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1.
  • Adriani, O., et al. (author)
  • Design of an Antimatter Large Acceptance Detector In Orbit (ALADInO)
  • 2022
  • In: Instruments. - : MDPI AG. - 2410-390X. ; 6:2
  • Journal article (peer-reviewed)abstract
    • A new generation magnetic spectrometer in space will open the opportunity to inves-tigate the frontiers in direct high-energy cosmic ray measurements and to precisely measure the amount of the rare antimatter component in cosmic rays beyond the reach of current missions. We propose the concept for an Antimatter Large Acceptance Detector In Orbit (ALADInO), designed to take over the legacy of direct measurements of cosmic rays in space performed by PAMELA and AMS-02. ALADInO features technological solutions conceived to overcome the current limi-tations of magnetic spectrometers in space with a layout that provides an acceptance larger than 10 m2 sr. A superconducting magnet coupled to precision tracking and time-of-flight systems can provide the required matter–antimatter separation capabilities and rigidity measurement resolution with a Maximum Detectable Rigidity better than 20 TV. The inner 3D-imaging deep calorimeter, designed to maximize the isotropic acceptance of particles, allows for the measurement of cosmic rays up to PeV energies with accurate energy resolution to precisely measure features in the cosmic ray spectra. The operations of ALADInO in the Sun–Earth L2 Lagrangian point for at least 5 years would enable unique revolutionary observations with groundbreaking discovery poten-tials in the field of astroparticle physics by precision measurements of electrons, positrons, and antiprotons up to 10 TeV and of nuclear cosmic rays up to PeV energies, and by the possible unam-biguous detection and measurement of low-energy antideuteron and antihelium components in cosmic rays. 
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2.
  • Adriani, O., et al. (author)
  • Pamela's measurements of magnetospheric effects on high-energy solar particles
  • 2015
  • In: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 801:1
  • Journal article (peer-reviewed)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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3.
  • Bongi, M, et al. (author)
  • PAMELA : A satellite experiment for antiparticles measurement in cosmic rays
  • 2004
  • In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 51:3, s. 854-859
  • Journal article (peer-reviewed)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.
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4.
  • Carbone, R., et al. (author)
  • Pamela observation of the 2012 may 17 gle event
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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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5.
  • Di Felice, V., et al. (author)
  • Solar modulation of galactic hydrogen and helium over the 23rd solar minimum with the PAMELA experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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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6.
  • Martucci, M., et al. (author)
  • Analysis on H spectral shape during the early 2012 SEPs with the PAMELA experiment
  • 2014
  • In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 742, s. 158-161
  • Journal article (peer-reviewed)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.
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7.
  • Munini, R., et al. (author)
  • Solar modulation of galactic cosmic rays electrons and positrons over the 23rd solar minimum with the pamela experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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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8.
  • Ricci, M., et al. (author)
  • Study on 2012 march 7 solar particle event and forbush decrease with the PAMELA experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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. 
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9.
  • Adriani, O., et al. (author)
  • Antiprotons in primary cosmic radiation with PAMELA experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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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10.
  • Adriani, O., et al. (author)
  • Cosmic-Ray Positron Energy Spectrum Measured by PAMELA
  • 2013
  • In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 111:8, s. 081102-
  • Journal article (peer-reviewed)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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11.
  • Adriani, O., et al. (author)
  • Measurement of Boron and Carbon Fluxes in Cosmic Rays with the Pamela Experiment
  • 2014
  • In: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 791:2, s. 93-
  • Journal article (peer-reviewed)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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12.
  • Boezio, M., et al. (author)
  • The PAMELA experiment and antimatter in the universe
  • 2014
  • In: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 228:1-3, s. 101-109
  • Journal article (peer-reviewed)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.
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13.
  • Bruno, A., et al. (author)
  • PAMELA's measurements of geomagnetic cutoff variations during solar energetic particle events
  • 2015
  • In: Proceedings of Science. - : Proceedings of Science (PoS).
  • Conference paper (peer-reviewed)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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14.
  • Bruno, A., et al. (author)
  • PAMELA's measurements of geomagnetically trapped and albedo protons
  • 2015
  • In: Proceedings of Science. - : Proceedings of Science (PoS).
  • Conference paper (peer-reviewed)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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15.
  • Bruno, A., et al. (author)
  • Solar energetic particle events : Trajectory analysis and flux reconstruction with PAMELA
  • 2015
  • In: Proceedings of Science. - : Proceedings of science.
  • Conference paper (peer-reviewed)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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16.
  • Casolino, M., et al. (author)
  • New upper limit on strange quark matter flux with the PAMELA experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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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17.
  • Formato, V., et al. (author)
  • Galactic boron and carbon fluxes measured by the PAMELA experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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. 
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18.
  • Formato, V., et al. (author)
  • Hydrogen and helium isotopes flux in cosmic rays with the PAMELA experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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. 
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19.
  • Formato, V., et al. (author)
  • Measurement of hydrogen and helium isotopes flux in galactic cosmic rays with the PAMELA experiment
  • 2014
  • In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 742, s. 273-275
  • Journal article (peer-reviewed)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.
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20.
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21.
  • Karelin, A. V., et al. (author)
  • Measurement of electron-positron spectrum in high-energy cosmic rays in the PAMELA experiment
  • 2015
  • In: 24TH EUROPEAN COSMIC RAY SYMPOSIUM (ECRS). - : IOP Publishing.
  • Conference paper (peer-reviewed)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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22.
  • Karelin, A. V., et al. (author)
  • Measurement of the large-scale anisotropy of cosmic rays in the PAMELA experiment
  • 2015
  • In: JETP Letters. - 0021-3640 .- 1090-6487. ; 101:5, s. 295-298
  • Journal article (peer-reviewed)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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23.
  • Koldobskiy, S. A., et al. (author)
  • Deuteron spectrum measurements under radiation belt with PAMELA instrument
  • 2016
  • In: Nuclear and Particle Physics Proceedings. - : Elsevier. - 2405-6014. ; 273-275, s. 2345-2347
  • Journal article (peer-reviewed)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.
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24.
  • Koldobskiy, S., et al. (author)
  • Measuring the albedo deuteron flux in the PAMELA satellite experiment
  • 2015
  • In: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 79:3, s. 294-297
  • Journal article (peer-reviewed)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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25.
  • Martucci, M., et al. (author)
  • Magnetospheric effects on high-energy solar particles during the 2012 May 17th event measured with the PAMELA experiment
  • 2015
  • In: Proceedings of Science. - : Proceedings of Science (PoS).
  • Conference paper (peer-reviewed)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.
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26.
  • Merge, M., et al. (author)
  • Multi-particle analysis of the december 13th 2006 forbush decrease with PAMELA experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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. 
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27.
  • Mikhailov, V. V., et al. (author)
  • Anisotropy analysis of positron data with the PAMELA experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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. 
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28.
  • Mikhailov, V. V., et al. (author)
  • Method of electrons and positrons separations by bremsstrahlung in the PAMELA experiment
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)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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29.
  • Mikhailov, V. V., et al. (author)
  • Searching for anisotropy of positrons and electrons in the PAMELA experiment
  • 2015
  • In: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 79:3, s. 298-301
  • Journal article (peer-reviewed)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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30.
  • Mocchiutti, E., et al. (author)
  • Cosmic–ray positron energy spectrum measured by PAMELA
  • 2013
  • In: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
  • Conference paper (peer-reviewed)abstract
    • The PAMELA satellite borne experiment is designed to study cosmic rays with great accuracy in a wide energy range. One of PAMELA’s main goal is the study of the antimatter component of cosmic rays. The experiment, housed on board the Russian satellite Resurs–DK1, was launched on June 15th 2006 and it is still taking data. In this work we present the measurement of galactic positron energy spectrum in the energy range between 500 MeV and few hundred GeV. 
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31.
  • Mori, N., et al. (author)
  • PAMELA measurements of the boron and carbon spectra
  • 2015
  • In: 24TH EUROPEAN COSMIC RAY SYMPOSIUM (ECRS). - : IOP Publishing.
  • Conference paper (peer-reviewed)abstract
    • The satellite-borne PAMELA experiment is aimed at precision measurements of the charged light component of the cosmic-ray spectrum, with a particular focus on antimatter. It consists of a magnetic spectrometer, a time-of-flight system, an electromagnetic calorimeter with a tail catcher scintillating layer, an anticoincidence system and a neutron detector. PAMELA has measured the absolute fluxes of boron and carbon and the B/C ratio, which plays a central role in galactic propagation studies in order to derive the injection spectra at sources from measurements at Earth. In this paper, the data analysis techniques and the final results are presented.
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32.
  • Mori, N., et al. (author)
  • The PAMELA experiment and cosmic ray observations
  • 2015
  • In: NUCLEAR AND PARTICLE PHYSICS PROCEEDINGS. - : Elsevier. - 2405-6014. ; , s. 242-244
  • Conference paper (peer-reviewed)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.
  •  
33.
  • Ricciarini, S. B., et al. (author)
  • PAMELA mission : Heralding a new era in cosmic ray physics
  • 2014
  • In: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X.
  • Conference paper (peer-reviewed)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.
  •  
34.
  • Stozhkov, Y. I., et al. (author)
  • About Separation of Hadron and Electromagnetic Cascades in the Pamela Calorimeter
  • 2005
  • In: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 20:29, s. 6745-6748
  • Journal article (peer-reviewed)abstract
    • Results of calibration of the PAMELA instrument at the CERN facilities are discussed. In September, 2003, the calibration of the Neutron Detector together with the Calorimeter was performed with the CERN beams of electrons and protons with energies of 20-180 GeV. The implementation of the Neutron Detector increases a rejection factor of hadrons from electrons about ten times. The results of calibration are in agreement with calculations.
  •  
35.
  • Usoskin, I. G., et al. (author)
  • Force-field parameterization of the galactic cosmic ray spectrum : Validation for Forbush decreases
  • 2015
  • In: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 55:12, s. 2940-2945
  • Journal article (peer-reviewed)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.
  •  
36.
  • Adriani, O., et al. (author)
  • Cosmic-Ray Electron Flux Measured by the PAMELA Experiment between 1 and 625 GeV
  • 2011
  • In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 106:20, s. 201101-
  • Journal article (peer-reviewed)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.
  •  
37.
  • Adriani, O., et al. (author)
  • Measurement of the flux of primary cosmic ray antiprotons with energies of 60 MeV to 350 GeV in the PAMELA experiment
  • 2013
  • In: JETP Letters. - 0021-3640 .- 1090-6487. ; 96:10, s. 621-627
  • Journal article (peer-reviewed)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.
  •  
38.
  • Adriani, O., et al. (author)
  • Measurement of the isotopic composition of hydrogen and helium nuclei in cosmic rays with the PAMELA experiment
  • 2013
  • In: Astrophysical Journal. - : IOP Publishing. - 0004-637X .- 1538-4357. ; 770:1, s. 2-
  • Journal article (peer-reviewed)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.
  •  
39.
  • Adriani, O., et al. (author)
  • MEASUREMENTS OF COSMIC-RAY HYDROGEN AND HELIUM ISOTOPES WITH THE PAMELA EXPERIMENT
  • 2016
  • In: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 818:1
  • Journal article (peer-reviewed)abstract
    • The cosmic-ray hydrogen and helium (H-1, H-2, He-3, He-4) isotopic composition has been measured with the satellite-borne experiment PAMELA, which was launched into low-Earth orbit on board the Resurs-DK1 satellite on 2006 June 15. The rare isotopes H-2 and He-3 in cosmic rays are believed to originate mainly from the interaction of high-energy protons and helium with the galactic interstellar medium. 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 2006 July to 2007 December.
  •  
40.
  • Adriani, O., et al. (author)
  • OBSERVATIONS OF THE 2006 DECEMBER 13 AND 14 SOLAR PARTICLE EVENTS IN THE 80 MeV n(-1)-3 GeV n(-1) RANGE FROM SPACE WITH THE PAMELA DETECTOR
  • 2011
  • In: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 742:2, s. 102-
  • Journal article (peer-reviewed)abstract
    • We present the space spectrometer PAMELA observations of proton and helium fluxes during the 2006 December 13 and 14 solar particle events. This is the first direct measurement of the solar energetic particles in space with a single instrument in the energy range from similar to 80 MeV n(-1) up to similar to 3 GeV n(-1). For the December 13 event, measured energy spectra of solar protons and helium are compared with results obtained by neutron monitors and other detectors. Our measurements show a spectral behavior different from those derived from the neutron monitor network. No satisfactory analytical fitting was found for the energy spectra. During the first hours of the December 13 event, solar energetic particles spectra were close to the exponential form, demonstrating rather significant temporal evolution. Solar He with energy up to 1 GeV n(-1) was recorded on December 13. For the December 14 event, energy of solar protons reached 600 MeV, whereas the maximum energy of He was below 100 MeV n(-1). The spectra were slightly bent in the lower energy range and preserved their form during the second event. Differences in the particle flux appearance and temporal evolution of these two events may argue for special conditions leading to the acceleration of solar particles up to relativistic energies.
  •  
41.
  • Adriani, O., et al. (author)
  • PAMELA Measurements of Cosmic-Ray Proton and Helium Spectra
  • 2011
  • In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 332:6025, s. 69-72
  • Journal article (peer-reviewed)abstract
    • Protons and helium nuclei are the most abundant components of the cosmic radiation. Precise measurements of their fluxes are needed to understand the acceleration and subsequent propagation of cosmic rays in our Galaxy. We report precision measurements of the proton and helium spectra in the rigidity range 1 gigavolt to 1.2 teravolts performed by the satellite-borne experiment PAMELA (payload for antimatter matter exploration and light-nuclei astrophysics). We find that the spectral shapes of these two species are different and cannot be described well by a single power law. These data challenge the current paradigm of cosmic-ray acceleration in supernova remnants followed by diffusive propagation in the Galaxy. More complex processes of acceleration and propagation of cosmic rays are required to explain the spectral structures observed in our data.
  •  
42.
  • Adriani, O., et al. (author)
  • Reentrant albedo proton fluxes measured by the PAMELA experiment
  • 2015
  • In: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 120:5, s. 3728-3738
  • Journal article (peer-reviewed)abstract
    • We present a precise measurement of downward going albedo proton fluxes for kinetic energy above similar to 70 MeV performed by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) experiment at an altitude between 350 and 610 km. On the basis of a trajectory tracing simulation, the analyzed protons were classified into quasi-trapped, concentrating in the magnetic equatorial region, and untrapped spreading over all latitudes, including both short-lived (precipitating) and long-lived (pseudotrapped) components. In addition, features of the penumbra region around the geomagnetic cutoff were investigated in detail. PAMELA results significantly improve the characterization of the high-energy albedo proton populations at low-Earth orbits.
  •  
43.
  •  
44.
  • Adriani, O., et al. (author)
  • The PAMELA Mission : Heralding a new era in precision cosmic ray physics
  • 2014
  • In: Physics reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 544:4, s. 323-370
  • Research review (peer-reviewed)abstract
    • On the 15th of June 2006, the PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) satellite-borne experiment was launched onboard the Russian Resurs-DK1 satellite by a Soyuz rocket from the Baikonur space centre. The satellite was placed in a quasi-polar 70 degrees inclination orbit at an altitude varying between 350 km and 600 km. New results on the antiparticle component of the cosmic radiation were obtained. The positron energy spectrum and positron fraction were measured from 400 MeV up to 200 GeV revealing a positron excess over the predictions of commonly used propagation models. This can be interpreted either as evidence that the propagation models should be revised or in terms of dark matter annihilation or a pulsar contribution. The antiproton spectrum was measured over the energy range from 60 MeV to 350 GeV. The antiproton spectrum is consistent with secondary production and significantly constrains dark matter models. The energy spectra of protons and helium nuclei were measured up to 1.2 TV. The spectral shapes of these two species are different and cannot be described well by a single power law. For the First time the electron spectrum was measured up to 600 GeV complementing the information obtained from the positron data. Nuclear and isotopic composition was obtained with unprecedented precision. The variation of the low energy proton, electron and positron energy spectra was measured from July 2006 until December 2009 accurately sampling the unusual conditions of the most recent solar minimum activity period (2006-2009). Low energy particle spectra were accurately measured also for various solar events that occurred during the PAMELA mission. The Earth's magnetosphere was studied measuring the particle radiation in different regions of the magnetosphere. Energy spectra and composition of sub-cutoff and trapped particles were obtained. For the first time a belt of trapped antiprotons was detected in the South Atlantic Anomaly region. The flux was found to exceed that for galactic cosmic-ray antiprotons by three order of magnitude.
  •  
45.
  • Adriani, O., et al. (author)
  • Time Dependence Of The Proton Flux Measured By Pamela During The 2006 July-2009 December Solar Minimum
  • 2013
  • In: Astrophysical Journal. - : IOP Publishing. - 0004-637X .- 1538-4357. ; 765:2, s. 91-
  • Journal article (peer-reviewed)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.
  •  
46.
  • Bazilevskaya, G. A., et al. (author)
  • Solar energetic particle events in 2006-2012 in the PAMELA experiment data
  • 2013
  • In: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 409:1
  • Journal article (peer-reviewed)abstract
    • The PAMELA magnetic spectrometer launched in June 2006 has observed the last strong energetic solar particle event of the 23rd solar cycle in December 2006. Subsequent long minimum of solar activity and weak development of the 24th solar cycle led to a deficit in the solar energetic particle events on the Earth orbit. As a result, only few events with protons accelerated above 100 MeV occurred in 2010-2012. The paper gives the preliminary results on energetic solar particles in the beginning of the 24th solar circle as measured with the PAMELA instrument.
  •  
47.
  • Bazilevskaya, G. A., et al. (author)
  • Solar proton events at the end of the 23rd and start of the 24th solar cycle recorded in the PAMELA experiment
  • 2013
  • In: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 77:5, s. 493-496
  • Journal article (peer-reviewed)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.
  •  
48.
  • Boezio, M., et al. (author)
  • Nine years of cosmic rays investigation by the PAMELA experiment
  • 2015
  • In: Proceedings of Science. - : Proceedings of Science (PoS).
  • Conference paper (peer-reviewed)abstract
    • The PAMELA cosmic ray detector was launched on June 15th of 2006 on board the Russian Resurs-DK1 satellite and during nine years of continuous data-taking it has ob- served very interesting features in cosmic rays, namely in the fluxes of protons, helium and electrons. Its discoveries might change our basic vision of the mechanisms of pro- duction, acceleration and propagation of cosmic rays in the Galaxy. Moreover, PAMELA measurements of cosmic antiproton and positron fluxes and positron-to-all-electron ratio have been setting strong constraints to the nature of Dark Matter. Measurements of boron, carbon, lithium and beryllium (together with the isotopic fraction) will also shed new light on the elemental composition of the cosmic radiation. Search for signatures of more exotic processes (such as the ones involving Strange Quark Matter) is also pursued. Furthermore, the instrument is still functional allowing a constant monitoring of the solar activity during its maximum and a detailed and prolonged study of the solar modulation, improving the comprehension of the heliosphere mechanisms. PAMELA is also measur- ing the radiation environment around the Earth, and it detected for the first time the presence of an antiproton radiation belt surrounding our planet. In this highlight paper PAMELA main results will be reviewed.
  •  
49.
  • Bruno, A., et al. (author)
  • First detection of geomagnetically trapped antiprotons by the PAMELA experiment
  • 2011
  • In: Proceedings of the 32nd International Cosmic Ray Conference, ICRC 2011. - : Institute of High Energy Physics. ; , s. 86-89
  • Conference paper (peer-reviewed)abstract
    • We present the measurement of geomagnetically trapped antiprotons in the South Atlantic Anomaly performed by the PAMELA satellite-bourne experiment. The existence of an antiproton radiation belt, predicted by several models as the product of cosmic ray interactions with the residual terrestrial atmosphere, is evidenced for the first time. PAMELA measured the antiproton spectrum in the kinetic energy range between 60 and 750 MeV, reporting a trapped antiproton flux which exceeds by about 3 orders of magnitude the interplanetary cosmic ray antiproton flux. An estimation of the mean under-cutoff antiproton flux outside radiation belts has been also provided.
  •  
50.
  • Bruno, A., et al. (author)
  • Geomagnetically trapped, albedo and solar energetic particles : Trajectory analysis and flux reconstruction with PAMELA
  • 2017
  • In: Advances in Space Research. - : Elsevier. - 0273-1177 .- 1879-1948. ; 60:4, s. 788-795
  • Journal article (peer-reviewed)abstract
    • The PAMELA satellite experiment is providing comprehensive observations of the interplanetary and magnetospheric radiation in the near-Earth environment. Thanks to its identification capabilities and the semi-polar orbit, PAMELA is able to precisely measure the energetic spectra and the angular distributions of the different cosmic-ray populations over a wide latitude region, including geomagnetically trapped and albedo particles. Its observations comprise the solar energetic particle events between solar cycles 23 and 24, and the geomagnetic cutoff variations during magnetospheric storms. PAMELA's measurements are supported by an accurate analysis of particle trajectories in the Earth's magnetosphere based on a realistic geomagnetic field modeling, which allows the classification of particle populations of different origin and the investigation of the asymptotic directions of arrival.
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