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Sökning: WFRF:(Koldashov S. V.)

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1.
  • Adriani, O., et al. (författare)
  • Measurements of quasi-trapped electron and positron fluxes with PAMELA
  • 2009
  • Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 114, s. A12218-
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper presents precise measurements of the differential energy spectra of quasi-trapped secondary electrons and positrons and their ratio between 80 MeV and 10 GeV in the near-equatorial region (altitudes between 350 km and 600 km). Latitudinal dependences of the spectra are analyzed in detail. The results were obtained from July until November 2006 onboard the Resurs-DK satellite by the PAMELA spectrometer, a general purpose cosmic ray detector system built around a permanent magnet spectrometer and a silicon-tungsten calorimeter.
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2.
  • Mayorov, A. G., et al. (författare)
  • Antiprotons of galactic cosmic radiation in the PAMELA experiment
  • 2013
  • Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 77:5, s. 602-605
  • Tidskriftsartikel (refereegranskat)abstract
    • A method for antiproton selection against a background of electrons, based on a mathematical model of data classification using variations in interparticle interaction in a calorimeter, and a method for excluding events accompanied by scattering in the inner detectors of a tracking system (which result in errors in the measured trajectory's curvature and charge sign) from analysis are discussed in this paper. Antiproton spectra and antiproton/proton flux ratio at energies of 0.06 to 350 GeV with statistics of events surpassing those in [1] are obtained. The results can be used to create models for the generation and distribution of particles in the Galaxy, and for searching and studying the nature of hypothetical dark matter particles.
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3.
  • Bazilevskaya, G. A., et al. (författare)
  • Solar proton events at the end of the 23rd and start of the 24th solar cycle recorded in the PAMELA experiment
  • 2013
  • Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 77:5, s. 493-496
  • Tidskriftsartikel (refereegranskat)abstract
    • The PAMELA magnetic spectrometer was launched into a near-Earth orbit on board the Resurs-DK1 satellite in June 2006; in December 2006, it recorded the last strong solar high-energy particle event of the 23rd solar cycle. A deficit was thereafter observed in solar energetic particle events because of the lengthy solar activity minimum and the weak evolution of the next (24th) solar cycle. As a result, only a few solar events involving protons with energies of more than 100 MeV were recorded between 2010 and 1012. This work presents the preliminary results from measurements of charged particle fluxes in these events, recorded by the Pamela spectrometer.
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4.
  • Koldobskiy, S. A., et al. (författare)
  • Measurement of galactic cosmic-ray deuteron spectrum in the PAMELA experiment
  • 2013
  • Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - : Allerton Press. - 1062-8738. ; 77:5, s. 606-608
  • Tidskriftsartikel (refereegranskat)abstract
    • This work presents the results of measuring the deuteron spectrum of Galactic cosmic rays (GCRs) with the PAMELA experiment. The PAMELA is an international experiment. Its main objectives are to search for antimatter and measure proton, helium nuclei, electron, and positron spectra over a wide range of energies. In addition, the experimental setup allows the detection of deuterons and the reconstruction of their spectra at low energies. Cosmic ray deuteron spectrum and the deuteron-proton ratio measured in the PAMELA experiment in the energy range of 50-650 MeV/nucleon are presented below.
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5.
  • Mikhailov, V., et al. (författare)
  • Cosmic ray electron and positron spectra measured with PAMELA
  • 2013
  • Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 409:1, s. 012035-
  • Tidskriftsartikel (refereegranskat)abstract
    • The PAMELA experiment is carried out on board of the satellite Resurs DK1 launched on June 15th 2006 on polar orbit (the inclination is 70, the altitude is 350-600 km). The instrument which consists of magnetic spectrometer, silicon-tungsten imaging electromagnetic calorimeter gives a possibility to measure electron and positron fluxes over wide energy range from hundreds MeVs to hundreds GeVs. Measurements made in June 2006- January 2010 are presented and compared with other results and models. Positron spectrum appears to be harder than standard diffusive propagation models predict.
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6.
  • 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.
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7.
  • Adriani, O., et al. (författare)
  • Measurement of the flux of primary cosmic ray antiprotons with energies of 60 MeV to 350 GeV in the PAMELA experiment
  • 2013
  • Ingår i: JETP Letters. - 0021-3640 .- 1090-6487. ; 96:10, s. 621-627
  • Tidskriftsartikel (refereegranskat)abstract
    • It is interesting to measure the antiproton galactic component in cosmic rays in order to study the mechanisms by which particles and antiparticles are generated and propagate in the Galaxy and to search for new sources of, e.g., annihilation or decay of dark matter hypothetical particles. The antiproton spectrum and the ratio of the fluxes of primary cosmic ray antiprotons to protons with energies of 60 MeV to 350 GeV found from the data obtained from June 2006 to January 2010 in the PAMELA experiment are presented. The usage of the advanced data processing method based on the data classification mathematical model made it possible to increase statistics and analyze the region of higher energies than in the earlier works.
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8.
  • Adriani, O., et al. (författare)
  • Time Dependence Of The Proton Flux Measured By Pamela During The 2006 July-2009 December Solar Minimum
  • 2013
  • Ingår i: Astrophysical Journal. - : IOP Publishing. - 0004-637X .- 1538-4357. ; 765:2, s. 91-
  • Tidskriftsartikel (refereegranskat)abstract
    • The energy spectra of galactic cosmic rays carry fundamental information regarding their origin and propagation. These spectra, when measured near Earth, are significantly affected by the solar magnetic field. A comprehensive description of the cosmic radiation must therefore include the transport and modulation of cosmic rays inside the heliosphere. During the end of the last decade, the Sun underwent a peculiarly long quiet phase well suited to study modulation processes. In this paper we present proton spectra measured from 2006 July to 2009 December by PAMELA. The large collected statistics of protons allowed the time variation to be followed on a nearly monthly basis down to 400 MV. Data are compared with a state-of-the-art three-dimensional model of solar modulation.
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9.
  • 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.
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10.
  • 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. 
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11.
  • Grishantseva, L. A., et al. (författare)
  • Sub-cutoff electrons and positrons in the near Earth space
  • 2009
  • Ingår i: 31st International Cosmic Ray Conference, ICRC 2009. - : University of Lodz.
  • Konferensbidrag (refereegranskat)abstract
    • Precise spectra of electron and positron fluxes in energy range from 80 MeV to several GeV below the geomagnetic cutoff rigidity were obtained using data of the PAMELA spectrometer. It was launched on June 15th 2006 onboard the Resurs-DK satellite on an elliptical orbit (the inclination is 70°, the altitude is 350-610 km). The work presents measurements of secondary lepton fluxes produced in interactions of cosmic ray protons with the atmosphere in the near Earth space (out of the South Atlantic Anomaly). Latitudinal dependences are discussed. These results are particularly interesting for more accurate definition of electron/positron flux model in the Earth magnetosphere.
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12.
  • Koldobskiy, S. A., et al. (författare)
  • Galactic deuteron spectrum measured in PAMELA experiment
  • 2013
  • Ingår i: 23Rd European Cosmic Ray Symposium (And 32Nd Russian Cosmic Ray Conference). - : IOP Publishing.
  • Konferensbidrag (refereegranskat)abstract
    • Results of galactic deuteron spectrum measurement by means of PAMELA apparatus are described. PAMELA is an international experiment developed for antimatter search and measurement of p, He, electron and positron spectra in wide energy range. In addition, PAMELA allows to identify and measure deuteron spectrum at low energies. In this paper deuteron-to-proton ratio and deuteron spectrum are presented.
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13.
  • 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.
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14.
  • 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.
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15.
  • 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. 
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16.
  • 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. 
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17.
  • Adriani, O., et al. (författare)
  • Cosmic-Ray Electron Flux Measured by the PAMELA Experiment between 1 and 625 GeV
  • 2011
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 106:20, s. 201101-
  • Tidskriftsartikel (refereegranskat)abstract
    • Precision measurements of the electron component in the cosmic radiation provide important information about the origin and propagation of cosmic rays in the Galaxy. Here we present new results regarding negatively charged electrons between 1 and 625 GeV performed by the satellite-borne experiment PAMELA. This is the first time that cosmic-ray e(-) have been identified above 50 GeV. The electron spectrum can be described with a single power-law energy dependence with spectral index -3.18 +/- 0.05 above the energy region influenced by the solar wind (> 30 GeV). No significant spectral features are observed and the data can be interpreted in terms of conventional diffusive propagation models. However, the data are also consistent with models including new cosmic-ray sources that could explain the rise in the positron fraction.
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18.
  • 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.
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19.
  • Adriani, O., et al. (författare)
  • Measurement of the isotopic composition of hydrogen and helium nuclei in cosmic rays with the PAMELA experiment
  • 2013
  • Ingår i: Astrophysical Journal. - : IOP Publishing. - 0004-637X .- 1538-4357. ; 770:1, s. 2-
  • Tidskriftsartikel (refereegranskat)abstract
    • The satellite-borne experiment PAMELA has been used to make new measurements of cosmic ray H and He isotopes. The isotopic composition was measured between 100 and 600 MeV /n for hydrogen and between 100 and 900 MeV /n for helium isotopes over the 23rd solar minimum from 2006 July to 2007 December. The energy spectrum of these components carries fundamental information regarding the propagation of cosmic rays in the galaxy which are competitive with those obtained from other secondary to primary measurements such as B/C.
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20.
  • Adriani, O., et al. (författare)
  • Measurements of cosmic-ray proton and helium spectra with the PAMELA calorimeter
  • 2013
  • Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 51:2, s. 219-226
  • Tidskriftsartikel (refereegranskat)abstract
    • We present a new measurement of the cosmic ray proton and helium spectra by the PAMELA experiment performed using the "thin" (in terms of nuclei interactions) sampling electromagnetic calorimeter. The described method, optimized by using Monte Carlo simulation, beam test and experimental data, allows the spectra to be measured up to 10 TeV, thus extending the PAMELA observational range based on the magnetic spectrometer measurement.
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21.
  • 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.
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22.
  • Adriani, O., et al. (författare)
  • Secondary electron and positron fluxes in the near-Earth space observed in the ARINA and PAMELA experiments
  • 2009
  • Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 73:3, s. 364-366
  • Tidskriftsartikel (refereegranskat)abstract
    • Secondary electron and positron fluxes in the energy range from 3 MeV to 7 GeV were measured with the ARINA and PAMELA spectrometers onboard the Resurs-DK satellite launched on June 15, 2006 into an elliptical orbit with an inclination of 70.4° and an altitude of 350-600 km. It is shown that positrons dominate over electrons by a factor of up to 4-5 in the geomagnetic equator region (L < 1.2 and B > 0.25).
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23.
  • 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.
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24.
  • 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.
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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. 
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26.
  • Casolino, M., et al. (författare)
  • Cosmic-ray observations of the heliosphere with the PAMELA experiment
  • 2006
  • Ingår i: Astrophysics. - : Elsevier BV. ; , s. 1848-1852
  • Konferensbidrag (refereegranskat)abstract
    • The PAMELA experiment is a multi-purpose apparatus built around a permanent magnet spectrometer, with the main goal of studying in detail the antiparticle component of cosmic rays. The apparatus will be carried in space by means of a Russian satellite, due to launch in 2005, for a three year-long mission. The characteristics of the detectors composing the instrument, alongside the long lifetime of the mission and the orbital characteristics of the satellite, will allow to address several items of cosmic-ray physics. In this paper, we will focus on the solar and heliospheric observation capabilities of PAMELA.
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27.
  • 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. 
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28.
  • Giaccari, U., et al. (författare)
  • Anisotropy studies in the cosmic ray proton flux with the PAMELA experiment
  • 2013
  • Ingår i: Proceedings of the 9th workshop on Science with the New Generation of High Energy Gamma-ray Experiments: From high energy gamma sources to cosmic rays, one century after their discovery. - : Elsevier. ; , s. 123-128
  • Konferensbidrag (refereegranskat)abstract
    • Using data taken by the Pamela experiment during 5 years of operation we studied the anisotropy in the arrival direction distribution of cosmic ray protons with rigidity above 40 GV. In this survey we used two different and independent techniques to investigate the large and medium anisotropy patterns in the proton spectrum. With both methods the observed distribution of arrival directions is consistent with the isotropic expectation and no significant evidence of strong anisotropies has been observed.
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29.
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30.
  • 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.
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31.
  • 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.
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32.
  • Karelin, A. V., et al. (författare)
  • Measuring the spectra of high-energy cosmic-ray particles in the PAMELA experiment
  • 2015
  • Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 79:3, s. 289-293
  • Tidskriftsartikel (refereegranskat)abstract
    • The available data on the energy spectra of electrons, protons, and helium nuclei in the high-energy region are fragmentary, a situation made worse by their scarcity. Due to limitations imposed on the use of the magnetic spectrometer in the PAMELA satellite experiment, the calorimeter must be used for measurements performed in the high-energy region. The processing of experimental data accumulated in more than eight years of measurements with the calorimeter, neutron detector, and scintillation counters allows the spectra of high-energy particles to be obtained, greatly expanding our understanding of the nature of primary cosmic rays.
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33.
  • Karelin, A. V., et al. (författare)
  • New measurements of the energy spectra of high-energy cosmic-ray protons and helium nuclei with the calorimeter in the PAMELA experiment
  • 2014
  • Ingår i: Journal of Experimental and Theoretical Physics. - 1063-7761 .- 1090-6509. ; 119:3, s. 448-452
  • Tidskriftsartikel (refereegranskat)abstract
    • New measurements of the energy spectra of cosmic-ray protons and helium nuclei with significantly increased statistics owing to an improvement of the event selection technique and the involvement of all data over the period 2006-2013 in the analysis have been made at energies above 0.8 TeV/nucleon with a position-sensitive calorimeter based on data from the PAMELA satellite-borne experiment.
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34.
  • Karelin, A. V., et al. (författare)
  • North-south asymmetry for high-energy cosmic-ray electrons measured with the PAMELA experiment
  • 2013
  • Ingår i: Journal of Experimental and Theoretical Physics. - 1063-7761 .- 1090-6509. ; 117:2, s. 268-273
  • Tidskriftsartikel (refereegranskat)abstract
    • The north-south asymmetry for cosmic-ray particles was measured with one instrument of the PAMELA satellite-borne experiment in the period June 2006-May 2009. The analysis has been performed by two independent methods: by comparing the count rates in regions with identical geomagnetic conditions and by comparing the experimental distribution of particle directions with the simulated distribution that would be in the case of an isotropic particle flux. The dependences of the asymmetry on energy release in the PAMELA calorimeter and on time have been constructed. The asymmetry (N (n) - N (s) )/(N (n) + N (s) ) is 0.06 +/- 0.004 at the threshold energy release in the calorimeter and gradually decreases with increasing energy release. The observed effect is shown to be produced by electrons in the energy range 10-100 GeV.
  •  
35.
  • 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.
  •  
36.
  • Koldobskiy, S. A., et al. (författare)
  • Study of deuteron spectra under radiation belt with PAMELA instrument
  • 2015
  • Ingår i: 24TH EUROPEAN COSMIC RAY SYMPOSIUM (ECRS). - : IOP Publishing.
  • Konferensbidrag (refereegranskat)abstract
    • This paper presents the results of measurements of proton and deuteron fluxes of albedo radiation in the Earth vicinity, obtained in the PAMELA experiment. PAMELA is an international experiment meant to study cosmic rays. PAMELA is carried out on board the satellite Resurs-DK1. High-precision equipment of the experiment allows registration and identification of cosmic ray particles of different varieties in a wide energy range. The albedo deuteron spectrum and albedo deuteron-to-proton fluxes ratio in the energy range 70 - 600 MeV/nucleon at altitude of 350 - 600 km for different geomagnetic latitudes is presented.
  •  
37.
  • Malakhov, V. V., et al. (författare)
  • Time variations of proton flux in Earth inner radiation belt during 23/24 solar cycles based on the PAMELA and the ARINA data.
  • 2015
  • Ingår i: 24TH EUROPEAN COSMIC RAY SYMPOSIUM (ECRS). - : IOP Publishing.
  • Konferensbidrag (refereegranskat)abstract
    • The PAMELA and the ARINA experiments are carried out on the board of satellite RESURS-DK1 since 2006 up to now. Main goal of the PAMELA instrument is measurements of high energy antiparticles in cosmic rays while the ARINA instrument is intended studying high energy charged particle bursts in the magnetosphere. Both of these experiments have a possibility to study trapped particles in the inner radiation belt. Complex of these two instruments covers proton energy range from 30 MeV up to trapping limit (E= similar to 2 GeV). Continuous measurements with the PAMELA and the ARINA spectrometers include falling and rising phases of 23/24 solar cycles and maximum of 24th one. In this report we present temporal profiles of proton flux in the inner zone of the radiation belt (1.11 < L < 1.18, 0.18 < B < 0.22G). Dependence of proton fluxes on a magnitude of the solar activity was studied for various phases of 23/24 solar cycles. At that it was shown that proton fluxes at the solar minimum are several times greater than at the solar maximum.
  •  
38.
  • 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.
  •  
39.
  • 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.
  •  
40.
  • Menn, W., et al. (författare)
  • Lithium and beryllium isotopes in the pamela-experiment
  • 2015
  • Ingår i: Proceedings of Science. - : Proceedings of Science (PoS).
  • Konferensbidrag (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 apparatus comprises a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anti-coincidence system, a shower tail counter scintillator and a neutron detector. The scientific objectives addressed by the mission are the measurement of the antiprotons and positrons spectra in cosmic rays, the hunt for antinuclei as well as the determination of light nuclei fluxes from hydrogen to oxygen in a wide energy range and with very high statistics. In this paper the identification capability for lithium and beryllium isotopes for two different techniques are presented, combining the rigidity measurement from the magnetic spectrometer with the velocity information derived either with the time-of-flight or with multiple dE/dx measurements in the calorimeter. Preliminary results of the isotopic ratios will be presented.
  •  
41.
  • Menn, W., et al. (författare)
  • Measurement of the isotopic composition of hydrogen and helium nuclei in cosmic rays with the pamela-experiment
  • 2015
  • Ingår i: Proceedings of Science. - : Proceedings of Science (PoS).
  • Konferensbidrag (refereegranskat)abstract
    • The cosmic-ray hydrogen and helium (1H,2H,3He,4He) isotopic composition between 100 MeV/n and 1.4 GeV/n has been measured with the satellite-borne experiment PAMELA, which was launched into low-Earth orbit on-board the Resurs-DK1 satellite on June 15th 2006. The rare isotopes 2H and 3He in cosmic rays are believed to originate mainly from the interaction of high energy protons and helium with the galactic interstellar medium. The energy spectrum of these components carries fundamental information regarding the propagation of cosmic rays in the galaxy which are competitive with those obtained from other secondary to primary measurements such as B/C. The isotopic composition was measured between 100 and 1100 MeV/n for hydrogen and between 100 and 1400 MeV/n for helium isotopes using two different detector systems over the 23rd solar minimum from July 2006 to December 2007.
  •  
42.
  • Menn, W., et al. (författare)
  • The PAMELA space experiment
  • 2013
  • Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 51:2, s. 209-218
  • 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 apparatus is comprised of a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail counter scintillator and a neutron detector. The combination of these devices allows precision studies of the charged cosmic radiation to be conducted over a wide energy range (100 MeV to 100's GeV) with high statistics. The primary scientific goal is the measurement of the antiproton and positron energy spectra in order to search for exotic sources, such as dark matter particle annihilations. PAMELA is also searching for primordial antinuclei (anti-helium), and testing cosmic-ray propagation models through precise measurements of the antiparticle energy spectrum and precision studies of light nuclei and their isotopes. Moreover, PAMELA is investigating phenomena connected with solar and earth physics. After 4 years of operation in flight, PAMELA is now delivering coherent results about spectra and chemical composition of the charged cosmic radiation, allowing scenarios of production and propagation of cosmic rays to be fully established and understood.
  •  
43.
  • 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. 
  •  
44.
  • 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. 
  •  
45.
  • Mori, N., et al. (författare)
  • The PAMELA experiment and cosmic ray observations
  • 2015
  • Ingår i: NUCLEAR AND PARTICLE PHYSICS PROCEEDINGS. - : Elsevier. - 2405-6014. ; , s. 242-244
  • Konferensbidrag (refereegranskat)abstract
    • The PAMELA space experiment is aimed at precise measurements of the charged light component of the cosmic ray spectrum in the energy range spanning from the sub-GeV region to the TeV region, with a particular focus on antimatter. The instrument consists of a magnetic spectrometer, an electromagnetic sampling calorimeter,a time-off-light system, an anticoincidence shield, a tail-catcher scintillator and a neutron detector. Launched in June 2006 and hosted on the Resurs-DK1 satellite, PAMELA has been taking data for more than eight years, providing scientific results with unprecedented statistics and a continuous monitoring of the sun activity and the heliosphere.
  •  
46.
  • Munini, R., et al. (författare)
  • Solar modulation of galactic cosmic ray electrons and positrons over the 23rd solar minimum with the PAMELA experiment
  • 2015
  • Ingår i: Proceedings of Science. - : Proceedings of Science (PoS).
  • 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 unprecedented statistics. The apparatus design is particularly suited for particle and antiparticle identification. The PAMELA experiment has measured the time variation of electron and positron spectrum at Earth in great detail, extending the measurement down to 70 MeV and 200 MeV respectively. The spectra have been evaluated with data collected from July 2006 to December 2009, i.e. during the A<0 solar minimum of solar cycle 23, over six-months intervals. These spectra provide important information for the study of CR propagation inside the heliosphere and the investigation of the charge-dependent solar modulation.
  •  
47.
  • Munini, R., et al. (författare)
  • Solar modulation of GCR electrons over the 23rd solar minimum with PAMELA
  • 2015
  • Ingår i: 24TH EUROPEAN COSMIC RAY SYMPOSIUM (ECRS). - : IOP Publishing.
  • 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 unprecedented statistics. The apparatus design is particularly suited for particle and antiparticle identification. The PAMELA experiment has measured the electron spectrum at Earth in great detail, extending up to about 100 GeV and down to about 200 MeV. The galactic cosmic ray electron spectra for 2007 and 2009, i.e. measured during the A<0 solar minimum of solar cycle 23, are presented. These fluxes provide important information for the study of charge dependent solar modulation effects.
  •  
48.
  • 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. 
  •  
49.
  • Ricciarini, S. B., et al. (författare)
  • PAMELA mission : Heralding a new era in cosmic ray physics
  • 2014
  • Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X.
  • Konferensbidrag (refereegranskat)abstract
    • After seven years of data taking in space, the experiment PAMELA is showing very interesting features in cosmic rays, namely in the fluxes of protons, helium, electrons, that might change our basic vision of the mechanisms of production, acceleration and propagation of cosmic rays in the galaxy. In addition, PAMELA measurements of cosmic antiproton and positron fluxes are setting strong constraints to the nature of Dark Matter. The continuous particle detection is allowing a constant monitoring of the solar activity and detailed study of the solar modulation for a long period, giving important improvements to the comprehension of the heliosphere mechanisms. PAMELA is also measuring the radiation environment around the Earth, and has recently discovered an antiproton radiation belt.
  •  
50.
  • Usoskin, I. G., et al. (författare)
  • Force-field parameterization of the galactic cosmic ray spectrum : Validation for Forbush decreases
  • 2015
  • Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 55:12, s. 2940-2945
  • Tidskriftsartikel (refereegranskat)abstract
    • A useful parametrization of the energy spectrum of galactic cosmic rays (GCR) near Earth is offered by the so-called force-field model which describes the shape of the entire spectrum with a single parameter, the modulation potential. While the usefulness of the force-field approximation has been confirmed for regular periods of solar modulation, it was not tested explicitly for disturbed periods, when GCR are locally modulated by strong interplanetary transients. Here we use direct measurements of protons and alpha-particles performed by the PAMELA space-borne instrument during December 2006, including a major Forbush decrease, in order to directly test the validity of the force-field parameterization. We conclude that (1) The force-field parametrization works very well in describing the energy spectra of protons and alpha-particles directly measured by PAMELA outside the Earths atmosphere; (2) The energy spectrum of GCR can be well parameterized by the force-field model also during a strong Forbush decrease; (3) The estimate of the GCR modulation parameter, obtained using data from the world-wide neutron monitor network, is in good agreement with the spectra directly measured by PAMELA during the studied interval. This result is obtained on the basis of a single event analysis, more events need to be analyzed.
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