the satellite position on the orbit. Backtracking in geomagnetic field was done to obtain initial spatial distribution of particles outside of the Earth magnetosphere. This paper discuss a result of search a possible local sources by anisotropy analysis of positron data.
49.	Mikhailov, V. V., et al. (författare) Method of electrons and positrons separations by bremsstrahlung in the PAMELA experiment 2013 Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293 Konferensbidrag (refereegranskat)abstract Imaging calorimeter of the PAMELA instrument on board the Resurs DK satellite has high spatial resolution and allows to measure separately electromagnetic showers from electrons and positrons and their bremsstahlung produced in ToF detectors of the instrument. Measuring events with two showers provides proton rejection coefficient more than 104 at energy between 0.5 and 3 GeV. Results of positrons fractions obtained by this method are in agreement with previously published data of the PAMELA experiment at low energy. It confirms in independent way strong positron modulation during period of negative polarity of the Sun magnetic field.
50.	Mikhailov, V. V., et al. (författare) Searching for anisotropy of positrons and electrons in the PAMELA experiment 2015 Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 79:3, s. 298-301 Tidskriftsartikel (refereegranskat)abstract The PAMELA experiment has been under way aboard the Resurs DK-1 satellite since June 2006. The results have revealed an increase in the ratio of the positron intensity to the total electron and positron intensity at energies in excess of 10 GeV. This increase suggests an additional source of cosmic rays that is associated with either some astrophysical objects (e.g., pulsars) or the probable annihilation of particles of dark matter. Local positron sources can produce notable anisotropy in their flux. The results from the search for anisotropy of positrons and electrons in the events detected by the PAMELA experiment in the 2006–2013 timeframe are described in detail in this work.

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